Jiahua Chen, Jinqiao Hou, Yangui Zhou, Min Jiang, Yongyao Li, Hexiang He
For a floating display system using a prism or bread type retro-reflector, non-retro-reflected light is the key causes of the deterioration in image resolution. In the present study, a micro aperture array (pinhole array) is used to enhance image resolution of aerial imaging display based on prism and bread retro-reflector. The effects of different micro aperture parameters on the divergence angle and stray light of the retro-reflector are experimentally studied, and the modulation of the point spread function of different retro-reflectors is also explored in detail. The experimental results show that by properly arranging the micro aperture array, the divergence angle of the retro-reflective light can be effectively reduced; Moreover, the full width at half maxima of the point spread function of the retro reflector has been effectively narrowed. Finally, after the modulation of micro aperture array, the imaging resolution can be increased by 119% compared to the original one. The proposed micro array is low cost, easy processing and flexible when it is applied to retro-reflector based aerial imaging system to provide high image quality.
{"title":"Resolution enhancement in retro-reflector based on aerial imaging using micro aperture arrays","authors":"Jiahua Chen, Jinqiao Hou, Yangui Zhou, Min Jiang, Yongyao Li, Hexiang He","doi":"10.1117/12.3007189","DOIUrl":"https://doi.org/10.1117/12.3007189","url":null,"abstract":"For a floating display system using a prism or bread type retro-reflector, non-retro-reflected light is the key causes of the deterioration in image resolution. In the present study, a micro aperture array (pinhole array) is used to enhance image resolution of aerial imaging display based on prism and bread retro-reflector. The effects of different micro aperture parameters on the divergence angle and stray light of the retro-reflector are experimentally studied, and the modulation of the point spread function of different retro-reflectors is also explored in detail. The experimental results show that by properly arranging the micro aperture array, the divergence angle of the retro-reflective light can be effectively reduced; Moreover, the full width at half maxima of the point spread function of the retro reflector has been effectively narrowed. Finally, after the modulation of micro aperture array, the imaging resolution can be increased by 119% compared to the original one. The proposed micro array is low cost, easy processing and flexible when it is applied to retro-reflector based aerial imaging system to provide high image quality.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"80 1","pages":"1296208 - 1296208-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175126","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}
A frontside-illuminated single photon avalanche diode based on 110 nm CMOS process is proposed in this paper. The P-well/Deep N well multiplication junction is adopted to enhance the near infrared absorption. To reduce the dark count rate, only the well guard ring is used in the photosensitive region to avoid the defects caused by shallow trench isolation process. The SPAD achieves a DCR of 3.2 cps/μm2 at room temperature, a peak photon detection probability over 40% at 500 nm, and over 3.6% at 905 nm with 2.0 V excess bias voltage. The device we designed is very suitable for LiDAR applications.
{"title":"A frontside-illuminated single-photon avalanche diode with high photon detection probability","authors":"Yihan Zhao, Yang Liu, Zhangming Zhu","doi":"10.1117/12.3006826","DOIUrl":"https://doi.org/10.1117/12.3006826","url":null,"abstract":"A frontside-illuminated single photon avalanche diode based on 110 nm CMOS process is proposed in this paper. The P-well/Deep N well multiplication junction is adopted to enhance the near infrared absorption. To reduce the dark count rate, only the well guard ring is used in the photosensitive region to avoid the defects caused by shallow trench isolation process. The SPAD achieves a DCR of 3.2 cps/μm2 at room temperature, a peak photon detection probability over 40% at 500 nm, and over 3.6% at 905 nm with 2.0 V excess bias voltage. The device we designed is very suitable for LiDAR applications.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"64 ","pages":"129661E - 129661E-6"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175323","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}
With the integration of the Internet of Things and artificial intelligence technology, the amount of data is increasing exponentially. However, the traditional von Neumann architecture makes the processing of nonstructural visual data inefficient. In view of this, many neuromorphic visual systems have been proposed. However, the data transmission process through the photoreceptors to the computing unit still results in data redundancy and additional power consumption. Therefore, it is necessary to develop intelligent visual systems capable of performing calculations within pixels, which requires the development of photodetectors with sensing, memory and processing functions. Here, a neuromorphic synaptic phototransistor based on MoS2 is prepared. The proposed phototransistor shows synaptic properties, including short-term/long-term synaptic plasticity, paired-pulse facilitation and forgetting properties. As a proof of concept, it is demonstrated that the image preprocessing and memory ability of the intelligent visual system based on this neuromorphic phototransistor. The proposed phototransistor can be used as a photoreceptor and a biological synapse in an intelligent visual system, which shows its potential application in the efficient processing of visual information.
{"title":"A synaptic phototransistor for image processing and memory","authors":"Wen Du, Caihong Li, Tingting Zhang","doi":"10.1117/12.3006657","DOIUrl":"https://doi.org/10.1117/12.3006657","url":null,"abstract":"With the integration of the Internet of Things and artificial intelligence technology, the amount of data is increasing exponentially. However, the traditional von Neumann architecture makes the processing of nonstructural visual data inefficient. In view of this, many neuromorphic visual systems have been proposed. However, the data transmission process through the photoreceptors to the computing unit still results in data redundancy and additional power consumption. Therefore, it is necessary to develop intelligent visual systems capable of performing calculations within pixels, which requires the development of photodetectors with sensing, memory and processing functions. Here, a neuromorphic synaptic phototransistor based on MoS2 is prepared. The proposed phototransistor shows synaptic properties, including short-term/long-term synaptic plasticity, paired-pulse facilitation and forgetting properties. As a proof of concept, it is demonstrated that the image preprocessing and memory ability of the intelligent visual system based on this neuromorphic phototransistor. The proposed phototransistor can be used as a photoreceptor and a biological synapse in an intelligent visual system, which shows its potential application in the efficient processing of visual information.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"39 ","pages":"129591Q - 129591Q-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175652","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}
Current research is focused on the miniaturization and integration of detection devices for biological targets in order to adapt to outdoor and emergency field settings, as well as to enhance the flexibility and practicality of detection. This study proposes an ultra-high integrated silicon nitride fluorescence excitation chip for point-to-point excitation of biological fluorescence signals. By employing the finite-difference time-domain(FDTD) method and utilizing silicon nitride as the functional material, a visible light fluorescence excitation chip operating at the wavelength of 645nm was designed and fabricated. The chip is composed of an input grating coupler, multiple multimode interferometers, and output grating couplers. A grating array containing 2016 excitation points is constructed cascading multiple multimode interference splitters and connecting excitation gratings at the terminals. The single grating coupling efficiency of the chip is 30% with a total excitation light area of 4×4mm² and an emitted light angle of around 80 degrees. By adjusting the positions of different output grating couplers, the chip can adapt to excitation requirements at different locations, making it suitable for various applications such as fluorescence quantitative polymerase chain reaction(PCR) and digital PCR. With the help of microfluidic chambers and a photodetector, the chip successfully achieved the detection limit of 0.5 µmol/L Cyanine 5(Cy5) fluorescent reagent solution, which is sufficient for direct detection of PCR fluorescence signals.
{"title":"Ultra-high integrated silicon nitride fluorescence excitation chip for point-to-point excitation of biofluorescence signals","authors":"zejun yan, Qing Shi, Bo Wang, Shilun Feng, Jijun Feng, Chang Chen, Jianglong zhao","doi":"10.1117/12.3007667","DOIUrl":"https://doi.org/10.1117/12.3007667","url":null,"abstract":"Current research is focused on the miniaturization and integration of detection devices for biological targets in order to adapt to outdoor and emergency field settings, as well as to enhance the flexibility and practicality of detection. This study proposes an ultra-high integrated silicon nitride fluorescence excitation chip for point-to-point excitation of biological fluorescence signals. By employing the finite-difference time-domain(FDTD) method and utilizing silicon nitride as the functional material, a visible light fluorescence excitation chip operating at the wavelength of 645nm was designed and fabricated. The chip is composed of an input grating coupler, multiple multimode interferometers, and output grating couplers. A grating array containing 2016 excitation points is constructed cascading multiple multimode interference splitters and connecting excitation gratings at the terminals. The single grating coupling efficiency of the chip is 30% with a total excitation light area of 4×4mm² and an emitted light angle of around 80 degrees. By adjusting the positions of different output grating couplers, the chip can adapt to excitation requirements at different locations, making it suitable for various applications such as fluorescence quantitative polymerase chain reaction(PCR) and digital PCR. With the help of microfluidic chambers and a photodetector, the chip successfully achieved the detection limit of 0.5 µmol/L Cyanine 5(Cy5) fluorescent reagent solution, which is sufficient for direct detection of PCR fluorescence signals.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"32 ","pages":"129631Y - 129631Y-5"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175655","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}
Drag balloon deorbit device faces problems such as low packaging density and membrane damage during folding, as well as oscillations caused by inappropriate mass rates. In this study, aimed at improving the folding efficiency of drag balloons and ensuring smooth deployment, we propose a new folding method that combines flat spiral bonding with Z-folding. LSDYNA is used to establish a simulation model, and the deployment process of this folding model is analyzed using the Corpuscular Method (CPM). Specifically, we explore the necessary conditions for the smooth inflation and deployment of a drag balloon from the perspectives of the number of valves and mass rate. The results demonstrate that the proposed folding method is a low-damage, high-density one. Increasing the number of valves reduces the oscillation amplitude during the deployment process, enabling the drag balloon to reach a stable state earlier. Increasing the mass rate accelerates the oscillation frequency during the deployment process, which in turn requires more time for the drag balloon to regain stability. Therefore, to ensure the smooth deployment of the drag balloon during inflation, methods such as increasing the number of valves and reducing the mass rate can be employed.
拖拽气球脱轨装置面临着包装密度低、折叠过程中薄膜损坏以及质量速率不合适导致的振荡等问题。本研究以提高拖拽气球的折叠效率、确保平稳布放为目标，提出了一种将平面螺旋粘合与 Z 折叠相结合的新型折叠方法。我们使用 LSDYNA 建立了一个仿真模型，并使用靠谱方法 (CPM) 分析了该折叠模型的展开过程。具体而言，我们从阀门数量和质量速率的角度探讨了阻力气球顺利充气和展开的必要条件。结果表明，所提出的折叠方法是一种低损伤、高密度的方法。增加气阀数量可降低布放过程中的振荡幅度，使阻力气球更早达到稳定状态。增加质量率会加快布放过程中的振荡频率，这反过来又需要更多时间让拖拽气球恢复稳定。因此，为确保阻力气球在充气过程中顺利展开，可采用增加阀门数量和降低质量速率等方法。
{"title":"Research on folding and inflation process of the drag balloon deorbit device","authors":"Ning Jiao, Keying Yang, Jingrui Zhang","doi":"10.1117/12.3006360","DOIUrl":"https://doi.org/10.1117/12.3006360","url":null,"abstract":"Drag balloon deorbit device faces problems such as low packaging density and membrane damage during folding, as well as oscillations caused by inappropriate mass rates. In this study, aimed at improving the folding efficiency of drag balloons and ensuring smooth deployment, we propose a new folding method that combines flat spiral bonding with Z-folding. LSDYNA is used to establish a simulation model, and the deployment process of this folding model is analyzed using the Corpuscular Method (CPM). Specifically, we explore the necessary conditions for the smooth inflation and deployment of a drag balloon from the perspectives of the number of valves and mass rate. The results demonstrate that the proposed folding method is a low-damage, high-density one. Increasing the number of valves reduces the oscillation amplitude during the deployment process, enabling the drag balloon to reach a stable state earlier. Increasing the mass rate accelerates the oscillation frequency during the deployment process, which in turn requires more time for the drag balloon to regain stability. Therefore, to ensure the smooth deployment of the drag balloon during inflation, methods such as increasing the number of valves and reducing the mass rate can be employed.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"122 ","pages":"129590O - 129590O-11"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175810","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}
Detection and identification of hydrogen isotopes and their oxides is a key point in emission monitoring of nuclear facilities. Therefore, the establishment of an accurate and stable identification system for hydrogen isotopes and their oxides has important application value in the management of nuclear facilities. Raman spectroscopy is a non-contact and non-destructive component analysis method. This method is based on inelastic scattering of photons generated in the interaction between laser and matter, and can generate different characteristic signal peaks according to the structure of molecular bonds. Therefore, different hydrogen isotopes and their oxides can be qualitatively analyzed by Raman characteristic peaks, and a certain degree of quantitative results can be obtained by signal intensity and spectral peak information. Based on the self-built dual-wavelength laser Raman spectroscopy system (532 nm and 785 nm), the vibration spectra of D-O chemical bonds in heavy water (D2O) were detected and compared, which provided data support for further analysis and identification of nuclear facility emissions.
{"title":"Detection of deuteroxide by dual-wavelength Raman spectroscopy","authors":"Jiahao Wang, Xiaohua Zhang, Qiushi Liu, Chong Lv, Yanlei Yang, Yun He, Zhixing Gao","doi":"10.1117/12.3007942","DOIUrl":"https://doi.org/10.1117/12.3007942","url":null,"abstract":"Detection and identification of hydrogen isotopes and their oxides is a key point in emission monitoring of nuclear facilities. Therefore, the establishment of an accurate and stable identification system for hydrogen isotopes and their oxides has important application value in the management of nuclear facilities. Raman spectroscopy is a non-contact and non-destructive component analysis method. This method is based on inelastic scattering of photons generated in the interaction between laser and matter, and can generate different characteristic signal peaks according to the structure of molecular bonds. Therefore, different hydrogen isotopes and their oxides can be qualitatively analyzed by Raman characteristic peaks, and a certain degree of quantitative results can be obtained by signal intensity and spectral peak information. Based on the self-built dual-wavelength laser Raman spectroscopy system (532 nm and 785 nm), the vibration spectra of D-O chemical bonds in heavy water (D2O) were detected and compared, which provided data support for further analysis and identification of nuclear facility emissions.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"72 ","pages":"129620E - 129620E-4"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139175986","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 the development of astronomy, high spatial resolution imaging technology plays a crucial role in astronomical observations. The introduction of the optical synthetic aperture concept satisfies the demand for high spatial resolution imaging, gradually becoming a novel direction in the advancement of optical interferometry. This study focuses on the investigation of Fizeau-type synthetic aperture imaging system and presents the design and performance analysis of a system based on requirements. The Fizeau-type synthetic aperture imaging system designed in this paper adopts reflective structure. The system operates in the visible light band (400nm~700nm), with a full field of view angle of 0.3°, an entrance pupil diameter of 300mm, and a focal length of 3598 mm. The sub-telescopes adopt the structure of coaxial two-mirror telescope system. The optical delay line adopts a parallel mirror structure. The beam combiner adopts an off-axis three-mirror structure. The performance of each sub-system and the whole system is analyzed. The results demonstrate that the synthetic aperture imaging system enhances the spatial resolution compared with the single sub-aperture system.
{"title":"Design of reflective Fizeau optical synthetic aperture imaging system","authors":"Wenmao Zhang, Jianfeng Yang, Yi-yi Zhao","doi":"10.1117/12.3007833","DOIUrl":"https://doi.org/10.1117/12.3007833","url":null,"abstract":"In the development of astronomy, high spatial resolution imaging technology plays a crucial role in astronomical observations. The introduction of the optical synthetic aperture concept satisfies the demand for high spatial resolution imaging, gradually becoming a novel direction in the advancement of optical interferometry. This study focuses on the investigation of Fizeau-type synthetic aperture imaging system and presents the design and performance analysis of a system based on requirements. The Fizeau-type synthetic aperture imaging system designed in this paper adopts reflective structure. The system operates in the visible light band (400nm~700nm), with a full field of view angle of 0.3°, an entrance pupil diameter of 300mm, and a focal length of 3598 mm. The sub-telescopes adopt the structure of coaxial two-mirror telescope system. The optical delay line adopts a parallel mirror structure. The beam combiner adopts an off-axis three-mirror structure. The performance of each sub-system and the whole system is analyzed. The results demonstrate that the synthetic aperture imaging system enhances the spatial resolution compared with the single sub-aperture system.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"39 10","pages":"129640M - 129640M-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139176104","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}
Yuan Zhang, Huan Tang, Zhuoyuan Shi, Renxian Li, Bing Wei, Bing Yan, I. Minin, O. Minin
This paper studies the photonic hooks (PH) generated by the interaction of a dielectric sphere rotating at a certain angular velocity with a plane wave. Based on the instantaneous static frame theory and the partial-wave series expansion method in spherical coordinates, with the help of the separated variable method, we obtain the analytical solutions for the internal and external electric fields of a homogeneous isotropic dielectric sphere rotating around the z-axis irradiated by a plane wave of arbitrary direction. This article focuses on the effect of size parameters (ka), relative refractive index (m1), and rotational dimensionless parameters 𝛾 on PH. The PH produced by this non-reciprocal system can be used not only for trapping off-axis particles, but also has promising applications in low-loss waveguiding, subdiffraction-resolution nanopatterning, and nanolithography.
本文研究了以一定角速度旋转的介质球与平面波相互作用产生的光子钩（PH）。基于瞬时静帧理论和球面坐标下的偏波数列展开法，借助分离变量法，我们得到了绕 z 轴旋转的各向同性均匀介质球在任意方向的平面波照射下的内外电场解析解。本文重点讨论了尺寸参数（ka）、相对折射率（m1）和旋转无量纲参数𝛾对 PH 的影响。这种非互易系统产生的 PH 不仅可用于捕获离轴粒子，而且在低损耗波导、亚衍射分辨率纳米图案和纳米光刻方面也有广阔的应用前景。
{"title":"Photonic hooks generated by a rotating dielectric sphere","authors":"Yuan Zhang, Huan Tang, Zhuoyuan Shi, Renxian Li, Bing Wei, Bing Yan, I. Minin, O. Minin","doi":"10.1117/12.3007550","DOIUrl":"https://doi.org/10.1117/12.3007550","url":null,"abstract":"This paper studies the photonic hooks (PH) generated by the interaction of a dielectric sphere rotating at a certain angular velocity with a plane wave. Based on the instantaneous static frame theory and the partial-wave series expansion method in spherical coordinates, with the help of the separated variable method, we obtain the analytical solutions for the internal and external electric fields of a homogeneous isotropic dielectric sphere rotating around the z-axis irradiated by a plane wave of arbitrary direction. This article focuses on the effect of size parameters (ka), relative refractive index (m1), and rotational dimensionless parameters 𝛾 on PH. The PH produced by this non-reciprocal system can be used not only for trapping off-axis particles, but also has promising applications in low-loss waveguiding, subdiffraction-resolution nanopatterning, and nanolithography.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"48 ","pages":"129610A - 129610A-9"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139176320","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}
To meet the demand of weak ultraviolet signal acquisition and transmission for solar-blind ultraviolet flame detectors, this paper develops a signal acquisition system based on a β-Ga2O3 thin-film photoconductive sensor. Firstly, the weak signal acquisition circuit is designed according to the electrical characteristics of the β-Ga2O3 photoconductive sensor. Secondly, real-time data transmission and processing are achieved by using field-programmable gate array (FPGA). Thirdly, the experimental platform of solar-blind UV imaging system is built, and the joint test of the β-Ga2O3 photoconductive sensor and the readout electronics system is conducted. The experimental results demonstrate that the system is capable of acquiring, transmitting, and storing the solar-blind UV signal data from a 1×8 pixel array. The sampling rate can reach up to 20 kHz and exhibits stable performance.
{"title":"Solar-blind UV signal detection system","authors":"Junjie Xiang, Yonglin Bai, Weiwei Cao","doi":"10.1117/12.3007712","DOIUrl":"https://doi.org/10.1117/12.3007712","url":null,"abstract":"To meet the demand of weak ultraviolet signal acquisition and transmission for solar-blind ultraviolet flame detectors, this paper develops a signal acquisition system based on a β-Ga2O3 thin-film photoconductive sensor. Firstly, the weak signal acquisition circuit is designed according to the electrical characteristics of the β-Ga2O3 photoconductive sensor. Secondly, real-time data transmission and processing are achieved by using field-programmable gate array (FPGA). Thirdly, the experimental platform of solar-blind UV imaging system is built, and the joint test of the β-Ga2O3 photoconductive sensor and the readout electronics system is conducted. The experimental results demonstrate that the system is capable of acquiring, transmitting, and storing the solar-blind UV signal data from a 1×8 pixel array. The sampling rate can reach up to 20 kHz and exhibits stable performance.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"32 ","pages":"1296316 - 1296316-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139173014","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}
Gold-coated photoresist grating (GCPG) is commonly employed in high-power femtosecond laser systems for its broadband and simple structure. The pyrolysis and low heat conductivity of photoresist substrates are well known to result in a low GCPG laser damage threshold, which restricts the power increase of laser systems. Gold-coated fused silica grating (GCFSG) has a high threshold potential since the grating pattern is transferred from the photoresist to the fused silica substrate by etching. In this paper, a rectangular GCFSG with a period of 1740 l/mm was designed and fabricated. Using rigorous coupled-wave analysis (RCWA), the ideal slot form for GCFSG with high diffraction efficiency was designed. After a comprehensive analysis of the impact of gold plating coating flaws on efficiency, iterations of the coating process were carried out to optimize the slot shape. For these GCFSG samples, magnetron sputtering was used as the gold deposition process and the samples had a bandwidth of at least 150 nm with the -1st-order diffraction efficiency of 93% around the central wavelength of 800 nm. The measured efficiency results were compared with our simulation calculations and good agreement was achieved. After being damaged by lasers, GCFSG can be reused with good economics by being cleaned and then gold-coated.
{"title":"Design of rectangular gold-coated fused silica gratings with high diffraction efficiency for femtosecond pulse compression","authors":"Angran Li, Tao Ren, Fanfan Lu, Debo Yuan, Yilin Hong, Keqiang Qiu","doi":"10.1117/12.3007758","DOIUrl":"https://doi.org/10.1117/12.3007758","url":null,"abstract":"Gold-coated photoresist grating (GCPG) is commonly employed in high-power femtosecond laser systems for its broadband and simple structure. The pyrolysis and low heat conductivity of photoresist substrates are well known to result in a low GCPG laser damage threshold, which restricts the power increase of laser systems. Gold-coated fused silica grating (GCFSG) has a high threshold potential since the grating pattern is transferred from the photoresist to the fused silica substrate by etching. In this paper, a rectangular GCFSG with a period of 1740 l/mm was designed and fabricated. Using rigorous coupled-wave analysis (RCWA), the ideal slot form for GCFSG with high diffraction efficiency was designed. After a comprehensive analysis of the impact of gold plating coating flaws on efficiency, iterations of the coating process were carried out to optimize the slot shape. For these GCFSG samples, magnetron sputtering was used as the gold deposition process and the samples had a bandwidth of at least 150 nm with the -1st-order diffraction efficiency of 93% around the central wavelength of 800 nm. The measured efficiency results were compared with our simulation calculations and good agreement was achieved. After being damaged by lasers, GCFSG can be reused with good economics by being cleaned and then gold-coated.","PeriodicalId":502341,"journal":{"name":"Applied Optics and Photonics China","volume":"18 ","pages":"129590X - 129590X-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139174020","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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