Photonic integrated circuits are emerging as a promising platform for accelerating matrix multiplications in deep learning, leveraging the inherent parallel nature of light. Although various schemes have been proposed and demonstrated to realize such photonic matrix accelerators, the in situ training of artificial neural networks using photonic accelerators remains challenging due to the difficulty of direct on-chip backpropagation on a photonic chip. In this work, we propose a silicon microring resonator (MRR) optical crossbar array with a symmetric structure that allows for simple on-chip backpropagation, potentially enabling the acceleration of both the inference and training phases of deep learning. We demonstrate a 4×4 circuit on a Si-on-insulator platform and use it to perform inference tasks of a simple neural network for classifying iris flowers, achieving a classification accuracy of 93.3%. Subsequently, we train the neural network using simulated on-chip backpropagation and achieve an accuracy of 91.1% in the same inference task after training. Furthermore, we simulate a convolutional neural network for handwritten digit recognition, using a 9×9 MRR crossbar array to perform the convolution operations. This work contributes to the realization of compact and energy-efficient photonic accelerators for deep learning.
{"title":"Symmetric silicon microring resonator optical crossbar array for accelerated inference and training in deep learning","authors":"Rui Tang, Shuhei Ohno, Ken Tanizawa, Kazuhiro Ikeda, Makoto Okano, Kasidit Toprasertpong, Shinichi Takagi, Mitsuru Takenaka","doi":"10.1364/prj.520518","DOIUrl":"https://doi.org/10.1364/prj.520518","url":null,"abstract":"Photonic integrated circuits are emerging as a promising platform for accelerating matrix multiplications in deep learning, leveraging the inherent parallel nature of light. Although various schemes have been proposed and demonstrated to realize such photonic matrix accelerators, the <jats:italic toggle=\"yes\">in situ</jats:italic> training of artificial neural networks using photonic accelerators remains challenging due to the difficulty of direct on-chip backpropagation on a photonic chip. In this work, we propose a silicon microring resonator (MRR) optical crossbar array with a symmetric structure that allows for simple on-chip backpropagation, potentially enabling the acceleration of both the inference and training phases of deep learning. We demonstrate a 4×4 circuit on a Si-on-insulator platform and use it to perform inference tasks of a simple neural network for classifying iris flowers, achieving a classification accuracy of 93.3%. Subsequently, we train the neural network using simulated on-chip backpropagation and achieve an accuracy of 91.1% in the same inference task after training. Furthermore, we simulate a convolutional neural network for handwritten digit recognition, using a 9×9 MRR crossbar array to perform the convolution operations. This work contributes to the realization of compact and energy-efficient photonic accelerators for deep learning.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"1 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xinrui Zhu, Yaowen Hu, Shengyuan Lu, Hana K. Warner, Xudong Li, Yunxiang Song, Letícia Magalhães, Amirhassan Shams-Ansari, Andrea Cordaro, Neil Sinclair, Marko Lončar
The recent emergence of thin-film lithium niobate (TFLN) has extended the landscape of integrated photonics. This has been enabled by the commercialization of TFLN wafers and advanced nanofabrication of TFLN such as high-quality dry etching. However, fabrication imperfections still limit the propagation loss to a few dB/m, restricting the impact of this platform. Here, we demonstrate TFLN microresonators with a record-high intrinsic quality (Q) factor of twenty-nine million, corresponding to an ultra-low propagation loss of 1.3 dB/m. We present spectral analysis and the statistical distribution of Q factors across different resonator geometries. Our work pushes the fabrication limits of TFLN photonics to achieve a Q factor within 1 order of magnitude of the material limit.
{"title":"Twenty-nine million intrinsic Q-factor monolithic microresonators on thin-film lithium niobate","authors":"Xinrui Zhu, Yaowen Hu, Shengyuan Lu, Hana K. Warner, Xudong Li, Yunxiang Song, Letícia Magalhães, Amirhassan Shams-Ansari, Andrea Cordaro, Neil Sinclair, Marko Lončar","doi":"10.1364/prj.521172","DOIUrl":"https://doi.org/10.1364/prj.521172","url":null,"abstract":"The recent emergence of thin-film lithium niobate (TFLN) has extended the landscape of integrated photonics. This has been enabled by the commercialization of TFLN wafers and advanced nanofabrication of TFLN such as high-quality dry etching. However, fabrication imperfections still limit the propagation loss to a few dB/m, restricting the impact of this platform. Here, we demonstrate TFLN microresonators with a record-high intrinsic quality (<jats:italic>Q</jats:italic>) factor of twenty-nine million, corresponding to an ultra-low propagation loss of 1.3 dB/m. We present spectral analysis and the statistical distribution of <jats:italic>Q</jats:italic> factors across different resonator geometries. Our work pushes the fabrication limits of TFLN photonics to achieve a <jats:italic>Q</jats:italic> factor within 1 order of magnitude of the material limit.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"104 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sandro C. Oliveira, Maria S. Soares, Bárbara V. Gonçalves, Andreia C. M. Rodrigues, Amadeu M. V. M. Soares, Rita G. Sobral, Nuno F. Santos, Jan Nedoma, Pedro L. Almeida, Carlos Marques
The consumption of contaminated food may cause serious illnesses, and traditional methods to detect Escherichia coli are still associated with long waiting times and high costs given the necessity to transport samples to specialized laboratories. There is a need to develop new technologies that allow cheap, fast, and direct monitoring at the site of interest. Thus, in this work, we developed optical immunosensors for the selective detection of E. coli, based on liquid crystal technology, whose molecules can align in different manners depending on the boundary conditions (such as substrates) as well as the environment that they experience. Each glass substrate was functionalized with anti-E. coli antibody using cysteamine as an intermediate, and a vertical alignment was imposed on the liquid crystal molecules by using DMOAP during functionalization. The presence of bacteria disrupts the alignment of the liquid crystal molecules, changing the intensity of light emerging between cross polarizers, measured using a polarized optical microscope and a monochromator. It was possible to detect E. coli in suspensions in the concentration range from 2.8 cells/mL to 2.8×109 cells/mL. Selectivity was also evaluated, and the sensors were used to analyze contaminated water samples. A prototype was developed to allow faster, in-situ, and easier analysis avoiding bulky instruments.
{"title":"Liquid crystal immunosensors for the selective detection of Escherichia coli with a fast analysis tool","authors":"Sandro C. Oliveira, Maria S. Soares, Bárbara V. Gonçalves, Andreia C. M. Rodrigues, Amadeu M. V. M. Soares, Rita G. Sobral, Nuno F. Santos, Jan Nedoma, Pedro L. Almeida, Carlos Marques","doi":"10.1364/prj.524660","DOIUrl":"https://doi.org/10.1364/prj.524660","url":null,"abstract":"The consumption of contaminated food may cause serious illnesses, and traditional methods to detect <jats:italic toggle=\"yes\">Escherichia coli</jats:italic> are still associated with long waiting times and high costs given the necessity to transport samples to specialized laboratories. There is a need to develop new technologies that allow cheap, fast, and direct monitoring at the site of interest. Thus, in this work, we developed optical immunosensors for the selective detection of <jats:italic toggle=\"yes\">E. coli</jats:italic>, based on liquid crystal technology, whose molecules can align in different manners depending on the boundary conditions (such as substrates) as well as the environment that they experience. Each glass substrate was functionalized with anti-<jats:italic toggle=\"yes\">E. coli</jats:italic> antibody using cysteamine as an intermediate, and a vertical alignment was imposed on the liquid crystal molecules by using DMOAP during functionalization. The presence of bacteria disrupts the alignment of the liquid crystal molecules, changing the intensity of light emerging between cross polarizers, measured using a polarized optical microscope and a monochromator. It was possible to detect <jats:italic toggle=\"yes\">E. coli</jats:italic> in suspensions in the concentration range from 2.8 cells/mL to 2.8×10<jats:sup>9</jats:sup> cells/<jats:italic>mL</jats:italic>. Selectivity was also evaluated, and the sensors were used to analyze contaminated water samples. A prototype was developed to allow faster, <jats:italic toggle=\"yes\">in-situ</jats:italic>, and easier analysis avoiding bulky instruments.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"43 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polarization holography has been extensively applied in many fields, such as optical science, metrology, and biochemistry, due to its property of polarization modulation. However, the modulated polarization state of diffracted light corresponds strictly to that of incident light one by one. Here, a kind of tunable polarization holographic grating has been designed in terms of Jones matrices, and intensity-based polarization manipulation has been realized experimentally. The proposed tunable polarization holographic grating is recorded on an azobenzene liquid-crystalline film by a pair of coherent light beams with orthogonal polarization states and asymmetrically controlled intensities. It is found that the diffracted light can be actively manipulated from linearly to circularly polarized based on the light intensity of the recording holographic field when the polarization state of incident light keeps constant. Our work could enrich the field of light manipulation and holography.
{"title":"Tunable polarization holographic gratings obtained by varying the ratio of intensities of the recording beams","authors":"Hong Chen, Ziyao Lyu, and Changshun Wang","doi":"10.1364/prj.502730","DOIUrl":"https://doi.org/10.1364/prj.502730","url":null,"abstract":"Polarization holography has been extensively applied in many fields, such as optical science, metrology, and biochemistry, due to its property of polarization modulation. However, the modulated polarization state of diffracted light corresponds strictly to that of incident light one by one. Here, a kind of tunable polarization holographic grating has been designed in terms of Jones matrices, and intensity-based polarization manipulation has been realized experimentally. The proposed tunable polarization holographic grating is recorded on an azobenzene liquid-crystalline film by a pair of coherent light beams with orthogonal polarization states and asymmetrically controlled intensities. It is found that the diffracted light can be actively manipulated from linearly to circularly polarized based on the light intensity of the recording holographic field when the polarization state of incident light keeps constant. Our work could enrich the field of light manipulation and holography.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"81 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140321901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yong-Qiang Liu, Yong Zhu, Hongcheng Yin, Jinhai Sun, Yan Wang, and Yongxing Che
Controlling the dispersion characteristic of metasurfaces (or metalenses) along a broad bandwidth is of great importance to develop high-performance broadband metadevices. Different from traditional lenses that rely on the material refractive index along the light trajectory, metasurfaces or metalenses provide a new regime of dispersion control via a sub-wavelength metastructure, which is known as negative chromatic dispersion. However, broadband metalenses design with high-performance focusing especially with a reduced device dimension is a significant challenge in society. Here, we design, fabricate, and demonstrate a broadband high-performance diffractive-type plasmonic metalens based on a circular split-ring resonator metasurface with a relative working bandwidth of 28.6%. The metalens thickness is only 0.09λ0 (λ0 is at the central wavelength), which is much thinner than previous broadband all-dielectric metalenses. The full-wave simulation results show that both high transmissive efficiency above 80% (the maximum is even above 90%) and high average focusing efficiency above 45% (the maximum is 56%) are achieved within the entire working bandwidth of 9–12 GHz. Moreover, an average high numerical aperture of 0.7 (NA=0.7) of high-efficiency microwave metalens is obtained in the simulations. The broadband high-performance metalens is also fabricated and experimental measurements verify its much higher average focusing efficiency of 55% (the maximum is above 65% within the broad bandwidth) and a moderate high NA of 0.6. The proposed plasmonic metalens can facilitate the development of wavelength-dependent broadband diffractive devices and is also meaningful to further studies on arbitrary dispersion control in diffractive optics based on plasmonic metasurfaces.
{"title":"Broadband high-efficiency plasmonic metalens with negative dispersion characteristic","authors":"Yong-Qiang Liu, Yong Zhu, Hongcheng Yin, Jinhai Sun, Yan Wang, and Yongxing Che","doi":"10.1364/prj.513990","DOIUrl":"https://doi.org/10.1364/prj.513990","url":null,"abstract":"Controlling the dispersion characteristic of metasurfaces (or metalenses) along a broad bandwidth is of great importance to develop high-performance broadband metadevices. Different from traditional lenses that rely on the material refractive index along the light trajectory, metasurfaces or metalenses provide a new regime of dispersion control via a sub-wavelength metastructure, which is known as negative chromatic dispersion. However, broadband metalenses design with high-performance focusing especially with a reduced device dimension is a significant challenge in society. Here, we design, fabricate, and demonstrate a broadband high-performance diffractive-type plasmonic metalens based on a circular split-ring resonator metasurface with a relative working bandwidth of 28.6%. The metalens thickness is only <span><span style=\"color: inherit;\"><span><span><span>0.09</span><span><span style=\"margin-right: 0.05em;\">λ</span><span style=\"vertical-align: -0.4em;\">0</span></span></span></span></span><script type=\"math/mml\"><math display=\"inline\"><mrow><mn>0.09</mn><msub><mi>λ</mi><mn>0</mn></msub></mrow></math></script></span> (<span><span style=\"color: inherit;\"><span><span><span><span style=\"margin-right: 0.05em;\">λ</span><span style=\"vertical-align: -0.4em;\">0</span></span></span></span></span><script type=\"math/mml\"><math display=\"inline\"><mrow><msub><mi>λ</mi><mn>0</mn></msub></mrow></math></script></span> is at the central wavelength), which is much thinner than previous broadband all-dielectric metalenses. The full-wave simulation results show that both high transmissive efficiency above 80% (the maximum is even above 90%) and high average focusing efficiency above 45% (the maximum is 56%) are achieved within the entire working bandwidth of 9–12 GHz. Moreover, an average high numerical aperture of 0.7 (<span><span style=\"color: inherit;\"><span><span><span>NA</span><span style=\"margin-left: 0.333em; margin-right: 0.333em;\">=</span><span>0.7</span></span></span></span><script type=\"math/mml\"><math display=\"inline\"><mrow><mi>NA</mi><mo>=</mo><mn>0.7</mn></mrow></math></script></span>) of high-efficiency microwave metalens is obtained in the simulations. The broadband high-performance metalens is also fabricated and experimental measurements verify its much higher average focusing efficiency of 55% (the maximum is above 65% within the broad bandwidth) and a moderate high NA of 0.6. The proposed plasmonic metalens can facilitate the development of wavelength-dependent broadband diffractive devices and is also meaningful to further studies on arbitrary dispersion control in diffractive optics based on plasmonic metasurfaces.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"81 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140322080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wei Shi, Yingchuan He, Jianlin Wang, Lulu Zhou, Jianwei Chen, Liwei Zhou, Zeyu Xi, Zhen Wang, Ke Fang, and Yiming Li
Single-molecule localization microscopy (SMLM) enables three-dimensional (3D) investigation of nanoscale structures in biological samples, offering unique insights into their organization. However, traditional 3D super-resolution microscopy using high numerical aperture (NA) objectives is limited by imaging depth of field (DOF), restricting their practical application to relatively thin biological samples. Here, we developed a unified solution for thick sample super-resolution imaging using a deformable mirror (DM) which served for fast remote focusing, optimized point spread function (PSF) engineering, and accurate aberration correction. By effectively correcting the system aberrations introduced during remote focusing and sample aberrations at different imaging depths, we achieved high-accuracy, large DOF imaging (∼8μm) of the whole-cell organelles [i.e., nuclear pore complex (NPC), microtubules, and mitochondria] with a nearly uniform resolution of approximately 35 nm across the entire cellular volume.
{"title":"Aberration correction for deformable-mirror-based remote focusing enables high-accuracy whole-cell super-resolution imaging","authors":"Wei Shi, Yingchuan He, Jianlin Wang, Lulu Zhou, Jianwei Chen, Liwei Zhou, Zeyu Xi, Zhen Wang, Ke Fang, and Yiming Li","doi":"10.1364/prj.514414","DOIUrl":"https://doi.org/10.1364/prj.514414","url":null,"abstract":"Single-molecule localization microscopy (SMLM) enables three-dimensional (3D) investigation of nanoscale structures in biological samples, offering unique insights into their organization. However, traditional 3D super-resolution microscopy using high numerical aperture (NA) objectives is limited by imaging depth of field (DOF), restricting their practical application to relatively thin biological samples. Here, we developed a unified solution for thick sample super-resolution imaging using a deformable mirror (DM) which served for fast remote focusing, optimized point spread function (PSF) engineering, and accurate aberration correction. By effectively correcting the system aberrations introduced during remote focusing and sample aberrations at different imaging depths, we achieved high-accuracy, large DOF imaging (<span><span style=\"color: inherit;\"><span><span><span style=\"margin-left: 0em; margin-right: 0em;\">∼</span><span>8</span><span> </span><span>μm</span></span></span></span><script type=\"math/mml\"><math display=\"inline\"><mrow><mo form=\"prefix\" lspace=\"0em\" rspace=\"0em\">∼</mo><mn>8</mn><mtext> </mtext><mi>μm</mi></mrow></math></script></span>) of the whole-cell organelles [i.e., nuclear pore complex (NPC), microtubules, and mitochondria] with a nearly uniform resolution of approximately 35 nm across the entire cellular volume.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"175 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140322029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiarui Li, Taoran Le, Hongyuan Zhang, Haoyun Wei, and Yan Li
Brillouin microscopy, which maps the elastic modulus from the frequency shift of scattered light, has evolved to a faster speed for the investigation of rapid biomechanical changes. Impulsive stimulated Brillouin scattering (ISBS) spectroscopy has the potential to speed up measurement through the resonant amplification interaction from pulsed excitation and time-domain continuous detection. However, significant progress has not been achieved due to the limitation in signal-to-noise ratio (SNR) and the corresponding need for excessive averaging to maintain high spectral precision. Moreover, the limited spatial resolution also hinders its application in mechanical imaging. Here, by scrutinizing the SNR model, we design a high-speed ISBS microscope through multi-parameter optimization including phase, reference power, and acquisition time. Leveraging this, with the further assistance of the Matrix Pencil method for data processing, three-dimensional mechanical images are mapped under multiple contrast mechanisms for a millimeter-scale polydimethylsiloxane pattern immersed in methanol, enabling the identification of these two transparent materials without any contact or labeling. Our experimental results demonstrate the capability to maintain high spectral precision and resolution at a sub-millisecond integration time for one pixel. With a two-order improvement in the speed and a tenfold improvement in the spatial resolution over the state-of-the-art systems, this method makes it possible for ISBS microscopes to sensitively investigate rapid mechanical changes in time and space.
{"title":"High-speed impulsive stimulated Brillouin microscopy","authors":"Jiarui Li, Taoran Le, Hongyuan Zhang, Haoyun Wei, and Yan Li","doi":"10.1364/prj.509922","DOIUrl":"https://doi.org/10.1364/prj.509922","url":null,"abstract":"Brillouin microscopy, which maps the elastic modulus from the frequency shift of scattered light, has evolved to a faster speed for the investigation of rapid biomechanical changes. Impulsive stimulated Brillouin scattering (ISBS) spectroscopy has the potential to speed up measurement through the resonant amplification interaction from pulsed excitation and time-domain continuous detection. However, significant progress has not been achieved due to the limitation in signal-to-noise ratio (SNR) and the corresponding need for excessive averaging to maintain high spectral precision. Moreover, the limited spatial resolution also hinders its application in mechanical imaging. Here, by scrutinizing the SNR model, we design a high-speed ISBS microscope through multi-parameter optimization including phase, reference power, and acquisition time. Leveraging this, with the further assistance of the Matrix Pencil method for data processing, three-dimensional mechanical images are mapped under multiple contrast mechanisms for a millimeter-scale polydimethylsiloxane pattern immersed in methanol, enabling the identification of these two transparent materials without any contact or labeling. Our experimental results demonstrate the capability to maintain high spectral precision and resolution at a sub-millisecond integration time for one pixel. With a two-order improvement in the speed and a tenfold improvement in the spatial resolution over the state-of-the-art systems, this method makes it possible for ISBS microscopes to sensitively investigate rapid mechanical changes in time and space.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"76 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140340748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Baoqi Shi, Yi-Han Luo, Wei Sun, Yue Hu, Jinbao Long, Xue Bai, Anting Wang, and Junqiu Liu
Tunable lasers, with the ability to continuously vary their emission wavelengths, have found widespread applications across various fields such as biomedical imaging, coherent ranging, optical communications, and spectroscopy. In these applications, a wide chirp range is advantageous for large spectral coverage and high frequency resolution. Besides, the frequency accuracy and precision also depend critically on the chirp linearity of the laser. While extensive efforts have been made on the development of many kinds of frequency-agile, widely tunable, narrow-linewidth lasers, wideband yet precise methods to characterize and linearize laser chirp dynamics are also demanded. Here we present an approach to characterize laser chirp dynamics using an optical frequency comb. The instantaneous laser frequency is tracked over terahertz bandwidth at 1 MHz intervals. Using this approach we calibrate the chirp performance of 12 tunable lasers from Toptica, Santec, New Focus, EXFO, and NKT that are commonly used in fiber optics and integrated photonics. In addition, with acquired knowledge of laser chirp dynamics, we demonstrate a simple frequency-linearization scheme that enables coherent ranging without any optical or electronic linearization unit. Our approach not only presents novel wideband, high-resolution laser spectroscopy, but is also critical for sensing applications with ever-increasing requirements on performance.
{"title":"Frequency-comb-linearized, widely tunable lasers for coherent ranging","authors":"Baoqi Shi, Yi-Han Luo, Wei Sun, Yue Hu, Jinbao Long, Xue Bai, Anting Wang, and Junqiu Liu","doi":"10.1364/prj.510795","DOIUrl":"https://doi.org/10.1364/prj.510795","url":null,"abstract":"Tunable lasers, with the ability to continuously vary their emission wavelengths, have found widespread applications across various fields such as biomedical imaging, coherent ranging, optical communications, and spectroscopy. In these applications, a wide chirp range is advantageous for large spectral coverage and high frequency resolution. Besides, the frequency accuracy and precision also depend critically on the chirp linearity of the laser. While extensive efforts have been made on the development of many kinds of frequency-agile, widely tunable, narrow-linewidth lasers, wideband yet precise methods to characterize and linearize laser chirp dynamics are also demanded. Here we present an approach to characterize laser chirp dynamics using an optical frequency comb. The instantaneous laser frequency is tracked over terahertz bandwidth at 1 MHz intervals. Using this approach we calibrate the chirp performance of 12 tunable lasers from Toptica, Santec, New Focus, EXFO, and NKT that are commonly used in fiber optics and integrated photonics. In addition, with acquired knowledge of laser chirp dynamics, we demonstrate a simple frequency-linearization scheme that enables coherent ranging without any optical or electronic linearization unit. Our approach not only presents novel wideband, high-resolution laser spectroscopy, but is also critical for sensing applications with ever-increasing requirements on performance.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"14 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140182881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chang Qiao, Haoyu Chen, Run Wang, Tao Jiang, Yuwang Wang, and Dong Li
Optical aberrations degrade the performance of fluorescence microscopy. Conventional adaptive optics (AO) leverages specific devices, such as the Shack–Hartmann wavefront sensor and deformable mirror, to measure and correct optical aberrations. However, conventional AO requires either additional hardware or a more complicated imaging procedure, resulting in higher cost or a lower acquisition speed. In this study, we proposed a novel space-frequency encoding network (SFE-Net) that can directly estimate the aberrated point spread functions (PSFs) from biological images, enabling fast optical aberration estimation with high accuracy without engaging extra optics and image acquisition. We showed that with the estimated PSFs, the optical aberration can be computationally removed by the deconvolution algorithm. Furthermore, to fully exploit the benefits of SFE-Net, we incorporated the estimated PSF with neural network architecture design to devise an aberration-aware deep-learning super-resolution model, dubbed SFT-DFCAN. We demonstrated that the combination of SFE-Net and SFT-DFCAN enables instant digital AO and optical aberration-aware super-resolution reconstruction for live-cell imaging.
{"title":"Deep learning-based optical aberration estimation enables offline digital adaptive optics and super-resolution imaging","authors":"Chang Qiao, Haoyu Chen, Run Wang, Tao Jiang, Yuwang Wang, and Dong Li","doi":"10.1364/prj.506778","DOIUrl":"https://doi.org/10.1364/prj.506778","url":null,"abstract":"Optical aberrations degrade the performance of fluorescence microscopy. Conventional adaptive optics (AO) leverages specific devices, such as the Shack–Hartmann wavefront sensor and deformable mirror, to measure and correct optical aberrations. However, conventional AO requires either additional hardware or a more complicated imaging procedure, resulting in higher cost or a lower acquisition speed. In this study, we proposed a novel space-frequency encoding network (SFE-Net) that can directly estimate the aberrated point spread functions (PSFs) from biological images, enabling fast optical aberration estimation with high accuracy without engaging extra optics and image acquisition. We showed that with the estimated PSFs, the optical aberration can be computationally removed by the deconvolution algorithm. Furthermore, to fully exploit the benefits of SFE-Net, we incorporated the estimated PSF with neural network architecture design to devise an aberration-aware deep-learning super-resolution model, dubbed SFT-DFCAN. We demonstrated that the combination of SFE-Net and SFT-DFCAN enables instant digital AO and optical aberration-aware super-resolution reconstruction for live-cell imaging.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"27 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140015411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ilya Kondratyev, Veronika Ivanova, Suren Fldzhyan, Artem Argenchiev, Nikita Kostyuchenko, Sergey Zhuravitskii, Nikolay Skryabin, Ivan Dyakonov, Mikhail Saygin, Stanislav Straupe, Alexander Korneev, and Sergei Kulik
We introduce a programmable eight-port interferometer with the recently proposed error-tolerant architecture capable of performing a broad class of transformations. The interferometer has been fabricated with femtosecond laser writing, and it is the largest programmable interferometer of this kind to date. We have demonstrated its advantageous error tolerance by showing an operation in a broad wavelength range from 920 to 980 nm, which is particularly relevant for quantum photonics due to efficient photon sources existing in this wavelength range. Our work highlights the importance of developing novel architectures of programmable photonics for information processing.
{"title":"Large-scale error-tolerant programmable interferometer fabricated by femtosecond laser writing","authors":"Ilya Kondratyev, Veronika Ivanova, Suren Fldzhyan, Artem Argenchiev, Nikita Kostyuchenko, Sergey Zhuravitskii, Nikolay Skryabin, Ivan Dyakonov, Mikhail Saygin, Stanislav Straupe, Alexander Korneev, and Sergei Kulik","doi":"10.1364/prj.504588","DOIUrl":"https://doi.org/10.1364/prj.504588","url":null,"abstract":"We introduce a programmable eight-port interferometer with the recently proposed error-tolerant architecture capable of performing a broad class of transformations. The interferometer has been fabricated with femtosecond laser writing, and it is the largest programmable interferometer of this kind to date. We have demonstrated its advantageous error tolerance by showing an operation in a broad wavelength range from 920 to 980 nm, which is particularly relevant for quantum photonics due to efficient photon sources existing in this wavelength range. Our work highlights the importance of developing novel architectures of programmable photonics for information processing.","PeriodicalId":20048,"journal":{"name":"Photonics Research","volume":"16 1","pages":""},"PeriodicalIF":7.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140015512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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