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111.
王佳怡;刘涛;唐晓锋;胡佳琪;王兴;李国卿;何韬;杨树明 《光子学报》2021,50(11):123-136
利用Zemax优化设计了结构简单、低成本的非球面色散镜组,搭建了光纤式色散共焦三维测量软硬件系统。结合实验测试数据定量比较了峰值法、质心法、高斯拟合法和样条插值法的色散共焦光谱响应峰值波长提取性能,通过轴向分辨率和位移精度测试实验对比分析了两种测量曲线标定方法对于系统测量性能的影响。实验结果表明：系统轴向测量范围为1mm,高斯拟合法在四种峰值波长提取算法中精度较高且适应性更好,两种标定方法对应的轴向分辨率均达到0.2μm,在整个量程范围内,位移测量精度优于1%;对厚度为0.219mm的石英玻璃进行测量,均值的相对误差为0.5%。利用该系统实际测量了台阶结构、柔性电极和MEMS器件的三维形貌,充分验证了本系统可实际应用于三维微观形貌和透明材料厚度的高精度测量。 相似文献
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114.
HUANG Yi;YOU Yue;DENG Chuanlu;HU Chengyong;WANG Lisen;ZHANG Xiaobei;WANG Tingyun 《光子学报》2023,52(2):71-81
The output stability of semiconductor lasers is simultaneously affected by current and temperature, and the power and wavelength of lasers are prone to fluctuations in practice, which may even damage lasers permanent. In this paper, a high-stability Modulated Grating Y-branch （MG-Y） laser control system based on self-adaptive current compensation is proposed to address the problems of poor stability of wavelength and power as well as the complexity of the laser control system. The whole system is integrated into a printed circuit board with a small size, light weight and low power consumption. Based on the current inner loop feedback, we optimize the parameters of Fuzzy Proportional-Integral-Differential （PID） algorithm by orthogonal experiments and propose a wavelength calibration algorithm based on self-adaptive current compensation.The high-stability MG-Y laser control system is described in detail. Firstly, we introduce the system device and principle of operation. MG-Y laser is controlled by 5 currents and operates at 25℃. Left reflector current （I left）, right reflector current （I right）, and phase section current （I phase） are used for wavelength adjustment, while the power is adjusted by the gain section current （I gain） and the semiconductor optical amplifier current （I SOA）. The control system is mainly composed of MG-Y laser, constant current source chip ADN8810, temperature control chip ADN8834, and operational amplifier chip AD8620. Secondly, in terms of power stability, a Fuzzy PID control parameter optimization algorithm based on orthogonal experiments is proposed to reduce both the overshoot of laser power and adjustment times of control system. The number of orthogonal experiments and the range of Fuzzy PID parameters need to be confirmed, then we design the orthogonal tables by screening the value range of each control parameter. The algorithm can effectively approach the optimal value of each parameter and also improve the performance of the laser control system. In the wavelength calibration part, we propose a wavelength calibration algorithm based on self-adaptive current compensation to reduce the central wavelength drift of MG-Y laser at different power levels. The algorithm takes advantage of the wavelength fine-tuning characteristics of the phase section current I phase, by adjusting I phase from 0 to 7.5 mA, continuous tuning of wavelength in the range of about 0.3 nm is possible. After setting a standard wavelength λ , the I phase region with stable wavelength variation and broad coverage is selected as linear compensation data region. I SOA scans in 1 mA steps until the range of the laser output power is fully covered, while the calibrated wavelength λ * is obtained by updating I phase according to the compensation data region so that λ * is infinitely close to λ . We establish the look-up table for I SOA and I phase and also fit the data in the table into segments. When the laser changes its power, the system adaptively calculates the corresponding I phase according to I SOA and sets the wavelength to the standard wavelength λ adaptively. The algorithm solves the cross-influence problem between wavelength and power caused by current inner loop feedback, and improves the output stability of the MG-Y laser.The simulation and test results of the whole laser control system are shown at last, including the laser output power stability and wavelength drift. First, the performance of Fuzzy PID parameters optimization algorithm based on orthogonal experiments is simulated, and the results show that the overshoot of the laser power is reduced from 1.528% to 0.014% after optimization, and adjustment times of control system are lowered from 21 to 17. Then, we test the performance of MG-Y laser, and the results are almost consistent with the simulation results. The power stability is measured by the optical power meter PM400 and integrating sphere probe S145C. Before power stabilization, the output power fluctuation of 3 000 samples （about 60 min） is 0.021 9 mW, and the stability is 0.269 8%. In comparison, the maximum fluctuation of laser power is 0.004 4 mW, and the stability can reach 0.060 4% in 60 min after stabilization. Finally, the wavelength stability is measured by fiber Bragg grating analyzer FBGA. The wavelength drift is 1.9 pm within 60 min. After wavelength calibration, the wavelength drift at different power levels is reduced from 23.4 pm to 2.6 pm at 1 559.68 nm. In order to verify the accuracy of the wavelength calibration method, the output wavelength of the laser is increased from 1 531 nm to 1 569 nm with a step of 1 nm, and the output spectrum of the MG-Y laser was collected by spectrometer AQ6370D. Before wavelength calibration, the wavelength fluctuated at 1 553 nm and 1 555 nm where the drifts were as high as 91 pm and 76 pm respectively. After wavelength calibration, the wavelength drifts at 1 553 nm and 1 555 nm are lowered to 2 pm and 1 pm separately. The stability of wavelength under different output power is greatly improved. The simulation and test results show that the laser control system has excellent control capability and expands the application scenarios of MG-Y laser. 相似文献
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116.
Bingliang HU 《光子学报》2022,51(7):13-33
Interferometric spectroscopic imaging technology has undergone decades of experience accumulation and technological development. At present, it has extensive and mature applications in the fields of astronomical exploration, atmospheric pollution, water environment monitoring, surface geological mineral exploration, vegetation survey and other fields. Compared with dispersive and filter-type spectral imaging techniques, interferometric spectroscopic imaging technology has the advantages of high resolution, high sensitivity, and high wave number accuracy. According to the type of optical path acquisition method, this paper summarizes the research status of interferometric spectroscopic imaging technology at domestic and abroad from three aspects： time modulation, spatial modulation, and spatio-temporal joint modulation. Then introduces and reviews their representative research results. For time-modulated interferometric spectroscopy imaging, the interferogram acquired by the detector can be seen as a collection of time series. Interference maps are acquired one by one over time. The main advantages of this technique are the high spectral resolution and detection sensitivity. However, this type of optical system requires a continuously moving precision part to produce an optical path difference that changes over time. The main technical difficulty of time-modulated interferometer spectroscopy is how to develop a set of stable, reliable and long-working high-precision moving mirror scanning system. Spatial modulation interferometric spectroscopy records interference information at different cell positions of the detector for different optical path differences of the measured target. A complete interference map of the target can be obtained with a single exposure. This technology fundamentally overcomes the problem of precision moving mirror scanning system in time-modulated spectrometers, and also improves the real-time performance of obtaining spectral information. The essence of spatiotemporal combined modulation interferometer spectroscopy is to insert a transverse shear interferometer into the camera system. Since there is no slit in the front optical system, this type of instrument not only has the characteristics of high detection sensitivity, high stability and high signal-to-noise ratio, but also has the advantages of high throughput. It can be seen that different modulation methods use different optical path structures. Of course, each spectroscopic principle also has its advantages and disadvantages, which can be applied to different application areas. The research of interferometric spectroscopy imaging technology has always attracted much attention. There is no doubt that the emergence of relevant new technologies is often very eye-catching. Over the past three decades, interferometric imaging spectroscopy technology has been rapidly developed in the field of remote sensing, and has gradually become an effective tool for high-resolution remote sensing detection.With the rapid development of detector focal plane array, precision machinery, high-speed data transmission and storage compression, data quantification and computer image processing, the future of spectral imagers will have a large field of view, wide spectral range, high sensitivity, high spectral resolution, high spatial resolution and other performance. Moreover, the technology gradually tends to develop in the direction of new principles, integration, automation, wireless, intelligence, single cylinder and miniaturization. 相似文献
117.
Bowen JIANG;Tao YUE;Xuemei HU 《光子学报》2022,51(6):1-18
Radar is a sensor that uses electromagnetic waves for detection and ranging. The Light Radar （LIDAR） has been widely applied in many fields, such as robotics, ocean detection, atmospheric detection, intelligent driving, etc. Recently, LIDAR, based on the aperiodic random signal, has aroused great attention. The chaotic signal is one of the various aperiodic random signals, and the LIDAR systems taking the chaotic signal as the detection signal are named chaotic laser ranging systems. Considerable simulation and experimental results have illustrated that this kind of LIDAR system can perform attractive qualities, such as anti-jamming properties, high precision （mm-level）, and multi-target real-time ranging ability. Nevertheless, up to now, existing work has not proposed a simulation model based on a realistic physical processes for chaotic laser ranging systems yet; also, there is no work that quantitatively analyzes the main degradation factors affecting the accuracy of chaotic laser ranging systems and the quality of reconstructed depth maps. In order to solve the problems above, a computational model based on the physical process for chaotic laser ranging systems is proposed in this paper. The computational model comprehensively considers various factors which will possibly cause chaotic signal degradation and ranging error during the realistic ranging process, including atmospheric attenuation, atmospheric turbulence, geometric attenuation, surface information of the object and its Bidirectional Reflection Distribution Function （BRDF）, multipath noise, ambient noise, thermal noise and the degradation model of photodiodes. The program of the computational model is implemented with MATLAB. Among various degradation factors, there are three factors that require special awareness which namely BRDF, ambient noise, and multipath noise. In order to explore the influence of these three degradation factors on the accuracy of depth map reconstruction, this paper further uses the discrete chaotic sequence generated from the simulated Chua's chaotic circuit as the detection signal to scan the synthesized depth images and reconstructs depth maps by means of the cross-correlation mathematical method. To comprehensively assess the quality of the depth maps reconstructed under different degradation factors and degradation levels, we not only calculate the Peak Signal-to-Noise Ratio （PSNR） and Structural Similarity （SSIM） between the reconstruction result and ground truth but also visualize both the reconstructed and ground-truth depth images. The experimental results show that the quality of depth maps reconstructed by the chaotic laser simulation ranging system is slightly affected by the roughness coefficient in BRDF model, but as the roughness coefficient increases, the influence of multipath noise will become non-negligible. Additionally, the chaotic laser simulation ranging system studied in this paper performs satisfying robustness against ambient noise when it is not extremely intense. However, the chaotic ranging system is relatively sensitive to multipath noise, i.e., even when the multipath noise is not intense, the depth map reconstruction quality will decrease rapidly. Therefore, when designing a realistic chaotic laser ranging system in practice, it is necessary to take the reflection and geometric property of the object and the influence of multipath noise into careful consideration. In conclusion, the computational model of a chaotic laser ranging system proposed and analyzed in this paper can serve as an important reference for analyzing the degradation factors affecting the ranging quality before designing and implementing a practical chaotic laser ranging system. Moreover, with the help of this computational model, it is possible for researchers to quickly and efficiently generate synthetic chaotic laser ranging datasets similar to the data measured in a realistic environment. 相似文献
118.
FU Ming-lei;HU Wei-jie;LE Zi-chun;Manko D. Y.;Antonov E. E.;Kryuchyn A. A.;Petrov V. V. 《光子学报》2017,46(11):1123003
为了填补我国学术界和产业界在压贴三棱镜的国产化设计、制作以及测试等方面工作的空白,研究了压贴三棱镜镜片结构设计理论,并推导了压贴三棱镜镜片透过率以及畸变的计算公式,数值模拟了不同材料、不同棱镜度数的压贴三棱镜的透过率以及压贴三棱镜的畸变情况.数值模拟结果表明：与现有PVC材料相比,PMMA材料具有更大的阿贝系数和更小的材料吸收率,是一种制作低成本压贴三棱镜的理想材料.利用金刚石切割工艺制作出精密的压贴三棱镜模版,模版的表面光洁度达到14级,并采用热压工艺,在温度为180℃压力为130kg/cm 相似文献
119.
酰胺型双冠醚的振动光谱分析 总被引：4，自引：1，他引：3
对邻苯-二(氧乙酰胺-4'-本并-15-冠-5)、间苯-二(氧乙酰胺-4'-苯并-15-冠-5)、对苯-二(氧乙酰胶-4'-苯并-15-冠-5)三种酰胺型双冠醚和苯并15-冠-5的喇曼光谱及红外光谱进行了测定和归属分析,并与15-冠-5的喇曼及红外光谱进行了比较研究. 相似文献
120.
单重态CCl2与O3反应机理的理论研究 总被引：2，自引：0，他引：2
用量子化学从头算方法,研究了单重态CCl_2与O_3反应的机理.在HF/6-31G(d)水平上用梯度解析技术全参数优化上述反应的反应物、中间体、过渡态和产物构型,MP2/6-31G(d)//HF/6-31G(d)方法计算能量.给出了有关化合物的结构数据.结果表明:CCl_2与O_3首先生成富能中间体CCl_2O_3,然后中间体裂解生成CCl_2O和O_2.该反应为强放热反应,放出的热量为516.88kJ·mol~(-1)[MP2/6-31G(d)//HF/6-31G(d)].通过内禀反应坐标(IRC)计算,获得了沿反应途径的势能剖面. 相似文献