In a MEMS mirror-based dual interference Fourier transform spectrometer (FTS) with a laser interferometer as the position sensing mechanism, making the two interferometers coaxial is very challenging. To solve this problem, a single interference MEMS FTS based on asynchronous calibration is designed. This single interference FTS uses a dichroic mirror to couple a laser beam and a broadband light beam into the same interferometer. Since the two optical beams share the same optical path, they will experience the same change when the position of any optical component along the optical path is adjusted. In data acquisition, the two interference signals are acquired asynchronously by the same InGaAs photodetector. This asynchronous calibration can effectively eliminate the laser coupling issue. According to the experimental results, compared with the dual interference spectrometer, the proposed spectrometer based on asynchronous calibration can improve the spectral repeatability and make the system simpler and lower power consumption.
{"title":"A miniature Fourier transform spectrometer based on an electrothermal MEMS mirror with asynchronous calibration","authors":"Ruifan Zhao, Qiangqiang Liu, Chao Chen, Jiqiang Cao, Yuan Xue, Donglin Wang, Qian Chen, Huikai Xie","doi":"10.1117/12.3008011","DOIUrl":"https://doi.org/10.1117/12.3008011","url":null,"abstract":"In a MEMS mirror-based dual interference Fourier transform spectrometer (FTS) with a laser interferometer as the position sensing mechanism, making the two interferometers coaxial is very challenging. To solve this problem, a single interference MEMS FTS based on asynchronous calibration is designed. This single interference FTS uses a dichroic mirror to couple a laser beam and a broadband light beam into the same interferometer. Since the two optical beams share the same optical path, they will experience the same change when the position of any optical component along the optical path is adjusted. In data acquisition, the two interference signals are acquired asynchronously by the same InGaAs photodetector. This asynchronous calibration can effectively eliminate the laser coupling issue. According to the experimental results, compared with the dual interference spectrometer, the proposed spectrometer based on asynchronous calibration can improve the spectral repeatability and make the system simpler and lower power consumption.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose a precision linewidths measurement using short-delay self-heterodyne interferometers and multiple peak-to-valley differences (MPVD). The method of MPVD of the coherent envelope to determine the laser linewidth is proved to be stable. Based on the relationship within MPVD values, the delay length and laser linewidth were calculated theoretically and via simulations. We also eliminate the effect of the broadened spectrum induced by the 1/f frequency noise and the influence of noise floor on the measurement using short-delay self-heterodyne techniques, providing MPVD that can satisfy high-precision measurements without being affected by noise. The results showed that this new method is capable of significantly improving the measurement accuracy of narrow linewidth.
{"title":"Precise linewidths measurement using short delay self-heterodyne interferometry and multiple peak-to-valley differences","authors":"Yu Hao Zhang, Xu Hua Cao, Wei Chen","doi":"10.1117/12.3006300","DOIUrl":"https://doi.org/10.1117/12.3006300","url":null,"abstract":"We propose a precision linewidths measurement using short-delay self-heterodyne interferometers and multiple peak-to-valley differences (MPVD). The method of MPVD of the coherent envelope to determine the laser linewidth is proved to be stable. Based on the relationship within MPVD values, the delay length and laser linewidth were calculated theoretically and via simulations. We also eliminate the effect of the broadened spectrum induced by the 1/f frequency noise and the influence of noise floor on the measurement using short-delay self-heterodyne techniques, providing MPVD that can satisfy high-precision measurements without being affected by noise. The results showed that this new method is capable of significantly improving the measurement accuracy of narrow linewidth.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ultrasound has strong penetrability in opaque media, which makes it one of the most important detection tools for structural safety monitoring. Compared with the traditional piezoelectric transducers(PZTs) used for ultrasonic detection, fiber-optic ultrasonic sensing system based on optical adaptivity of two-wave mixing (TWM) photorefractive crystal has strong characteristics of anti-electromagnetic interference, high sensitivity and strong multiplexing, as well as the adaptive detection for optical phase modulation and permanent dynamic recording of the interference pattern current position, which has a large quantity of applications in structural health monitoring. For the interferometric properties and ultrasonic detection technology of TWM in the field of structural safety monitoring, this paper introduces the principle of adaptive two-wave mixing interferometry, the sensing devices, and methods in various fiber Bragg grating (FBG) sensor systems and dynamic signal detection of Er-doped fiber gratings and discusses the application of fiber-optic ultrasonic sensing systems in ultrasonic detection based on adaptive TWM technology. Finally, the problems and solutions in the sensing system are analyzed. By miniaturizing the TWM interferometer and integrating the entire sensing system, it is expected to further improve the detection performance of the device and expand future research directions.
{"title":"Adaptive two-wave mixing interferometry for ultrasonic detection","authors":"Fuxiang Peng, Chuanyi Tao, Jingke Li, Yubing Liu, Hao Wang, Pinsheng Huang, Yueqing Zhu, Ping Su","doi":"10.1117/12.3005972","DOIUrl":"https://doi.org/10.1117/12.3005972","url":null,"abstract":"Ultrasound has strong penetrability in opaque media, which makes it one of the most important detection tools for structural safety monitoring. Compared with the traditional piezoelectric transducers(PZTs) used for ultrasonic detection, fiber-optic ultrasonic sensing system based on optical adaptivity of two-wave mixing (TWM) photorefractive crystal has strong characteristics of anti-electromagnetic interference, high sensitivity and strong multiplexing, as well as the adaptive detection for optical phase modulation and permanent dynamic recording of the interference pattern current position, which has a large quantity of applications in structural health monitoring. For the interferometric properties and ultrasonic detection technology of TWM in the field of structural safety monitoring, this paper introduces the principle of adaptive two-wave mixing interferometry, the sensing devices, and methods in various fiber Bragg grating (FBG) sensor systems and dynamic signal detection of Er-doped fiber gratings and discusses the application of fiber-optic ultrasonic sensing systems in ultrasonic detection based on adaptive TWM technology. Finally, the problems and solutions in the sensing system are analyzed. By miniaturizing the TWM interferometer and integrating the entire sensing system, it is expected to further improve the detection performance of the device and expand future research directions.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to meet the requirements of high precision automatic measurement of surface brightness temperature, which is used for in-orbit calibration and product verification of infrared remote sensor, the design and verification of field thermal infrared brightness temperature radiometer are studied. The difference and compensation method is used to obtain the radiance of the ground target. First, the thermopile detector is used to measure the target and the background respectively for difference, and then the standard platinum resistance is used to improve the measurement accuracy. The optical spectrum of 8~14 μm, 8.2~9.2 μm, 10.3~ 11.3 μm, 11.5~l2.5 μm is achieved by the optical spectrum and rotation of the filter wheel, and the photoelectric amplification and acquisition are realized by the high-precision pre-amplification and acquisition circuit. After the radiometer is developed, radiation calibration based on the surface source blackbody is carried out, and the temperature measurement is compared with the laboratory water blackbody. The deviation of measurement is less than 0.14K. The field thermal infrared bright temperature radiometer was compared with thermal infrared radiometer CE312 in the field, and the average deviation of the two devices was less than 0.12K, which verified the feasibility and rationality of the temperature measurement method.
{"title":"Design and verification of thermal infrared automatic brightness temperature radiometer","authors":"Yanna Zhang, Yunxiang Zhang, Wei Wei","doi":"10.1117/12.3008010","DOIUrl":"https://doi.org/10.1117/12.3008010","url":null,"abstract":"In order to meet the requirements of high precision automatic measurement of surface brightness temperature, which is used for in-orbit calibration and product verification of infrared remote sensor, the design and verification of field thermal infrared brightness temperature radiometer are studied. The difference and compensation method is used to obtain the radiance of the ground target. First, the thermopile detector is used to measure the target and the background respectively for difference, and then the standard platinum resistance is used to improve the measurement accuracy. The optical spectrum of 8~14 μm, 8.2~9.2 μm, 10.3~ 11.3 μm, 11.5~l2.5 μm is achieved by the optical spectrum and rotation of the filter wheel, and the photoelectric amplification and acquisition are realized by the high-precision pre-amplification and acquisition circuit. After the radiometer is developed, radiation calibration based on the surface source blackbody is carried out, and the temperature measurement is compared with the laboratory water blackbody. The deviation of measurement is less than 0.14K. The field thermal infrared bright temperature radiometer was compared with thermal infrared radiometer CE312 in the field, and the average deviation of the two devices was less than 0.12K, which verified the feasibility and rationality of the temperature measurement method.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, quantum communication has received extensive attention due to its high security of transmitted information. Quantum key distribution (QKD), an important branch of quantum information, is developing rapidly and has been gradually moving toward practicality and networking. The use of phase coding through fiber optic channels is the basis for the implementation of QKD systems. In QKD systems, electro-optical modulation techniques are mainly used to change the photon phase through phase modulators to realize the phase coding scheme. Among them, lithium niobate is a common material for making phase modulators in QKD systems. Lithium niobate (LN) crystals are an optical material with excellent acousto-optical and electro-optical properties. It has good physical and chemical stability, a wide optical low-loss window, a large electro-optical coefficient and an excellent second-order nonlinear effect. It has a wide range of applications in high-speed electro-optical tuning, holographic storage, nonlinear frequency conversion, etc. Thin-film lithium niobate (LNOI), as a new integrated optical material, can well combine the excellent electro-optical, acousto-optical and nonlinear properties of the material with a compact optical waveguide. It also has the advantages of a small waveguide cross-section size, high electric field density, strong nonlinear effect, low half-wave voltage length product, and small size. It has significant advantages in the integration of optoelectronic devices. In the phase-coded QKD system, the coding object of the information is the phase of the optical signal. The polarization state of the optical signal can have a serious impact on the system. The phase-encoded QKD system based on the Faraday-Michaelson interference loop is able to self-compensate for the polarization variations in the system to remove the relevant effects of polarization variations on the QKD system. The application of a phase modulator based on thin film lithium niobate preparation in quantum key distribution can effectively enhance the rate of the quantum key distribution system. However, there is still a need to study the transmission and modulation characteristics of LNOI waveguides on polarized optical signals. In this paper, we develop a phase modulator based on thin-film lithium niobate for high-speed QKD systems. Simulation and analysis of the polarization mode of the optical signal transmitted in the optical waveguide. Test and study the transmission loss and modulation efficiency difference of a thin-film lithium niobate optical waveguide for TE and TM polarization state optical signals. To build a test system for application to the measurement and modulation test of the polarization state of optical signals in a high-speed phase-encoded QKD system.
{"title":"Analysis and measurement of optical polarization state modulation in thin-film lithium niobate waveguides","authors":"Ziyang Li, Feng Yang, Jianfeng Bao, Xutao Zhang, Changfa Tang, Dengcai Yang","doi":"10.1117/12.3006597","DOIUrl":"https://doi.org/10.1117/12.3006597","url":null,"abstract":"In recent years, quantum communication has received extensive attention due to its high security of transmitted information. Quantum key distribution (QKD), an important branch of quantum information, is developing rapidly and has been gradually moving toward practicality and networking. The use of phase coding through fiber optic channels is the basis for the implementation of QKD systems. In QKD systems, electro-optical modulation techniques are mainly used to change the photon phase through phase modulators to realize the phase coding scheme. Among them, lithium niobate is a common material for making phase modulators in QKD systems. Lithium niobate (LN) crystals are an optical material with excellent acousto-optical and electro-optical properties. It has good physical and chemical stability, a wide optical low-loss window, a large electro-optical coefficient and an excellent second-order nonlinear effect. It has a wide range of applications in high-speed electro-optical tuning, holographic storage, nonlinear frequency conversion, etc. Thin-film lithium niobate (LNOI), as a new integrated optical material, can well combine the excellent electro-optical, acousto-optical and nonlinear properties of the material with a compact optical waveguide. It also has the advantages of a small waveguide cross-section size, high electric field density, strong nonlinear effect, low half-wave voltage length product, and small size. It has significant advantages in the integration of optoelectronic devices. In the phase-coded QKD system, the coding object of the information is the phase of the optical signal. The polarization state of the optical signal can have a serious impact on the system. The phase-encoded QKD system based on the Faraday-Michaelson interference loop is able to self-compensate for the polarization variations in the system to remove the relevant effects of polarization variations on the QKD system. The application of a phase modulator based on thin film lithium niobate preparation in quantum key distribution can effectively enhance the rate of the quantum key distribution system. However, there is still a need to study the transmission and modulation characteristics of LNOI waveguides on polarized optical signals. In this paper, we develop a phase modulator based on thin-film lithium niobate for high-speed QKD systems. Simulation and analysis of the polarization mode of the optical signal transmitted in the optical waveguide. Test and study the transmission loss and modulation efficiency difference of a thin-film lithium niobate optical waveguide for TE and TM polarization state optical signals. To build a test system for application to the measurement and modulation test of the polarization state of optical signals in a high-speed phase-encoded QKD system.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lina Zhao, Hongyu Zhang, Anna Zhao, Tianhe Wang, Chen Yang, Jihong Wang, Shuozhi Li
Steel structure has been widely used in modern buildings because of its excellent building performance such as lightness, low-cost. However, the poor fire resistant of steel structure can lead to a lot of hidden troubles including life safety and economic losses, cause the construction of steel structure become a key research direction in fire investigationwork. Currently, the experts for fire investigation have to analyse the surface trace of the steel evidence after the fire throughempirical data by person because of the lack of intelligent methods and equipment, which have a great influence on the investigation efficiency. This article proposes an intelligent detection method for steel structure fire traces based spectral imaging technology. The surface spectrum and morphology information of heated steel structure can be collected through standard spectral imaging equipment in 400-1000nm, then establishing the connections between the highest temperature or time and its feature of spectral imaging data. More than 150 groups of steel plate samples were prepared in various temperature including 100 ℃ to 1200 °C by muffle furnace and stacking fire in the experiment. The spectral imaging data can be obtained and imported to the classification and recognition algorithm, 90%of the samples conditions can be identified recognized accurately. The results indicate that spectral imaging technology can effectively assist in the development of fire investigation work by quickly and intelligently identifying fire traces, and has good application prospects in the field of fire investigation.
{"title":"Study on intelligent fire investigation in steel structure by spectral imaging technology","authors":"Lina Zhao, Hongyu Zhang, Anna Zhao, Tianhe Wang, Chen Yang, Jihong Wang, Shuozhi Li","doi":"10.1117/12.3007955","DOIUrl":"https://doi.org/10.1117/12.3007955","url":null,"abstract":"Steel structure has been widely used in modern buildings because of its excellent building performance such as lightness, low-cost. However, the poor fire resistant of steel structure can lead to a lot of hidden troubles including life safety and economic losses, cause the construction of steel structure become a key research direction in fire investigationwork. Currently, the experts for fire investigation have to analyse the surface trace of the steel evidence after the fire throughempirical data by person because of the lack of intelligent methods and equipment, which have a great influence on the investigation efficiency. This article proposes an intelligent detection method for steel structure fire traces based spectral imaging technology. The surface spectrum and morphology information of heated steel structure can be collected through standard spectral imaging equipment in 400-1000nm, then establishing the connections between the highest temperature or time and its feature of spectral imaging data. More than 150 groups of steel plate samples were prepared in various temperature including 100 ℃ to 1200 °C by muffle furnace and stacking fire in the experiment. The spectral imaging data can be obtained and imported to the classification and recognition algorithm, 90%of the samples conditions can be identified recognized accurately. The results indicate that spectral imaging technology can effectively assist in the development of fire investigation work by quickly and intelligently identifying fire traces, and has good application prospects in the field of fire investigation.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The integration time refers to the time for the infrared focal plane array (IRFPA) imaging system detector pixel that accumulate radiation signals to generate electrical signals. For the infrared seeker, in order to accurately capture the target, the integration time seriously affects the overall performance of the detection system, such as the output voltage, responsivity, noise equivalent temperature difference (NETD), and so on. This paper introduces the traditional method of setting the integration time, which is based on user’s experience and subjective judgment. This method often cannot give full play to the best performance of the detector. Moreover, because it’s highly subjective, different people may come up with different results. In order to make full use of the performance of the detector and obtain a consistent calibration effect, this paper proposes an integration time calibration method based on histogram and the response characteristics of the detector. And it is applied to the HgCdTe 640×512/15μm pitch MWIR. By comparison, after adopting the new method, the Residual fixed pattern noise (RFPN) and NETD of the device have been greatly improved after NUC. Compared with the traditional method, the new method can form a standardized process, and then provide guidance for the automatic calibration of IRFPA.
{"title":"Research on an innovative method of setting the integration time of cooled infrared focal plane array","authors":"Haihu Wang, Peiqi Fan, Wenqing Hong, Yuanni Gong, Lizhen Liu, Chuanming Liu","doi":"10.1117/12.3000447","DOIUrl":"https://doi.org/10.1117/12.3000447","url":null,"abstract":"The integration time refers to the time for the infrared focal plane array (IRFPA) imaging system detector pixel that accumulate radiation signals to generate electrical signals. For the infrared seeker, in order to accurately capture the target, the integration time seriously affects the overall performance of the detection system, such as the output voltage, responsivity, noise equivalent temperature difference (NETD), and so on. This paper introduces the traditional method of setting the integration time, which is based on user’s experience and subjective judgment. This method often cannot give full play to the best performance of the detector. Moreover, because it’s highly subjective, different people may come up with different results. In order to make full use of the performance of the detector and obtain a consistent calibration effect, this paper proposes an integration time calibration method based on histogram and the response characteristics of the detector. And it is applied to the HgCdTe 640×512/15μm pitch MWIR. By comparison, after adopting the new method, the Residual fixed pattern noise (RFPN) and NETD of the device have been greatly improved after NUC. Compared with the traditional method, the new method can form a standardized process, and then provide guidance for the automatic calibration of IRFPA.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
RuiLin Yang, Feng Xu, YanLi Li, Yi Cao, Fan Zhang, Biao Liu, Shilin Ming
The alignment of mask and wafer is a very important step in the process of lithography. When a specific pattern in the exposure image is selected as the alignment mark, the traditional automatic alignment methods which are based pre-set markers and image processing are not suitable. To address this issue, we propose a novel accurate image recognition method for arbitrarily selected mark patterns, which combines Support Vector Machine (SVM) with feature extraction to achieve adaptive switching of alignment templates. Firstly, based on the distinct linear contour features of silicon wafer exposure patterns, which lack color and texture characteristics, we extract Histogram of Oriented Gradients (HOG) features from the images to construct feature vectors ; then, we select the optimal SVM kernel function through experimental comparisons, and select regions of interest on silicon wafer exposure images for testing ; finally, we utilize HU-based shape features for secondary matching and recognition decisions. The experimental results demonstrate that the proposed method achieves a recognition accuracy of 100%, enabling the implementation of adaptive alignment template selection and switching.
光罩和晶片的对准是光刻过程中非常重要的一步。当选择曝光图像中的特定图案作为对准标记时，传统的基于预设标记和图像处理的自动对准方法就不适用了。针对这一问题，我们提出了一种针对任意选择标记图案的新型精确图像识别方法，该方法将支持向量机（SVM）与特征提取相结合，实现了对准模板的自适应切换。首先，基于硅片曝光图案线性轮廓特征明显，缺乏颜色和纹理特征的特点，我们从图像中提取方向梯度直方图（HOG）特征来构建特征向量；然后，通过实验比较选择最优 SVM 核函数，并在硅片曝光图像上选择感兴趣区域进行测试；最后，利用基于 HU 的形状特征进行二次匹配和识别决策。实验结果表明，所提方法的识别准确率达到了 100%，实现了自适应配准模板选择和切换。
{"title":"Research on accurate recognition of arbitrarily selected mark patterns in alignment of lithography","authors":"RuiLin Yang, Feng Xu, YanLi Li, Yi Cao, Fan Zhang, Biao Liu, Shilin Ming","doi":"10.1117/12.3007831","DOIUrl":"https://doi.org/10.1117/12.3007831","url":null,"abstract":"The alignment of mask and wafer is a very important step in the process of lithography. When a specific pattern in the exposure image is selected as the alignment mark, the traditional automatic alignment methods which are based pre-set markers and image processing are not suitable. To address this issue, we propose a novel accurate image recognition method for arbitrarily selected mark patterns, which combines Support Vector Machine (SVM) with feature extraction to achieve adaptive switching of alignment templates. Firstly, based on the distinct linear contour features of silicon wafer exposure patterns, which lack color and texture characteristics, we extract Histogram of Oriented Gradients (HOG) features from the images to construct feature vectors ; then, we select the optimal SVM kernel function through experimental comparisons, and select regions of interest on silicon wafer exposure images for testing ; finally, we utilize HU-based shape features for secondary matching and recognition decisions. The experimental results demonstrate that the proposed method achieves a recognition accuracy of 100%, enabling the implementation of adaptive alignment template selection and switching.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding and dealing with complex, large-scale, nonlinear complex systems such as those studied in the fields of bionic computing, climate change, molecular modelling, economic development, and language processing are important. In recent decades, artificial intelligence (AI) technology has played a prominent role in dealing with complex systems and problems, and the continuous improvement of the performance of various AI computing equipment is one of the decisive factors for its rapid development.
{"title":"Development of integrated photonic AI based on reservoir computing with wavelength nodes","authors":"Ning Jing, Chao Wang","doi":"10.1117/12.3005119","DOIUrl":"https://doi.org/10.1117/12.3005119","url":null,"abstract":"Understanding and dealing with complex, large-scale, nonlinear complex systems such as those studied in the fields of bionic computing, climate change, molecular modelling, economic development, and language processing are important. In recent decades, artificial intelligence (AI) technology has played a prominent role in dealing with complex systems and problems, and the continuous improvement of the performance of various AI computing equipment is one of the decisive factors for its rapid development.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138964340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Modern space optical remote sensors use many off-axis aspheric surfaces to improve performance and increase the field of view. The geometric parameters of the off-axis aspheric surface include its vertex radius of curvature and aspheric surface coefficients, which have an important influence on the performance of the remote sensor. With the continuous improvement of remote sensor performance indicators, the aspheric surface diameter and vertex radius of curvature continue to increase, and the tolerances are becoming more and more strict. Traditional geometric parameter measurement methods such as three-coordinates and compensator control cannot meet the requirements. In order to achieve high-precision measurement of geometric parameters of aspheric surfaces, a laser tracker cooperated with CGH to measure geometric parameters was researched. The structure of CGH is simple, and the optical reference is easy to accurately establish, convert and reproduce. The tracker has high measurement accuracy and wide range. Its software can model and calculate angle relationships, and can perform spatial measurement and positioning of complex optical paths with folding mirrors. Using the simple structure of CGH and the laser tracker to accurately measure the distance, the aspheric surface detection optical path high-precision positioning (0.01mm) and optical axis reference lead (5") to meet the tolerance requirements of geometric parameters. Through simulation analysis and experimental verification. The calculation accuracy of the vertex curvature radius can reach 0.01%, and the accuracy of the aspheric coefficient can reach 0.0001.
{"title":"High-precision measurement and control of geometric parameters of off-axis aspheric surface","authors":"Mengjuan Li, Zhaoming Wang, Tianbin Lv, Qiuyue Yu, Zhaojian Zhang","doi":"10.1117/12.3000980","DOIUrl":"https://doi.org/10.1117/12.3000980","url":null,"abstract":"Modern space optical remote sensors use many off-axis aspheric surfaces to improve performance and increase the field of view. The geometric parameters of the off-axis aspheric surface include its vertex radius of curvature and aspheric surface coefficients, which have an important influence on the performance of the remote sensor. With the continuous improvement of remote sensor performance indicators, the aspheric surface diameter and vertex radius of curvature continue to increase, and the tolerances are becoming more and more strict. Traditional geometric parameter measurement methods such as three-coordinates and compensator control cannot meet the requirements. In order to achieve high-precision measurement of geometric parameters of aspheric surfaces, a laser tracker cooperated with CGH to measure geometric parameters was researched. The structure of CGH is simple, and the optical reference is easy to accurately establish, convert and reproduce. The tracker has high measurement accuracy and wide range. Its software can model and calculate angle relationships, and can perform spatial measurement and positioning of complex optical paths with folding mirrors. Using the simple structure of CGH and the laser tracker to accurately measure the distance, the aspheric surface detection optical path high-precision positioning (0.01mm) and optical axis reference lead (5\") to meet the tolerance requirements of geometric parameters. Through simulation analysis and experimental verification. The calculation accuracy of the vertex curvature radius can reach 0.01%, and the accuracy of the aspheric coefficient can reach 0.0001.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138964357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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