Pub Date : 2024-12-16DOI: 10.1109/JPHOT.2024.3518583
Jiaqi Wei;Yuan Wang;Nuo Huang;Yan-Yu Zhang;Yi-Jun Zhu;Wenliang Hao;Chen Gong
This paper studies the constellation optimization approach for multiple-input multiple-output (MIMO) visible light communication (VLC) systems with signal-dependent noise (SDN). We propose a constellation optimization method aiming at minimizing the system pairwise error probability. In order to obtain the transmitter constellation, we design the demapping rules from the perspective of energy efficiency and illumination uniformity. For the scenario where receiver randomly moves, the constellation lookup table is proposed to transform real-time optimization into table lookup operation, which effectively reduces the real-time computational complexity. Simulation results show that the optimized constellation leads to lower symbol error rate (SER) than the method of maximizing minimum Euclidean distance. In addition, the constellation lookup table operation shows negligible SER performance degradation.
{"title":"Constellation Optimization for MIMO VLC System With Signal-Dependent Noise: Receiver-Side Design and Lookup Table Establishment","authors":"Jiaqi Wei;Yuan Wang;Nuo Huang;Yan-Yu Zhang;Yi-Jun Zhu;Wenliang Hao;Chen Gong","doi":"10.1109/JPHOT.2024.3518583","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3518583","url":null,"abstract":"This paper studies the constellation optimization approach for multiple-input multiple-output (MIMO) visible light communication (VLC) systems with signal-dependent noise (SDN). We propose a constellation optimization method aiming at minimizing the system pairwise error probability. In order to obtain the transmitter constellation, we design the demapping rules from the perspective of energy efficiency and illumination uniformity. For the scenario where receiver randomly moves, the constellation lookup table is proposed to transform real-time optimization into table lookup operation, which effectively reduces the real-time computational complexity. Simulation results show that the optimized constellation leads to lower symbol error rate (SER) than the method of maximizing minimum Euclidean distance. In addition, the constellation lookup table operation shows negligible SER performance degradation.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10804068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-16DOI: 10.1109/JPHOT.2024.3518299
Devika Padmakumar Nair;Michaël Ménard
We demonstrate a compact and low-loss 1 × 2 power splitter that efficiently splits and couples light from one strip to two slot waveguides. The splitter is optimized over a broad wavelength span ranging from 1.3 to 1.7 ${mu }$ m through finite difference time domain simulations. The splitter junction footprint is only 2.00 × 1.61 ${mu }$ m. The structure does not require an adiabatic transition region and is compatible with standard commercial silicon photonic fabrication processes. Experimental results show an insertion loss of less than 0.7dB for the TE polarization.
{"title":"A Compact and Broadband Splitter to Interface Between Strip and Slot Waveguides","authors":"Devika Padmakumar Nair;Michaël Ménard","doi":"10.1109/JPHOT.2024.3518299","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3518299","url":null,"abstract":"We demonstrate a compact and low-loss 1 × 2 power splitter that efficiently splits and couples light from one strip to two slot waveguides. The splitter is optimized over a broad wavelength span ranging from 1.3 to 1.7 \u0000<inline-formula><tex-math>${mu }$</tex-math></inline-formula>\u0000m through finite difference time domain simulations. The splitter junction footprint is only 2.00 × 1.61 \u0000<inline-formula><tex-math>${mu }$</tex-math></inline-formula>\u0000m. The structure does not require an adiabatic transition region and is compatible with standard commercial silicon photonic fabrication processes. Experimental results show an insertion loss of less than 0.7dB for the TE polarization.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10803043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quantum Key Distribution (QKD) systems have the potential to provide secure communication by offering unconditionally secure key exchange between distant parties. However, the integration of QKD into existing communication networks presents challenges, particularly when it comes to the deployment of trusted nodes and the establishment of secure connections over metropolitan distances. In this study, we present a novel approach to address these issues by introducing a trusted-node-free design on a metropolitan scale for the seamless integration of a QKD system into the Berlin OpenQKD optical fiber testbed. Our innovative design leverages conventional telecom modulators and a standard Wavelength-Division Multiplexing - Arrayed Waveguide Grating (WDM-AWG), offering a practical solution for flexible multi-partner communication and enabling full connectivity between non-adjacent nodes. In this study, we not only observed relatively low QBER ( $< $ 5.5%) but also a rather stable key rate between nodes in the Qline system over approximately 130 hours ( $approx$ 5.4 days) for a lab-based back-to-back setup. Later on, a more complex experimental scheme is integrated into Berlin OpenQKD optical fiber testbed encompassing multiple C-band frequencies (191.75–195.75 THz) and extending over metropolitan distances (up to 39.8 km), providing a foundation for secure quantum communication networks with enhanced scalability and versatility.
{"title":"Deploying the Qline System for a QKD Metropolitan Network on the Berlin OpenQKD Testbed","authors":"Matheus Sena;Georg Harder;Ronny Döring;Ralf-Peter Braun;Michaela Ritter;Oliver Holschke;Marc Kaplan;Marc Geitz","doi":"10.1109/JPHOT.2024.3516138","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3516138","url":null,"abstract":"Quantum Key Distribution (QKD) systems have the potential to provide secure communication by offering unconditionally secure key exchange between distant parties. However, the integration of QKD into existing communication networks presents challenges, particularly when it comes to the deployment of trusted nodes and the establishment of secure connections over metropolitan distances. In this study, we present a novel approach to address these issues by introducing a trusted-node-free design on a metropolitan scale for the seamless integration of a QKD system into the Berlin OpenQKD optical fiber testbed. Our innovative design leverages conventional telecom modulators and a standard Wavelength-Division Multiplexing - Arrayed Waveguide Grating (WDM-AWG), offering a practical solution for flexible multi-partner communication and enabling full connectivity between non-adjacent nodes. In this study, we not only observed relatively low QBER (\u0000<inline-formula><tex-math>$< $</tex-math></inline-formula>\u0000 5.5%) but also a rather stable key rate between nodes in the Qline system over approximately 130 hours (\u0000<inline-formula><tex-math>$approx$</tex-math></inline-formula>\u0000 5.4 days) for a lab-based back-to-back setup. Later on, a more complex experimental scheme is integrated into Berlin OpenQKD optical fiber testbed encompassing multiple C-band frequencies (191.75–195.75 THz) and extending over metropolitan distances (up to 39.8 km), providing a foundation for secure quantum communication networks with enhanced scalability and versatility.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-11"},"PeriodicalIF":2.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10795138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The optical chaos communication (OCC) can provide physical layer security for high-speed data transmission. In these OCC systems, the time delay signature (TDS) serves as a crucial encryption key. We propose a method based on reservoir computing (RC) network for TDS extraction of OCC systems. The output weight matrix of the RC network provides a numerical representation of nonlinear correlation between a chaotic time series and its time-delayed variants. Then, we can extract TDS by quantifying the features of the weight matrix. The effectiveness is verified by extracting TDS of the two main types of optical time-delay feedback chaos systems. The results demonstrate that, even in cases of strong nonlinearity, noise, and external random disturbance, the TDS can be successfully extracted from time series. Moreover, the required amount of data is significantly reduced in our method.
{"title":"Time Delay Signature Extraction of Optical Time-Delay Chaos Systems From Short and Noisy Time Series","authors":"Shuhui Gong;Jing Zhu;Shiyuan Chen;Jun Wang;Mengfan Cheng;Xiaojing Gao","doi":"10.1109/JPHOT.2024.3516115","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3516115","url":null,"abstract":"The optical chaos communication (OCC) can provide physical layer security for high-speed data transmission. In these OCC systems, the time delay signature (TDS) serves as a crucial encryption key. We propose a method based on reservoir computing (RC) network for TDS extraction of OCC systems. The output weight matrix of the RC network provides a numerical representation of nonlinear correlation between a chaotic time series and its time-delayed variants. Then, we can extract TDS by quantifying the features of the weight matrix. The effectiveness is verified by extracting TDS of the two main types of optical time-delay feedback chaos systems. The results demonstrate that, even in cases of strong nonlinearity, noise, and external random disturbance, the TDS can be successfully extracted from time series. Moreover, the required amount of data is significantly reduced in our method.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10795181","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-11DOI: 10.1109/JPHOT.2024.3515468
Pratyasha Sahani;Yoshiaki Kanamori
A tunable air-gap Fabry–Pérot filter consisting of distributed Bragg reflectors as cavity mirrors was developed to operate in the visible wavelength range. The wavelength tunability of the filter was achieved based on the piezo actuation mechanism. Four in-plane identical piezo actuators were employed to simultaneously achieve both wavelength tunability and cavity air-gap parallelism in the filter. Two pairs of piezo actuators positioned at crossed locations enabled independent control of cavity air-gap dimensions along orthogonal directions in the cavity plane. Optical transmission measurements were performed at different spatial positions on the cavity region to estimate the cavity air-gap dimensions. The initial maximum spectral separation among different spatial positions owing to the initial non-parallelism of the cavity air gap was estimated to be ∼28 nm. After achieving cavity air-gap parallelism via piezo actuation, the final maximum spectral separation was reduced to ∼3 nm. The proposed device configuration significantly improved the cavity air-gap parallelism by minimizing the maximum variation of the cavity air-gap dimension from an initial value of 535 nm to a final value of 18 nm, resulting in an improvement by a factor of ∼30. This device prototype can enable high-resolution and high-throughput spectral transmission with improved spatial uniformity across a large cavity area, showing great promise for advancing hyperspectral imaging systems.
{"title":"Piezo-Actuated Distributed Bragg Reflector–Based Tunable Fabry–Pérot Filter for Visible Light Hyperspectral Imaging","authors":"Pratyasha Sahani;Yoshiaki Kanamori","doi":"10.1109/JPHOT.2024.3515468","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3515468","url":null,"abstract":"A tunable air-gap Fabry–Pérot filter consisting of distributed Bragg reflectors as cavity mirrors was developed to operate in the visible wavelength range. The wavelength tunability of the filter was achieved based on the piezo actuation mechanism. Four in-plane identical piezo actuators were employed to simultaneously achieve both wavelength tunability and cavity air-gap parallelism in the filter. Two pairs of piezo actuators positioned at crossed locations enabled independent control of cavity air-gap dimensions along orthogonal directions in the cavity plane. Optical transmission measurements were performed at different spatial positions on the cavity region to estimate the cavity air-gap dimensions. The initial maximum spectral separation among different spatial positions owing to the initial non-parallelism of the cavity air gap was estimated to be ∼28 nm. After achieving cavity air-gap parallelism via piezo actuation, the final maximum spectral separation was reduced to ∼3 nm. The proposed device configuration significantly improved the cavity air-gap parallelism by minimizing the maximum variation of the cavity air-gap dimension from an initial value of 535 nm to a final value of 18 nm, resulting in an improvement by a factor of ∼30. This device prototype can enable high-resolution and high-throughput spectral transmission with improved spatial uniformity across a large cavity area, showing great promise for advancing hyperspectral imaging systems.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10791869","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The growing Internet traffic urgently needs large-capacity and cost-effective optical transmissions. To maintain system performance under low-cost conditions, the silicon-based integrated coherent transmit and receive optical sub-assembly (IC-TROSA) and the complex-valued convolutional neural network (CVCNN) algorithm provide an effective solution for high-capacity and long-distance WDM optical transmission. The proposed CVCNN can improve the system performance under nonlinear damage conditions, which fully considers the orthogonality of IQ signals in this paper. This algorithm exhibits different equalization performances for 64QAM signals under various encoding schemes considering 20%-overhead, achieving up to 2dB maximum decrease in the required optical signal-to-noise ratio at the optical back-to-back case. Regarding transmission distance, employing CVCNN extends the maximum reach from 3500 km to 3850 km. The paper also demonstrates the application of CVCNN in WDM systems, enhancing system performance across different WDM encoding schemes. Finally, the experiment verified that CVCNN requires fewer computational resources than real-valued convolutional neural networks (RVCNN).
{"title":"Complex-Valued CNN Nonlinear Equalization Enabled 36-Tbit/s (45×800-Gbit/s) WDM Transmission Over 3150 Km Using Silicon-Based IC-TROSA","authors":"Yuhan Gong;Xiaoshuo Jia;Ying Zhu;Kailai Liu;Ming Luo;Jin Tao;Zhixue He;Chao Li;Zichen Liu;Yan Li;Jian Wu;Chao Yang","doi":"10.1109/JPHOT.2024.3510791","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3510791","url":null,"abstract":"The growing Internet traffic urgently needs large-capacity and cost-effective optical transmissions. To maintain system performance under low-cost conditions, the silicon-based integrated coherent transmit and receive optical sub-assembly (IC-TROSA) and the complex-valued convolutional neural network (CVCNN) algorithm provide an effective solution for high-capacity and long-distance WDM optical transmission. The proposed CVCNN can improve the system performance under nonlinear damage conditions, which fully considers the orthogonality of IQ signals in this paper. This algorithm exhibits different equalization performances for 64QAM signals under various encoding schemes considering 20%-overhead, achieving up to 2dB maximum decrease in the required optical signal-to-noise ratio at the optical back-to-back case. Regarding transmission distance, employing CVCNN extends the maximum reach from 3500 km to 3850 km. The paper also demonstrates the application of CVCNN in WDM systems, enhancing system performance across different WDM encoding schemes. Finally, the experiment verified that CVCNN requires fewer computational resources than real-valued convolutional neural networks (RVCNN).","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10777400","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Excellent disturbance rejection ability is essential for a photoelectric tracking system (PTS) based on the Charge-Couple Device (CCD) sensor, which is a premise guarantee for obtaining highly accurate tracking, especially under the condition of moving carriers with intense disturbances. The feedforward control method based on disturbance estimated from the system model output and sensor output is currently a commonly used strategy for disturbance compensation due to its ability to directly counteract the disturbances. This disturbance feedforward compensation method behaves sensitively in case of model mismatch caused by internal disturbances, which may lead to a significant reduction in the disturbance compensation effect or even cause system instability. In this paper, unlike disturbance feedforward compensation, a pure disturbance sliding-mode feedback control (DSMFBC) based on disturbance observation without additional sensors is proposed, ensuring faster and precise compensation for disturbance. In case of model mismatch, the observed disturbance is used to build the disturbance feedback control to maintain a more efficient disturbance compensation through the robustness that feedback naturally possesses. To achieve a stronger anti-disturbance capability, a sliding-mode nonlinear control method is used to design the control law. The experimental setup of PTS based on the fast-steering mirror (FSM) demonstrates that the method has better dynamic performance and disturbance rejection ratio.
{"title":"Pure Disturbance Sliding-Mode Feedback Control Based on Disturbance Observation for CCD-Assisted Line-of-Sight Stabilization","authors":"Yong Luo;Yi Cheng;Yongmei Huang;Qiongyan Wu;Dong He;Ge Ren;Guan Wang;Shi Zheng","doi":"10.1109/JPHOT.2024.3511573","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3511573","url":null,"abstract":"Excellent disturbance rejection ability is essential for a photoelectric tracking system (PTS) based on the Charge-Couple Device (CCD) sensor, which is a premise guarantee for obtaining highly accurate tracking, especially under the condition of moving carriers with intense disturbances. The feedforward control method based on disturbance estimated from the system model output and sensor output is currently a commonly used strategy for disturbance compensation due to its ability to directly counteract the disturbances. This disturbance feedforward compensation method behaves sensitively in case of model mismatch caused by internal disturbances, which may lead to a significant reduction in the disturbance compensation effect or even cause system instability. In this paper, unlike disturbance feedforward compensation, a pure disturbance sliding-mode feedback control (DSMFBC) based on disturbance observation without additional sensors is proposed, ensuring faster and precise compensation for disturbance. In case of model mismatch, the observed disturbance is used to build the disturbance feedback control to maintain a more efficient disturbance compensation through the robustness that feedback naturally possesses. To achieve a stronger anti-disturbance capability, a sliding-mode nonlinear control method is used to design the control law. The experimental setup of PTS based on the fast-steering mirror (FSM) demonstrates that the method has better dynamic performance and disturbance rejection ratio.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10778198","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-04DOI: 10.1109/JPHOT.2024.3511344
Yakshita Malhotra;Xianhe Liu;Zetian Mi
While micro-LEDs are crucial for ultrahigh resolution micro-displays, the efficiency of currently reported micro-LEDs degrades dramatically with decreasing size. Recently, the bottom-up nanowire approach has shown promise to break the efficiency bottleneck of this size effect. In this article, we investigated the design of nanowire photonic crystal structure for micro-LED applications and revealed its correlation with the Purcell effect. Key performance characteristics including efficiency, emission directionality, and spectral linewidth are thoroughly studied. For an LED structure with low internal quantum efficiency (IQE) of 10% due to high non-radiative recombination, an enhancement of ∼30% is found viable by using a properly designed photonic crystal. High emission directionality and a narrow spectral linewidth (∼ 5 nm) can be obtained with 60% of the light being emitted within a 20° acceptance angle.
虽然微型发光二极管对于超高分辨率微型显示器至关重要，但目前报道的微型发光二极管的效率会随着尺寸的减小而急剧下降。最近，自下而上的纳米线方法有望打破这种尺寸效应的效率瓶颈。本文研究了用于微型 LED 应用的纳米线光子晶体结构设计，并揭示了其与 Purcell 效应的相关性。我们对包括效率、发射方向性和光谱线宽在内的关键性能特征进行了深入研究。对于由于高度非辐射性重组而导致内部量子效率（IQE）低至 10%的 LED 结构，通过使用设计适当的光子晶体，可以将其效率提高 ∼ 30%。60% 的光可在 20° 接受角内发射，从而获得高发射方向性和窄光谱线宽（∼ 5 nm）。
{"title":"Design Principles and Performance Limitation of InGaN Nanowire Photonic Crystal Micro-LEDs","authors":"Yakshita Malhotra;Xianhe Liu;Zetian Mi","doi":"10.1109/JPHOT.2024.3511344","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3511344","url":null,"abstract":"While micro-LEDs are crucial for ultrahigh resolution micro-displays, the efficiency of currently reported micro-LEDs degrades dramatically with decreasing size. Recently, the bottom-up nanowire approach has shown promise to break the efficiency bottleneck of this size effect. In this article, we investigated the design of nanowire photonic crystal structure for micro-LED applications and revealed its correlation with the Purcell effect. Key performance characteristics including efficiency, emission directionality, and spectral linewidth are thoroughly studied. For an LED structure with low internal quantum efficiency (IQE) of 10% due to high non-radiative recombination, an enhancement of ∼30% is found viable by using a properly designed photonic crystal. High emission directionality and a narrow spectral linewidth (∼ 5 nm) can be obtained with 60% of the light being emitted within a 20° acceptance angle.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"17 1","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10777399","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present the design and experimental evaluation of low-loss advanced bends in silicon nitride (SiN) waveguides for the C-band. The advanced bends, with a radius of 25 μm, exhibit a bending loss of approximately 0.025 dB per 90°, comparable to the loss of a circular bend with a radius of 50 μm. Consequently, the 25 μm radius advanced bend is proposed for routing in SiN photonic integrated circuits to reduce the overall footprint. Furthermore, the use of these advanced bends in micro ring resonators results in quality factors of 5.8 × 10 3 and 5.5 × 10 4 , with relatively large free spectral ranges and extinction ratios for radii of 15 μm and 25 μm, respectively.
{"title":"Advanced Bends and Micro Ring Resonators in Silicon Nitride Photonic Waveguides for C-Band","authors":"Jeong Hwan Song;Tangla D. Kongnyuy;Mathias Prost;Aritrio Bandyopadhyay;Sarvagya Dwivedi;Diego Carbajal Altamirano;Cian Cummins;Sandeep Seema Saseendran;Philippe Helin;Joost Brouckaert;Marcus Dahlem","doi":"10.1109/JPHOT.2024.3509312","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3509312","url":null,"abstract":"We present the design and experimental evaluation of low-loss advanced bends in silicon nitride (SiN) waveguides for the C-band. The advanced bends, with a radius of 25 μm, exhibit a bending loss of approximately 0.025 dB per 90°, comparable to the loss of a circular bend with a radius of 50 μm. Consequently, the 25 μm radius advanced bend is proposed for routing in SiN photonic integrated circuits to reduce the overall footprint. Furthermore, the use of these advanced bends in micro ring resonators results in quality factors of 5.8 × 10\u0000<sup>3</sup>\u0000 and 5.5 × 10\u0000<sup>4</sup>\u0000, with relatively large free spectral ranges and extinction ratios for radii of 15 μm and 25 μm, respectively.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 6","pages":"1-5"},"PeriodicalIF":2.1,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10771684","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optical diffractive neural networks have sparked extensive research due to their low power consumption and high-speed capabilities in image processing. Here we propose and design a reconfigurable all-optical diffractive neural network structure with digital non-volatile optical neurons. The optical neurons are built with Sb 2 Se 3 phase-change material and can switch between crystalline and amorphous states with no constant energy supply. Using three reconfigurable non-volatile digital diffractive layers and 10 photodetectors connected to a reconfigurable resistor network, our model achieves an accuracy of 94.46% in the handwritten digit recognition task. Moreover, the fabrication and assembly robustness of the proposed optical diffractive neural network is verified through full-vector diffractive simulation. Thanks to its reconfigurability and low energy supply, the digital optical diffractive neural network holds great potential to facilitate a programmable and low-power-consumption photonic processor for optical-artificial-intelligence.
{"title":"Non-Volatile Reconfigurable Optical Digital Diffractive Neural Network Based on Phase Change Material","authors":"Qiaomu Hu;Jingyu Zhao;Chu Wu;Rui Zeng;Xiaobing Zhou;Shuang Zheng;Minming Zhang","doi":"10.1109/JPHOT.2024.3508052","DOIUrl":"https://doi.org/10.1109/JPHOT.2024.3508052","url":null,"abstract":"Optical diffractive neural networks have sparked extensive research due to their low power consumption and high-speed capabilities in image processing. Here we propose and design a reconfigurable all-optical diffractive neural network structure with digital non-volatile optical neurons. The optical neurons are built with Sb\u0000<sub>2</sub>\u0000Se\u0000<sub>3</sub>\u0000 phase-change material and can switch between crystalline and amorphous states with no constant energy supply. Using three reconfigurable non-volatile digital diffractive layers and 10 photodetectors connected to a reconfigurable resistor network, our model achieves an accuracy of 94.46% in the handwritten digit recognition task. Moreover, the fabrication and assembly robustness of the proposed optical diffractive neural network is verified through full-vector diffractive simulation. Thanks to its reconfigurability and low energy supply, the digital optical diffractive neural network holds great potential to facilitate a programmable and low-power-consumption photonic processor for optical-artificial-intelligence.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"16 6","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10770557","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142777729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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