Pub Date : 2026-01-22DOI: 10.1109/JPHOT.2026.3656488
Ziming Liu;Lilong Zhao;Xiang Yao;Yaya Mao;Xiumin Song;Tingting Sun
This paper proposes a security-enhanced NOMA scheme based on dynamically concealed key-accompanying transmission. To improve security, in this paper, the 3D-LHemon model is utilized to encrypt the bit stream, symbols and subcarriers of high-power quadrature phase shift keying (QPSK) signals. The key is placed in a low-power binary phase shift keying (BPSK) signal, which is transmitted in parallel and superimposed with the high-power QPSK signal. Meanwhile, the phase points of the constellation diagram of the low-power signal are subjected to chaotic perturbation through Sinusoidal mapping. At the receiver, successive interference cancellation (SIC) decodes the high-power and low-power signals sequentially. Experimental results demonstrate the transmission of a 56 Gb/s orthogonal frequency division multiplexing (OFDM) signal over a 2-km 7-core optical fiber. Furthermore, the proposed scheme achieves an expansive key space of up to 10^87, effectively ensuring robust physical layer security. In contrast to existing chaos-based physical layer encryption for Non-Orthogonal Multiple Access (NOMA), this method applies chaotic encryption to high-power and low-power signals independently. This dual-layer approach significantly enhances system security without increasing computational overhead. Consequently, this scheme is capable of supporting a larger user base and holds promising potential for application in future optical networks.
{"title":"A Security-Enhanced NOMA Scheme Based on Dynamically Concealed Key- Accompanying Transmission","authors":"Ziming Liu;Lilong Zhao;Xiang Yao;Yaya Mao;Xiumin Song;Tingting Sun","doi":"10.1109/JPHOT.2026.3656488","DOIUrl":"https://doi.org/10.1109/JPHOT.2026.3656488","url":null,"abstract":"This paper proposes a security-enhanced NOMA scheme based on dynamically concealed key-accompanying transmission. To improve security, in this paper, the 3D-LHemon model is utilized to encrypt the bit stream, symbols and subcarriers of high-power quadrature phase shift keying (QPSK) signals. The key is placed in a low-power binary phase shift keying (BPSK) signal, which is transmitted in parallel and superimposed with the high-power QPSK signal. Meanwhile, the phase points of the constellation diagram of the low-power signal are subjected to chaotic perturbation through Sinusoidal mapping. At the receiver, successive interference cancellation (SIC) decodes the high-power and low-power signals sequentially. Experimental results demonstrate the transmission of a 56 Gb/s orthogonal frequency division multiplexing (OFDM) signal over a 2-km 7-core optical fiber. Furthermore, the proposed scheme achieves an expansive key space of up to 10^87, effectively ensuring robust physical layer security. In contrast to existing chaos-based physical layer encryption for Non-Orthogonal Multiple Access (NOMA), this method applies chaotic encryption to high-power and low-power signals independently. This dual-layer approach significantly enhances system security without increasing computational overhead. Consequently, this scheme is capable of supporting a larger user base and holds promising potential for application in future optical networks.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 2","pages":"1-7"},"PeriodicalIF":2.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11361037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102962","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 : 2026-01-21DOI: 10.1109/JPHOT.2026.3656585
Xiaoxiao Wei;Jintao Chen;Miao Fan;Hao Zhang;Yunfeng Nie
Autofocus (AF) technology plays a critical role in applications such as microscopic measurement, 3D visual scanning, and semiconductor defect inspection. Conventional photoelectric sensor-based AF systems in microscopy face challenges in simultaneously achieving high precision and a large operational range, primarily due to distortions introduced by objective lenses. To address this limitation, this paper presents a conjugate line-laser-based autofocus method. The proposed approach employs a semicircular light-blocking diaphragm to generate a line-semi-ellipse laser spot on the sample surface. Combined with a laser spot image feature extraction algorithm and mathematical modeling, the system achieves an autofocus range of 500 μm with a positioning accuracy within ±1/5 of the depth of field (DOF) when using a 20× objective lens. The developed AF system offers a simple, robust, and efficient solution for high-speed, high-precision microscopic autofocusing, enabling extended range without compromising accuracy.
{"title":"Design and Experimental Validation of a Line-Laser Autofocusing System With Extended Working Range","authors":"Xiaoxiao Wei;Jintao Chen;Miao Fan;Hao Zhang;Yunfeng Nie","doi":"10.1109/JPHOT.2026.3656585","DOIUrl":"https://doi.org/10.1109/JPHOT.2026.3656585","url":null,"abstract":"Autofocus (AF) technology plays a critical role in applications such as microscopic measurement, 3D visual scanning, and semiconductor defect inspection. Conventional photoelectric sensor-based AF systems in microscopy face challenges in simultaneously achieving high precision and a large operational range, primarily due to distortions introduced by objective lenses. To address this limitation, this paper presents a conjugate line-laser-based autofocus method. The proposed approach employs a semicircular light-blocking diaphragm to generate a line-semi-ellipse laser spot on the sample surface. Combined with a laser spot image feature extraction algorithm and mathematical modeling, the system achieves an autofocus range of 500 μm with a positioning accuracy within ±1/5 of the depth of field (DOF) when using a 20× objective lens. The developed AF system offers a simple, robust, and efficient solution for high-speed, high-precision microscopic autofocusing, enabling extended range without compromising accuracy.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 2","pages":"1-9"},"PeriodicalIF":2.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11359988","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102976","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 : 2026-01-13DOI: 10.1109/JPHOT.2026.3653792
Tonglu Xing;Hua Tao;Cheng Liu;Jianqiang Zhu
Conjugate image is an inherent problem of coherent diffraction imaging (CDI) and direct analysis and research on them have long been incomplete. By writing diffraction intensities into linear equation set, it was demonstrated that the fundamental mathematical reason for the generation of conjugate image lies on the real-value coefficients of these linear equations, and then the conjugate image could be eliminated by adopting optical alignments that can lead to complex–value coefficients. While theoretical analysis was proposed its feasibility was verified both numerically and experimentally. The study provides new insights into the physical mechanism of CDI and new strategies to improve the image quality of other phase retrieval techniques.
{"title":"Study on the Generation and Elimination of Conjugate Image in Coherent Different Imaging","authors":"Tonglu Xing;Hua Tao;Cheng Liu;Jianqiang Zhu","doi":"10.1109/JPHOT.2026.3653792","DOIUrl":"https://doi.org/10.1109/JPHOT.2026.3653792","url":null,"abstract":"Conjugate image is an inherent problem of coherent diffraction imaging (CDI) and direct analysis and research on them have long been incomplete. By writing diffraction intensities into linear equation set, it was demonstrated that the fundamental mathematical reason for the generation of conjugate image lies on the real-value coefficients of these linear equations, and then the conjugate image could be eliminated by adopting optical alignments that can lead to complex–value coefficients. While theoretical analysis was proposed its feasibility was verified both numerically and experimentally. The study provides new insights into the physical mechanism of CDI and new strategies to improve the image quality of other phase retrieval techniques.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 2","pages":"1-8"},"PeriodicalIF":2.4,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11348091","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146102951","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 : 2026-01-12DOI: 10.1109/JPHOT.2026.3651843
Dongqin Guo;Gang Xin;Qi Wu;Jian Zhang
To improve the security performance of Visible Light Communications (VLC) systems, this paper explores a novel secure scheme that incorporates reconfigurable intelligent surfaces (RIS) and jamming technologies. Specifically, the system includes a transmitter, a legitimate user who can control the jamming, and an eavesdropper. In addition, a mirror array-based RIS (mRIS) is arranged on the wall of the room. Adjusting the configuration of the mRIS units enables the reshaping of the channel environment, thereby improving the system’s secrecy rate. Then, a secrecy rate maximization problem is formulated. To address the proposed optimization problem, a genetic algorithm-based (GA)-based optimization algorithm is put forward. Simulation results demonstrate that the proposed VLC security system, combined with the optimization algorithm, can effectively enhance the system’s security performance.
{"title":"RIS-Aided Physical Layer Security for Visible Light Communication Systems","authors":"Dongqin Guo;Gang Xin;Qi Wu;Jian Zhang","doi":"10.1109/JPHOT.2026.3651843","DOIUrl":"https://doi.org/10.1109/JPHOT.2026.3651843","url":null,"abstract":"To improve the security performance of Visible Light Communications (VLC) systems, this paper explores a novel secure scheme that incorporates reconfigurable intelligent surfaces (RIS) and jamming technologies. Specifically, the system includes a transmitter, a legitimate user who can control the jamming, and an eavesdropper. In addition, a mirror array-based RIS (mRIS) is arranged on the wall of the room. Adjusting the configuration of the mRIS units enables the reshaping of the channel environment, thereby improving the system’s secrecy rate. Then, a secrecy rate maximization problem is formulated. To address the proposed optimization problem, a genetic algorithm-based (GA)-based optimization algorithm is put forward. Simulation results demonstrate that the proposed VLC security system, combined with the optimization algorithm, can effectively enhance the system’s security performance.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 1","pages":"1-6"},"PeriodicalIF":2.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11340672","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982184","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 : 2026-01-12DOI: 10.1109/JPHOT.2026.3652318
Ryotaro Harada;Akihiro Maruta;Ken Mishina
Multilevel modulation schemes based on the inverse scattering transform (IST) are some of the promising technologies for achieving a significant advancement in transmission capacity within optical fiber communication systems overcoming the nonlinear Shannon limit. Despite the recognized potential of multilevel modulation using the scattering coefficient $b$ to enhance the transmission capacity, previous studies assumed that the distributions of eigenvalues and $b$ follow a Gaussian distribution for the signal point assignment. Because the distributions of eigenvalues and $b$ do not exactly follow a Gaussian distribution, signal design considering these distributions is to be studied. In this paper, we propose a novel signal point arrangement method for the $b$-modulation considering the distribution to maximize transmission capacity. The amplitude and argument of $b$ correspond to the temporal center position $T_{c}$ and phase $theta$ of the soliton component, respectively. Therefore, we arrange the signal points of the $b$-modulation after converting the coefficient $b$ from the $b$-plane to the $T_{c}$-$theta$ -plane in this paper. Through numerical simulations in the back-to-back configuration, we demonstrate that the proposed method improves the bit error rate (BER) performance by approximately 10–12dB compared with a conventional signal point assignment method such as QAM. Moreover, the result of the transmission simulation demonstrates that the proposed method can extend the achievable transmission distance by 1000–3000 km. Furthermore, by performing the analysis of the noise characteristics of $b$ on the $T_{c}$-$theta$-plane, the estimation accuracy of the generalized mutual information can be improved in the $b$ modulation scheme.
{"title":"Design and Analysis for Multilevel-Modulated Signal Using the Scattering Coefficient $b$ in Inverse Scattering Transform","authors":"Ryotaro Harada;Akihiro Maruta;Ken Mishina","doi":"10.1109/JPHOT.2026.3652318","DOIUrl":"https://doi.org/10.1109/JPHOT.2026.3652318","url":null,"abstract":"Multilevel modulation schemes based on the inverse scattering transform (IST) are some of the promising technologies for achieving a significant advancement in transmission capacity within optical fiber communication systems overcoming the nonlinear Shannon limit. Despite the recognized potential of multilevel modulation using the scattering coefficient <inline-formula><tex-math>$b$</tex-math></inline-formula> to enhance the transmission capacity, previous studies assumed that the distributions of eigenvalues and <inline-formula><tex-math>$b$</tex-math></inline-formula> follow a Gaussian distribution for the signal point assignment. Because the distributions of eigenvalues and <inline-formula><tex-math>$b$</tex-math></inline-formula> do not exactly follow a Gaussian distribution, signal design considering these distributions is to be studied. In this paper, we propose a novel signal point arrangement method for the <inline-formula><tex-math>$b$</tex-math></inline-formula>-modulation considering the distribution to maximize transmission capacity. The amplitude and argument of <inline-formula><tex-math>$b$</tex-math></inline-formula> correspond to the temporal center position <inline-formula><tex-math>$T_{c}$</tex-math></inline-formula> and phase <inline-formula><tex-math>$theta$</tex-math></inline-formula> of the soliton component, respectively. Therefore, we arrange the signal points of the <inline-formula><tex-math>$b$</tex-math></inline-formula>-modulation after converting the coefficient <inline-formula><tex-math>$b$</tex-math></inline-formula> from the <inline-formula><tex-math>$b$</tex-math></inline-formula>-plane to the <inline-formula><tex-math>$T_{c}$</tex-math></inline-formula>-<inline-formula><tex-math>$theta$</tex-math></inline-formula> -plane in this paper. Through numerical simulations in the back-to-back configuration, we demonstrate that the proposed method improves the bit error rate (BER) performance by approximately 10–12dB compared with a conventional signal point assignment method such as QAM. Moreover, the result of the transmission simulation demonstrates that the proposed method can extend the achievable transmission distance by 1000–3000 km. Furthermore, by performing the analysis of the noise characteristics of <inline-formula><tex-math>$b$</tex-math></inline-formula> on the <inline-formula><tex-math>$T_{c}$</tex-math></inline-formula>-<inline-formula><tex-math>$theta$</tex-math></inline-formula>-plane, the estimation accuracy of the generalized mutual information can be improved in the <inline-formula><tex-math>$b$</tex-math></inline-formula> modulation scheme.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 1","pages":"1-13"},"PeriodicalIF":2.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11339870","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145982190","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 : 2025-12-31DOI: 10.1109/JPHOT.2025.3649903
Xiangxin Shao;Shijie Wu;Yuanting Yang;Ming Liu;Minglai Han;Qi Zhang;Hanbing Wang
This paper reports a photonic approach to generate triangular, square, and sawtooth waveforms based on optoelectronic modulation structures integrated with Particle Swarm Optimization-Convolutional Neural Network (PSO-CNN) algorithm. Distinct from the traditional algebraic method relies on solving the mathematical equations, this approach can solve the best parameters of the analytical equations. The integration of PSO enhances the performance of CNN by automatic hyperparameter tuning. The performances of PSO-CNN to predict parameters of triangular, square, and sawtooth waveforms are evaluated against CNN based on four metrics of root means square error (RMSE), coefficient of determination (R2), percent bias (PBias), and Nash-Sutcliffe efficiency (NSE), that (RMSE = 0.0321, R2 = 0.961, PBias = −0.52%, NSE = 0.959) performs best. Based on the predictions, a proof-of-concept experiment is conducted to generate high fidelity waveforms with repetition rates of 1 GHz, 2 GHz, and 3 GHz.
{"title":"Photonic Generation of Microwave Waveforms Based on Cascaded Modulator Using PSO-CNN Algorithm","authors":"Xiangxin Shao;Shijie Wu;Yuanting Yang;Ming Liu;Minglai Han;Qi Zhang;Hanbing Wang","doi":"10.1109/JPHOT.2025.3649903","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3649903","url":null,"abstract":"This paper reports a photonic approach to generate triangular, square, and sawtooth waveforms based on optoelectronic modulation structures integrated with Particle Swarm Optimization-Convolutional Neural Network (PSO-CNN) algorithm. Distinct from the traditional algebraic method relies on solving the mathematical equations, this approach can solve the best parameters of the analytical equations. The integration of PSO enhances the performance of CNN by automatic hyperparameter tuning. The performances of PSO-CNN to predict parameters of triangular, square, and sawtooth waveforms are evaluated against CNN based on four metrics of root means square error (RMSE), coefficient of determination (R<sup>2</sup>), percent bias (PBias), and Nash-Sutcliffe efficiency (NSE), that (RMSE = 0.0321, R<sup>2</sup> = 0.961, PBias = −0.52%, NSE = 0.959) performs best. Based on the predictions, a proof-of-concept experiment is conducted to generate high fidelity waveforms with repetition rates of 1 GHz, 2 GHz, and 3 GHz.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 1","pages":"1-9"},"PeriodicalIF":2.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11320309","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929363","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 : 2025-12-26DOI: 10.1109/JPHOT.2025.3648206
Mengmeng Wang;Haoting Liu;Shaohua Yang;Gang Li;Lu Liu;Qing Li
The Intensified Complementary Metal Oxide Semiconductor (ICMOS) camera has important applications in the field of nuclear radiation source detection. The study of the optical performance of Fiber Optic Taper (FOT), as a core component of the ICMOS camera, holds significant importance role in the optical path design of ICMOS. First, a three-dimensional physical model is constructed based on the manufacturing parameters of FOT. The photon transmission model is used to simulate the propagation behavior of rays in the optical system. Second, the collimated and diffuse light sources are both considered to obtain transmittance data of FOT models with different physical parameters and the models are also built to analyze the effects of taper ratio, length, and refractive index difference on transmittance. Finally, the relationship between the waist curve and distribution of photon loss is constructed. The simulation results indicate that the photon loss during internal transmission of FOT with a linear waist is 69.49% greater than that with a curved waist. The photon loss distribution is related to the slope of waist tangent, and the sudden change in tangent slope at boundary of base and taper regions can lead to an increase in photon loss.
{"title":"Optical Path Simulation of Fiber Optic Taper and Modeling of Its Transmittance Mechanism","authors":"Mengmeng Wang;Haoting Liu;Shaohua Yang;Gang Li;Lu Liu;Qing Li","doi":"10.1109/JPHOT.2025.3648206","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3648206","url":null,"abstract":"The Intensified Complementary Metal Oxide Semiconductor (ICMOS) camera has important applications in the field of nuclear radiation source detection. The study of the optical performance of Fiber Optic Taper (FOT), as a core component of the ICMOS camera, holds significant importance role in the optical path design of ICMOS. First, a three-dimensional physical model is constructed based on the manufacturing parameters of FOT. The photon transmission model is used to simulate the propagation behavior of rays in the optical system. Second, the collimated and diffuse light sources are both considered to obtain transmittance data of FOT models with different physical parameters and the models are also built to analyze the effects of taper ratio, length, and refractive index difference on transmittance. Finally, the relationship between the waist curve and distribution of photon loss is constructed. The simulation results indicate that the photon loss during internal transmission of FOT with a linear waist is 69.49% greater than that with a curved waist. The photon loss distribution is related to the slope of waist tangent, and the sudden change in tangent slope at boundary of base and taper regions can lead to an increase in photon loss.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 1","pages":"1-9"},"PeriodicalIF":2.4,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11315861","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886704","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}
Commercial light-emitting diodes (LEDs) offer fixed lighting patterns with limited canopy coverage, creating a mismatch with dragon fruit’s dynamic photosynthetic and phenological needs. To mitigate the inherent limitations of conventional unidirectional irradiance distributions, a bi-directional emission LED system incorporating adjustable focusing mechanisms is engineered. Monte Carlo ray-tracing and numerical integration are employed to quantitatively analyze the influence of plant architectural complexity, LED positioning strategies, and angular emission profiles on canopy light distribution. Concurrently, three optimization algorithms—Simulated Annealing (SA), Genetic Algorithm (GA), and Ant Colony Optimization (ACO)—are comparatively evaluated for their efficacy in maximizing radiation efficiency (RE) and utilization efficiency (UE). The proposed method (1) achieves targeted photon delivery while minimizing light spillage between canopies, resulting in 39.39% and 206.67% higher UE compared with the other two schemes under the same static fixture at a height of 1.7 m and an emission angle of 50°, and (2) achieves high prediction accuracy, with RE and UE determination coefficients (R2) of 96% and 97%, respectively.
{"title":"Enhancing Light Utilization Efficiency of Dragon Fruit Canopies Using Bi-Directional Adjustable-Focusing LED Lighting System","authors":"Qiannan Jiang;Qiaoyang Zhang;Haiyun Chen;Jiacheng Ruan;Wensong Wang;Tama Fouzder;Ji Wang;Hua Xiao","doi":"10.1109/JPHOT.2025.3647536","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3647536","url":null,"abstract":"Commercial light-emitting diodes (LEDs) offer fixed lighting patterns with limited canopy coverage, creating a mismatch with dragon fruit’s dynamic photosynthetic and phenological needs. To mitigate the inherent limitations of conventional unidirectional irradiance distributions, a bi-directional emission LED system incorporating adjustable focusing mechanisms is engineered. Monte Carlo ray-tracing and numerical integration are employed to quantitatively analyze the influence of plant architectural complexity, LED positioning strategies, and angular emission profiles on canopy light distribution. Concurrently, three optimization algorithms—Simulated Annealing (SA), Genetic Algorithm (GA), and Ant Colony Optimization (ACO)—are comparatively evaluated for their efficacy in maximizing radiation efficiency (RE) and utilization efficiency (UE). The proposed method (1) achieves targeted photon delivery while minimizing light spillage between canopies, resulting in 39.39% and 206.67% higher UE compared with the other two schemes under the same static fixture at a height of 1.7 m and an emission angle of 50°, and (2) achieves high prediction accuracy, with RE and UE determination coefficients (R<sup>2</sup>) of 96% and 97%, respectively.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 1","pages":"1-9"},"PeriodicalIF":2.4,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11314704","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082213","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}
A photonics-assisted approach to multi-band dual linear frequency modulated (LFM) waveform generation with center frequency tunability and reconfigurable bandwidth is proposed and demonstrated using an on-chip silicon-based dual-drive Mach-Zehnder modulator (DD-MZM). In this scheme, an intermediate-frequency (IF) LFM signal drives the upper arm of the DD-MZM while the lower arm is driven by a radio-frequency (RF) carrier signal to obtain a modulated optical signal. The beating of the LFM sideband with the higher-order sidebands of the RF carrier at the photodetector results in broadband dual-LFM waveform generation in multiple frequency bands. The center frequency and bandwidth can be flexibly adjusted by precise control of the RF carrier and baseband LFM signal. Dual-LFM waveforms are generated over a pulse duration of 2 $mu$s with center frequency tunability up to 12 GHz and a maximum spectral bandwidth of 8 GHz, which corresponds to a time-bandwidth product (TBWP) of $bm {1.6 times 10^{4}}$. The multi-format waveform generation ability of this scheme is also explored by realizing a cross-type LFM waveform. Furthermore, the pulse compression capability of the system is investigated to qualify the performance for target detection. The proposed scheme generates dual- and cross-LFM signals with tunable center frequency and bandwidth reconfigurability in C- and X-bands, and emerges as a potential solution in realizing on-chip multi-function radars.
{"title":"Silicon Photonics Enabled Tunable Multi-Format Multi-Band Linear Frequency Modulated Waveform Generation","authors":"Viresh Bhan;Vadivukkarasi Jeyaselvan;Shankar Kumar Selvaraja","doi":"10.1109/JPHOT.2025.3647136","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3647136","url":null,"abstract":"A photonics-assisted approach to multi-band dual linear frequency modulated (LFM) waveform generation with center frequency tunability and reconfigurable bandwidth is proposed and demonstrated using an on-chip silicon-based dual-drive Mach-Zehnder modulator (DD-MZM). In this scheme, an intermediate-frequency (IF) LFM signal drives the upper arm of the DD-MZM while the lower arm is driven by a radio-frequency (RF) carrier signal to obtain a modulated optical signal. The beating of the LFM sideband with the higher-order sidebands of the RF carrier at the photodetector results in broadband dual-LFM waveform generation in multiple frequency bands. The center frequency and bandwidth can be flexibly adjusted by precise control of the RF carrier and baseband LFM signal. Dual-LFM waveforms are generated over a pulse duration of 2 <italic><inline-formula><tex-math>$mu$</tex-math></inline-formula></i>s with center frequency tunability up to 12 GHz and a maximum spectral bandwidth of 8 GHz, which corresponds to a time-bandwidth product (TBWP) of <inline-formula><tex-math>$bm {1.6 times 10^{4}}$</tex-math></inline-formula>. The multi-format waveform generation ability of this scheme is also explored by realizing a cross-type LFM waveform. Furthermore, the pulse compression capability of the system is investigated to qualify the performance for target detection. The proposed scheme generates dual- and cross-LFM signals with tunable center frequency and bandwidth reconfigurability in C- and X-bands, and emerges as a potential solution in realizing on-chip multi-function radars.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 1","pages":"1-7"},"PeriodicalIF":2.4,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11313076","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145886688","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 : 2025-12-23DOI: 10.1109/JPHOT.2025.3647059
Qi Zhang;Dian-Wu Yue;Si-Nian Jin;Xian-Ying Xu;Meng Wang
Ocean exploration is leading to growing attention on the Internet of Underwater Things (IoUT). Underwater wireless optical communication (UWOC) is a promising technology for massive data transmission of IoUT due to its high speed, low delay, and wide applications. However, the underwater optical link can be interrupted by the obstacles of marine life, seamounts, and some underwater equipment. Reconfigurable intelligent surface (RIS) technology is an effective method to improve the reliability of UWOC. In fact, a single RIS has limited service coverage and performance enhancement to the UWOC system. Therefore, in this paper, we present the multi-RIS-assisted UWOC system and provide two schemes, i.e., the full receiving scheme and the selective receiving scheme. In addition, the cascaded turbulence channels from source to destination through RIS and the pointing errors caused by beam jitter and RIS jitter are considered. The probability density function (PDF) and the cumulative distribution function (CDF) of the end-to-end instantaneous signal-to-noise ratio (SNR) are derived in terms of multivariate Fox-H function with the moment-generating function (MGF) method and the inverse Laplace transform. Based on these SNR statistical analyses, we give the closed-form expressions of the outage probability and the average bit error rate (BER). Furthermore, we provide asymptotic analyses of the outage probability and the average BER to obtain more insights into the coding gain and the diversity order. Finally, Monte-Carlo simulation results are used to verify our derived results. The results show that the performance of the proposed multi-RIS-assisted UWOC systems is significantly better than that of the existing single-RIS-assisted UWOC system, and the selective receiving scheme performs better than the full receiving scheme.
{"title":"Performance Analysis of Multi-RIS-Assisted UWOC Systems: Full Receiving Scheme and Selective Receiving Scheme","authors":"Qi Zhang;Dian-Wu Yue;Si-Nian Jin;Xian-Ying Xu;Meng Wang","doi":"10.1109/JPHOT.2025.3647059","DOIUrl":"https://doi.org/10.1109/JPHOT.2025.3647059","url":null,"abstract":"Ocean exploration is leading to growing attention on the Internet of Underwater Things (IoUT). Underwater wireless optical communication (UWOC) is a promising technology for massive data transmission of IoUT due to its high speed, low delay, and wide applications. However, the underwater optical link can be interrupted by the obstacles of marine life, seamounts, and some underwater equipment. Reconfigurable intelligent surface (RIS) technology is an effective method to improve the reliability of UWOC. In fact, a single RIS has limited service coverage and performance enhancement to the UWOC system. Therefore, in this paper, we present the multi-RIS-assisted UWOC system and provide two schemes, i.e., the full receiving scheme and the selective receiving scheme. In addition, the cascaded turbulence channels from source to destination through RIS and the pointing errors caused by beam jitter and RIS jitter are considered. The probability density function (PDF) and the cumulative distribution function (CDF) of the end-to-end instantaneous signal-to-noise ratio (SNR) are derived in terms of multivariate Fox-H function with the moment-generating function (MGF) method and the inverse Laplace transform. Based on these SNR statistical analyses, we give the closed-form expressions of the outage probability and the average bit error rate (BER). Furthermore, we provide asymptotic analyses of the outage probability and the average BER to obtain more insights into the coding gain and the diversity order. Finally, Monte-Carlo simulation results are used to verify our derived results. The results show that the performance of the proposed multi-RIS-assisted UWOC systems is significantly better than that of the existing single-RIS-assisted UWOC system, and the selective receiving scheme performs better than the full receiving scheme.","PeriodicalId":13204,"journal":{"name":"IEEE Photonics Journal","volume":"18 1","pages":"1-19"},"PeriodicalIF":2.4,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11313086","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082176","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：