Pub Date : 2023-11-07DOI: 10.1117/1.oe.62.11.116102
Tianjiang He, Qiong Qi, Nan Lin, Wei Li, Xiaoyu Ma, Suping Liu
The preparation of a non-absorption window (NAW) through impurity-free vacancy disordering (IFVD) induced quantum well intermixing (QWI) in 915 nm GaInAsP/GaAsP semiconductor lasers is aimed at enhancing the catastrophic optical mirror damage (COMD) threshold and output power of semiconductor lasers. A process for the fabrication of high-power semiconductor lasers has been explored through the intermixing study of primary epitaxial wafers. In the experimental procedure, the epitaxial layers at the front and rear facets were first selectively etched, followed by the deposition of a 200 nm SiO2 dielectric layer on their surfaces. Additionally, a 100 nm TiO2 dielectric layer is applied to suppress QWI in the gain emission region. A NAW is achieved through a rapid thermal annealing process at 830°C for 180 s under atmospheric pressure. In the wafer-scale fabrication process, wide-stripe single-tube devices are produced with a light-emitting region width of 200 μm and a cavity length of 4000 μm. Test results reveal that conventional single-tube devices typically experience COMD at an input current of ∼20 A, with power output at around 19 W. In contrast, the single-tube devices with the NAW reach a continuous output power of 27.7 W at an input current of 30 A, representing a power enhancement of ∼45.8 % . No optical catastrophic damage is observed, and characteristics, such as slope efficiency and threshold current, remain unaltered. This research demonstrates that IFVD combined with the wafer-scale fabrication can effectively enhance the COMD threshold of 915 nm GaInAsP/GaAsP semiconductor laser devices, offering valuable insights into the study of high-power semiconductor lasers.
{"title":"Research on the fabrication of high-power semiconductor lasers by impurity-free vacancy disordering","authors":"Tianjiang He, Qiong Qi, Nan Lin, Wei Li, Xiaoyu Ma, Suping Liu","doi":"10.1117/1.oe.62.11.116102","DOIUrl":"https://doi.org/10.1117/1.oe.62.11.116102","url":null,"abstract":"The preparation of a non-absorption window (NAW) through impurity-free vacancy disordering (IFVD) induced quantum well intermixing (QWI) in 915 nm GaInAsP/GaAsP semiconductor lasers is aimed at enhancing the catastrophic optical mirror damage (COMD) threshold and output power of semiconductor lasers. A process for the fabrication of high-power semiconductor lasers has been explored through the intermixing study of primary epitaxial wafers. In the experimental procedure, the epitaxial layers at the front and rear facets were first selectively etched, followed by the deposition of a 200 nm SiO2 dielectric layer on their surfaces. Additionally, a 100 nm TiO2 dielectric layer is applied to suppress QWI in the gain emission region. A NAW is achieved through a rapid thermal annealing process at 830°C for 180 s under atmospheric pressure. In the wafer-scale fabrication process, wide-stripe single-tube devices are produced with a light-emitting region width of 200 μm and a cavity length of 4000 μm. Test results reveal that conventional single-tube devices typically experience COMD at an input current of ∼20 A, with power output at around 19 W. In contrast, the single-tube devices with the NAW reach a continuous output power of 27.7 W at an input current of 30 A, representing a power enhancement of ∼45.8 % . No optical catastrophic damage is observed, and characteristics, such as slope efficiency and threshold current, remain unaltered. This research demonstrates that IFVD combined with the wafer-scale fabrication can effectively enhance the COMD threshold of 915 nm GaInAsP/GaAsP semiconductor laser devices, offering valuable insights into the study of high-power semiconductor lasers.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"9 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135480121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Lithium niobate thin film (TFLN) electro-optic modulators (EOM) are widely used in optical communication systems due to their high bandwidth, low half-wave voltage, and low energy loss. Based on the analysis of the finite element method, we optimize the structure parameters of the modulator and propose an EOM with an S-bend coupler and an electrode gap covered with a SiO2 layer. The device exhibited a half-wave voltage-length product of 2.13 V · F, a bandwidth greater than 75 GHz, and an optical loss <0.1 dB / cm. Besides, we also propose employing the linear regression algorithm in machine learning to help determine the parameters of high-performance modulators, which provides a new idea for the design and optimization of TFLN modulators.
摘要铌酸锂薄膜（TFLN）电光调制器（EOM）具有带宽高、半波电压低、能量损耗小等特点，被广泛应用于光通信系统。基于有限元法的分析，我们优化了调制器的结构参数，并提出了一种带有 S 形弯曲耦合器和覆盖有二氧化硅层的电极间隙的 EOM。该器件的半波压长乘积为 2.13 V - F，带宽大于 75 GHz，光损耗小于 0.1 dB / cm。此外，我们还提出利用机器学习中的线性回归算法来帮助确定高性能调制器的参数，这为 TFLN 调制器的设计和优化提供了新思路。
{"title":"Structure simulation and design optimization of high-performance lithium niobate thin film electro-optic modulator","authors":"Hao Chen, Wenyuan Liao, Shaohua Yang, Huafeng Dong, Ying Shi, Huangfan Wang, Fugen Wu","doi":"10.1117/1.OE.62.11.115103","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.115103","url":null,"abstract":"Abstract. Lithium niobate thin film (TFLN) electro-optic modulators (EOM) are widely used in optical communication systems due to their high bandwidth, low half-wave voltage, and low energy loss. Based on the analysis of the finite element method, we optimize the structure parameters of the modulator and propose an EOM with an S-bend coupler and an electrode gap covered with a SiO2 layer. The device exhibited a half-wave voltage-length product of 2.13 V · F, a bandwidth greater than 75 GHz, and an optical loss <0.1 dB / cm. Besides, we also propose employing the linear regression algorithm in machine learning to help determine the parameters of high-performance modulators, which provides a new idea for the design and optimization of TFLN modulators.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"16 1","pages":"115103 - 115103"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139291685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1117/1.oe.62.11.119801
Tran The Son, Vuong Cong Dat, H. Le‐Minh, Zabih Ghassemlooy, Duong Huu Ai, Huynh Cong Phap
Abstract. Erratum corrects an error in Fig. 8.
摘要。勘误纠正了图 8 中的一处错误。
{"title":"Adaptive received signal strength-based localization and channel state information estimation model for indoor multiple-input multiple-output visible light communication using the distance vector (Erratum)","authors":"Tran The Son, Vuong Cong Dat, H. Le‐Minh, Zabih Ghassemlooy, Duong Huu Ai, Huynh Cong Phap","doi":"10.1117/1.oe.62.11.119801","DOIUrl":"https://doi.org/10.1117/1.oe.62.11.119801","url":null,"abstract":"Abstract. Erratum corrects an error in Fig. 8.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"191 1","pages":"119801 - 119801"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139296436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1117/1.OE.62.11.114104
Yu Han, D. Salido-Monzú, A. Wieser
Abstract. Multispectral light detection and ranging (LiDAR) is an emerging active remote sensing technique that combines distance and spectroscopy measurements. The reflectance spectrum is known to enable material classification. However, the spectrum also depends on other surface parameters, particularly roughness. Herein, we propose an extension of multispectral to polarimetric multispectral LiDAR and introduce unpolarized and linearly polarized reflectance spectra as additional features for classifying materials and roughness. Using a bench-top prototype instrument, we demonstrate the feasibility and benefit of acquiring unpolarized and linearly polarized reflectance spectra. We analyze and interpret the spectra obtained with two different spectral resolutions (10 and 40 nm) from measurements on test specimens consisting of five different materials with two different levels of surface roughness. Using a linear support vector machine, we demonstrate the potential of the different features for enabling material and roughness classification. We find that the unpolarized reflectance spectrum is well suited for classifying materials, and the linearly polarized one for classifying roughness. In both cases, the performance is much better than using a standard reflectance spectrum offered by multispectral LiDAR. We identify polarimetric multispectral LiDAR as a technology that may significantly enhance surface and material probing capabilities for remote sensing applications.
{"title":"Classification of material and surface roughness using polarimetric multispectral LiDAR","authors":"Yu Han, D. Salido-Monzú, A. Wieser","doi":"10.1117/1.OE.62.11.114104","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.114104","url":null,"abstract":"Abstract. Multispectral light detection and ranging (LiDAR) is an emerging active remote sensing technique that combines distance and spectroscopy measurements. The reflectance spectrum is known to enable material classification. However, the spectrum also depends on other surface parameters, particularly roughness. Herein, we propose an extension of multispectral to polarimetric multispectral LiDAR and introduce unpolarized and linearly polarized reflectance spectra as additional features for classifying materials and roughness. Using a bench-top prototype instrument, we demonstrate the feasibility and benefit of acquiring unpolarized and linearly polarized reflectance spectra. We analyze and interpret the spectra obtained with two different spectral resolutions (10 and 40 nm) from measurements on test specimens consisting of five different materials with two different levels of surface roughness. Using a linear support vector machine, we demonstrate the potential of the different features for enabling material and roughness classification. We find that the unpolarized reflectance spectrum is well suited for classifying materials, and the linearly polarized one for classifying roughness. In both cases, the performance is much better than using a standard reflectance spectrum offered by multispectral LiDAR. We identify polarimetric multispectral LiDAR as a technology that may significantly enhance surface and material probing capabilities for remote sensing applications.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"13 1","pages":"114104 - 114104"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139304665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1117/1.OE.62.11.117103
Andrew R. Novoselov, Dmitriy Protasov, V. Kostyuchenko
Abstract. It was shown that the concentration of charge carriers and the stoichiometry of near-surface region are changed in p-type HgCdTe films with non-passivated and soiled by indium surface under storage temperatures 80°C and 120°C. The concentration of holes increased up to 1024 cm − 3 and mobility dropped up to 12 cm2 / ( V × s ) under heating. From acquired Auger spectra, it was obtained that the mercury concentration decreased but the cadmium concentration increased in near-surface region as the indium spot approached. The surface passivation by photoresist prevented these degradation processes. The current–voltage characteristics of p-n junctions around the indium spots on the surface of p-type HgCdTe films passivated by SiO2 / Si3N4 layers were measured after storage temperatures from 60°C up to 120° C. It was found that the p-n junctions closest to the indium spots have an increased dark current. The usage of an additional passivation layer of anodic oxide suppressed the appearance of regions with increased dark currents. It was concluded that the additional passivation layer of anodic oxide is necessary for durable and stable work of infrared detector arrays based on HgCdTe films.
摘要研究表明，在 80°C 和 120°C 的储存温度下，表面未钝化和被铟污染的 p 型碲化镉汞薄膜中电荷载流子的浓度和近表面区域的化学计量发生了变化。在加热条件下，空穴浓度增加到 1024 cm - 3，迁移率下降到 12 cm2 / ( V × s )。从获得的奥杰光谱可以看出，随着铟点的接近，汞浓度降低，但镉浓度在近表面区域增加。光刻胶的表面钝化防止了这些降解过程。在 60°C 至 120°C 的储存温度下，测量了经 SiO2 / Si3N4 层钝化的 p 型 HgCdTe 薄膜表面铟点周围 p-n 结的电流-电压特性。使用阳极氧化物附加钝化层可以抑制暗电流增加区域的出现。由此得出结论，阳极氧化物附加钝化层是基于碲化镉汞薄膜的红外探测器阵列持久稳定工作的必要条件。
{"title":"Effect of passivation coating on the HgCdTe heterostructures stability at elevated storage temperature","authors":"Andrew R. Novoselov, Dmitriy Protasov, V. Kostyuchenko","doi":"10.1117/1.OE.62.11.117103","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.117103","url":null,"abstract":"Abstract. It was shown that the concentration of charge carriers and the stoichiometry of near-surface region are changed in p-type HgCdTe films with non-passivated and soiled by indium surface under storage temperatures 80°C and 120°C. The concentration of holes increased up to 1024 cm − 3 and mobility dropped up to 12 cm2 / ( V × s ) under heating. From acquired Auger spectra, it was obtained that the mercury concentration decreased but the cadmium concentration increased in near-surface region as the indium spot approached. The surface passivation by photoresist prevented these degradation processes. The current–voltage characteristics of p-n junctions around the indium spots on the surface of p-type HgCdTe films passivated by SiO2 / Si3N4 layers were measured after storage temperatures from 60°C up to 120° C. It was found that the p-n junctions closest to the indium spots have an increased dark current. The usage of an additional passivation layer of anodic oxide suppressed the appearance of regions with increased dark currents. It was concluded that the additional passivation layer of anodic oxide is necessary for durable and stable work of infrared detector arrays based on HgCdTe films.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"1 1","pages":"117103 - 117103"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139301232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. The self-rotating three-dimensional (3D) visual scanning system is a prevalent technique for 3D reconstruction. However, the misalignment of the scanner’s rotation axis with the camera’s origin often necessitates specialized calibration tools to establish their relative positions. We propose a rotating axis calibration method for the rotation axis, which eliminates the need for specific tools. A rotating mechanism is used to rotate the 3D camera to different angles and carry out 3D reconstruction of the same object with curved surface characteristics, respectively. The resulting sequence of 3D point clouds is registered to derive the camera’s position transformation matrix corresponding to each rotation angle. Subsequently, we compute the positional relationship between the camera and the rotation axis by solving the equation. To prevent excessively large rotation angles that would cause the object beyond the camera’s field of view, the camera field extension method is proposed, which enhances equation redundancy and leads to improved calibration accuracy. Experiments prove the flexibility and accuracy of the proposed method.
摘要自旋转三维（3D）视觉扫描系统是一种流行的 3D 重建技术。然而，扫描仪的旋转轴与相机的原点不对准，往往需要专门的校准工具来确定它们的相对位置。我们提出了一种旋转轴校准方法，无需专用工具。旋转机构用于将三维相机旋转到不同角度，并分别对具有曲面特征的同一物体进行三维重建。对生成的三维点云序列进行注册，从而得出每个旋转角度对应的相机位置变换矩阵。随后，我们通过求解方程计算出摄像机与旋转轴之间的位置关系。为了防止过大的旋转角度导致物体超出摄像机视场，我们提出了摄像机视场扩展法，该方法增强了方程冗余度，提高了校准精度。实验证明了所提方法的灵活性和准确性。
{"title":"Tool-free axis calibration method for self-rotating three-dimensional vision systems","authors":"Jinyue Liu, Xinyuan Cao, Xiaohui Jia, Yiran Ma, Guanghao Li, Tiejun Li","doi":"10.1117/1.OE.62.11.114105","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.114105","url":null,"abstract":"Abstract. The self-rotating three-dimensional (3D) visual scanning system is a prevalent technique for 3D reconstruction. However, the misalignment of the scanner’s rotation axis with the camera’s origin often necessitates specialized calibration tools to establish their relative positions. We propose a rotating axis calibration method for the rotation axis, which eliminates the need for specific tools. A rotating mechanism is used to rotate the 3D camera to different angles and carry out 3D reconstruction of the same object with curved surface characteristics, respectively. The resulting sequence of 3D point clouds is registered to derive the camera’s position transformation matrix corresponding to each rotation angle. Subsequently, we compute the positional relationship between the camera and the rotation axis by solving the equation. To prevent excessively large rotation angles that would cause the object beyond the camera’s field of view, the camera field extension method is proposed, which enhances equation redundancy and leads to improved calibration accuracy. Experiments prove the flexibility and accuracy of the proposed method.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"65 1","pages":"114105 - 114105"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139305172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1117/1.OE.62.11.113108
Guijin Tang, Yukang Song, Feng Liu
Abstract. Underwater images often suffer from problems such as low contrast, color distortion, and blurred details, which have a negative impact on subsequent image processing tasks. To mitigate such problems, we propose an algorithm that combines an underwater physical imaging model with a convolutional neural network. The physical imaging model has two important types of parameters: background scattering parameters and direct transmission parameters. For the background scattering parameters, we divide them into three levels, which are primary information, secondary information, and advanced information, and design three subnetworks for feature extraction to represent them. For the direct transmission parameters, we decompose them into two levels, which are shallow transmission information and deep transmission information, and also design two subnetworks to indicate them. Experimental results show that, compared with other enhancement algorithms, the proposed algorithm can not only effectively correct the color deviation and enhance the object edges and texture details but also can obtain superior values of objective evaluation metrics in terms of peak signal-to-noise ratio, structural similarity, underwater color image quality evaluation, and underwater image quality measure.
{"title":"Deep network for underwater image enhancement inspired by physical imaging model","authors":"Guijin Tang, Yukang Song, Feng Liu","doi":"10.1117/1.OE.62.11.113108","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113108","url":null,"abstract":"Abstract. Underwater images often suffer from problems such as low contrast, color distortion, and blurred details, which have a negative impact on subsequent image processing tasks. To mitigate such problems, we propose an algorithm that combines an underwater physical imaging model with a convolutional neural network. The physical imaging model has two important types of parameters: background scattering parameters and direct transmission parameters. For the background scattering parameters, we divide them into three levels, which are primary information, secondary information, and advanced information, and design three subnetworks for feature extraction to represent them. For the direct transmission parameters, we decompose them into two levels, which are shallow transmission information and deep transmission information, and also design two subnetworks to indicate them. Experimental results show that, compared with other enhancement algorithms, the proposed algorithm can not only effectively correct the color deviation and enhance the object edges and texture details but also can obtain superior values of objective evaluation metrics in terms of peak signal-to-noise ratio, structural similarity, underwater color image quality evaluation, and underwater image quality measure.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"105 1","pages":"113108 - 113108"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139306099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1117/1.OE.62.11.113106
Shreeyam Kacker, Kerri L. Cahoy
Abstract. Focus-tunable liquid lenses are used in various applications due to their compact size, light weight, low power consumption, and cost effectiveness. They have the potential for use in space applications, such as focus compensation, optical communications, and imaging systems. However, liquid lenses have not yet been evaluated for use in the space environment. This work focuses on characterizing operational differences of commercially available liquid lenses from Corning Varioptic and Optotune between Earth gravity, microgravity, and hypergravity environments. Results show a linear drift in the tip/tilt of 0.80 and 4.20 mrad going from 1 to 0 g for the Corning Varioptic A-39N0 lens and Optotune EL-16-40-TC-VIS lens, respectively, with lower optical aberrations in microgravity. Additionally, a significant but small increase in focal power going from 1 to 0 g by 0.02 D is observed for the Optotune lens. No significant change in focal power is observed for the Corning Varioptic lens tested in this experiment. Additionally, potential multi-beam interference is observed in defocus patterns of the Corning Varioptic lens tested during the experiment.
摘要。可调焦液体透镜因其体积小、重量轻、功耗低和成本效益高而被广泛应用于各种领域。它们有可能用于空间应用，如聚焦补偿、光通信和成像系统。然而，尚未对液体透镜在太空环境中的应用进行评估。这项工作的重点是鉴定康宁 Varioptic 和 Optotune 公司的市售液体透镜在地球重力、微重力和超重力环境下的运行差异。结果表明，康宁 Varioptic A-39N0 镜头和 Optotune EL-16-40-TC-VIS 镜头在微重力环境下的光学像差较低，从 1 g 到 0 g 的尖端/倾斜度线性漂移分别为 0.80 和 4.20 mrad。此外，Optotune 镜头的焦距功率从 1 g 到 0 g 显著但微小地增加了 0.02 D。本实验中测试的康宁变光透镜的焦距功率没有明显变化。此外，在实验中测试的康宁变焦镜头的散焦模式中也观察到了潜在的多光束干扰。
{"title":"Optical performance of commercial liquid lens assemblies in microgravity","authors":"Shreeyam Kacker, Kerri L. Cahoy","doi":"10.1117/1.OE.62.11.113106","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113106","url":null,"abstract":"Abstract. Focus-tunable liquid lenses are used in various applications due to their compact size, light weight, low power consumption, and cost effectiveness. They have the potential for use in space applications, such as focus compensation, optical communications, and imaging systems. However, liquid lenses have not yet been evaluated for use in the space environment. This work focuses on characterizing operational differences of commercially available liquid lenses from Corning Varioptic and Optotune between Earth gravity, microgravity, and hypergravity environments. Results show a linear drift in the tip/tilt of 0.80 and 4.20 mrad going from 1 to 0 g for the Corning Varioptic A-39N0 lens and Optotune EL-16-40-TC-VIS lens, respectively, with lower optical aberrations in microgravity. Additionally, a significant but small increase in focal power going from 1 to 0 g by 0.02 D is observed for the Optotune lens. No significant change in focal power is observed for the Corning Varioptic lens tested in this experiment. Additionally, potential multi-beam interference is observed in defocus patterns of the Corning Varioptic lens tested during the experiment.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"9 1","pages":"113106 - 113106"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139297211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1117/1.OE.62.11.113102
Nouf Alanazi, Partha P. Banerjee
Abstract. Transport of intensity (TI) is a well-known non-interferometric technique for phase retrieval. The TI and phase equations result from the Helmholtz equation and show the coupling of intensity and phase during optical propagation. TI is an alternative to digital holography, which requires a reference beam for a recording of the interference pattern. However, the conventional TI method has an experimental challenge in that mechanical displacement of the camera or object is needed to record the optical intensities at multiple defocused planes, which can cause errors from misalignments. This work expands on a modified TI technique that avoids mechanical displacements, instead invoking the use of electrooptic materials to create an optical phase difference and hence optical path length through the application of a bias voltage. We demonstrate the use of the modified TI equation (TIE) through simulation and experiment by selecting suitable objects and a biased nematic liquid crystal cell made from pentyl-4-cyanobiphenyl (5CB). The corresponding modified transport of phase equation is also derived and is used to enhance the accuracy of the modified TIE. After providing simulation results for imaged phase retrieval, we demonstrate the unwrapped image phase and hence height or profile extraction for an object with three-dimensional topography using this technique.
摘要强度传输（TI）是一种著名的非干涉相位检索技术。TI 和相位方程源于亥姆霍兹方程，显示了光传播过程中强度和相位的耦合。TI 是数字全息技术的替代方法，后者需要参考光束来记录干涉图案。然而，传统的 TI 方法在实验上有一个难题，即需要对照相机或物体进行机械位移，以记录多个散焦平面的光学强度，这可能会导致对位错误而产生误差。这项工作扩展了一种改良的 TI 技术，该技术避免了机械位移，而是利用电光材料产生光学相位差，从而通过施加偏置电压实现光路长度。我们通过模拟和实验，选择合适的对象和由戊基-4-氰基联苯（5CB）制成的偏压向列液晶电池，演示了修正 TI 方程（TIE）的使用。同时还推导出相应的修正传输相方程，用于提高修正 TIE 的精度。在提供了成像相位检索的模拟结果后，我们演示了使用该技术对具有三维地形的物体进行未包裹图像相位以及高度或轮廓提取。
{"title":"Retrieval of phase and three-dimensional topography using modified transport of intensity and phase equations with electrically programmable optical path lengths","authors":"Nouf Alanazi, Partha P. Banerjee","doi":"10.1117/1.OE.62.11.113102","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.113102","url":null,"abstract":"Abstract. Transport of intensity (TI) is a well-known non-interferometric technique for phase retrieval. The TI and phase equations result from the Helmholtz equation and show the coupling of intensity and phase during optical propagation. TI is an alternative to digital holography, which requires a reference beam for a recording of the interference pattern. However, the conventional TI method has an experimental challenge in that mechanical displacement of the camera or object is needed to record the optical intensities at multiple defocused planes, which can cause errors from misalignments. This work expands on a modified TI technique that avoids mechanical displacements, instead invoking the use of electrooptic materials to create an optical phase difference and hence optical path length through the application of a bias voltage. We demonstrate the use of the modified TI equation (TIE) through simulation and experiment by selecting suitable objects and a biased nematic liquid crystal cell made from pentyl-4-cyanobiphenyl (5CB). The corresponding modified transport of phase equation is also derived and is used to enhance the accuracy of the modified TIE. After providing simulation results for imaged phase retrieval, we demonstrate the unwrapped image phase and hence height or profile extraction for an object with three-dimensional topography using this technique.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"21 1","pages":"113102 - 113102"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139302153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1117/1.OE.62.11.118103
Mi Li, Anni Li, Chuanbo Zhang, Jiaqiang Nie, Yue-chun Shi, Yuejiang Song, Xiangfei Chen
Abstract. To evaluate the effect of crosstalk caused by wavelength deviation of reconstruction-equivalent-chirp (REC) integrated multi-wavelength laser arrays (MWLAs) on an optical free-space communication system in which wavelength division multiplexing (WDM) is applied, we derive the model of power penalty caused by the wavelength deviation of REC-MWLAs and the bit error rate (BER) of the system under atmospheric turbulence and conduct a numerical simulation. The two adjacent channels in arranged REC laser arrays are defined as the analysis scope. We find that the power penalty is more sensitive to the deviation of the channel itself than the adjacent channel as the frequency shift increases from 0 to 50 GHz. The numerical relationship between the BER and power penalty is drawn to further investigate the tolerance for wavelength deviation under the requirements of BER < 10 − 6 and BER < 10 − 9. In addition, for a smaller deviation of 5 GHz of the analyzed channel, the linewidth compression of the REC laser can decrease the power penalty from 1.3 to 0.7 dB, improving the system performance and moderating the demands for deviation of REC-MWLAs, and the gemination of channel spacing does not evidently reduce the requirement for deviation. The results of this work demonstrate the feasibility of REC-MWLAs as the light source of WDM free-space communication systems under atmospheric turbulence and provide an effective reference for the allowable deviation in the design and testing of MWLAs.
{"title":"Effect of wavelength accuracy of reconstruction-equivalent-chirp laser arrays on performance of wavelength division multiplexing space laser communication system","authors":"Mi Li, Anni Li, Chuanbo Zhang, Jiaqiang Nie, Yue-chun Shi, Yuejiang Song, Xiangfei Chen","doi":"10.1117/1.OE.62.11.118103","DOIUrl":"https://doi.org/10.1117/1.OE.62.11.118103","url":null,"abstract":"Abstract. To evaluate the effect of crosstalk caused by wavelength deviation of reconstruction-equivalent-chirp (REC) integrated multi-wavelength laser arrays (MWLAs) on an optical free-space communication system in which wavelength division multiplexing (WDM) is applied, we derive the model of power penalty caused by the wavelength deviation of REC-MWLAs and the bit error rate (BER) of the system under atmospheric turbulence and conduct a numerical simulation. The two adjacent channels in arranged REC laser arrays are defined as the analysis scope. We find that the power penalty is more sensitive to the deviation of the channel itself than the adjacent channel as the frequency shift increases from 0 to 50 GHz. The numerical relationship between the BER and power penalty is drawn to further investigate the tolerance for wavelength deviation under the requirements of BER < 10 − 6 and BER < 10 − 9. In addition, for a smaller deviation of 5 GHz of the analyzed channel, the linewidth compression of the REC laser can decrease the power penalty from 1.3 to 0.7 dB, improving the system performance and moderating the demands for deviation of REC-MWLAs, and the gemination of channel spacing does not evidently reduce the requirement for deviation. The results of this work demonstrate the feasibility of REC-MWLAs as the light source of WDM free-space communication systems under atmospheric turbulence and provide an effective reference for the allowable deviation in the design and testing of MWLAs.","PeriodicalId":19561,"journal":{"name":"Optical Engineering","volume":"24 1","pages":"118103 - 118103"},"PeriodicalIF":1.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139303441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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