Contents
2019
Volume: 41 Issue 3
14 Article(s)
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Tuning of the fluorescence enhancement of nanoporous gold by silica coating
MA Chao, and ZHANG Ling
In order to weaken the quenching effect of the metal substrate on surface enhanced fluorescence, a better fluorescent enhanced substrate was designed. In this experiment, the surface of nanoporous gold (NPG) was modified by chemical synthesis of silica, avoiding quenching effects caused by direct contact of fluorescentIn order to weaken the quenching effect of the metal substrate on surface enhanced fluorescence, a better fluorescent enhanced substrate was designed. In this experiment, the surface of nanoporous gold (NPG) was modified by chemical synthesis of silica, avoiding quenching effects caused by direct contact of fluorescent molecules with NPG surfaces. Rhodamine 6G (R6G) and a quantum dot with a center wavelength of 700 nm (QD 700) were assembled on the surface of SiO2@NPG respectively. The analysis of the corresponding fluorescence spectra shows that coating silica can make the surface enhanced fluorescence enhanced significantly, and the thickness of the silica has a regulatory effect on the fluorescent signal. As for quantum dots (QD), unless fluorescence enhancement of assembled QD, non-radiative energy transfer between the excited QD and NPG was observed with silica coated NPG, and the energy transfer reaches the strongest when the thickness of silica was 5 nm. The experiment provides a new method for detection based on fluorescence energy transfer..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 61 (2019)
Investigation of liquid polarity based on terahertz spectroscopy
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Terahertz (THz) wave has strong resonance absorption with the hydrogen bond of polar substances. The bigger the molecular polarity, the stronger the absorption. Based on this characteristic, monohydric alcohol liquids from methanol to 1-butanolwere have been detected by terahertz time-domain spectroscopy (THz-TDS) withTerahertz (THz) wave has strong resonance absorption with the hydrogen bond of polar substances. The bigger the molecular polarity, the stronger the absorption. Based on this characteristic, monohydric alcohol liquids from methanol to 1-butanolwere have been detected by terahertz time-domain spectroscopy (THz-TDS) within the spectral range of 0.2-1.0 THz. The relationship between the polarity of monohydric alcohol and their terahertz spectra are analyzed, which proves that the terahertz spectroscopy of monohydric alcohol molecules is mainly determined by the polarity, which can be quantitatively calculated. These results conclude that terahertz spectroscopy can realize the effective and fast identification of the polarity of chemical solution, which can provide a reference for liquid polarity detection..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 1 (2019)
Adjustment efficiency optimization for test equipment of mobile camera module
CHEN Yutian
With the improvement of mobile phone camera requirements and performance, phase detection autofocus (PDAF) module has gradually become the main stream of the market. At this stage, most small and medium-sized module manufacturers still use manual methods to test such modules, and the test efficiency is very low. In ordWith the improvement of mobile phone camera requirements and performance, phase detection autofocus (PDAF) module has gradually become the main stream of the market. At this stage, most small and medium-sized module manufacturers still use manual methods to test such modules, and the test efficiency is very low. In order to improve such drawbacks as low test efficiency, low measurement accuracy, and high labor intensity by the manual test equipment, based on the actual production situation, we comprehensively use mechanical design, mechanical theory, engineering materials, and other related knowledge to design and manufacture a three-station autofocus equipment through the combination of theoretical calculation and actual simulation. Actual production verifies that the production efficiency can reach 210 pieces/h. The three-station autofocus test equipment is optimized and modified into a six-station autofocus device, whose production efficiency can reach 360 pieces/h,and the test efficiency increases by about 70%..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 7 (2019)
Design of a novel ridge substrate integrated waveguide
XU Tao, WANG Ning, and JIA Hongzhi
In order to solve the problem of the narrow bandwidth of the substrate integrated waveguide, a new type of ridge substrate integrated waveguide (RSIW) is proposed. Based on the traditional RSIW, the structure is composed of two dielectric layers with different permittivity, and there are two rows of air holes arranged In order to solve the problem of the narrow bandwidth of the substrate integrated waveguide, a new type of ridge substrate integrated waveguide (RSIW) is proposed. Based on the traditional RSIW, the structure is composed of two dielectric layers with different permittivity, and there are two rows of air holes arranged periodically on the both sides of the structure. Simulation results demonstrate that the single-mode working bandwidth of the proposed structure is up to10.88 GHz, which is 57 % and 18.8 % higher than that of RSIW1 and RSIW2. Moreover, the B value of the proposed structure is 4.42, and the structure exhibits good transmission characteristics over the whole passband, which can be suitable for applications covering the entire ultra-wideband. The design provides a reference for solving the narrow bandwidth of the substrate integrated waveguide and forming a compact broadband interconnect..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 15 (2019)
VGG16 model-based fast loop closure detection algorithm
ZHANG Xuedian, GU Zhangqi, and QIN Xiaofei
Deep convolution neural network is superior to traditional manual features in the image feature representation, but it still has the problem that the calculation time increases with the increase of data in the loop-closure detection. In order to solve this problem, a fast closed-loop detection algorithm based on VGG16 Deep convolution neural network is superior to traditional manual features in the image feature representation, but it still has the problem that the calculation time increases with the increase of data in the loop-closure detection. In order to solve this problem, a fast closed-loop detection algorithm based on VGG16 model is proposed. The algorithm uses the VGG16 network model, which is pre-trained on ImageNet, to extract the image convolution features, and a loop-closure candidate frame is obtained by an adaptive particle filtering method to fix the operation time. The algorithm is tested in the mainstream loop-closure detection dataset City Centre and New College, and the experimental results show that the algorithm can achieve 70% recall rate under 92% accuracy and 61% recall rate under 96% accuracy on the two datasets, which exceeds the conventional algorithms, and effectively solves the problem of calculating time growth..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 20 (2019)
Amplitude and phase error correction method for full-waveform light detection and ranging
LIU Rongrong, and MAO Qingzhou
Aiming at the problem of amplitude and phase errors in full-waveform light detection and ranging (LiDAR), a method based on neural network and pulse feature parameters is proposed. The feature parameters of waveform, including shape information, energy information, gradient information, symmetry information, and distanAiming at the problem of amplitude and phase errors in full-waveform light detection and ranging (LiDAR), a method based on neural network and pulse feature parameters is proposed. The feature parameters of waveform, including shape information, energy information, gradient information, symmetry information, and distance information were extracted from non-cooperative target detection information and graded based on the Pearson correlation coefficient. A neural network model combining multi-echo characteristic information with amplitude-phase error correction was established to correct the amplitude and phase errors of each channel in full-waveform laser measurement. The experiment used 5%, 20%, 60% and 80% standard reflectorsand laser acquisition modules to collect pulse data at 7 different distances. The processed data was also compared with the traditional full waveform measurement method. The results show that this method could effectively reduce the influence of amplitude and phase errors in the full-waveform laser measurement, and the measurement accuracy is improved by more than 51.2%..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 27 (2019)
A novel high dynamic range microscopic video system based on REC.2020
[in Chinese], and BERNAL Salvador Garcia
High dynamic range (HDR) technology has become a new trend of the development of digital microscopes. Currently, due to the high computational complexity, the HDR video cannot be processed and displayed in real-time. Based on REC.2020 high definition (HD) standard, it is feasible and stable to generate the HDR video flHigh dynamic range (HDR) technology has become a new trend of the development of digital microscopes. Currently, due to the high computational complexity, the HDR video cannot be processed and displayed in real-time. Based on REC.2020 high definition (HD) standard, it is feasible and stable to generate the HDR video flow in real-time using GPU accelerated processing. The experimental results show that the presented algorithm not only provides a stable real-time HDR video flow, but also improves the performance of the recovered video in both detail and color, which has overcome the limitation in processing speed and quality of the traditional HDR imaging technology..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 35 (2019)
Three-dimensional fluorescence spectrum fingerprinting analysis method for crop starch
ZHANG Jindan, WU Mingwei, and FENG Min
This paper conducted fluorescent spectra of starch powder by using three dimensional fluorescence spectroscopy (EEMs) combined with parallel factors analysis (PARAFAC), revealing that different fluorescence features in the different crops. We built fluorescence fingerprint of several monocots seed starch such as rice, This paper conducted fluorescent spectra of starch powder by using three dimensional fluorescence spectroscopy (EEMs) combined with parallel factors analysis (PARAFAC), revealing that different fluorescence features in the different crops. We built fluorescence fingerprint of several monocots seed starch such as rice, sorghum and maize. Furthermore, we tested the correlations of fluorescence properties and rice variety. The results indicated that fluorescence components intensity were lower in indica varieties than that in japonica varieties. One-way analysis of variance test showed statistic differences between indica varieties and japonica varieties. This method can be used for different variety starch identification..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 42 (2019)
A programmatic design method of Czerny-Turner spectrometer based on compact optical structure
LONG Yaxue, WANG Xianjun, ZHENG Haiyan, GUO Hanming, and HU Jinbing
In order to minimize the size of the optical system of Czerny-Turner (CT) spectrometer and prevent interference of incident rays and diffracted rays, a complete selection system of structural parameters is created to satisfy the spectral performance. A variant of the grating equation is proposed, and the constraint conIn order to minimize the size of the optical system of Czerny-Turner (CT) spectrometer and prevent interference of incident rays and diffracted rays, a complete selection system of structural parameters is created to satisfy the spectral performance. A variant of the grating equation is proposed, and the constraint conditions are determined to prevent interference of incident rays and diffracted rays. A mathematical model of the optical structure is established and the calculation formulas of structural parameters are determined. On this basis, the determination of the parameters is simplified by programming and all design parameters of the optical structure can be directly obtained once the intended resolution, the wavelength range, the NA value and the minimum distance between components in the system are input into the system. A fast and universal design method of CT spectrometer is realized. A design example with a spectral range of 780～1020 nm, a resolution of 0.4 nm and a volume of 54×56×30 mm3 is given for verification. It can provide reference for other designs..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 49 (2019)
Study on parameter evaluation of optical wavefront
YANG Ying, LIU Mincai, CHEN Lei, ZHU Wenhua, and ZHENG Donghui
To evaluate the surface of glass elements that achieved by single point diamond turning (SPDT) operation, the wavelet analysis method is employed to analyze surface and surface ripple.In this work, the wavelet analysis method is introduced to decompose and reconstruct the sampled surface profile signals with the waveleTo evaluate the surface of glass elements that achieved by single point diamond turning (SPDT) operation, the wavelet analysis method is employed to analyze surface and surface ripple.In this work, the wavelet analysis method is introduced to decompose and reconstruct the sampled surface profile signals with the wavelet by using bior2.8 software. The surface is extracted effectively and the signals of the middle-frequency is separated from the surface. The characteristic frequency is 0.18 mm.1. The wavelet analysis method avoids the problem of amplitude distortion which exists in the spectral-filtering method. Moreover, the wavelet multiscale analysis method is applied to analyze the details and frequency performance of the wavefront..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 56 (2019)
Research on print image registration method based on jitter compensation technology
ZHANG Leihong, and XIONG Rui
In the actual process of defect detection of printed matter, there is a problem that the standard printed image and the image to be detected are inaccurately registered due to the camera bracket flutter. Therefore, based on the image de-jitter technique, a motion estimation algorithm combining SURF(speeded-up robust feIn the actual process of defect detection of printed matter, there is a problem that the standard printed image and the image to be detected are inaccurately registered due to the camera bracket flutter. Therefore, based on the image de-jitter technique, a motion estimation algorithm combining SURF(speeded-up robust features) and ORB(oriented FAST and rotated BRIEF) is proposed. Firstly, the feature points of the standard printed image and image to be detected are extracted based on the SURF algorithm. Secondly, the extracted feature points are described and matched based on the ORB algorithm. Then, the global motion vectors are obtained by affine model of the correctly matched feature points. Finally, the global motion vector is obtained to compensate the image, and the registration between the image to be detected and the standard printed image is completed. In the experiment, the performance of SURF-ORB, ORB and SIFT(scale-invariant feature transform) motion estimation algorithms are analyzed under three different changes. The motion estimation time of SURF-ORB and ORB is controlled at the millisecond level, which meets the real-time requirement of modern printing defect detection. In addition, SURF-ORB has the largest number of feature points matching, and the matching effect is good. Therefore, in the detection process, from the real-time and accuracy of registration, this method in this paper can accurately and real-time registration of images..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 67 (2019)
Uniform illumination design of HPV gene chip detection device
LIU Yihui, CHEN Jianguo, GAN Zhenhua, DU Min, and GAO Yueming
The human papilloma virus (HPV) gene chip detection device can read and analyze the hybrid point signal values of the HPV chip to distinguish different HPV virus types. The uniform illumination of the device is related to the difficulty and reliability of the HPV chip image processing algorithm. To achieve uniform illuThe human papilloma virus (HPV) gene chip detection device can read and analyze the hybrid point signal values of the HPV chip to distinguish different HPV virus types. The uniform illumination of the device is related to the difficulty and reliability of the HPV chip image processing algorithm. To achieve uniform illumination, the rectangular LED array is arranged and the uniform light diffusing plate is arranged. Firstly, the radiation intensity distribution of a single LED lamp bead is analyzed to establish a theoretical model of the rectangular LED array. Then, a rectangular LED array model of 4 rows and 8 columns is established in the simulation software. Finally, the HPV gene chip detection device is set up for experimental testing. The experimental results show that the illumination system has a gray level uniformity of 95.6% in the target surface of 70 mm×20 mm, which meets the uniform illumination requirements of the HPV gene chip detection device..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 75 (2019)
Properties and preparation of low stress SiNx film by PECVD
LI Pan, ZHANG Qian, XIA Jinsong, and LU Hong
In this paper, silicon nitride deposition process was carried out by using plasma enhanced chemical vapor deposition (PECVD). The influence of processing parameters on PECVD film properties were discussed. In conclusion, it was convenient to obtain low stress SiNx film by controlling the switching time of high and low In this paper, silicon nitride deposition process was carried out by using plasma enhanced chemical vapor deposition (PECVD). The influence of processing parameters on PECVD film properties were discussed. In conclusion, it was convenient to obtain low stress SiNx film by controlling the switching time of high and low frequencies respectively; dense high quality SiNx films with low tensile stress can be grown. The results showed that PECVD silicon nitride had the characteristics of small thickness deviation and stable refractive index, which establishes a foundation for its application in optics..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 81 (2019)
Research progress on eye tracking technology
SHI Jianjun, and XU Jian
Eye tracking refers to tracking eye movement by measuring the position of the eye's gaze point or the movement of the eyeball relative to the head. This paper introduces the eye tracking technology, focuses on the recent research progress, analyzes the various eye tracking technology principles, and compares the adEye tracking refers to tracking eye movement by measuring the position of the eye's gaze point or the movement of the eyeball relative to the head. This paper introduces the eye tracking technology, focuses on the recent research progress, analyzes the various eye tracking technology principles, and compares the advantages and disadvantages of various measurement methods in detail. With the continuous development of eye tracking devices and their wide application in various fields, we further introduce the development trend of eye tracking at home and abroad by comparing the characteristics of several new eye tracking devices. Finally, the research direction of eye tracking technology is introduced, and the application of eye tracking technology is prospected..
Optical Instruments
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 3, 87 (2019)
