Pub Date : 2024-02-29DOI: 10.1088/2040-8986/ad2bab
Ankit1, Kamal Kishor, Ravindra Kumar Sinha
We propose modeling and design of a low-loss all-dielectric metasurface (DM), comprised of Silicon on Insulator (SiO2) substrate to demonstrate a perfect reflector in the visible spectrum. The proposed metasurface unit cell consists of V and W shapes arranged in a mirror image configuration, with nanometre-sized gaps (g) between them. A narrow peak with a nearly 100% reflectance and a broad perfect reflectance spectrum is observed within the visible region (400–700 nm) of the electromagnetic spectrum. The effective electromagnetic parameters were also analyzed for electric and magnetic dipole resonance. The electric and magnetic field distributions at the resonant wavelength were also analyzed for the proposed structure. By altering the gap region ‘g’, the thickness of the dielectric Silica layer (ts), and the Si resonator (tm), the proposed structure exhibits tunable characteristics. We have successfully illustrated the consistent position of the scattering parameter’s response, regardless of the structure’s rotation, concluding the homogeneity of the designed structure across the entire visible spectrum. The all-DM exhibits a unique combination of features, including a distinct and wide reflectance spectrum as well as a tuned and enhanced electric field which makes it an ideal platform for the applications in filters, color printing, low-loss slow-light devices, and nonlinear optics.
我们提出了低损耗全介电元表面（DM）的建模和设计方案，该元表面由绝缘体硅（SiO2）衬底组成，可在可见光谱中实现完美反射。拟议的元表面单元格由以镜像配置排列的 V 形和 W 形组成，它们之间有纳米级的间隙 (g)。在电磁波谱的可见光区域（400-700 nm）内观察到一个反射率接近 100% 的窄峰和一个宽广的完美反射光谱。此外，还分析了电偶极子和磁偶极子共振的有效电磁参数。此外，还分析了拟议结构在谐振波长处的电场和磁场分布。通过改变间隙区域 "g"、介质二氧化硅层厚度（ts）和硅谐振器（tm），所提出的结构显示出可调特性。我们成功地证明了无论结构如何旋转，散射参数的响应位置都是一致的，从而得出结论：所设计的结构在整个可见光谱范围内都是均匀的。全 DM 具有独特的组合特性，包括独特而宽广的反射光谱以及可调且增强的电场，这使其成为滤光片、彩色印刷、低损耗慢光器件和非线性光学应用的理想平台。
{"title":"SOI Based metasurface for broadband perfect reflection in visible spectrum","authors":"Ankit1, Kamal Kishor, Ravindra Kumar Sinha","doi":"10.1088/2040-8986/ad2bab","DOIUrl":"https://doi.org/10.1088/2040-8986/ad2bab","url":null,"abstract":"We propose modeling and design of a low-loss all-dielectric metasurface (DM), comprised of Silicon on Insulator (SiO<sub>2</sub>) substrate to demonstrate a perfect reflector in the visible spectrum. The proposed metasurface unit cell consists of V and W shapes arranged in a mirror image configuration, with nanometre-sized gaps (g) between them. A narrow peak with a nearly 100% reflectance and a broad perfect reflectance spectrum is observed within the visible region (400–700 nm) of the electromagnetic spectrum. The effective electromagnetic parameters were also analyzed for electric and magnetic dipole resonance. The electric and magnetic field distributions at the resonant wavelength were also analyzed for the proposed structure. By altering the gap region ‘g’, the thickness of the dielectric Silica layer (<italic toggle=\"yes\">t<sub>s</sub>\u0000</italic>), and the Si resonator (<italic toggle=\"yes\">t</italic>\u0000<sub>m</sub>), the proposed structure exhibits tunable characteristics. We have successfully illustrated the consistent position of the scattering parameter’s response, regardless of the structure’s rotation, concluding the homogeneity of the designed structure across the entire visible spectrum. The all-DM exhibits a unique combination of features, including a distinct and wide reflectance spectrum as well as a tuned and enhanced electric field which makes it an ideal platform for the applications in filters, color printing, low-loss slow-light devices, and nonlinear optics.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"33 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
In this article, we study the effect of electron–phonon interaction on a spaser (surface plasmon amplification by stimulated emission of radiation) system consisting of a metal nanoparticle surrounded by a large number of quantum dots (QDs). Usually, the effect of electron–phonon interaction is neglected in the spaser-related literature. However, gain media, in this case QDs, attributed by the large Raman scattering cross-section, exhibit stronger electron–phonon interaction. In the present work, we investigate the effects of electron–phonon interaction on a three-level QD-based spaser. We consider two types of interaction potentials, linear and quadratic, and analyse their effects individually. First, we focus on the linear electron–phonon interaction that perturbs the electrons present in the excited state. This yields a periodic steady-state number of localized surface plasmons (LSPs). The accompanying analytic solution reveals that the population inversion of the gain medium depends on the linear potential strength (Frohlich constant) but does not affect the threshold of spaser considerably for the given numerical parameters. In addition to the LSP, phonons are generated during this process, the temporal dynamics of which are also presented here. Initially, the number of phonons exhibit decaying periodic oscillations, whose amplitude depends on the strength of the electron–phonon interaction. Under continuous pumping, at later times, the number of phonons reaches a steady-state value, which may find potential applications in the realization of continuous phonon nanolasers. Furthermore, the effect of the quadratic potential is investigated phenomenologically by increasing the excited-state decay rate. This results in numerous LSPs and an intense spaser spectrum.
{"title":"Effect of electron–phonon interactions on a three-level QD-based spaser: linear and quadratic potentials","authors":"Ankit Purohit, Vishvendra Singh Poonia, Akhilesh Kumar Mishra","doi":"10.1088/2040-8986/ad29ac","DOIUrl":"https://doi.org/10.1088/2040-8986/ad29ac","url":null,"abstract":"In this article, we study the effect of electron–phonon interaction on a spaser (surface plasmon amplification by stimulated emission of radiation) system consisting of a metal nanoparticle surrounded by a large number of quantum dots (QDs). Usually, the effect of electron–phonon interaction is neglected in the spaser-related literature. However, gain media, in this case QDs, attributed by the large Raman scattering cross-section, exhibit stronger electron–phonon interaction. In the present work, we investigate the effects of electron–phonon interaction on a three-level QD-based spaser. We consider two types of interaction potentials, linear and quadratic, and analyse their effects individually. First, we focus on the linear electron–phonon interaction that perturbs the electrons present in the excited state. This yields a periodic steady-state number of localized surface plasmons (LSPs). The accompanying analytic solution reveals that the population inversion of the gain medium depends on the linear potential strength (Frohlich constant) but does not affect the threshold of spaser considerably for the given numerical parameters. In addition to the LSP, phonons are generated during this process, the temporal dynamics of which are also presented here. Initially, the number of phonons exhibit decaying periodic oscillations, whose amplitude depends on the strength of the electron–phonon interaction. Under continuous pumping, at later times, the number of phonons reaches a steady-state value, which may find potential applications in the realization of continuous phonon nanolasers. Furthermore, the effect of the quadratic potential is investigated phenomenologically by increasing the excited-state decay rate. This results in numerous LSPs and an intense spaser spectrum.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"32 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140011427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-02-14DOI: 10.1088/2040-8986/ad2620
Francis Gracy Arockiaraj, Agnes Pristy Ignatius Xavier, Shivasubramanian Gopinath, Aravind Simon John Francis Rajeswary, Saulius Juodkazis, Vijayakumar Anand
Fresnel incoherent correlation holography (FINCH) is a well-established digital holography technique for 3D imaging of objects illuminated by spatially incoherent light. FINCH has a higher lateral resolution of 1.5 times that of direct imaging systems with the same numerical aperture. However, the other imaging characteristics of FINCH, such as axial resolution, temporal resolution, light throughput, and signal-to-noise ratio (SNR), are lower than those of direct imaging systems. Different techniques were developed by researchers around the world to improve the imaging characteristics of FINCH while retaining the inherent higher lateral resolution of FINCH. However, most of the solutions developed to improve FINCH presented additional challenges. In this study, we optimized FINCH in the framework of coded aperture imaging. Two recently developed computational methods, such as transport of amplitude into phase based on the Gerchberg Saxton algorithm and Lucy–Richardson–Rosen algorithm, were applied to improve light throughput and image reconstruction, respectively. The above implementation improved the axial resolution, temporal resolution, and SNR of FINCH and moved them closer to those of direct imaging while retaining the high lateral resolution. A point spread function (PSF) engineering technique has been implemented to prevent the low lateral resolution problem associated with the PSF recorded using pinholes with a large diameter. We believe that the above developments are beyond the state-of-the-art of existing FINCH-scopes.
{"title":"Optimizing the temporal and spatial resolutions and light throughput of Fresnel incoherent correlation holography in the framework of coded aperture imaging","authors":"Francis Gracy Arockiaraj, Agnes Pristy Ignatius Xavier, Shivasubramanian Gopinath, Aravind Simon John Francis Rajeswary, Saulius Juodkazis, Vijayakumar Anand","doi":"10.1088/2040-8986/ad2620","DOIUrl":"https://doi.org/10.1088/2040-8986/ad2620","url":null,"abstract":"Fresnel incoherent correlation holography (FINCH) is a well-established digital holography technique for 3D imaging of objects illuminated by spatially incoherent light. FINCH has a higher lateral resolution of 1.5 times that of direct imaging systems with the same numerical aperture. However, the other imaging characteristics of FINCH, such as axial resolution, temporal resolution, light throughput, and signal-to-noise ratio (SNR), are lower than those of direct imaging systems. Different techniques were developed by researchers around the world to improve the imaging characteristics of FINCH while retaining the inherent higher lateral resolution of FINCH. However, most of the solutions developed to improve FINCH presented additional challenges. In this study, we optimized FINCH in the framework of coded aperture imaging. Two recently developed computational methods, such as transport of amplitude into phase based on the Gerchberg Saxton algorithm and Lucy–Richardson–Rosen algorithm, were applied to improve light throughput and image reconstruction, respectively. The above implementation improved the axial resolution, temporal resolution, and SNR of FINCH and moved them closer to those of direct imaging while retaining the high lateral resolution. A point spread function (PSF) engineering technique has been implemented to prevent the low lateral resolution problem associated with the PSF recorded using pinholes with a large diameter. We believe that the above developments are beyond the state-of-the-art of existing FINCH-scopes.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"68 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140002501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-02-08DOI: 10.1088/2040-8986/ad247c
Hui Li, Wenhui Xu, Hang Xu, Chunyu Song, Qi Tan, Jianquan Yao
Polarization manipulation based on the Jones matrix facilitates the enhancement of light-matter interactions. Recently, arbitrarily tailorable polarization states generated with the assistance of a diatomic metasurface effectively reduce the complexity of the system. Nevertheless, a single polarization switching behavior hinders the application of meta-platforms in cryptographic imaging. Here, we theoretically propose and design a single-layer diatomic all-dielectric metasurface working in the terahertz band, which can efficiently realize bi-functional polarization switching according to the Jones matrix. Such a meta-platform is assembled from two anisotropic silicon pillars with carefully optimized lateral dimensions and in-plane twist angles. Benefiting from the flexible assembly of half-wave plate and quarter-wave plate, the polarization states generated by the constructed metasurfaces in the transmission mode can be arbitrarily tailored. The feasibility of this diatomic metasurface is further validated by a broadband near-field imaging device, paving the way for broader system applications in cryptographic imaging, data storage, and chiral sensing.
{"title":"Terahertz bi-functional polarization converter based on interference mechanism supported by diatomic metasurfaces","authors":"Hui Li, Wenhui Xu, Hang Xu, Chunyu Song, Qi Tan, Jianquan Yao","doi":"10.1088/2040-8986/ad247c","DOIUrl":"https://doi.org/10.1088/2040-8986/ad247c","url":null,"abstract":"Polarization manipulation based on the Jones matrix facilitates the enhancement of light-matter interactions. Recently, arbitrarily tailorable polarization states generated with the assistance of a diatomic metasurface effectively reduce the complexity of the system. Nevertheless, a single polarization switching behavior hinders the application of meta-platforms in cryptographic imaging. Here, we theoretically propose and design a single-layer diatomic all-dielectric metasurface working in the terahertz band, which can efficiently realize bi-functional polarization switching according to the Jones matrix. Such a meta-platform is assembled from two anisotropic silicon pillars with carefully optimized lateral dimensions and in-plane twist angles. Benefiting from the flexible assembly of half-wave plate and quarter-wave plate, the polarization states generated by the constructed metasurfaces in the transmission mode can be arbitrarily tailored. The feasibility of this diatomic metasurface is further validated by a broadband near-field imaging device, paving the way for broader system applications in cryptographic imaging, data storage, and chiral sensing.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"27 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139765100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-02-08DOI: 10.1088/2040-8986/ad237c
Alperen Saltik, Sueda Saylan, Onur Tokel
An accurate and computationally simple phase shifting interferometry (PSI) method is developed to reconstruct phase maps without a priori knowledge of the phase shift. Previous methods developed for random PSI either do not address general sources of error or require complex iterative processes and increased computational time. Here we demonstrate a novel method that is able to extract the phase using only Fourier transform (FT). With spatial FT analysis, randomly phase-shifted data is reordered to allow performing temporal FT on the intensity, which is a function of the phase shift. Since the entire process, including order analysis and phase calculation, is based only on Fourier analysis, it is rapid, easy to implement, and addresses general sources of error. The method exhibits high performance in experiments containing random phase shifts. Moreover, simulations incorporating common experimental error sources such as random intensity noise, intensity harmonics, and phase shift errors demonstrate that the proposed method performs as good as or better than the state-of-the-art phase reconstruction techniques in terms of accuracy and time.
{"title":"Fourier-transform-only method for random phase shifting interferometry","authors":"Alperen Saltik, Sueda Saylan, Onur Tokel","doi":"10.1088/2040-8986/ad237c","DOIUrl":"https://doi.org/10.1088/2040-8986/ad237c","url":null,"abstract":"An accurate and computationally simple phase shifting interferometry (PSI) method is developed to reconstruct phase maps without <italic toggle=\"yes\">a priori</italic> knowledge of the phase shift. Previous methods developed for random PSI either do not address general sources of error or require complex iterative processes and increased computational time. Here we demonstrate a novel method that is able to extract the phase using only Fourier transform (FT). With spatial FT analysis, randomly phase-shifted data is reordered to allow performing temporal FT on the intensity, which is a function of the phase shift. Since the entire process, including order analysis and phase calculation, is based only on Fourier analysis, it is rapid, easy to implement, and addresses general sources of error. The method exhibits high performance in experiments containing random phase shifts. Moreover, simulations incorporating common experimental error sources such as random intensity noise, intensity harmonics, and phase shift errors demonstrate that the proposed method performs as good as or better than the state-of-the-art phase reconstruction techniques in terms of accuracy and time.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"7 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139765174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-02-05DOI: 10.1088/2040-8986/ad21dc
Ankit Purohit, Akhilesh Kumar Mishra
In this article, we theoretically investigate a spaser (surface plasmon amplification by stimulated emission of radiation) comprising a spherical silver nanoparticle surrounded by a four-level gain medium of quantum dots. The spaser system is pumped coherently and incoherently with the same excitation rate, and the characteristics of the resultant coherent localized surface plasmon (LSP) mode are compared for the two pumping scenarios. We provide a detailed analytical expression for the steady state and demonstrate that the incoherent pump is more suitable for the continuous spaser mode. The reason is better understood by studying the temporal evolution of the number of LSPs Nn, where the LSP oscillation starts earlier for an incoherent drive and relaxes to a steady state with a large value of Nn. At a large pump rate, the spaser curve shows saturation. In addition, we have found that the resonance peak of the spaser field is independent of coherent and incoherent pumping, whereas the peak amplitude of the field depends on the pump rate.
本文从理论上研究了一种由球形银纳米粒子和四级量子点增益介质组成的spaser（受激发射辐射的表面等离子体放大）。我们以相同的激发率对 Spaser 系统进行相干和非相干泵浦，并比较了两种泵浦情况下产生的相干局部表面等离子体（LSP）模式的特性。我们提供了稳态的详细分析表达式，并证明非相干泵浦更适合连续溅射模式。通过研究 LSP 数量 Nn 的时间演化，我们可以更好地理解其中的原因。在非相干驱动下，LSP 振荡开始得更早，当 Nn 值较大时，LSP 振荡会放松到稳定状态。当泵浦速率较大时，溅射曲线会出现饱和。此外，我们还发现溅射场的共振峰值与相干和非相干泵浦无关，而场强的峰值振幅则取决于泵浦速率。
{"title":"A comparative study of coherent and incoherent drives in a four-level quantum dot–based spaser","authors":"Ankit Purohit, Akhilesh Kumar Mishra","doi":"10.1088/2040-8986/ad21dc","DOIUrl":"https://doi.org/10.1088/2040-8986/ad21dc","url":null,"abstract":"In this article, we theoretically investigate a spaser (surface plasmon amplification by stimulated emission of radiation) comprising a spherical silver nanoparticle surrounded by a four-level gain medium of quantum dots. The spaser system is pumped coherently and incoherently with the same excitation rate, and the characteristics of the resultant coherent localized surface plasmon (LSP) mode are compared for the two pumping scenarios. We provide a detailed analytical expression for the steady state and demonstrate that the incoherent pump is more suitable for the continuous spaser mode. The reason is better understood by studying the temporal evolution of the number of LSPs <inline-formula>\u0000<tex-math><?CDATA $left( {{N_n}} right)$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mfenced close=\")\" open=\"(\"><mml:mrow><mml:mrow><mml:msub><mml:mi>N</mml:mi><mml:mi>n</mml:mi></mml:msub></mml:mrow></mml:mrow></mml:mfenced></mml:math>\u0000<inline-graphic xlink:href=\"joptad21dcieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>, where the LSP oscillation starts earlier for an incoherent drive and relaxes to a steady state with a large value of <inline-formula>\u0000<tex-math><?CDATA ${N_n}$?></tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mrow><mml:msub><mml:mi>N</mml:mi><mml:mi>n</mml:mi></mml:msub></mml:mrow></mml:math>\u0000<inline-graphic xlink:href=\"joptad21dcieqn2.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>. At a large pump rate, the spaser curve shows saturation. In addition, we have found that the resonance peak of the spaser field is independent of coherent and incoherent pumping, whereas the peak amplitude of the field depends on the pump rate.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"20 1","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139765178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-01-06DOI: 10.1007/s12596-023-01494-2
Shreyas Jain, B. C. D. Devappa, Kalyani Pawar, A. V. Murthy
{"title":"Feasibility analysis of modulation formats in different seawater types and practical implementation on underwater optical communication testbed","authors":"Shreyas Jain, B. C. D. Devappa, Kalyani Pawar, A. V. Murthy","doi":"10.1007/s12596-023-01494-2","DOIUrl":"https://doi.org/10.1007/s12596-023-01494-2","url":null,"abstract":"","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"5 7","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139380660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-01-05DOI: 10.1007/s12596-023-01585-0
Long Wang, Wenhao Wang, Liuying Wang, Gu Liu, C. Ge, Kejun Xu, Bin Wang, Tonghao Liu
{"title":"Flexible and transparent visible-infrared-compatible stealth film based on ITO/Ag/ITO configuration","authors":"Long Wang, Wenhao Wang, Liuying Wang, Gu Liu, C. Ge, Kejun Xu, Bin Wang, Tonghao Liu","doi":"10.1007/s12596-023-01585-0","DOIUrl":"https://doi.org/10.1007/s12596-023-01585-0","url":null,"abstract":"","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"23 4","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139382014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-01-04DOI: 10.1088/2040-8986/ad1b11
Joyee Ghosh, Shivani Sharma, Vivek Venkataraman
We present a semi-classical numerical model to estimate the impact of linear scattering loss and nonlinear absorption losses on the biphoton flux and their quantum correlations generated via spontaneous four-wave mixing in silicon nanowaveguides. The counter-intuitive observed enhancement of pair correlations with increasing loss is attributed to the dominant effect of reduced accidental counts from multiphoton generation, with a corresponding trade-off for the source brightness. Silicon nanowaveguides are shown to be capable of generating highly correlated paired photons with coincidental-to-accidental ratio (CAR) as high as ∽3400 and spectral brightness 2.8×105 pairs/s/GHz/mW, even in the presence of linear propagation loss of 1 dB/cm and nonlinear losses (two-photon absorption (TPA) and free-carrier absorption (FCA)), over a length of 1-cm with an input pump power of 1 mW. Loss and the corresponding Langevin noise are modeled using distributed beam splitters along the waveguide length to encapsulate the phenomenological coupling to the background reservoir (vacuum fluctuations). The proposed numerical model is more general compared to previous analytical models, particularly for including dispersion and wavelength-dependent losses, and more accurate for noise estimation in the high-photon-flux regime such as optical parametric amplifiers and squeezed state generation.
{"title":"Impact of propagation losses on photon-pair generation in silicon","authors":"Joyee Ghosh, Shivani Sharma, Vivek Venkataraman","doi":"10.1088/2040-8986/ad1b11","DOIUrl":"https://doi.org/10.1088/2040-8986/ad1b11","url":null,"abstract":"\u0000 We present a semi-classical numerical model to estimate the impact of linear scattering loss and nonlinear absorption losses on the biphoton flux and their quantum correlations generated via spontaneous four-wave mixing in silicon nanowaveguides. The counter-intuitive observed enhancement of pair correlations with increasing loss is attributed to the dominant effect of reduced accidental counts from multiphoton generation, with a corresponding trade-off for the source brightness. Silicon nanowaveguides are shown to be capable of generating highly correlated paired photons with coincidental-to-accidental ratio (CAR) as high as ∽3400 and spectral brightness 2.8×105 pairs/s/GHz/mW, even in the presence of linear propagation loss of 1 dB/cm and nonlinear losses (two-photon absorption (TPA) and free-carrier absorption (FCA)), over a length of 1-cm with an input pump power of 1 mW. Loss and the corresponding Langevin noise are modeled using distributed beam splitters along the waveguide length to encapsulate the phenomenological coupling to the background reservoir (vacuum fluctuations). The proposed numerical model is more general compared to previous analytical models, particularly for including dispersion and wavelength-dependent losses, and more accurate for noise estimation in the high-photon-flux regime such as optical parametric amplifiers and squeezed state generation.","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"59 12","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139386790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Pub Date : 2024-01-03DOI: 10.1007/s12596-023-01581-4
Xinyu Wu, Tingting Li
{"title":"A deep learning-based car accident detection approach in video-based traffic surveillance","authors":"Xinyu Wu, Tingting Li","doi":"10.1007/s12596-023-01581-4","DOIUrl":"https://doi.org/10.1007/s12596-023-01581-4","url":null,"abstract":"","PeriodicalId":16775,"journal":{"name":"Journal of Optics","volume":"21 12","pages":""},"PeriodicalIF":2.1,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139388489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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