He Li, Zihang Zhu, Congrui Gao, Guodong Wang, Tao Zhou, Xuan Li, Qingqing Meng, Yi-Lin Zhou, Shanghong Zhao
In this paper, a dispersion-assisted multi-functional scheme with compact structure and high cost-effectiveness based on microwave photonics is proposed. By virtue of the amplitude regulation mechanism of intermediate frequency signal induced by fiber dispersion, combined with the optical high-precision time delay matching, the image interference and the self-interference can be eliminated simultaneously. It avoids applying electrical tuning devices with lower precision and electrical couplers with limited bandwidth or extra optical filters which is beneficial to improve the system performance and compactness. It is also compatible with optical fiber transmission, which can be combined with radio over fiber technology to bring out the advantages of high spectrum utilization, distributed configuration and low loss transmission of in-band full-duplex radio over fiber systems.
{"title":"Dispersion-assisted scheme with optical self-interference cancellation and image rejection mixing","authors":"He Li, Zihang Zhu, Congrui Gao, Guodong Wang, Tao Zhou, Xuan Li, Qingqing Meng, Yi-Lin Zhou, Shanghong Zhao","doi":"10.1117/12.3005325","DOIUrl":"https://doi.org/10.1117/12.3005325","url":null,"abstract":"In this paper, a dispersion-assisted multi-functional scheme with compact structure and high cost-effectiveness based on microwave photonics is proposed. By virtue of the amplitude regulation mechanism of intermediate frequency signal induced by fiber dispersion, combined with the optical high-precision time delay matching, the image interference and the self-interference can be eliminated simultaneously. It avoids applying electrical tuning devices with lower precision and electrical couplers with limited bandwidth or extra optical filters which is beneficial to improve the system performance and compactness. It is also compatible with optical fiber transmission, which can be combined with radio over fiber technology to bring out the advantages of high spectrum utilization, distributed configuration and low loss transmission of in-band full-duplex radio over fiber systems.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 38","pages":"129660G - 129660G-5"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138994899","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}
Significance: The production and characteristics of protonated small water clusters (PSWCs) were reported in this work, where in electrospray ionization (ESI) of pure water, the species obtained were singly charged molecular ions consisting of 2, 3, 4 or 5 water molecules attached to a hydrogen ion, [(H2O)n+H]+ , where n = 2, 3, 4 or 5. We proposed a new type of PSWCs structure: 2, 3, 4, 5 water molecules wrapped around a hydrogen ion which is located at the electrical and geometric center, forming a very stable molecular structure. Furthermore, biological tests of the PSWCs on mitochondrial function of intestinal epithelial cells and liver cells in mice showed the better therapeutic effect on inflammatory bowel diseases compared to that of the biologic agent Infliximab. Aim: To produce stable PSWCs as a new source of nutrient for health. Approach: The PSWCs were produced by electrospray technology, and identified by an electrospray mass spectrometer. The biological effects of the PSWCs on mitochondrial function of intestinal epithelial cells and liver cells in mice are carefully checked. Results: The production, characteristics and the biological effects of the PSWCs are studied, that we first generate the PSWCs by electrospray mechanism, which is proved to be charged (with positive charge). The obtained PSWCs are composed of 2, 3, 4, 5 water molecules plus a proton, respectively. The test of biological effects shows that the PSWCs can reduce radicals and improve the cell functions, indicating very important biological functions of the PSWCs. Conclusions: PSWCs was successfully produced by electrospray technology in our lab, the produced PSWCs were very stable under normal conditions without any obvious concentration changes of hydrogen ions in the last 3 years after produced, even the water is heated to 100 degrees Celsius. Furthermore, the effect of PSWCs on mitochondrial function of intestinal epithelial cells and liver cells in mice showed that the therapeutic effect of PSWCs on inflammatory bowel disease was better than that of the biologic agent Infliximab, where the higher the concentration of hydrogen ions, the better the therapeutic effect is.
{"title":"Production, characteristics, and biological effects of protonated small water clusters","authors":"Yixin Zhu","doi":"10.1117/12.3005480","DOIUrl":"https://doi.org/10.1117/12.3005480","url":null,"abstract":"Significance: The production and characteristics of protonated small water clusters (PSWCs) were reported in this work, where in electrospray ionization (ESI) of pure water, the species obtained were singly charged molecular ions consisting of 2, 3, 4 or 5 water molecules attached to a hydrogen ion, [(H2O)n+H]+ , where n = 2, 3, 4 or 5. We proposed a new type of PSWCs structure: 2, 3, 4, 5 water molecules wrapped around a hydrogen ion which is located at the electrical and geometric center, forming a very stable molecular structure. Furthermore, biological tests of the PSWCs on mitochondrial function of intestinal epithelial cells and liver cells in mice showed the better therapeutic effect on inflammatory bowel diseases compared to that of the biologic agent Infliximab. Aim: To produce stable PSWCs as a new source of nutrient for health. Approach: The PSWCs were produced by electrospray technology, and identified by an electrospray mass spectrometer. The biological effects of the PSWCs on mitochondrial function of intestinal epithelial cells and liver cells in mice are carefully checked. Results: The production, characteristics and the biological effects of the PSWCs are studied, that we first generate the PSWCs by electrospray mechanism, which is proved to be charged (with positive charge). The obtained PSWCs are composed of 2, 3, 4, 5 water molecules plus a proton, respectively. The test of biological effects shows that the PSWCs can reduce radicals and improve the cell functions, indicating very important biological functions of the PSWCs. Conclusions: PSWCs was successfully produced by electrospray technology in our lab, the produced PSWCs were very stable under normal conditions without any obvious concentration changes of hydrogen ions in the last 3 years after produced, even the water is heated to 100 degrees Celsius. Furthermore, the effect of PSWCs on mitochondrial function of intestinal epithelial cells and liver cells in mice showed that the therapeutic effect of PSWCs on inflammatory bowel disease was better than that of the biologic agent Infliximab, where the higher the concentration of hydrogen ions, the better the therapeutic effect is.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"13 9","pages":"129590L - 129590L-18"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995375","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}
wenjie hu, Yuqing He, Xiuqing Hu, Jiabiao Zhu, Xingwei He
As an important parameter characterizing the bi-directional reflectance of objects, the Bidirectional Reflectance Distribution Function (BRDF) is one of the key parameters in the on-orbit substitute calibration of satellite remote sensors based on stable ground targets. It is a crucial factor affecting the calibration accuracy. With the development of quantitative remote sensing, hyperspectral BRDF measurement for calibration and spectral analysis of land surface features has become increasingly important. Efficient and high-quality methods for collecting multi-angle reflectance data of land surfaces are currently a research focus. This study uses co-observation of two spectrometer to measure the BRDF characteristics of the pseudo-invariant calibration site in wild environment. Based on the selected results of the pseudo-invariant calibration site in Northwest China by previous research, BRDF for three different types of land surfaces were measured including desert, Gobi, and saline-alkali land. Based on the Ross-li kernel-driven model, a hyperspectral BRDF characteristic data set of the three different surface types is fitted, and the spatial distribution characteristics and hotspot effects of the BRDF directional reflection of the ground targets are analyzed. The results show that different surface types have different directional reflectance values and different hot spot effects. Therefore, a stable target radiation reference library with different radiation brightness levels can be constructed to provide a benchmark model for long-term consistent radiometric calibration of Chinese remote sensing satellites.
{"title":"BRDF modeling and analysis of the pseudo-invariant calibration site in northwest China","authors":"wenjie hu, Yuqing He, Xiuqing Hu, Jiabiao Zhu, Xingwei He","doi":"10.1117/12.3007854","DOIUrl":"https://doi.org/10.1117/12.3007854","url":null,"abstract":"As an important parameter characterizing the bi-directional reflectance of objects, the Bidirectional Reflectance Distribution Function (BRDF) is one of the key parameters in the on-orbit substitute calibration of satellite remote sensors based on stable ground targets. It is a crucial factor affecting the calibration accuracy. With the development of quantitative remote sensing, hyperspectral BRDF measurement for calibration and spectral analysis of land surface features has become increasingly important. Efficient and high-quality methods for collecting multi-angle reflectance data of land surfaces are currently a research focus. This study uses co-observation of two spectrometer to measure the BRDF characteristics of the pseudo-invariant calibration site in wild environment. Based on the selected results of the pseudo-invariant calibration site in Northwest China by previous research, BRDF for three different types of land surfaces were measured including desert, Gobi, and saline-alkali land. Based on the Ross-li kernel-driven model, a hyperspectral BRDF characteristic data set of the three different surface types is fitted, and the spatial distribution characteristics and hotspot effects of the BRDF directional reflection of the ground targets are analyzed. The results show that different surface types have different directional reflectance values and different hot spot effects. Therefore, a stable target radiation reference library with different radiation brightness levels can be constructed to provide a benchmark model for long-term consistent radiometric calibration of Chinese remote sensing satellites.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"28 22","pages":"129620B - 129620B-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138995625","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}
Jiongbin Deng, Jia Ye, Lian-shan Yan, W. Pan, Xihua Zou
Radio over fiber (RoF) has become a promising alternative for 5G mobile fronthaul due to its inherent advantages of large bandwidth, low susceptibility to radio frequency interference, and high flexibility. In traditional RoF system, analog signals are transmitted through optical fiber, which is susceptible to nonlinearity and dispersion. However, digitized radio over fiber (DRoF) can effectively mitigate these defects by digitizing the analog signals. This paper explores FPGA-based real-time DRoF transceiver technology, which utilizes varying numbers of quantization bits for real-time vector quantization across different modulation formats. This approach helps prevent the reduction of system spectral efficiency caused by excessive quantization bits. The simulation results demonstrate that, after real-time vector quantization and transmission with 8 and 10 quantization bits, the EVM performance of QPSK and 16-QAM signals stabilizes at 11.8% and 6.7%, respectively, thereby confirming the effectiveness of the proposed scheme.
{"title":"Real-time digitized RoF transceiver technology based on FPGA","authors":"Jiongbin Deng, Jia Ye, Lian-shan Yan, W. Pan, Xihua Zou","doi":"10.1117/12.3005659","DOIUrl":"https://doi.org/10.1117/12.3005659","url":null,"abstract":"Radio over fiber (RoF) has become a promising alternative for 5G mobile fronthaul due to its inherent advantages of large bandwidth, low susceptibility to radio frequency interference, and high flexibility. In traditional RoF system, analog signals are transmitted through optical fiber, which is susceptible to nonlinearity and dispersion. However, digitized radio over fiber (DRoF) can effectively mitigate these defects by digitizing the analog signals. This paper explores FPGA-based real-time DRoF transceiver technology, which utilizes varying numbers of quantization bits for real-time vector quantization across different modulation formats. This approach helps prevent the reduction of system spectral efficiency caused by excessive quantization bits. The simulation results demonstrate that, after real-time vector quantization and transmission with 8 and 10 quantization bits, the EVM performance of QPSK and 16-QAM signals stabilizes at 11.8% and 6.7%, respectively, thereby confirming the effectiveness of the proposed scheme.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 15","pages":"129660M - 129660M-4"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963473","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}
Aiming at the problem that the measurement of strong laser far-field focal spot based on side lobe beam diffraction inversion cannot extract the smallest measurable signal in the periphery of the side lobe image, this paper proposes a method for detecting the peak parameters of the weak signal region in the side lobe based on neighborhood vector principal component analysis (NVPCA) image enhancement. The main optimization measures are as follows: First, treat each pixel in the sidelobe image and its 8 neighborhood pixels as a column vector to construct a 9-dimensional data cube, and the first dimensional data after PCA transformation is an NVPCA image; Secondly, using angle transformation to transform the detection object, the various peak parameters of the one-dimensional sidelobe curve in all directions are detected, thereby obtaining the quantified energy distribution characteristics of the weak signal area of the sidelobe beam; Then, search for the maximum position points of each sidelobe peak in all directions, connect all position points to generate a maximum ring for each sidelobe peak, and calculate the grayscale mean of each maximum ring; Finally, the grayscale mean of the maximum rings that is greater than the LCM target separation threshold and the smallest is selected as the minimum measurable sidelobe peak signal of the entire sidelobe beam. The experimental results show that the sidelobe weak signal detection method based on NVPCA image enhancement can separate and extract the minimum measurable signal from the fifth peak ring on the periphery of the sidelobe image, increasing the dynamic range ratio by 1.528 times, improving the calculation accuracy of the dynamic range ratio, and laying a foundation for the future accurate measurement of strong laser far field in large scientific devices.
{"title":"The detection method of sidelobe peaks parameter in weak signal regions based on NVPCA image enhancement","authors":"Zhengzhou Wang, Jitong Wei, Li Wang","doi":"10.1117/12.3009387","DOIUrl":"https://doi.org/10.1117/12.3009387","url":null,"abstract":"Aiming at the problem that the measurement of strong laser far-field focal spot based on side lobe beam diffraction inversion cannot extract the smallest measurable signal in the periphery of the side lobe image, this paper proposes a method for detecting the peak parameters of the weak signal region in the side lobe based on neighborhood vector principal component analysis (NVPCA) image enhancement. The main optimization measures are as follows: First, treat each pixel in the sidelobe image and its 8 neighborhood pixels as a column vector to construct a 9-dimensional data cube, and the first dimensional data after PCA transformation is an NVPCA image; Secondly, using angle transformation to transform the detection object, the various peak parameters of the one-dimensional sidelobe curve in all directions are detected, thereby obtaining the quantified energy distribution characteristics of the weak signal area of the sidelobe beam; Then, search for the maximum position points of each sidelobe peak in all directions, connect all position points to generate a maximum ring for each sidelobe peak, and calculate the grayscale mean of each maximum ring; Finally, the grayscale mean of the maximum rings that is greater than the LCM target separation threshold and the smallest is selected as the minimum measurable sidelobe peak signal of the entire sidelobe beam. The experimental results show that the sidelobe weak signal detection method based on NVPCA image enhancement can separate and extract the minimum measurable signal from the fifth peak ring on the periphery of the sidelobe image, increasing the dynamic range ratio by 1.528 times, improving the calculation accuracy of the dynamic range ratio, and laying a foundation for the future accurate measurement of strong laser far field in large scientific devices.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 24","pages":"129631S - 129631S-19"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963651","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}
Zhe Chen, Xinnan Li, Zibo Jiang, Chen Xu, Ran Duan
Abrasive water jet processing technology is a processing method developed in recent decades using highenergy beams, which is suitable to removal and processing different materials, because its processing process has its own cooling effect and has incomparable advantages in other processing methods. Process studies involving multiple materials in the same area have not been reported. In this paper, the influence of abrasive water jet processing technology parameters on the removal rate of different materials in a small area is studied experimentally, and the removal rate of high-purity quartz glass, doped quartz glass and epoxy resin adhesive layer is tested by single factor and orthogonal test method. Experiments show that within a certain range of process parameters, jet pressure, nozzle diameter and nozzle height have obvious effects on the removal rate, while abrasive particle size have the lowest impact. Experiments are used to derive optimal process parameters for simultaneous removal of different materials.
{"title":"Experimental study on multi-material composite surface polishing by abrasive water jet","authors":"Zhe Chen, Xinnan Li, Zibo Jiang, Chen Xu, Ran Duan","doi":"10.1117/12.3007778","DOIUrl":"https://doi.org/10.1117/12.3007778","url":null,"abstract":"Abrasive water jet processing technology is a processing method developed in recent decades using highenergy beams, which is suitable to removal and processing different materials, because its processing process has its own cooling effect and has incomparable advantages in other processing methods. Process studies involving multiple materials in the same area have not been reported. In this paper, the influence of abrasive water jet processing technology parameters on the removal rate of different materials in a small area is studied experimentally, and the removal rate of high-purity quartz glass, doped quartz glass and epoxy resin adhesive layer is tested by single factor and orthogonal test method. Experiments show that within a certain range of process parameters, jet pressure, nozzle diameter and nozzle height have obvious effects on the removal rate, while abrasive particle size have the lowest impact. Experiments are used to derive optimal process parameters for simultaneous removal of different materials.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 17","pages":"129640K - 129640K-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963723","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}
Zhuoyuan Shi, Huan Tang, Yuan Zhang, Renxian Li, Bing Wei, I. Minin, O. Minin, Bing Yan
The resonance scattering caused by the interaction between a dielectric cylinder rotating at a steady angular velocity and a plane wave are studied using the method of separation of variables and the multipole expansion method. In addition, the effect of resonance on curved photonic nanojets (PNJ) is also analyzed. During the study, the critical value of resonance scattering is found by changing the dimensionless and dimensional parameters of the medium cylinder. It is found that the rotation of particles can create and destroy resonance phenomena. The resonance scattering of rotating dielectric cylinders produced by plane waves provides a new direction for the study of PNJ and whispering gallery mode (WGM), as well as the design and application of ultra-sensitive sensors and resonators
{"title":"Resonance scattering by a rotating cylinder","authors":"Zhuoyuan Shi, Huan Tang, Yuan Zhang, Renxian Li, Bing Wei, I. Minin, O. Minin, Bing Yan","doi":"10.1117/12.3007429","DOIUrl":"https://doi.org/10.1117/12.3007429","url":null,"abstract":"The resonance scattering caused by the interaction between a dielectric cylinder rotating at a steady angular velocity and a plane wave are studied using the method of separation of variables and the multipole expansion method. In addition, the effect of resonance on curved photonic nanojets (PNJ) is also analyzed. During the study, the critical value of resonance scattering is found by changing the dimensionless and dimensional parameters of the medium cylinder. It is found that the rotation of particles can create and destroy resonance phenomena. The resonance scattering of rotating dielectric cylinders produced by plane waves provides a new direction for the study of PNJ and whispering gallery mode (WGM), as well as the design and application of ultra-sensitive sensors and resonators","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":" 13","pages":"1296108 - 1296108-7"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138963727","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}
Tunable and low-power microcavities play a vital role in facilitating the development of large-scale photonic integrated circuits. Among various tuning methods, thermal tuning has gained significant popularity due to its convenience and stability, especially in the fields of optical neural networks and quantum information processing. In recent years, graphene thermal tuning has emerged as a promising technique, offering both tunability and power efficiency by eliminating the need for thick spacers to prevent light absorption. In this study, we propose and fabricate a silicon-based on-chip Fano resonator with graphene nano-heaters. This innovative Fano structure incorporates a scattering block and can be easily manufactured in large quantities. Experimental results demonstrate that the resonator exhibits desirable characteristics, including a high quality factor of approximately 31000 and a low state-switching power consumption of around 1 mW. The temporal responses of the microcavity exhibit satisfactory modulation speed, with a rise time of 9.8 μs and a fall time of 16.6 μs. The findings of this research offer an alternative solution for the future development of large-scale tunable and low-power-consumption optical networks, with potential applications in optical filters and switches.
{"title":"Thermally tunable high Q-factor and low-power silicon resonators using graphene transparent electrodes","authors":"Qilin Hong, Ping Xu, Wei Xu, Zhihong Zhu","doi":"10.1117/12.3006019","DOIUrl":"https://doi.org/10.1117/12.3006019","url":null,"abstract":"Tunable and low-power microcavities play a vital role in facilitating the development of large-scale photonic integrated circuits. Among various tuning methods, thermal tuning has gained significant popularity due to its convenience and stability, especially in the fields of optical neural networks and quantum information processing. In recent years, graphene thermal tuning has emerged as a promising technique, offering both tunability and power efficiency by eliminating the need for thick spacers to prevent light absorption. In this study, we propose and fabricate a silicon-based on-chip Fano resonator with graphene nano-heaters. This innovative Fano structure incorporates a scattering block and can be easily manufactured in large quantities. Experimental results demonstrate that the resonator exhibits desirable characteristics, including a high quality factor of approximately 31000 and a low state-switching power consumption of around 1 mW. The temporal responses of the microcavity exhibit satisfactory modulation speed, with a rise time of 9.8 μs and a fall time of 16.6 μs. The findings of this research offer an alternative solution for the future development of large-scale tunable and low-power-consumption optical networks, with potential applications in optical filters and switches.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"62 2","pages":"129591I - 129591I-4"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138965148","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 successful achievement of the scientific objectives of the Visible Telescope (VT) in the Space Multi-band Variable Object Monitor (SVOM) mission relies heavily on high-precision quantum efficiency calibration. The calibration process for the VT CCD presents a challenge due to the requirement for extremely low radiation levels given the long integration time of the CCD. To address the difficulty in accurately measuring such low radiance, a two-step calibration method is employed. This method involves the use of two photodiodes, one positioned at the CCD location and the other in an integrating sphere. In the first step, the proportional relationship between the measured illuminance values of the two photodiodes is calibrated under high illumination conditions. This step establishes a reliable reference for subsequent calibrations. In the second step, the CCD is calibrated using the integrating sphere photodiode under low illumination conditions. The measured illuminance is then converted to the CCD position. Experimental results have demonstrated the effectiveness of this two-step calibration method, achieving a quantum efficiency calibration uncertainty of 1.7%. This approach provides a reliable and accurate means of calibrating the quantum efficiency of the CCD in the VT instrument.
{"title":"Research on quantum efficiency calibration of SVOM VT CCDs","authors":"Yue Pan, Lijun Dan, Zhonghan Sun, Chao Huang, Wei Li, Fengtao Wang, Hui Zhao, Jian Zhang","doi":"10.1117/12.3007801","DOIUrl":"https://doi.org/10.1117/12.3007801","url":null,"abstract":"The successful achievement of the scientific objectives of the Visible Telescope (VT) in the Space Multi-band Variable Object Monitor (SVOM) mission relies heavily on high-precision quantum efficiency calibration. The calibration process for the VT CCD presents a challenge due to the requirement for extremely low radiation levels given the long integration time of the CCD. To address the difficulty in accurately measuring such low radiance, a two-step calibration method is employed. This method involves the use of two photodiodes, one positioned at the CCD location and the other in an integrating sphere. In the first step, the proportional relationship between the measured illuminance values of the two photodiodes is calibrated under high illumination conditions. This step establishes a reliable reference for subsequent calibrations. In the second step, the CCD is calibrated using the integrating sphere photodiode under low illumination conditions. The measured illuminance is then converted to the CCD position. Experimental results have demonstrated the effectiveness of this two-step calibration method, achieving a quantum efficiency calibration uncertainty of 1.7%. This approach provides a reliable and accurate means of calibrating the quantum efficiency of the CCD in the VT instrument.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"70 5","pages":"129650B - 129650B-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138965199","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}
Xinggui Xu, Hong Li, Yue-Jie Zhang, Weihe Ren, Tao Zhang
Background oriented system (BOS) technology is widely used for measuring flow field density information. The fingerprint information of high-speed target flow field can be calculated with the digital image correction (DIC) method. However, these traditional DIC algorithms are unable to obtain large-scale features of target flow fields and costing high computational complexity. To deal with those problems, a method combination of dual tree complex wavelet transform and optical flow (DTCWT-OF) is proposed. The proposed method adopts a much sparser gradient divergence regularization to obtain much more sparse statistical characteristics of the target flow field, and utilize the prior knowledge of the target flow field fingerprint information. Meanwhile, the reconstruction method is processed in the wavelet transform domain. Compared to traditional DIC methods, the experimental results show that the proposed method improves the SNR by 5dB and can achieve quasi real-time reconstruction.
{"title":"Target flow field reconstruction based on dual tree complex wavelet transform and optical flow","authors":"Xinggui Xu, Hong Li, Yue-Jie Zhang, Weihe Ren, Tao Zhang","doi":"10.1117/12.3006467","DOIUrl":"https://doi.org/10.1117/12.3006467","url":null,"abstract":"Background oriented system (BOS) technology is widely used for measuring flow field density information. The fingerprint information of high-speed target flow field can be calculated with the digital image correction (DIC) method. However, these traditional DIC algorithms are unable to obtain large-scale features of target flow fields and costing high computational complexity. To deal with those problems, a method combination of dual tree complex wavelet transform and optical flow (DTCWT-OF) is proposed. The proposed method adopts a much sparser gradient divergence regularization to obtain much more sparse statistical characteristics of the target flow field, and utilize the prior knowledge of the target flow field fingerprint information. Meanwhile, the reconstruction method is processed in the wavelet transform domain. Compared to traditional DIC methods, the experimental results show that the proposed method improves the SNR by 5dB and can achieve quasi real-time reconstruction.","PeriodicalId":298662,"journal":{"name":"Applied Optics and Photonics China","volume":"80 4","pages":"129591P - 129591P-8"},"PeriodicalIF":0.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138965276","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：