Journals >Acta Photonica Sinica
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2018
Volume: 47 Issue 2
27 Article(s)
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Locking of the Fringe Position and Period in Largesize Holographic Grating Exposure
ZHANG Dong, ZHAO Chengqiang, XU Wendong, ZHANG Yibin, and YAN Yuqi
The position and period of grating fringes will vary against the substrate during double beam interference exposure due to temperature variation, air flow, vibration and other factors in the fabrication of largesize holographic gratings. It will result in the decrease of grating contrast. The dynamic change of fringesThe position and period of grating fringes will vary against the substrate during double beam interference exposure due to temperature variation, air flow, vibration and other factors in the fabrication of largesize holographic gratings. It will result in the decrease of grating contrast. The dynamic change of fringes was analyzed during largesize grating exposure. The RootMeanSquare (RMS) errors of fringe translation and period in 3 hours are 1.87 and 1.20 period respectively. The corresponding simulative grating contrasts are 12.83% and 67.37% respectively. A fringe locking system composed of three monitoring subsystems, a computation and control subsystem and two piezo nanopositioners was set up. The translation and period of fringes can be locked at the same time. The groove shape and contrast of gratings are improved significantly after locking. The precision of this fringe locking system: the 3σ value of fringe translation and corresponding contrast are 0.009 period and 99.99% respectively; the RMS error of period change and corresponding contrast are 0.017 period and 99.77% respectively. This locking system satisfies the requirements of fringe stability for the exposure of largesize gratings..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 205001 (2018)
Large Aperture Membrane Diffractive Lens Deformation Error Analysis
LI Taojie, WU Peng, YANG Zheng, YIN Shaoyun, DU Chunlei, and WANG Yuefeng
Based on the ideal coordinate surface, a model of large aperture membrane diffractive lens and wavefront aberration was established. Firstly, the model of segmented lens deformation error was built. Secondly, according to the wavefront aberration relationship between segmented lens and large aperture membrane diffractiBased on the ideal coordinate surface, a model of large aperture membrane diffractive lens and wavefront aberration was established. Firstly, the model of segmented lens deformation error was built. Secondly, according to the wavefront aberration relationship between segmented lens and large aperture membrane diffractive lens, the deformation error accuracy limitations of the large aperture membrane diffractive lens by segmented lens of different regions was investigated. The edge wrinkle sag and sphere sag were demonstrated. At last, taking wavefront aberration of all segmented lens to fit the Zernike polynomial, the lower order aberration were obtained. This work can provide references for correcting image system aberration and assembling large aperture membrane diffractive lens on engineering..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 205002 (2018)
Practical Sensing Chip Based on Optical Trap
GE Xiaojia, SHEN Yu, SU Heming, SHE Xuan, and HU Huizhu
A chip of fiber optical trap was investigated, using the Vgrooved SiO2 platform to align the fibers and the piezoelectric components to break the constraints between particles and the substrate. After successfully trapping the particle with 10 μm diameter in the air, the axial fluctuation of the particle reaches to thA chip of fiber optical trap was investigated, using the Vgrooved SiO2 platform to align the fibers and the piezoelectric components to break the constraints between particles and the substrate. After successfully trapping the particle with 10 μm diameter in the air, the axial fluctuation of the particle reaches to the submicron scale (0.12 μm). Furthermore, combined with the micromachining technology, this paper realizes a sealed microcavity to contain few particles that not merely achieves integration into labonachip environments but also implements the reproducible launching of a single particle, promoting the application for engineering of optical trap sensing technique..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 206001 (2018)
Ultrasonic Sensing Method Based on Optical Fiber Doppler Effect
LI Yan, ZHOU Ciming, TIAN Tao, OU Yiwen, FAN Dian, and WANG Honghai
Doppler frequency shift in optical fiber is measured by fiber frequency shift interferometry, and a method of optical fiber ultrasonic sensing is obtained. The optical fiber loop wound on the piezoelectric ceramic is inserted into the frequencyshift interference Sagnac interferometer, where the piezoelectric ceramic iDoppler frequency shift in optical fiber is measured by fiber frequency shift interferometry, and a method of optical fiber ultrasonic sensing is obtained. The optical fiber loop wound on the piezoelectric ceramic is inserted into the frequencyshift interference Sagnac interferometer, where the piezoelectric ceramic is taken as the ultrasonic signal source, the acoustooptic modulator is adjusted so that the interference signal is biased at the zero point to reach the highest sensitivity of the system. Through the frequency and amplitude of the interference signal, the Doppler frequency shift in the fiber loop caused by ultrasound is measured, and the ultrasonic signal acting on the fiber loop is obtained. The experimental results show that, the relative error of the sensing method is 0.001% for the ultrasonic frequency measurement, and the frequency response has a good linearity in the measured range of 20 kHz to 200 kHz. There are some application prospects of the proposed method in the aspects of pipeline health monitoring, solid internal crack monitoring and structural damage monitoring of large machinery and equipment..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 206002 (2018)
Single Image Dehazing Algorithm Based on Adaptive Dark Channel Prior
LIU Guo, L Qunbo, and LIU Yangyang
In order to recover the degraded image induced by the fog or haze, this paper proposes a single image dehazing algorithm based on adaptive dark channel prior. The error during the estimation of transmittance by Dark Channel Prior(DCP) will directly cause Halo effect. To deal with this problem, the notion of Adaptive DaIn order to recover the degraded image induced by the fog or haze, this paper proposes a single image dehazing algorithm based on adaptive dark channel prior. The error during the estimation of transmittance by Dark Channel Prior(DCP) will directly cause Halo effect. To deal with this problem, the notion of Adaptive Dark Channel Prior(ADCP) was proposed, it means using adaptive in the acquisition of DCP, it can reduce the effect brought by the change of depth of focus, So it will obtain the transmittance correctly without the use of Guided Filtering(GF), this means it will avoid low efficiency and defog incomplete caused by the filtering. Experiments show that the improved dehazing algorithm could eliminate the Halo effect and achieve the dehazing image with high contrast, high color saturation and abundant details from both objective or subjective imagequality assessment. Meanwhile, the speed of image process is also improved..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 210001 (2018)
Remote Sensing Image Fusion Based on Minimum Hausdorff Distance and Nonsampled Shearlet Transform
WU Xiaoyan, CHAI Jing, LIU Fan, and CHEN Zehua
In order to preserve both spectral and spatial information simultaneously in fused image, we introduce the minimum Hausdorff distance and NonSampled Shearlet Transform (NSST) to construct a new method for remote sensing image fusion. Firstly, Principal Component Analysis (PCA) transform is applied in the original multIn order to preserve both spectral and spatial information simultaneously in fused image, we introduce the minimum Hausdorff distance and NonSampled Shearlet Transform (NSST) to construct a new method for remote sensing image fusion. Firstly, Principal Component Analysis (PCA) transform is applied in the original multispectral image to obtain the first principal component, this component and the panchromatic image are decomposed by NSST respectively to obtain the corresponding low frequency subband coefficients and high frequency subband coefficients. Then, the low frequency subband coefficients are fused by sparse representation, the sparse coefficients of sparse representation are fused with the region space frequency; for the high frequency subband coefficients, the regional structure similarity is utilized, using the minimum Hausdorff distance to represent the correlation of regions and different fusion strategies are adopted according to the correlation. Finally, the fused coefficients are transformed by inverse NSST to obtain the new principal component, the new component and other higher order principal components are transformed by inverse PCA transform to obtain the fused image. In this paper, three QuickBird satellite images and one SPOT satellite image are selected for testing, the results show that compared with the traditional fusion strategy algorithms, the fusion results obtained by proposed method have better objective evaluation index and subjective visual effect..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 210002 (2018)
CCD Camera MTF Enhancement Filter Design
ZHANG Jian, FAN Yangyu, ZHU Bo, XU Zhe, and ZHAO Yan
By the discussion of the impact to system MTF by each link in image chains based on the camera imaging model, the enhancement effect of filter quality factor, the impact to Signal to Noise Ratio (SNR), simulation results of the impact of quality factor on multiple pixels were analyzed. The analysis show that the appropBy the discussion of the impact to system MTF by each link in image chains based on the camera imaging model, the enhancement effect of filter quality factor, the impact to Signal to Noise Ratio (SNR), simulation results of the impact of quality factor on multiple pixels were analyzed. The analysis show that the appropriate filter quality factor could enhance the system MTF after the optical design is done and the sensor is confirmed. If the optimum quality factor setting value of the filter is 1, the system MTF at the Nyquist spatial frequency can be increased by 32%. The test results show that MTF enhancement filter can improve the system imaging performance when the quality factor is 1, and the noise suppression capability is comparable to that of the maximally flat filter in passband..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 211001 (2018)
Measurement Technique of Geometric Optical Transfer Function Based on Background Oriented Schlieren
ZHAO Xin-hai, YI Shi-he, DING Hao-lin, and NIU Hai-bo
The optical transfer function is accepted as an essential index to evaluate the imaging quality and is an important auxiliary parameter for designing the optical system. Based on the background oriented schlieren, the displacement field data of the light passing through the refractive index field are obtained, and the The optical transfer function is accepted as an essential index to evaluate the imaging quality and is an important auxiliary parameter for designing the optical system. Based on the background oriented schlieren, the displacement field data of the light passing through the refractive index field are obtained, and the corresponding wavefront gradient data is obtained by combining the Marius theorem. Combined with the geometric optical transfer function formula, the optical transfer function can be achieved. The optical transfer function of a flat convex lens is measured by the above idea and is compared with the optical transfer function results calculated by ZEMAX. Comparison of the experimental results and theoretical results at low frequencies is conducted and the error is less than 4%. Feasibility and validity of background oriented schlieren for measuring the optical transfer function of low-pass systems are verified..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 211002 (2018)
Spatial Resolution for the Time Dilation X-ray Framing Camera
ZHANG Ke, CAI Hou-zhi, LIU Jin-yuan, and FU Wen-yong
The spatial resolution of the time dilation X-ray framing camera is simulated by using the Monte Carlo method, the finite element method and the finite difference method. While DC bias on the photo-cathode is -3 kV and three large aperture magnetic lens are used to image the electrons from the photo-cathode onto the miThe spatial resolution of the time dilation X-ray framing camera is simulated by using the Monte Carlo method, the finite element method and the finite difference method. While DC bias on the photo-cathode is -3 kV and three large aperture magnetic lens are used to image the electrons from the photo-cathode onto the microchannel plate with the image ratio of 21, the theoretical static spatial resolution is better than 110 μm. The relationship between the spatial resolution and the point of electron emitted from the photo-cathode is obtained. While the distance of the electron emitting point to the center of the photo-cathode is increased, the spatial resolution is worse. The variation of the spatial resolution with the photo-cathode voltage is provided. The spatial resolution is improved with increasing photo-cathode voltage. In addition, the spatial resolution is better by increasing the numbers of the magnetic lens. Furthermore, it can be seen from the simulation results that the image plane is a curved surface while the photo-cathode is a plane..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 211003 (2018)
Solar Vector Measurement Algorithm Based on Multiple Polarization Sensors
YANG Zhongguang, ZHOU Jun, and HUANG He
It is put forward that the solar vector (direction of the sun) can be measured through multiple polarization sensors, according to the formation principle of the atmospheric polariztion pattern. First, the formation of the atmospheric polarization pattern is introduced. Then, the polarization sensor consisting of two gIt is put forward that the solar vector (direction of the sun) can be measured through multiple polarization sensors, according to the formation principle of the atmospheric polariztion pattern. First, the formation of the atmospheric polarization pattern is introduced. Then, the polarization sensor consisting of two groups of polarization units is designed, and the optimal angle between polarization units is demonstrated, and the method of extracting the solar azimuthal information from the atmospheric polarization pattern is analyzed. Finally, with the least squares algorithm united, the method of measuring the solar vector with multiple polarization sensors is put forward, and the experiment is conducted consequently. The results indicate that it can get precise solar vector using the method proposed, and the errors of the solar azimuth angle and elevation angle are 0.2° and 1.0° respectively. In addition, it has solved the mutation problem which is caused by the parallelism of the maximum polarization directions measured by double polarization sensors. Therefore, the algorithm is feasible to measure solar vector with multiple polarization sensors..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 212001 (2018)
Dynamic Deformation Measurement of Discontinuous Surfaces Using Digital Speckle Pattern Interferometry and Spatiotemporal Threedimensional Phase Unwrapping
WU Sijin, YANG Jing, PAN Siyang, LI Weixian, and YANG Lianxiang
Digital Speckle Pattern Interferometry (DSPI) with a Spatiotemporal Threedimensional Phase Unwrapping (STPU) is used to measure the dynamic deformation distributions with the presence of object discontinuities. It overcomes the phase unwrapping failure of traditional DSPI in such conditions. Elaborate description of tDigital Speckle Pattern Interferometry (DSPI) with a Spatiotemporal Threedimensional Phase Unwrapping (STPU) is used to measure the dynamic deformation distributions with the presence of object discontinuities. It overcomes the phase unwrapping failure of traditional DSPI in such conditions. Elaborate description of the measurement priciple and procedure of the DSPI with STPU is given. The experiments exibited that dynamic deformation of discontinuous surface, with a maximum deformation rate of 25.12 μm/s, can be determined perfectly by the proposed method while an ordinary camera with 70 fps was used. The research benefits the enlargement of the application areas of DSPI and the improvement of its applicability..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 212002 (2018)
Cophasing Experiment of Active Optics for Segmented Mirror
LI Bin, WU Jian, LIU Yande, XIE Fengyun, CHEN Mo, and XIAN Hao
In order to solve the prolem of cophasing detection for the segmented mirror of telescope, the piston errors measurement of segmented mirror by the broadband and narrowband ShackHartmann algorithm are theoretical analyzed and simulated, and an active optics and cophasing experiment system is built. The segmented miIn order to solve the prolem of cophasing detection for the segmented mirror of telescope, the piston errors measurement of segmented mirror by the broadband and narrowband ShackHartmann algorithm are theoretical analyzed and simulated, and an active optics and cophasing experiment system is built. The segmented mirror is consisted of four hexagonal segments with the flat to flat lengths of 100 mm and the curvature of radius is 2 000 mm. Firstly, the ShackHartmann is used to detect the errors of cofocus ,and the active optics is used to control piezoelectric actuators to realize the fine cofocus of segmented mirror. Then the broadband phasing algorithm is used to realize the measurement of corse cophasing of segmented mirror. Finally, the narrowband phasing algorithm is used to realize the measurement of fine cophasing of segmented mirror, and the active optics is used to control piezoelectric actuators to realize of the segmented mirror cophasing adjustment. The experimental results show that the range is dozens of micros and the measurement accuracy is better than 15 nm of broadband and narrowband phasing algorithm, which demonstrates that the methods are suitable for the segmented mirror cophasing measurement and adjustment..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 212003 (2018)
Influence of the Clamping and Gravity Deformation on Absolute Test of Large Plane
ZHAO Siwei, TIAN Ailing, WANG Dasen, LIU Bingcai, ZHU Xueliang, and LIU Weiguo
Aiming at the vertical large plane interferometer, the method of threeflat test with Zernike polynomials was used to study the influence of the clamping and gravity deformation of the large plane on the absolute surface test results. The method of ANSYS finite element analysis was used to simulate the clamping and graAiming at the vertical large plane interferometer, the method of threeflat test with Zernike polynomials was used to study the influence of the clamping and gravity deformation of the large plane on the absolute surface test results. The method of ANSYS finite element analysis was used to simulate the clamping and gravity deformation under different parameters. The clamping parameters of the ring width of 15 mm and the plane thickness of 90 mm are optimized, and the deformation quantity peakvalley value is 0.023λ (λ=632.8 nm). The result of simulation experiment and comparative analysis base on the threeflat test with reference plane deformation show that the clamping and gravity deformation of the large reference plane in the vertical large plane interferometer is not only effects on the reference surface shape of the reference plane itself, but also affects the absolute surface shape of the large plane without deformation, and the surface deviation peakvalley value is basically 0.011λ, so the clamping and gravity deformation influence can′t be ignored. This study will provide references for future research on deformation compensation.v.
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 212004 (2018)
2 μm Dissipative Soliton Fiber Laser Based on External Cavity Compression
CHEN Hualong, JIN Liang, XU Yingtian, ZHANG He, LI Yan, and MA Xiaohui
The modulation instability generated by 2 μm dissipative soliton fiber laser under high peak power is studied. The effect of nonlinear effects on the optical pulse characteristics is analyzed by calculating the dynamic process of the dissipative soliton modelocked model. By introducing the dispersion compensation fibeThe modulation instability generated by 2 μm dissipative soliton fiber laser under high peak power is studied. The effect of nonlinear effects on the optical pulse characteristics is analyzed by calculating the dynamic process of the dissipative soliton modelocked model. By introducing the dispersion compensation fiber into the annular cavity and adding the radius of the mode field, the net positive dispersion is enlarged and the selfphase modulation effect is reduce in the cavity. Aiming at the larger linear chirp pulse output, 46.83 m large mode area fibers is taken to compress out of cavity. Finally the stable pulse output with peak power of 17.1 kW and pulse width of 169 fs is obtained..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 214001 (2018)
Investigation on Passively Q-switch Output Characteristics of Nd∶YAG/Cr4+YAG/YAG Composite Crystal Laser
GUO Jun-hong, DUAN Yan-min, ZHANG Jing, YUAN Xian-zhang, YAN Li-fen, WANG Hong-yan, and ZHU Hai-yong
The output characteristics of a passively Q-switched Nd∶YAG/Cr4+∶YAG/YAG composite crystal laser at 1 064 nm was studied with diode-end-pumped system. The laser output characteristic parameters were compared among five output couplers with different transmittance, and between two Cr4+∶YAG crystals with initial transmitThe output characteristics of a passively Q-switched Nd∶YAG/Cr4+∶YAG/YAG composite crystal laser at 1 064 nm was studied with diode-end-pumped system. The laser output characteristic parameters were compared among five output couplers with different transmittance, and between two Cr4+∶YAG crystals with initial transmittance of 84.1% and 90.6%. The experiment results show that the output parameters as average output power, pulse repetition frequency and pulse width could be optimized with transmittance of the output coupler. And the optimized transmittance also increased with the pump power. By the comparison of laser output characteristics between two crystals with different initial transmittance, the crystal having initial transmittance of 84.9% produced relatively low average power output, but its low pulse repetition frequency and narrow pulse width made the Q-switched laser peak power improved significantly. Under the incident pump power of 10.4 W, the maximum output power of 3.2 W was obtained using the output coupler with 30% transmittance. The calculated peak power was up to 6.3 kW as corresponding pulse width and pulse repetition frequency of 9.7 ns and 52 kHz, respectively..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 214002 (2018)
Optical Leaky Wave Antenna with Ellipsoid Holes Array in Fourlayer Plasmons Structure
ZHONG Dongzhou, and LIU Chengpeng
Based on the fourlayer plasmons structure (siliconmetalsiliconsilica), two types of optical leakywaveantennas that have different ellipsoidhole array structures in the metal layer were proposed. The structures include onedimensional symmetric tapered array and twodimensional symmetric tapered array. Based on aBased on the fourlayer plasmons structure (siliconmetalsiliconsilica), two types of optical leakywaveantennas that have different ellipsoidhole array structures in the metal layer were proposed. The structures include onedimensional symmetric tapered array and twodimensional symmetric tapered array. Based on antenna theory and finite element method, some physical characteristics for the antennas were investigated numerically. It is found that when the operating wavelength is fixed at 1550nm, the two antennas appear ultra wide bandwidth with 80 THz that covers the band of S+L+. With their ports filled in the air and the silicon nitride, respectively, they both show low return loss and insertion loss. But for two types of different filled materials, their characteristics show some differences, for example, in a onedimensional symmetric structure, the antenna has less return loss and insertion loss, lower side lobe level, and better directionality when its ports is filled with silicon nitride. The antenna can be generalized to apply in the fields of optical integrated interconnection, the control of highly integrated optical beam and space optical communication..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 223001 (2018)
Graphene Electrically Modulating Terahertz Transmission Enhanced by Arm Type Metal Mesh Structure
ZOU Yixuan, DONG Lianhe, XIA Liangping, and LIU Songlin
In order to improve the modulation depth of the single layered graphene electronic controlled terahertz modulator, a terahertz transmission modulator with an arm type metal mesh structure combined with graphene is proposed. The resonant coupling field excited by the arm type metal mesh structure enhances the interactioIn order to improve the modulation depth of the single layered graphene electronic controlled terahertz modulator, a terahertz transmission modulator with an arm type metal mesh structure combined with graphene is proposed. The resonant coupling field excited by the arm type metal mesh structure enhances the interaction between graphene and terahertz wave, which greatly improves the modulation depth of the terahertz modulator when the modulation voltage is applied. The influences on the interaction enhancement of graphene and terahertz wave at different metal structure parameters are analyzed by finite element method simulation. The theoretical results indicate that the arm type metal grid structure increases the modulation depth from 7.7% to 28.2%. On the basis of the theoretical results, the device is fabricated with the photolithography process. The 24% modulation depth is obtained in the experimental measurements, and the experimental modulation depth curve is basically in agreement with the theoretical simulation..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 223002 (2018)
Laminated Remote Phosphor Film Spectral Reabsorption and Its Packaging Application
ZHUO Ningze, ZHANG Na, ZHU Yuehua, and WANG Haibo
Singlelayer and laminated phosphor films were prepared by high temperature molding method with the using of green and red phosphor as raw materials, then white light emitting diode devices with three different structures (single type, greenred type and redgreen type) were packaged with chip on board blue light sourcSinglelayer and laminated phosphor films were prepared by high temperature molding method with the using of green and red phosphor as raw materials, then white light emitting diode devices with three different structures (single type, greenred type and redgreen type) were packaged with chip on board blue light sources. Based on fluorescence spectrophotometer system, double integral sphere system, the visible spectrum analysis system and spectral color luminance meter, the spectral reabsorption characteristics of phosphor in remote phoaphor film and the photochromic properties of white light emitting diode packaged were studied, and the corresponding mechanisms were analyzed then. The results showed that, the red phosphor in remote phosphor film has obvious reabsorption affection on green spectrum emitted fromgreen phosphor, and the spectral chromaticity coordinates of mobile satisfy linear equations as y=－0.881 6x+0.922 5, R2=0.998 6. Laminated film can improve the uniformity of color temperature, the difference of space color temperature of single type, greenred type and redgreen type are 485 K, 487 K and 799 K. And the standard deviation and relative standard deviation of color temperature in space are 173.1, 172.3, 284.6 and 0.0373, 0.052, 0.066, respectively, in which the white LED device packaged by greenred type remote phosphor film achieve the highest luminous efficiency of 301.1 lm·W－1 (@350 mA, 9.2 V)..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 223003 (2018)
Design of the Square Concave Ring Resonantor MIM Filter Based on the Surface Plasmon Polaritons
LIU Hairui, ZHANG Guanmao, WANG Zhishuang, and QIAO Litao
Based on the surface plasmon polaritons, a MetalInsulatorMetal (MIM) structure filter which is coupled by a square concave ring resonantor and a waveguide is proposed . The magnetic field distributions, the transmission spectrums and the resonant wavelength distribution curves of the MIM structure are obtained througBased on the surface plasmon polaritons, a MetalInsulatorMetal (MIM) structure filter which is coupled by a square concave ring resonantor and a waveguide is proposed . The magnetic field distributions, the transmission spectrums and the resonant wavelength distribution curves of the MIM structure are obtained through the numerical simulation software which is based on the finite element method.The results show that its stopband has a minimum transmittance of 0.01 while its passband transmittance can reach up to 0.96 and the top is smooth.When the parameter I or H of the waveguide structure is increased, the corresponding transmission curve has obvious red shift and the transmittance of different stopband modes will also change. In addition, the resonance wavelength shows a linear relationship with the structure parameters. When the structure parameter D is increased, the transmittance of mode 1 increases from 0.63 to 0.80, the mode 1 disappears eventually and the other modes are almost unchanged. the resonance wavelength shows no relationship with D. After optimization of structure parameters, the quality factor of waveguide structure can be improved from 14.82 to 17.07 and the bandwidth of the passband is increased. The MIM structure filters have the advantages of small footprint size, multimodes, narrow stopband, smooth passband, good quality factor and adjustability. Therefore the MIM structure filters may have good applications in Micronano integrated optical devices, especially in wavelenth division multiplexing system..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 223004 (2018)
Generation and Propagation Characteristics of Generalized Airy Beams with Tunable Trajectories
QIAN Yixian, and MAO Hongxing
In order to control the propagation trajectory of an Airy beam, generalized Airy beams are proposed theoretically. Such beams can be generated by modulating a Gaussian beam imposed on a tunable phase pattern, where two angle factors θ1 and θ2 are introduced in cubic phase. The hyperbolic parabola is investigated based In order to control the propagation trajectory of an Airy beam, generalized Airy beams are proposed theoretically. Such beams can be generated by modulating a Gaussian beam imposed on a tunable phase pattern, where two angle factors θ1 and θ2 are introduced in cubic phase. The hyperbolic parabola is investigated based on diffraction catastrophe theory. We focus on the nondiffracting property in the propagation distances of 0, 3, 6, 10cm in the case of θ1=π/3 andθ2=7π/6, and the selfhealing property in the case of θ1=3π/2 and θ2=π/4. The experiment and numerical simulations demonstrate that such beams still possess the nondiffracting, selfhealing properties to some extent, although the theory shows that they are not the solutions for paraxial wave equation. The generalized Airy beams can propagate along arbitrarily appointed parabolic trajectories and directions in free space, and their intensity distributions are different from that of traditional Airy beams, which make the generalized Airy beams have potential applications in optical trapping and biomedicine..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 226001 (2018)
Mathieu Beam Generated by Partially Coherent Beam
FENG Cong, WANG Shuochen, and WU Fengtie
The Mathieu beam produced by partially coherent light was studied theoretically and experimentally, based on Fresnel diffraction theory and Fourier transform. The intensity expression of the Mathieu beam was derived with sampling theory and dispersion formula. The section intensity distribution of the Mathieu beam at dThe Mathieu beam produced by partially coherent light was studied theoretically and experimentally, based on Fresnel diffraction theory and Fourier transform. The intensity expression of the Mathieu beam was derived with sampling theory and dispersion formula. The section intensity distribution of the Mathieu beam at different propagation distances was simulated. And the experiment was designed to verify the simulation results. We would choose multiwavelength blue LED as the light source in the the experiment. The Mathieu beam would be obtained using a axicon and a film with an elliptical aperture. Both simulated and experimental results show that partially coherent light can produce Mathieu beams. The results provide a theory evidence for extending the application range of Mathieu beam..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 226002 (2018)
Multisite High-frequency Radiometric Calibration of GF-1 Wide Field of View
WEI Wei, ZHANG Yan-na, ZHANG Meng, ZHAO Chun-yan, LI Xin, and ZHENG Xiao-bing
To increase the calibration frequency of Chinese optical remote sensing satellite sensor, a high-frequency calibration method based on domestic multisite was presented. And the in-flight high-frequency absolute radiometric calibration of GF-1 Wide Field of View (WFV) was conducted using this method. The theory of high-To increase the calibration frequency of Chinese optical remote sensing satellite sensor, a high-frequency calibration method based on domestic multisite was presented. And the in-flight high-frequency absolute radiometric calibration of GF-1 Wide Field of View (WFV) was conducted using this method. The theory of high-frequency calibration based on multisite was intruduced. The optimized selection principle of domestic calibration site was presented according to the parameters and characteristics of GF-1 WFV. And the temporal stability of site surface was analyzed. MODIS land and atmosphere products were used to instead of in-situ measurements to increase the amount of available calibration data. The validation of MODIS land product was conducted using in-site measurements. The high-frequency calibration of GF-1 WFV4 based on Chinese multisite was carried out, and the calibration coefficients were compared with the official calibration coefficients.The result shows that time series calibration coefficients of GF-1 WFV can be obtained using the multisite high-frequency calibration method. The calibration results of GF-1 WFV4 are in good agreement with the results of the official calibration. The relative differences of GF-1 WFV4 all bands calibration coefficients of the two methods are -0.49%, 1.33%, -1.01% and 3.86% respectively, which illustrates the availability of this method. The method can be used to improve the calibration frequency of Chinese remote sensing sensor, and timely track the changes of sensor..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 228001 (2018)
Measurement Method for Lowconcentration SO2 Based on Statistics and DOAS
ZHANG Bao, GAO Chao, GUO Yongcai, LIU Guoqing, and CHEN Fang
In order to monitor SO2 emission from coalfired power factories and meet national ultralow emission standards, measurement method for lowconcentration SO2 via short optical length is proposed. At known pressure and temperature conditions, dataset of differential absorption cross section was constructed with various In order to monitor SO2 emission from coalfired power factories and meet national ultralow emission standards, measurement method for lowconcentration SO2 via short optical length is proposed. At known pressure and temperature conditions, dataset of differential absorption cross section was constructed with various concentrations of standard gas, utilizing differential optical absorption spectroscopy (DOAS). In accordance with standard deviation and average of the dataset, combined with results of concentration inversion, spectral window was gradually reduced from 200~400 nm to 294~308 nm. For each point in 294~308 nm, where there are 137 sampling points, statistics and standard deviation were applied to characterize consistency of differential absorption cross section. It was only when standard deviation and average at sampling point met requirements that the point was reserved to optimal point set. So optimal dataset of differential absorption cross section and optimal sampling points were constructed eventually. At same pressure and temperature conditions, SO2 concentration in flue gases can be accurately calculated by the optimal dataset and DOAS. In the laboratory, measurement range is 2~30 μL/L, temperature and pressure are 299.05 K, 101.33 kPa, while optical length and volume of gas cell are 420 cm, 0.5 L correspondingly. Experimental results show that inversion concentration performs superior repeatability within 72 h, relative error is less than 1.7%, full scale error is below 1.3%, and zero drift is 0.09 μL/L. With 420 cm optical length, the method can precisely measure lowconcentration SO2 under 30 μL/L, resolve conflicts between concentration and optical length, which is suitable for study of ultralow emission monitoring system used in coalfired power plants..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 230001 (2018)
Pressure Measurement and Compensation for Mid-infrared Methane Detection
LIU Zhi-wei, LI Zi-wen, LI Ya-fei, ZHENG Wen-xue, ZHENG Chuan-tao, and WANG Yi-ding
A pressure measurement and compensation technique was studied by employing a 3.291 μm Continuous Wave (CW) Interband Cascade Laser (ICL) and a dense-patterned Multipass Gas Cell (MPGC) with an effective optical path length of 54.6 m. The pressure inside the MPGC was measured based on direct Lorentzian absorption line fA pressure measurement and compensation technique was studied by employing a 3.291 μm Continuous Wave (CW) Interband Cascade Laser (ICL) and a dense-patterned Multipass Gas Cell (MPGC) with an effective optical path length of 54.6 m. The pressure inside the MPGC was measured based on direct Lorentzian absorption line fitting on the measured absorption spectral signal of CH4, and then pressure compensation was made on the masured CH4 concentration. Pressure calibration was performed from 1.33×104 Pa to 10.64×104 Pa using a 2.1×10-6 CH4 sample. An Allan deviation analysis of the measured pressure of a 2.1×10-6 CH4 at 9.31×104 Pa pressure indicates a measurement precision of ~219.5 Pa with a 2.2 s averaging time. Fiveteen groups of pressure/concentration measurements of 1.0×10-6, 1.2×10-6, 1.4×10-6, 1.6×10-6 and 2.1×10-6 CH4 samples at different pressures of 1.33×104, 3.99×104 and 6.65×104 Pa were performed, and the results proved the feasibility of the proposed pressure measurement and compensation technique..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 230002 (2018)
Study on Fabrication Technology and Properties of High Quality Perovskite Quantum Dots Film
YU Bin-hai, YAN Cai-man, RAO Long-shi, TANG Yong, LI Zong-tao, CHEN Song-mao, and LU Han-guang
Perovskite quantum dots have attracted great attention due to their narrow emission spectrum, tunable spectrum and high quantum yield, however, their poor stability because of the sensitivity of water and oxygen molecules limits their application. Polymethyl methacrylate (PMMA) and polystyrene-polyethylene-polybutene-pPerovskite quantum dots have attracted great attention due to their narrow emission spectrum, tunable spectrum and high quantum yield, however, their poor stability because of the sensitivity of water and oxygen molecules limits their application. Polymethyl methacrylate (PMMA) and polystyrene-polyethylene-polybutene-polystyrene block copolymer (SEBS) were selected as two kinds of polymer materials to study their perovskite quantum dots film performances. The high-quality perovskite quantum dots films were fabricated by one-step package method. The decay rate of PMMA perovskite films was about 4 times and 6 times that of SEBS films under continuous 365 nm UV excitation and LED remote package, which indicated SEBS perovskite films had better stability than PMMA. Furthermore, the stability of SEBS perovskite films in air and water was studied. Compared with the 18% recession after about 4 h of the perovskite quantum dots solution, it was found that SEBS perovskite films in the air and water about 18% degradation extended to 55 h and 240 h, indicating that SEBS package enhanced the stability of the perovskite quantum dots, which has great significance to the application of perovskite quantum dot package in the future..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 231001 (2018)
Optical Properties of Lanthanum Titanate Films Irradiated by Lasers with the Wavelengths of 1 064 nm and 532 nm
XU Jun-qi, WANG Jian, LI Mian, LI Hou-jun, and SU Jun-hong
Lanthanum titanate (H4) films were deposited by the thermal vapor deposition technique. After irradiating with a 1 064 nm and 532 nm lasers, the refractive index, extinction coefficient, Laser-Induced Damage Threshold (LIDT) of the films and damaging process of the films were investigated. The results showed that the rLanthanum titanate (H4) films were deposited by the thermal vapor deposition technique. After irradiating with a 1 064 nm and 532 nm lasers, the refractive index, extinction coefficient, Laser-Induced Damage Threshold (LIDT) of the films and damaging process of the films were investigated. The results showed that the refractive index of H4 films slightly increased after laser irradiating. The LIDT increased from 10.2 J/cm2 to 15.7 J/cm2 (5-pulse irradiation) after irradiating by using a 1 064 nm laser, however, the change of LIDT of the films was unobvious after irradiating by using a 532 nm laser. For the same sample, the LIDT which measured with a 1 064 nm laser was higher than that with a 532 nm laser. H4 film′s damage process underwent a slow 4-stage, slight, mild, moderate and extreme damage by using a 1 064 nm laser, whereas the damage process was a sudden change by using a 532 nm laser, underwent a 2-stage, moderate and extreme damage...
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 231002 (2018)
Preparation and Structural Properties of Sb-doped Si3N4-based Si Quantum Dot Thin Films
MO Jing-hui, YUAN Jun-bao, YANG Pei-zhi, ZHANG Zhi-heng, WANG Yun-xiang, and LIU Li-ming
The thin films of Sb-doped Silicon Quantum Dots (Si-QDs) embedded in Si3N4 matrix were prepared by using muti-target radio frequency magnetron sputtering deposition technique combined with a rapid thermal process. The microstructure and luminescence properties of the films were studied by transmission electron microscoThe thin films of Sb-doped Silicon Quantum Dots (Si-QDs) embedded in Si3N4 matrix were prepared by using muti-target radio frequency magnetron sputtering deposition technique combined with a rapid thermal process. The microstructure and luminescence properties of the films were studied by transmission electron microscopy, grazing incidence X-ray diffraction, Raman spectroscopy and photoluminescence spectroscopy. The effect of Sb doping on the microstructure and luminescent properties of Si-QDs films was discussed. The results show that the Sb-doping films exhibit obvious Sb-induced crystallization effect in annealing process. The doping of Sb contributes to the diffusion of Si atoms in the Si3N4 matrix and formation of Si-QDs. With the rise of Sb doping amount, the size of Si-QDs gradually is enlarged, and the crystallinity Xc of the films increases effectively. As Sb doping amount rises, the intensity of the PL peaks of the Si-QDs films enhances, and the full width at half maximum of the peaks becomes narrower. Meanwhile, due to the rise of the Si-QDs size, a red-shift is observed in the films with higher Sb doping density..
Acta Photonica Sinica
- Publication Date: Jan. 01, 1900
- Vol. 47, Issue 2, 231003 (2018)
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