Journals >Acta Photonica Sinica
Contents
2014
Volume: 43 Issue 5
37 Article(s)
Export citation format
Research Article
Controlled Bidirectional Quantum Secure Direct Communication without Information Leakage Based on Bell States and Bell Measurements
YE Tian-yu
A controlled bidirectional quantum secure direct communication protocol without information leakage was proposed. In the proposed protocol, two authenticated communication parties, Alice and Bob, were able to securely exchange their secret messages simultaneously under the control of the controller, Charlie. The probleA controlled bidirectional quantum secure direct communication protocol without information leakage was proposed. In the proposed protocol, two authenticated communication parties, Alice and Bob, were able to securely exchange their secret messages simultaneously under the control of the controller, Charlie. The problem of information leakage was overcome by making full use of the measurement correlation property after entanglement swapping among three Bell states. Moreover, the proposed protocol merely took the Bell state as quantum resource and merely needed the Bell measurement so that it was convenient to implement. Security analysis shows that the proposed protocol can detect not only the active attacks from the outside eavesdropper, but also the dishonest behavior from the controller, Charlie. It can be concluded that the proposed protocol has good security..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 502701 (2014)
Design on Indoor Hardware-in-loop Simulation System for Terminal Sensitivity Projectile
YUAN Wei, ZHANG Jian-qi, and ZHANG Dong-yang
The hardware-in loop simulation technology was employed to design the indoor hardware-in loop simulation system for infrared sensor of terminal sensitivity projectile. This system employs the Multi-Gen Creator to build the scene model and the attacked target three-dimensional geometrical model as well as employs the MuThe hardware-in loop simulation technology was employed to design the indoor hardware-in loop simulation system for infrared sensor of terminal sensitivity projectile. This system employs the Multi-Gen Creator to build the scene model and the attacked target three-dimensional geometrical model as well as employs the Multi-Gen Vega to produce the digital scene of detection field for terminal sensing projectile. Meanwhile, the detection system of terminal sensitivity projectile-infrared sensor was served as the substance and introduced into the simulation system to participate in the test and consist of the closed loop with other software systems and optical system complete the real-time simulation function of terminal sensitivity projectile. The simulation result indicates that the infrared sensor can completely identify the target and is provided with such advantages as low false detection ratio and low omission ratio..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 504001 (2014)
Simulation Study of Spiral Photon Sieves in Phase-contrast Imaging
YU Jian, LI Jun, YI Tao, LIU Shen-ye, XIAO Sha-li, YANG Zhi-wen, LI Shou-bei, CHEN Li, DENG Ke-li, and ZHENG Jian-hua
In order to improve the imaging resolution and image contrast, the method proposed in this paper to achieve phase-contrast imaging with a spiral photon sieves.The transmission zone of the spiral zone plate is replaced appropriately by a large number of pinholes, with Bessel-like function as the spiral photon sieves apoIn order to improve the imaging resolution and image contrast, the method proposed in this paper to achieve phase-contrast imaging with a spiral photon sieves.The transmission zone of the spiral zone plate is replaced appropriately by a large number of pinholes, with Bessel-like function as the spiral photon sieves apodization window.The same minimum features sizes, the numerical aperture of spiral photon sieves is increased compared to spiral zone plate, so spiral photon sieves show substantially better spatial resolution the spiral zone plate according to the Rayleigh resolution criterion.The advantage of spiral photon sieves is that can modulate the population of the pinholes per zone with an apodization window, resulting in high signal-to-noise ratio or extremely low side lobe. So the spiral photon sieves have a high imaging contrast based on the principle of pupil apodization. Compared with the spiral zone plate, the point spread function of the spiral photon sieve the main lobe width is relatively narrow and the side lobe amplitude is relatively lower. In phase-contrast imaging, spiral photon sieve can not only eliminate image “relief” effect in the circular phase object imaging but also can distinguish dense phase jump in the periodic rectangular strip phase object imaging, improving greatly the image contrast. Therefore, the spiral photon sieves has higher resolution and contrast in phase-contrast imaging, so that it will have broad application prospects in the field of medicine..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 504002 (2014)
Improvement of Time Response Characteristics of Direct Coupling-enhanced Digital Camera Static Imaging
WANG Xue-mei, CAO Feng-mei, and CUI Zhi-gang
When CIDC1816 direct coupling-enhanced digital camera was collecting still images, the effects of image intensifier cathode voltage decay time on the electron-optical systems were analyzed in theory, and it was proved that cathode voltage decay time also had impact on screen brightness decay time. A method was proposedWhen CIDC1816 direct coupling-enhanced digital camera was collecting still images, the effects of image intensifier cathode voltage decay time on the electron-optical systems were analyzed in theory, and it was proved that cathode voltage decay time also had impact on screen brightness decay time. A method was proposed using the high-speed response characteristics of electronic switches to reduce cathode voltage decay time and improve this kind of digital camera time response characteristics. Using this method during the period of collecting still images, the results show that image intensifier cathode voltage decay time was reduced from 80~130 ms to 50~60 ns, the impact on the electron-optical systems by cathode voltage decay time was reduced, and the screen brightness decay time was reduced from 12~26 ms to 3~4 ms, when the outside light conditions was greater than 10－4 lx. The results prove that this method can effectively reduce the image intensifier cathode voltage decay time and screen brightness decay time and be used as reference scheme for improving this kind of camera still-picture quality..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 504003 (2014)
Temperature Distributed Sensing Technique for the Local-area of the Surface Based on Fiber Bragg Gratings
YU You-long, XUE Hang, WANG Yan-xiao, and DUAN Ying-ying
Micro-packaged fiber Bragg grating temperature sensor is used to perform the distributed temperature sensing for the local area of the object surface. Packaged with steel capillary, ten wavelength-division-multiplexed temperature sensors are cascaded and placed in parallel along the tangential direction at the observedMicro-packaged fiber Bragg grating temperature sensor is used to perform the distributed temperature sensing for the local area of the object surface. Packaged with steel capillary, ten wavelength-division-multiplexed temperature sensors are cascaded and placed in parallel along the tangential direction at the observed point for making quasi-distributed detection. The response time of the packaged sensors is 2.74 s. Using ANSYS software to analyze the thermal steady-state laminar flow of air the contour plots of temperature distribution was obtained. Experiments show that the first-order change rate of the curves of temperature change with height is －24.262, and the second-order change rate is 10.117 2. Comparing with the result of ANSYS simulation (its first-order change rate is －22.842, and second-order change rate is 8.613), the reliability of this measurement method was verified. This technology provides a technical support for knowing the local distribution of temperature as well as a new testing program for aircraft material selecting and configuration determining..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 506001 (2014)
Analysis of the Impact of FRFT Combined with PAPR Reducing Algorithm in CO-OFDM System
TONG Zheng-rong, LIU Chang, CAO Ye, and ZHANG Wei-hua
Due to the high peak to average power ratio in coherent optical orthogonal frequency division multiplexing system, fractional Fourier transform combined with peak to average power ratio reduction algorithm was proposed. With the decrease of fractional Fourier transform order, the peak to average power ratio of signal iDue to the high peak to average power ratio in coherent optical orthogonal frequency division multiplexing system, fractional Fourier transform combined with peak to average power ratio reduction algorithm was proposed. With the decrease of fractional Fourier transform order, the peak to average power ratio of signal is reduced. Fractional Fourier transform combined with the reduction algorithm can reduce the peak to average power ratio further, and improve the degradation of transmission performance caused by the reduction algorithm. The simulation analyses have three aspects including compatibility of the combination, inhibition effect of peak to average power ratio and improvement of the negative effects in the reduction algorithm. The results show that the probability of the selective mapping algorithm combined with fractional Fourier transform is 104 less than that of the single selective mapping algorithm when the rotation factor is 4 and the peak to average power ratio is higher than 6.6 dB. When the same degree of inhibition of peak to average power ratio is chosen, the time complexity of the combined algorithm decrease by 8 times than single algorithm. The simulation results using clipping algorithm combined with fractional Fourier transform have great improvement than single algorithm, which shows combined algorithm has good performance of compatibility..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 506002 (2014)
Research on All-optical Wavelength Conversion Based on Orthogonal Dual-pump Four-wave Mixing in Semiconductor Optical Amplifier for Polarization Multiplexing Quadrature Phase Shift Keying Signals
ZHOU Hui, HE Jing, and CHEN Lin
Based on orthogonal dual-pump four wavelength mixing in an semiconductor optical amplifier，theorectical model of all-optical wavelength conversion for polarization multiplexing quadrature phase shift keying signals was set up for studing the characteristics of wavelength conversion for polarization multiplexing phase-mBased on orthogonal dual-pump four wavelength mixing in an semiconductor optical amplifier，theorectical model of all-optical wavelength conversion for polarization multiplexing quadrature phase shift keying signals was set up for studing the characteristics of wavelength conversion for polarization multiplexing phase-modulated signals. The simulation system was built based on the theoretical analysis. Results show that the frequency spacing between the pump and signal lightwave, the polarization angle between pump1 and one of the polarization multiplexing signals have effects on the converion efficiency and the quality of the signals; and the phase noise generated by cross phase modulation in wavelength conversion also has effect on the quality of the signals, and when the power of two pumps is much larger than that of the signal lightwave, the cross phase modulation has small effect on the quality of the signals. The simulation results are consistent with the theoretical analysis. The methods and some results can be useful to research wavelength conversion system for other polarization multiplexing signal based on four wavelength mixing in SOA..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 506003 (2014)
A Laser Detection Method of Micro-defects for Optical Fibers
WANG Rong, LI Zhen-hua, BIAN Bao-min, LIU Cheng-lin, and JI Yun-jing
In order to solve the problem of inspecting the optical fiber defects, a detection method based laser was proposed to inspect the optical fiber defects in this paper. Though analyzing the basic structure of optical fiber defectstheoretically the principle of detection, a kind of experimental device was designed and estIn order to solve the problem of inspecting the optical fiber defects, a detection method based laser was proposed to inspect the optical fiber defects in this paper. Though analyzing the basic structure of optical fiber defectstheoretically the principle of detection, a kind of experimental device was designed and established, which was used to carry out the detection experiments of the defects. In the experiment, a collimated He-Ne laser beam transverse incident fiber and the distribution image of optical forward scattering pattern on the optical scree were obtained for the next step image processing. Compared to the experimental results of the microscope method, it is found that the laser detection method is more effective to detect the defect of the optical fiber and has the same detection accuracy as the microscope method. The method can be used as a fiber drawing repetition measurement before coating the optical fiber..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 506004 (2014)
A Fiber-optical Perimeter Intrusion Detection System Based on the Fiber Bragg Grating Vibration Sensors and its Identification Method
XIE Xin, WU Hui-juan, and RAO Yun-jiang
A fiber-optical perimeter intrusion detection system based on high-sensitivity FBG vibrating sensors with intelligent identification function was proposed. Stasitical features with an adaptive dynamic threshold were extracted in the time domain first. By inputting the extracted features into a three-layer Back-PropagatA fiber-optical perimeter intrusion detection system based on high-sensitivity FBG vibrating sensors with intelligent identification function was proposed. Stasitical features with an adaptive dynamic threshold were extracted in the time domain first. By inputting the extracted features into a three-layer Back-Propagation Artificial Neural Network classifier, the type of the event can be descerned and determined. The simulated signals and acquired data in the test field were both tested to validate the effectiveness of the proposed system and its identification method. The results show that the average identification rate of the system for the simulation signals can be up to 100%, and that for the actually acquired signals, the average identification rate of the system achieves 96.83%..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 506005 (2014)
Flat-top Pulse Generation with Pulsewidth Tunable Based on Polarization Controller in Fiber Laser
CHEN Jin-hua, FANG Xiao-hui, DING Zhi-qun, and ZHAO Hong-Xia
A pulsewidth tunable 10 GHz flat-top pulse train was generated based on the combined action of active mode locking and nonlinear-polarization-rotation pulse shaping. The laser cavity consisted of two parts: one was a commonly used active-mode-locking fiber laser; the other was for NPR based pulse shaping, which was comA pulsewidth tunable 10 GHz flat-top pulse train was generated based on the combined action of active mode locking and nonlinear-polarization-rotation pulse shaping. The laser cavity consisted of two parts: one was a commonly used active-mode-locking fiber laser; the other was for NPR based pulse shaping, which was composed of two PCs between which a high nonlinear fiber was inserted, and an in-line polarizer, was inserted into the cavity to control the pulse shape. The setup has previously been used for pulse compression, while the generation of FTP was proposed based on it. As a result, 10 GHz flat-top pulse with pulsewith tunable from 12~19 ps by tuning polarization controllers was generated, and flat-top pulse were obtained at different wavelength by tuning band pass filter. The output pulse shows good stability, with the measured side mode supress ratio of 65 dB and the timing jitter of 145 fs..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 506006 (2014)
Effects of Multiple Disturbances on the Location Precision of Fiber-Optic Distributed Disturbance Sensor
ZHANG Chun-xi, LI Qin, LI Li-jing, LI Chuan-sheng, and ZHONG Xiang
The mathematic models of the Mach-Zehnder interferometers based fiber-optic distributed disturbance sensor for the multiple disturbances applications were established in accordance with coherent lightwave theory. According to the models, the influences of the multiple disturbances on the location precision of the fiberThe mathematic models of the Mach-Zehnder interferometers based fiber-optic distributed disturbance sensor for the multiple disturbances applications were established in accordance with coherent lightwave theory. According to the models, the influences of the multiple disturbances on the location precision of the fiber-optic distributed disturbance sensor were simulated. The relationship concerning the location precision, the amplitude ratio and the distance of the disturbances were presented. The simulation results demonstrate that the stronger disturbance can be located when the amplitude ratio of the multiple disturbances is larger than or equals to 20. The multiple disturbances can be regarded as a disturbance when the distances of the disturbances are less than 100 m. The polarization beam splitters were utilized to eliminate the influence of the polarization induced fading. Then the signal generator produced sine wave, applied to the two piezoelectric transducers simultaneously to simulate the disturbances. The experimental results show that when the amplitude ratio of the two disturbances imposed on the sensing fiber at 5 km and 10 km is larger than or equals to 20, the maximum location error from the strongest disturbance is 200 m. The maximum location error from the 5 km position is 100 m when the amplitude ratio of the two disturbances applied at 5 km and 5.05 km is 1. The numerical simulation results were proved by the experiments and helpful to improve the location precision and reduce the false alarm rate for multiple disturbances applications..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 506007 (2014)
A Method for Spectrum Extraction of 3D Object with Object Points
JIAN Xian-zhong, ZHOU Hai, YANG Xin, HOU Le-xin, and GUO Qiang
To simplify the calculation of three-dimensional objects and accelerate the computation time about holographic data, a method for spectrum extraction of 3D object with object points was presented. The spectrum method for model was analyzed and the spectrum could be derived from the integration of a perspective image muTo simplify the calculation of three-dimensional objects and accelerate the computation time about holographic data, a method for spectrum extraction of 3D object with object points was presented. The spectrum method for model was analyzed and the spectrum could be derived from the integration of a perspective image multiplied by a factor of a specific plane wave. The algorithm for perspectives generation of an object was discussed in detail. The parallel computation with Matlab language was used to reduce the computational burden. And a 3D bird was tested with this method to generated perspectives. Based on the spectrum distribution of real object, a simplified extraction model with high order Gauss probability distribution was proposed which could hugely reduce the number of perspectives needed to form 3D spectrum. The inverse Fourier transform was used to get complex amplitude distribution in a plane of object field and the result was diffracted and added a reference wave in order to code as Fresnel hologram. The numerical reconstruction and experiment indicate that only 17.75% of the total original views can get high-quality reconstructed image and validity of the proposed method. The 3D spectrum can be coded as different kind of holograms for 3D display and it extends the application of 3D spectrum..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 509001 (2014)
Multi-plane Holographic Projection Using Programmable Fresnel Phase Lenses
SHEN Chuan, LIU Kai-feng, ZHANG Cheng, CHENG Hong, and WEI Sui
A method to achieve multi-plane holographic projection using programmable Fresnel phase lenses was investigated. A multi-plane holographic projection system was developed with liquid crystal on silicon phase modulator. First, the programmable Fresnel phase lenses were substituted for the Fourier lens, in addition, the A method to achieve multi-plane holographic projection using programmable Fresnel phase lenses was investigated. A multi-plane holographic projection system was developed with liquid crystal on silicon phase modulator. First, the programmable Fresnel phase lenses were substituted for the Fourier lens, in addition, the phase of Fresnel phase lenses were added to the computer generated phase holograms. Then based on the principles of time division multiplexing and space division multiplexing, two different methods combined programmable Fresnel phase lenses and phase holograms displayed on a phase modulating spatial light modulator were presented. Finally, the method to acquire dynamic 360°viewing-angle images corresponding to the object rotation in each image plane of multi-plane holographic projection was discussed. Experimental results show that holographic projection images could be recorded at different distances such as 500, 800, 1 100 and 1 400 mm from the LCOS. Dynamically change the focal length offered by the programmable Fresnel phase lenses, multi-plane holographic projection could be performed..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 509002 (2014)
Iterative Feedback Algorithm for Phase-only Fresnel Hologram and Display Using Liquid Crystal on Silicon
LIU Kai-feng, SHEN Chuan, ZHANG Cheng, and WEI Sui
A method of produce phase-only Fresnel Computer Generated Hologram (CGH) was researched, and an algorithm for the phase-only Fresnel CGH was presented. Firstly, numerical simulation algorithm of Fresnel diffraction was studied. Computation speed of two numerical simulation algorithms was analyzed. The iterative feedbacA method of produce phase-only Fresnel Computer Generated Hologram (CGH) was researched, and an algorithm for the phase-only Fresnel CGH was presented. Firstly, numerical simulation algorithm of Fresnel diffraction was studied. Computation speed of two numerical simulation algorithms was analyzed. The iterative feedback algorithm of phase-only Fresnel CGH was obtained by combination of the iterative algorithm and Fresnel diffraction numerical simulation algorithms and the proportional feedback. Secondly, experimental research of selection of proportional feedback factor k was given and the optimal empiric value of k was obtained. Simulation results show that reconstruction noise is reduced and the quality of the reconstructed image is improved. Finally, an experimental system for hologram display based on liquid crystal on silicon was built and the algorithm was verified by the optoelectronic experiment..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 509003 (2014)
Remote Sensing Image Fusion Based on Improved Gradient Projection NMF and Complex Contourlet Transform
WU Yi-quan, SHEN Yi, and YIN Jun
In order to preserve both spectral and spatial information simultaneously in fused image, a method of remote sensing image fusion based on improved gradient projection Non-negative Matrix Factorization (NMF) and Complex Contourlet Transform (CCT) was proposed. Firstly, the panchromatic image was histogram matched to thIn order to preserve both spectral and spatial information simultaneously in fused image, a method of remote sensing image fusion based on improved gradient projection Non-negative Matrix Factorization (NMF) and Complex Contourlet Transform (CCT) was proposed. Firstly, the panchromatic image was histogram matched to the intensity component of multispectral image to obtain a new panchromatic image. Then, the intensity component of multispectral image and the new panchromatic image were decomposed by CCT, respectively. Corresponding low frequency images and high frequency images were obtained. Next, the new low frequency image was obtained by fusion of two low frequency images using improved gradient projection NMF, and the new high frequency image was obtained by fusion of two high frequency images with absolute maximum criterion. Finally, the fused image was reconstructed by inverse CCT and inverse Hue-Saturation-Intensity (HSI) transform. A large number of experimental results show that, compared with other existing relative methods such as HSI method, the method combining NMF with nonsubsampled contourlet transform and the method combining lifting wavelet with HSI, the images fused by proposed method have higher spatial resolution and more spectral information..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 510001 (2014)
A Method for Compressive Sensing of Images Based on Zone Control of Digital Micromirror Device and Super-resolution
LIU Hai-ying, LI Yun-song, and WU Cheng-ke
A compressive sensing based imaging framework was proposed. At the sampling end, in order to enhance the acquisition accuracy of information, a new measurement matrix was designed to carry out zone control on digital micromirror device and the new digital micromirror device with zone control was used to make compressivA compressive sensing based imaging framework was proposed. At the sampling end, in order to enhance the acquisition accuracy of information, a new measurement matrix was designed to carry out zone control on digital micromirror device and the new digital micromirror device with zone control was used to make compressive measurements. At the recovery end, a low resolution image was first recovered by solving an optimization problem from the received measurements. Then, the modeling of a super-resolution problem in a compressive sensing framework was constructed according to the zone control process, and a total variation algorithm was exploited to solve such a compressive sensing based super-resolution problem for the high resolution image. Experimental results show that the proposed method based on zone control of digital micromirror device and super-resolution reconstruction can greatly shorten the imaging time and has very low computational complexity and excellent recovery performance..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 510002 (2014)
Bandwidth-adaptive Mean Shift Infrared Target Tracking Algorithm
WANG Shou-feng, and BAI Jun-qi
For the fixed-bandwidth windows, the tracking target will be lost in traditional mean shift algorithm with target scale changed. To solve this problem, an adaptive-bandwidth mean shift tracking algorithm was proposed. The shape features were extracted under the algorithm in the framework of mean shift, the bandwidth waFor the fixed-bandwidth windows, the tracking target will be lost in traditional mean shift algorithm with target scale changed. To solve this problem, an adaptive-bandwidth mean shift tracking algorithm was proposed. The shape features were extracted under the algorithm in the framework of mean shift, the bandwidth was adjusted adaptively based on target shape motions, and the target template was updated. Experimental results indicate that the proposed algorithm can track the target with scale changed and improve the target tracking precision effectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 510003 (2014)
Method of Underwater Polarization Image Fusion Based on Hierarchical and Multi-scale Transform
WANG Hui-bin, LIAO Yan, SHEN Jie, and WANG Xin
An efficient hierarchical multi-scale image fusion method was proposed. Several polarization parametric images were fused for enhancement by non-negative matrix factorization. A polarization parametric fusion image was obtained. This image contained complete polarization information with low redundancy. Then, with two-An efficient hierarchical multi-scale image fusion method was proposed. Several polarization parametric images were fused for enhancement by non-negative matrix factorization. A polarization parametric fusion image was obtained. This image contained complete polarization information with low redundancy. Then, with two-dimensional empirical mode decomposition, polarization parameters fusion image and polarization intensity image were decomposed. High-frequency component and low-frequency component were fused by weighted average function. In order to determine fusion weight, exhaustive search method was taken. Finally, the given results of high-frequency sub-images and low-frequency sub-images were inverse transformed. The experiments demonstrate that the proposed fusion method has the ability to enhance the details and contrast of polarization image..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 510004 (2014)
Image Processing Algorithm Study of Large FOV Compound Eye Structure
CAO A-xiu, SHI Li-fang, SHI Rui-ying, DENG Qi-ling, and DU Chun-lei
For the large field of view compound eye structure with multi-dimensional sub-eye imaging channels aranged on a curve surface, the segmentation-rotation-projection image processing algorithm was presented to realize a large field of view synthesized of multi-channels. By confirming the arrangement characteristics of thFor the large field of view compound eye structure with multi-dimensional sub-eye imaging channels aranged on a curve surface, the segmentation-rotation-projection image processing algorithm was presented to realize a large field of view synthesized of multi-channels. By confirming the arrangement characteristics of the compound eye structure, the relation among all sub-eye images captured by corresponding imaging channels was analyzed and the overlap regions between nearby sub-eye images were eliminated. Meanwhile, by using the principle of geometrical optics and imaging optics, the relation between the sub-eye images and the three-dimensional projection space was studied to achieve the large field of view of two-dimensional sub-eye images synthesized in a three-dimensional space. An artificial compound eye consisted of 37 lenses with field of view over 118 degrees was fabricated and the corresponding sub-eye images captured by the fabricated compound eye structure were processed based on the presented algorithm. The results show that the resolution of the sub-eye images can be ensured of no decrease during the image processing precedure and the algorithm can effectively realise a large field of view synthesized of multi-channel images meeting the practical requirements with high visual effect. All of the above studies could put forword the application of the compound eye imaging system..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 510005 (2014)
Analysis of Viewing Zone and Simulation of the Crosstalk Based on Multi-view Autostereoscopic Display
HOU Chun-ping, XU Guo, and SHEN Li-li
The cause of crosstalk based on multi-view autostereoscopic display was analyzed. The relation between sweet spots and parallax barrier parameters was deduced. Then, analysis of the model of crosstalk was processed respectively in vertical and horizontal directions to the flat-panel displays, which aimed to obtain the The cause of crosstalk based on multi-view autostereoscopic display was analyzed. The relation between sweet spots and parallax barrier parameters was deduced. Then, analysis of the model of crosstalk was processed respectively in vertical and horizontal directions to the flat-panel displays, which aimed to obtain the distribution characteristics of crosstalk in three-dimensional space before the screen. The simulation results show that viewing zone in vertical direction along the screen is greater than it in horizontal direction. And, each view has multiple observation points without any crosstalk in a horizontal direction parallel to the screen, but in the direction perpendicular to the screen, each view has only one such point. Through the simulation analysis of viewing zone, the accuracy of the crosstalk calculation was further validated. The research results of this paper establish a simulation basic platform for the optimum design and concrete realization of autostereoscopic display system..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 512001 (2014)
Measurement of 3D Pose of Objects Based on Weak Perspective Model
ZHAO Ru-jin, LIU En-Hai, ZHANG Wen-Ming, and ZHAO Lian-jun
In the fields of tracking target and navigation based on vision, to measure the 3D pose of rigid objects besides the special location, the research of measuring the 3D pose of the object based on mono-view was performed. An algorithm of measuring 3D pose was proposed from the weak perspective model and the information In the fields of tracking target and navigation based on vision, to measure the 3D pose of rigid objects besides the special location, the research of measuring the 3D pose of the object based on mono-view was performed. An algorithm of measuring 3D pose was proposed from the weak perspective model and the information of right-angled triangle formed by characteristic points of object that was the ratio of side-length. The algorithm was applicable under the condition that the interior parameters were unknown and it avoided iteration. The result of mathematical simulating experiment shows that the error of the 3D pose angles are less than 1.5° when the distance from object to camera is in the range of 1~3 km.The result of actual images shows that the remnants difference between the raw results and smooth results of pitch and yaw are less than 1°, and of roll angle is less than 2°. The experiment proves the correctness and stability of the proposed algorithm, which shows that the 3D pose of object can be measured effectively in the proposed algorithm, which can be perfectly applied to the objects with long distance and small visual angle..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 512002 (2014)
Error Analysis of Monocular Visual Position Measurement Based on Coplanar Feature Points
HUO Ju, CUI Jia-shan, and WANG Wei-xing
In order to overcome the lack of depth information in monocular vision measurement, an improved two-stage iterative algorithm was proposed to optimize the posture and attitude measurement models. The characteristics of the target layout optimization were given. The relationships between the calculating accuracy with thIn order to overcome the lack of depth information in monocular vision measurement, an improved two-stage iterative algorithm was proposed to optimize the posture and attitude measurement models. The characteristics of the target layout optimization were given. The relationships between the calculating accuracy with the target size, baseline length and characteristics of the target dot size were analyzed theoretically. Experimental results show that optimizing the layout of the target characteristic, the larger the length of the baseline and smaller characteristics of the target dots can improve the measurement target solver accuracy. The actual research has a certain guiding theoretical significance to improve the practical measurement system calculation accuracy..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 512003 (2014)
Monte-Carlo Simulation for the Infrared Radiation Attenuation by Water Fogs and the Analysis for Transmission Field
ZHANG Shuo, PU Jin-yun, LI Dong-zhen, and WU Chang-ming
A photon tracking model for heat radiation attenuation with water fogs was established based on the Monte-Carlo Method. The parameters of the water fogs such as extinction coefficient, concentration and the asymmetry parameter were analyzed, all of which had impact on the extinction character, and it was found that theA photon tracking model for heat radiation attenuation with water fogs was established based on the Monte-Carlo Method. The parameters of the water fogs such as extinction coefficient, concentration and the asymmetry parameter were analyzed, all of which had impact on the extinction character, and it was found that the asymmetry parameter was also an important one. The research indicates that for the medium with the same extinction coefficient, the lower the value of the asymmetry parameter is, the more exquisitely the water fogs can build down the heat radiation, however one can′t get the conclusion based on the Lambert-Beer′s law; when the radiuses of the water fogs are much bigger than the infrared wavelength, the attenuation effect can be enhanced by increasing the mass concentration of the water fogs and decreasing the radiuses of the particles..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 512004 (2014)
Design and Implementation of Integrated Diagnostic Beam Fast Automatic Alignment System
WANG Zheng-zhou, WANG Wei, HU Bing-liang, WANG Wei, CAO Shi-Kang, and LI Dong-jian
Parallel processing, fast convergent motor model and characteristic points extracted from the smallest outer circle were proposed to design the automatic alignment system, which can integrated diagnostic fast automatic alignment. First, all the alignment steps were executed in parallel and serial-parallel mode, and theParallel processing, fast convergent motor model and characteristic points extracted from the smallest outer circle were proposed to design the automatic alignment system, which can integrated diagnostic fast automatic alignment. First, all the alignment steps were executed in parallel and serial-parallel mode, and the important steps were reduced to unit alignment model. Second, the mathematical model for fast automatic alignment was used and the fast convergent algorithm of the unit alignment model was implemented. Finally, according to the characteristics of small laser spot, which contrast was low, distribution was asymmetrical, spot was not complete, the 100 characteristic points were extracted from the smallest outer circle and any two points distance was maximal, then a new method of circle fitting using least square method to calculate small laser spot center was proposed. Through the improvement of the above three aspects, alignment time reduced from 40 minutes to 8 minutes before the three aspects were optimized, the error of small laser spot centre is less than 2 pixels, and meet the experiment requirements..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 512005 (2014)
Binarization Methods of Sinusoidal Grating in 3D Measurement Base on Defocused Fringe Projection
GAO Peng, LI Yong, TU Yan-shuai, and WANG Jian
The non-linear intensity response of digital projector can be eliminated in 3D shape measurement using defocused binary fringe projection technique. The speed of projecting can be increased and it is possible to realize high speed measurement as well. Typical binary fringes used in digital projection were adopted as a The non-linear intensity response of digital projector can be eliminated in 3D shape measurement using defocused binary fringe projection technique. The speed of projecting can be increased and it is possible to realize high speed measurement as well. Typical binary fringes used in digital projection were adopted as a study subject. The relation between the fundamental frequency, higher harmonics and fringe period of binary fringe was studied through the theoretical analysis and experiments. According to suitable phase shifting algorithm, the performance of various binary fringes was measured using the measurement error of phase as its target. The results showed that sinusoidal fringe with high performance could be generated by defocusing the Ronchi grating and pattern generated using 2D error diffusion algorithm under the condition that fringe with short period was adopted. The measurement accuracy of defocused Ronchi grating was higher than that of other pattern, when the algorithm of odd step phase-shifting with equal interval in one period was used for 3D measurement; the highest measurement accuracy was obtained by using defocused optimal pulse width modulation fringe, when the period of fringe was long. The research results provide the evidence for selection of binary grating in the 3D measurement based on defocused projection..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 512006 (2014)
Small-scale Self-focusing of Finite Energy Airy Beam
YU Wen-long, ZHANG Li-fu, TAN Chao, and FU Xi-quan
The nonlinear propagation of finite energy Airy beam (FEAB) in Kerr media was investigated numerically. The characteristics of whole beam self-focusing (WBSF) and small-scale self-focusing (SSFS) of the FEAB were thoroughly studied during its nonlinear propagation. It was found that the SSFS is more likely to take placThe nonlinear propagation of finite energy Airy beam (FEAB) in Kerr media was investigated numerically. The characteristics of whole beam self-focusing (WBSF) and small-scale self-focusing (SSFS) of the FEAB were thoroughly studied during its nonlinear propagation. It was found that the SSFS is more likely to take place than the WBSF, and the growth rate of noise modulation decreases with increasing the truncation factor. By comparing the gain spectra of SSFS for different truncaed factors, it can been seen that the truncation factor has a large impact on the gain spectrum of the FEAB indicating the possibility of the breakup of the FEAB induced by noise is inversely proportional to the truncated factor. In addition, the gain spectrum of FEAB is more similar to that of the Gaussian beam fitted from the main lobe of FEAB in the case of larger truncation factor. These results are very important for the potential application of the FEAB..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 519001 (2014)
Third-order Nonlinear Optical Properties of PbSe/PVA Composite film
ZENG Hai-jun, ZHENG Miao, HAN Jun-he, and GU Yu-zong
PbSe/polyvinyl alcohol composite film with third-order nonlinear optical property was prepared by wet-chemical method. The morphology of the PbSe nanocrystals was characterized by transmission electron microscope, and the surface morphology of the composite film was characterized by scanning electron microscope. The thPbSe/polyvinyl alcohol composite film with third-order nonlinear optical property was prepared by wet-chemical method. The morphology of the PbSe nanocrystals was characterized by transmission electron microscope, and the surface morphology of the composite film was characterized by scanning electron microscope. The third-order optical nonlinearity of film was investigated by using the laser Z-scan technique with 38 ps pulses width at 532 nm. The experimental results show that the diameter of PbSe nanocrystals is about 10 nm, which is in strong quantum confinement regime, and the film has a flat surface. Negative nonlinear refraction and reverse saturable absorption properties were observed, the third-order nonlinear refractive index χ(3) was found to be 3.6×10－11 esu..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 519002 (2014)
New Hybrid Light Trapping Structure in Silicon Thin Film Solar Cells
SHI Yan-peng, WANG Xiao-dong, LIU Wen, YANG Tian-shu, and YANG Fu-hua
In this paper, a kind of hybrid light trapping structures in thin film crystalline silicon solar cells, combined of dielectric nanoparticles on the front and metal nanoparticles on the rear, was reported. Numerical simulations were performed based on the finite-difference time-domain solutions, and the wavelength rangeIn this paper, a kind of hybrid light trapping structures in thin film crystalline silicon solar cells, combined of dielectric nanoparticles on the front and metal nanoparticles on the rear, was reported. Numerical simulations were performed based on the finite-difference time-domain solutions, and the wavelength ranges that the dielectric nanoparticles and metal nanoparticles had impact on, were systematically analyzed. The absorption enhancement mechanisms were shown through the electric filed figures, including the scattering of these two kinds of nanoparticles, and the near field enhancement of surface plasmons excited by the metal nanoparticles. Simulation-based optimizations of the periods and sizes of Ag, TiO2 etc nanoparticles were given. Furthermore, a 30.3% increase in the short circuit current density was obtained in a solar cell with the optimized hybrid light trapping structure. This structure, combined of the different nanoparticles with different locations, is a new way to improve the conversion efficiency of thin film solar cells..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 523001 (2014)
Research on Coupled Resonator Induced Transparency in Fourth-order Microring Resonator
CUI Dan-feng, XIE Cheng-feng, LIU Yao-ying, LI Yan-na, WEI Li-ping, WANG Yong-hua, LIU Jun, and XUE Chen-yang
A fourth-order microring resonator structure was designed based on quantum coherence effects of electromagnetic induced transparency. Coupled-resonator-induced-transparency phenomenon which produced in resonator was analyzed theoretically. Key parameters of structures were simulated by Finite Difference Time Domain MetA fourth-order microring resonator structure was designed based on quantum coherence effects of electromagnetic induced transparency. Coupled-resonator-induced-transparency phenomenon which produced in resonator was analyzed theoretically. Key parameters of structures were simulated by Finite Difference Time Domain Method and Beam Propagation Method. The ring resonators were fabricated with electron beam lithography and the induction coupled plasma etching process. The structure was tested by vertical grating coupling method , the results show that a narrow transparent peak was obtained which is caused by interference due to phase elimination. Optical transmission delay is realized by two transmission peaks which are generated from mutual interference among ring resonators and one of the transmission spectrum full width at half maximum is 0.022 nm. This structure can achieve high quality factor (Q=0.72×105), and the distance between the two resonance peaks separated by 0.084 nm. The through port and drop port transmission spectra are coincided well with each other which excellent agree with the theoretical analysis..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 523002 (2014)
Luminous Performance of Remote Phosphor White LED
XIAO Hua, LV Yi-jun, ZHU Li-hong, WANG Yang-xia, CHEN Guo-long, GAO Yu-lin, LIN Si-qi, and XU Yun-xin
The luminous properties of sphere-like remote phosphor white LEDs with high Correlated Color Temperature(CCT) and low CCT were studied under different drive currents and heat sink temperatures. The result shown that the quantum efficiency and luminous efficacy of both LEDs raise with the increase of heat sink temperatuThe luminous properties of sphere-like remote phosphor white LEDs with high Correlated Color Temperature(CCT) and low CCT were studied under different drive currents and heat sink temperatures. The result shown that the quantum efficiency and luminous efficacy of both LEDs raise with the increase of heat sink temperatures; the high-CCT LED’s quantum efficiency and luminous efficacy decrease with rising currents. However, the low-CCT LED shows a reverse trend. The reason is attributed to the quantum confinement stark effect in the active region, which makes the wavelength move towards short-wavelength so as to deviate from the optimum stimulation wavelength of the high-CCT phosphor, but close to the optimum stimulation wavelength of the low-CCT phosphor. The CCT of the high-CCT LED increase with rising currents, again, the low-CCT LED shows a reverse trend with rising currents. This trend is mainly related to the drifting of color coordinates caused by quantum efficiency changing. To sum up, the high-CCT LED possesses better optical properties but inferior color properties than the low-CCT LED..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 523003 (2014)
Time Delay Characteristics of Microring Resonator Device Based on Optical Kerr Effect
GAO Lei, and WANG Tao
The time delay characteristics of microring resonator device based on optical Kerr effect were studied. The coupling coeffecient was calculated by the coupled mode theory. The designed parameters were introduced including the material and component. The radius of microring was 300 μm. The sectional dimension was 400The time delay characteristics of microring resonator device based on optical Kerr effect were studied. The coupling coeffecient was calculated by the coupled mode theory. The designed parameters were introduced including the material and component. The radius of microring was 300 μm. The sectional dimension was 400×1 000 nm2. The controlling methods of time delay was presented. The motivation was large time delay value as much as possible on the condition of less than ±5 ps ripple. The results show that the delay time is more than 130 ps; compensating bandwidth is about 20 GHz; free spectral range is 50 GHz; the working wavelength which is 1 550 nm satisfies the demand of dense wavelength division multiplexing system. The energy consumption is less than 0.8 dBm. The fast operating speed is ps order and small capacity which is less than 3 mm2 is great advantages for the device. The devices provide references for the delay lines in all optical communication networks..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 523004 (2014)
Support Vector Machine Model for predicting the Cadmium Concentration of Soil-wheat System in Mine Reclamation Farmland Using Hyperspectral Data
XU Ji-ren, DONG Ji-hong, YANG Yuan-xuan, TAN Kun, and CHENG Wei
Data for the spectral reflectance of soil and wheat were collected using an ASD field spectrometer in the laboratory, and the soil samples and wheat samples were collected for chemical analysis of Cadmium concentrations. A normalization spectral pre-processing method such as the weighted smoothing, first derivative, coData for the spectral reflectance of soil and wheat were collected using an ASD field spectrometer in the laboratory, and the soil samples and wheat samples were collected for chemical analysis of Cadmium concentrations. A normalization spectral pre-processing method such as the weighted smoothing, first derivative, continuum removal and logarithm of reciprocal transform spectrometer were employed. On this basis, choosing the sensitive wave band which has significant correlations with Cadmium pollution in soil and wheat as the correlation factors, and establishing the cadmium pollution content in soil-wheat system prediction model. The result shows that both of the content of Cd in reclaimed soils tested on the sites by filling mining coal gangue and fly ash are qualified for the third level criterion of Environmental quality standards for soils, but neither of the wheat planted on it does. The correlation coefficient of prediction model of soil is 0.974, and the correlation coefficient of prediction model of wheat is 0.782, which prove that the model can be ideal for estimate the cadmium content of the soil and wheat in mine reclamation farmland. The study can provide new method for monitoring heavy metals pollution level of soil and crop timely, dynamically, widely and speedy by using hyperspectral data, and providing constructive idea for guarantee of food security..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 530001 (2014)
Study of Cloud Background Suppression for Oil Spill Detection from Hyperspectral Data
LIU De-lian, LI ZHAO-hui, and ZHANG Jian-qi
Hyperspectral sensors can acquire the radiance of a scene in a high resolution both in spatial and spectral dimensions, which produces good benefits for oil spill detection. Because the cloud background in hyperspectral scene severely interfere oil spill detection result, a new method is presented to reduce the cloud bHyperspectral sensors can acquire the radiance of a scene in a high resolution both in spatial and spectral dimensions, which produces good benefits for oil spill detection. Because the cloud background in hyperspectral scene severely interfere oil spill detection result, a new method is presented to reduce the cloud background in hyperspectal scenes. Firstly, the spectral reflectance characteristics of oil spill are analyzed. According to the spectral characteristics of the C-H bond of oil spill, the false color generation based oil spill detection method is introduced. Secondly, the radiance characteristics of seawater, oil spill and cloud is compared. Based on the radiation characteristics of cloud, a new model is build to extract the radiance features of cloud. On this basis, the difference of cloud and seawater, and oil spill are considered. And the band image which has maximum cloud radiance is selected. The cloud background suppression map is then generated by using the band image and the radiance feature of the cloud background. Finally, the background suppression result is obtained by multiplying the false color image by background suppression map. The proposed method is applied to the real Airborne Visible InfraRed Imaging Spectrometer hyperspectral image captured during the Deepwater Horizon oil spill in the Gulf of Mexico for oil spill detection. The results show that the proposed method can effectively suppress the cloud background for oil spill detection from hyperspectral data, and does not affect the oil spill detection performance..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 530002 (2014)
Fabrication of Four Wavelengths Cavity Surface Film Based on Nd∶YVO4 Crystal
FU Xiu-hua, HAN Fang, ZHANG Jing, KOU Yang, and PAN Yong-gang
The yellow laser, which is close to the sensitive area of human eyes, plays an important role in many fields, and the resonant cavity is an important component of laser. A four wavelengths cavity surface film by using a vacuum coating equipment was developed based on Nd∶YVO4 crystal (c-cut). First, in the process of fiThe yellow laser, which is close to the sensitive area of human eyes, plays an important role in many fields, and the resonant cavity is an important component of laser. A four wavelengths cavity surface film by using a vacuum coating equipment was developed based on Nd∶YVO4 crystal (c-cut). First, in the process of film system design, the distribution of standing wave field reasonably in the film was made by analyzing the film field strength and optimizing the film system, thus to reduce the possibility of film damage theoretically. Then, through technics feedback analysis to the test result by TFCalc and several simulation experiments, it was found that in different wavelengths the film thickness ratio is different even in the same monitoring method. And the problem of spectral curve drift was solved by adjusting the tool factor. Finally, the yellow laser cavity surface film with firm film and stable chemical performance was prepared, which also met the requirements of four wavelengths spectral output..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 531001 (2014)
Growth Process Parameters of BaTiO3 Crystal Thin Film in PLD Method
ZHANG Jing, FU Xiu-hua, YANG Fei, YANG Bin, and SUN De-gui
BaTiO3 (BTO) waveguide thin films were prepared by pulsed laser deposition (PLD) on single crystal MgO substrate. In order to improve the crystalline quality and surface roughness, two process parameters of growth temperature and laser energy were studied and optimized, and the film sample was conducted in-situ annealiBaTiO3 (BTO) waveguide thin films were prepared by pulsed laser deposition (PLD) on single crystal MgO substrate. In order to improve the crystalline quality and surface roughness, two process parameters of growth temperature and laser energy were studied and optimized, and the film sample was conducted in-situ annealing. The crystallization effect of BTO thin film was found in the first direction. The dependent relations of quality characteristics and growth temperature were analyzed, and the effects of different laser energy on the crystalline film surface roughness were studied. The crystallization effect and characteristic of the film were characterized by X-ray diffraction. The surface morphology and roughness were detected by atomic force microscopy. The results indicate that BTO film could be c-axial oriented film. High strength sharp diffraction peak appeared in the direction of (001) and (002). The film has good crystal quality and small surface roughness of 0.563 nm..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 531002 (2014)
Long Lived Photoexcitation in RR-P3HT and PCBM Blended Films
SHA Chun-fang
Continuous wave photoinduced absorption spectroscopy was used to investigate long lived Delocalized Polaron (DP) and Localized Polaron (LP) in the blend of regio-regular poly (3-hexylthiophene) (RR-P3HT) and ［6,6］-Phenyl-C61-Butyric acid Methyl ester (PCBM). From the modulation frequency dependence of PIA signals at vaContinuous wave photoinduced absorption spectroscopy was used to investigate long lived Delocalized Polaron (DP) and Localized Polaron (LP) in the blend of regio-regular poly (3-hexylthiophene) (RR-P3HT) and ［6,6］-Phenyl-C61-Butyric acid Methyl ester (PCBM). From the modulation frequency dependence of PIA signals at various pump intensities and sample temperatures, in millisecond time regime both LP and DP exhibited dispersive bimolecular recombination which was limited by the trap states and could be activated thermally; the activation energy for recombination of DP and LP is 25 meV and 13 meV with laser intensity similar to one sun illumination, respectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 531003 (2014)
Calibration of Stiffness of Optical Tweezers in Three Dimensions with Power Spectral Density Method
LIANG Yan-sheng, YAO Bao-li, LEI Ming, YU Xiang-hua, YAN Shao-hui, YANG Yan-long, DAN Dan, GAO Peng, MIN Jun-wei, and YE Tong
An optical tweezers system which can accurately and quickly calibrate the stiffness of optical tweezers in three dimensions was set up combined with quadrant photodiode detector and power spectral density method. The limited Brownian motion of the trapped particle was recorded by a quadrant photodiode detector, and theAn optical tweezers system which can accurately and quickly calibrate the stiffness of optical tweezers in three dimensions was set up combined with quadrant photodiode detector and power spectral density method. The limited Brownian motion of the trapped particle was recorded by a quadrant photodiode detector, and the stiffness of optical tweezers was calibrated by power spectral density method. The relations of the laser power with the stiffness of a 0.97 μm-diameter silica bead and of the 1 μm-diameter PMMA bead were investigated. The results indicate that the stiffness is proportional to the laser power at the range from 50 mW to 120 mW of laser power for a 0.97 μm-diameter silica bead and at the range from 80 mW to 130 mW for a 1 μm-diameter PMMA bead. This system can be used as a precise force measuring tool for microscopic investigation in biology, physics, etc..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 43, Issue 5, 535001 (2014)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20