2024

• Record 493 of
  
  Title:Output Facet Temperature of High-Power Semiconductor Lasers Using Optical-Thermal Reflection Method
  
  Author Full Names:Xu, Zibang(1,2,3); Miao, Xinlian(1,2,3); Liu, Yuxian(4); Lan, Yu(4); Zhao, Yuliang(4); Zhang, Xiang(1,2,3); Yang, Guowen(5); Yuan, Xiao(1,2,3)

  Source Title:Zhongguo Jiguang/Chinese Journal of Lasers

  Language:Chinese

  Document Type:Journal article (JA)

  Abstract:Objective Semiconductor lasers have been widely used in industrial, medical, and other fields owing to their high electro-optical conversion efficiency, wide spectrum, and high power-to-volume ratio characteristics. However, as the application field expanded, higher power and reliability requirements have been stated. When manufacturing a high-power semiconductor laser, catastrophic optical mirror damage (COMD) is a key factor limiting the output power and reliability characteristics. COMD occurs due to a local temperature rise at the facet, which exceeds the material damage threshold, and it denotes the irreversible physical damage inflicted on the facet. Note that the occurrence of COMD is closely related to the output facet temperature; thus, accurately measuring the temperature and plotting its distribution are crucial for assessing the failure characteristics of high-power semiconductor lasers. Methods This study is based on the optical thermal reflection method used to construct a semiconductor laser output surface temperature measurement system. Accordingly, the distribution characteristics of the output surface temperature are studied. First, the thermal reflection coefficient of the output facet material used in the semiconductor laser is measured, based on which the measurement system is calibrated. Second, the lock-in method is used to improve the signal-to-noise ratio of the measurement system by increasing the number of image acquisitions. Finally, the output facet temperatures are measured under different operating currents, and the temperature information along the fast and slow axes is extracted and analyzed. Results and Discussions The thermal reflection coefficient of the active region is 5.06 × 10-4 [Fig. 3(a)], and that of the substrate is 6.03 × 10-4 [Fig. 3(b)]. After 1000 iterations, the amplitude fluctuation of the thermal reflection signal tends to a smooth curve, causing a temperature fluctuation of less than 0.4 °C (Fig. 6). The output facet temperature under the 1-10 A current is measured; the output facet temperature of the active region of the semiconductor laser increases with an increase in the injection current (Fig. 8). The output facet temperature of the quantum well layer exhibits strong non-uniformity along the slow axis. At 10 A, the maximum temperature difference at the output facet is approximately 7.5 °C. However, at 1 A, the maximum difference exceeds 3 °C (Fig. 9). The output facet temperatures of the quantum well region under currents of 2, 4, 6, 8, and 10 A are 1.4, 3.1, 4.6, 6.9, and 8.7 °C higher than the junction temperature, respectively. In the region with an approximate thickness of 1.3 pun at both sides of the quantum well, the output facet temperature is higher than the junction temperature. However, in other regions, the output facet temperature is lower than the junction temperature (Fig. 11). Conclusions This article presents a study on the high-resolution measurement of the temperature distribution at the semiconductor laser output facet using the optical thermal reflection method. The temperature distribution information from the output facet of the semiconductor laser is collected under working currents of 1-10 A. The results indicate that the measurement method presented in this study can distinguish small temperature variations at the output facet of the semiconductor laser. Moreover, it is observed that the temperature distribution at the output facet of the semiconductor laser exhibits strong non-uniformity along the slow axis, primarily due to heat generation from light absorption and non-radiative recombination occurring at the facet defects. The highest temperature is observed near the quantum well layer at the output facet, which is consistent with the fact that COMD usually occurs in this region, indicating that abnormal temperatures exceeding the damage threshold are the direct cause of COMD failure in semiconductor lasers. The research method and results presented in this study contribute to obtaining a better understanding of the heat generation mechanism at the output facet of semiconductor lasers, which hold significant practical value for optimizing their design for improving their output performance and reliability. © 2024 Science Press. All rights reserved.

  Affiliations:(1) School of Optoelectronic Science and Engineering, Soochow University, Jiangsu, Suzhou; 215006, China; (2) Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province, Jiangsu, Suzhou; 215006, China; (3) Key Lab of Modern Optical Technologies of Education Ministry of China, Jiangsu, Suzhou; 215006, China; (4) State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Shaanxi, Xi'an; 710119, China; (5) Dogain Optoelectronic Technology (Suzhou) Co., Ltd., Jiangsu, Suzhou; 215000, China

  Publication Year:2024

  Volume:51

  Issue:13

  Article Number:1301004

  DOI Link:10.3788/CJL231574

  数据库ID（收录号）:20243216840207
• Record 494 of
  
  Title:Cold shield matching of cooled infrared system based on telecentric optical structure
  
  Author Full Names:Hu, Xinrong(1); Wang, Jing(1); Chen, Su(1); Li, Jing(2); Feng, Ye(2)

  Source Title:Proceedings of SPIE - The International Society for Optical Engineering

  Language:English

  Document Type:Conference article (CA)

  Conference Title:2023 Advanced Fiber Laser Conference, AFL 2023

  Conference Date:November 10, 2023 - November 12, 2023

  Conference Location:Shenzhen, China

  Conference Sponsor:Chinese Society for Optical Engineering

  Abstract:To solve the problem of cold shield matching in a cooled infrared (IR) imaging optical system with aperture stop placed away from the lens, a pupil matching method based on the telecentric optical structure is proposed. The formulae of Gaussian parameters between the relay lens and the objective lens are derived by using the ideal imaging process. A specific discussion and numerical analysis are carried out. The objective lens is designed as image-space telecentric and the relay lens is designed as object-space telecentric to achieve the requirement that the aperture stop far away from the objective lens. And a specific designing example is added to show the effectiveness of the analysis. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

  Affiliations:(1) China Academy of Space Technology (Xi'an), Xi'an; 710000, China; (2) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China

  Publication Year:2024

  Volume:13104

  Article Number:131046Y

  DOI Link:10.1117/12.3023902

  数据库ID（收录号）:20241816027603
• Record 495 of
  
  Title:A 4×112Gbps Compact Polarization-Insensitive Silicon Photonic WDM Receiver
  
  Author Full Names:Xue, Jintao(1,2); Wu, Jinyi(1,3); Cheng, Chao(1,3); Zhang, Wenfu(1,2); Wang, Binhao(1,2)

  Source Title:2024 Optical Fiber Communications Conference and Exhibition, OFC 2024 - Proceedings

  Language:English

  Document Type:Conference article (CA)

  Conference Title:2024 Optical Fiber Communications Conference and Exhibition, OFC 2024

  Conference Date:March 24, 2024 - March 28, 2024

  Conference Location:San Diego, CA, United states

  Conference Sponsor:Acacia Communications, Inc.; acphotonics; Amphenol Communications Solutions; ATOP; Aurea Technology; et al.

  Abstract:A 4×112Gbps polarization-insensitive silicon photonic WDM receiver with a two-dimensional grating coupler, cascaded dual-ring filters and bidirectional photodiodes is demonstrated. A polarization-dependent loss of 0.45dB is achieved. © 2024 OSA.

  Affiliations:(1) Chinese Academy of Sciences, State Key Laboratory of Transient Optics and Photonics, Xi 'An Institute of Optics and Precision Mechanics, Xi'an; 710119, China; (2) University of Chinese Academy of Sciences, School of Future Technology, Beijing; 100049, China; (3) University of Chinese Academy of Sciences, School of Optoelectronics, Beijing; 100049, China

  Publication Year:2024

  数据库ID（收录号）:20242216177152
• Record 496 of
  
  Title:1.9 μm ultra-narrow spectral width mode-locked pulsed laser based on femtosecond laser inscribed FBG
  
  Author Full Names:Guo, Xiaoxiao(1); Huang, Xiwei(1); Li, Xiaohui(1); Luo, Pengtao(2); Gao, Cunxiao(3); Wang, Ruohui(2); Wang, Yishan(3); Xi, Fei(4); Yin, Xiaoqiang(5); Zhang, Kai(6)

  Source Title:Optics and Lasers in Engineering

  Language:English

  Document Type:Journal article (JA)

  Abstract:The ultra-narrow spectral width laser with excellent temporal coherence is an important light source for microphysics, space detection, and high-precision measurements. However, less attention seems to be paid to mode-locked pulsed lasers in the ∼ 1.9 μm. Due to the narrow bandwidth of femtosecond laser inscribed fiber Bragg gratings (FBG), the thulium-doped fiber laser (TDFL) can generate ultra-narrow spectral width pulse. The central wavelength and 3-dB bandwidth of the output soliton is 1877.938 nm and 0.044 nm. The linewidth of the output pulse reaches 3.7 GHz. To the best of our knowledge, this is the narrowest spectral width in 1.9 μm. Additionally, when the FBG is compressed or stretched, the central wavelength of pulses will be tuned. This work extends the application scope of FBG and provides a new and simple method for realizing an all-fiber mode-locked laser with ultra-narrow spectra width at 1.9 μm. © 2024

  Affiliations:(1) School of Physics & Information Technology, Shaanxi Normal University, Xi'an; 710062, China; (2) School of Physics, Northwest University, Xi'an; 710127, China; (3) State Key Laboratory of Transient Optics and Photonics, Xi′an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi′an; 710119, China; (4) Shaanxi Runchenglai Optoelectric Science & Technology Co. Ltd, China; (5) Shenzhen BYD Lithium Battery Company Limited, China; (6) Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou; 215123, China

  Publication Year:2024

  Volume:181

  Article Number:108441

  DOI Link:10.1016/j.optlaseng.2024.108441

  数据库ID（收录号）:20243016751488
• Record 497 of
  
  Title:Rapid and Nanometric-Precision Distance Measurement with Hybrid Comb Lasers
  
  Author Full Names:Zhi, Jiawen(1); Wang, Zhichuang(2,3); Wu, Hanzhong(1); Little, Brent E.(2); Chu, Sai T.(4); Wang, Panpan(1); Shao, Chenggang(1); Wang, Weiqiang(2,3); Zhang, Wenfu(2,3)

  Source Title:Conference on Lasers and Electro-Optics/Pacific Rim, CLEO-PR 2024 in Proceedings 2024 Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)

  Language:English

  Document Type:Conference article (CA)

  Conference Title:2024 Conference on Lasers and Electro-Optics/Pacific Rim, CLEO-PR 2024

  Conference Date:August 4, 2024 - August 8, 2024

  Conference Location:Incheon, Korea, Republic of

  Abstract:We demonstrate a dual-hybrid-comb distance meter with a fully-stabilized microcomb, enabling ultra-rapid and nanometric-precision distance measurement. The precision can reach 3.572 μm at 4.136 μs and 432 nm at 827.2 μs averaging time. © 2024 The Author(s)

  Affiliations:(1) MOE Key Laboratory of Fundamental Physical Quantities Measurements, Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan; 430074, China; (2) State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, China; (4) Department of Physics and Materials Science, City University of Hong Kong, Hong Kong

  Publication Year:2024

  数据库ID（收录号）:20250517776785
• Record 498 of
  
  Title:Research on Rough Road Detection Link Model
  
  Author Full Names:Yang, Yi(1); Zhang, Leilei(1); Ruan, Chi(2); He, Fengtao(1); Zhao, Zixuan(1); Jiao, Liang(1)

  Source Title:Guangzi Xuebao/Acta Photonica Sinica

  Language:Chinese

  Document Type:Journal article (JA)

  Abstract:Non-contact road surface meteorological detection technologies have emerged as a significant area of development due to their non-destructive impact on the road foundation and the simplicity of installation and maintenance. Typically， these non-contact road surface meteorological detection technologies utilize optical detection methods，and factors such as the roughness of the road surface and the optical angle of incidence significantly influence the system's performance and the accuracy of the meteorological measurements. According to the optical geometric ray method，an improved microfacet model is proposed，which introduces multiple random parameters generated by the reflection of light from rough road surfaces， and establishes a hemispherical equivalent simulation model. This model microscopically elucidates the reflective properties of photons when interacting with rough road surfaces，and it allows for the convenient and precise simulation and analysis of the distribution of photons after reflecting off rough surfaces. Building on this，a rough road surface link transmission model based on wireless laser transmission theory has been developed to study and simulate the optical power characteristics received by the detection system under different road roughness levels and angles of incidence. The random distribution function of the normals of road microfacets under varying degrees of roughness is obtained by using refusal sampling technique，which determines the changes in photon reflection direction， and the distribution state of photons after reflection from the rough surface is statistically analyzed by using the Monte Carlo method，which derived the variations in reflected optical power under different angles of incidence and road roughness conditions. Subsequently，the validity of the model is confirmed. For the experimental design，a non-contact laser-based road surface meteorological condition detection system operating at a wavelength of 850 nm is constructed，which mainly consists of the light source drive circuit with emitting the light power of 50 mW，the laser receiving unit，and the optical system（including an optical antenna，the optical filters，and an optical collimator，etc.）. The system is positioned at a vertical height of 2 m from the road surface to be measured，which is capable of not only monitoring road conditions in real time but also validating the photon distribution and optical power variation predicted by the simulation model. The simulation results and experimental data both reveal a trend where the received optical power gradually decreases as the incident angle between the incident light and the road surface normal increases. Notably，at an incidence angle less than 15°，the greater the road surface roughness，the lower the received optical power. Conversely，at angles greater than 15°，the trend reverses—the greater the road surface roughness，the higher the optical power，and this relationship tends to become linear at certain roughness levels. When the incidence angle reaches 60°，the received optical power stabilizes and undergoes minimal further change. Additionally，the experimental results indicate that the signal-to-noise ratio of the received optical signal does not change with the variation of road roughness，but closely correlates with the incident angle. This study presents and validates an equivalent simulation model for the reflection of light from rough road surfaces， and confirms the model's accuracy and feasibility in practical applications through experiments with an actual non-contact road surface meteorological detection system. The findings not only enhance our understanding of road surface reflective properties but also offer practical insights for the optimization of road detection techniques and meteorological condition monitoring. Thus，the research provides a theoretical and technical support for further improving road detection technology and monitoring meteorological conditions，ultimately contributing to the advancement of road safety measures. © 2024 Chinese Optical Society. All rights reserved.

  Affiliations:(1) School of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an; 710121, China; (2) Xi'an Institute of Optics and Precision Mechanics of CAS, Xi'an; 710119, China

  Publication Year:2024

  Volume:53

  Issue:7

  Article Number:0712005

  DOI Link:10.3788/gzxb20245307.0712005

  数据库ID（收录号）:20243116788002
• Record 499 of
  
  Title:The temperature variation of different cooling methods for the preparation of chalcogenide glasses
  
  Author Full Names:Fan, Wenwen(1); Xu, Junfeng(1); Yao, Zhirui(1); Li, Na(1); Li, Xuyang(2)

  Source Title:Infrared Physics and Technology

  Language:English

  Document Type:Journal article (JA)

  Abstract:The cooling rate has a great influence on the performance of chalcogenide glass, but it is unclear how much the actual cooling rate changes with different cooling methods. In this study, the infrared thermal imaging technology was employed to observe the temperature change in various cooling methods. The temperature curves and the cooling rates between different cooling methods were analyzed from the infrared images. The results show that at 250 °C, the cooling rates follow the order: water quenching > air compressor cooling > salt bath cooling > air cooling > asbestos wrapping cooling; whereas at 150 °C, the sequence is: water quenching > air compressor cooling > air cooling > asbestos wrapping cooling > salt bath cooling. Then the temperature changes inside the sample was simulated and the result shows that the temperature gradient of water quenching is much greater than that of air cooling method, which is why cracks often appear in the glass prepared by water quenching. Finally, Gex-S(90-x)-Sb10 glass was successfully prepared using the air cooling method and it shows excellent optical properties that can transmit both visible and infrared light. © 2023 Elsevier B.V.

  Affiliations:(1) School of Materials and Chemical Engineering, Xi'an Technological University, 710021, China; (2) Xi'an Institute of Optics and Precision Machanicas, CAS Shaanxi, Xi'an; 710119, China

  Publication Year:2024

  Volume:136

  Article Number:105083

  DOI Link:10.1016/j.infrared.2023.105083

  数据库ID（收录号）:20240115321626
• Record 500 of
  
  Title:Generation of chiral optical vortex lattice for controlled aggregation of particles
  
  Author Full Names:Yang, X.B.(1); Zhang, H.(1); Tang, M.M.(1); Ma, H.X.(2); Tai, Y.P.(1,3,4); Li, X.Z.(1,3,4)

  Source Title:Applied Physics Letters

  Language:English

  Document Type:Journal article (JA)

  Abstract:The chiral light field has attracted great attention owing to its interaction with chiral matter. The generation of chiral light fields with rich structures has become crucial as it can expand application scenarios. Herein, we introduce a chiral optical vortex lattice. As a whole, the optical vortex lattice has a chiral intensity distribution, with each spiral arm having sub-vortices (chiral phase). By using an expansion factor to adjust the involute of a circular lattice, this helical optical vortex lattice can be continuously varied from a circular lattice. The chirality of intensity and phase can be controlled independently. Furthermore, the optical tweezers using the lattice demonstrate the capability of sub-vortices to manipulate particle movement, with the chiral intensity determining the trajectory of particle motion. As the lattice possesses both intensity and phase chirality, it may also find potential applications in tasks such as chiral structure microfabrication. © 2024 Author(s).

  Affiliations:(1) School of Physics and Engineering, School of Chemistry and Chemical Engineering, Henan University of Science and Technology, Luoyang; 471023, China; (2) Research Center for Frontier Fundamental Studies, Zhejiang Lab, Hangzhou; 311100, China; (3) State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China; (4) Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology, Luoyang; 471023, China

  Publication Year:2024

  Volume:125

  Issue:1

  Article Number:011106

  DOI Link:10.1063/5.0214498

  数据库ID（收录号）:20242816677455
• Record 501 of
  
  Title:An Infrared Evanescent Wave Sensor for Detection of Ascorbic Acid in Food and Drugs
  
  Author Full Names:You, Tianxiang(1); Zhao, Yongkun(1); Xu, Yantao(2); Guo, Haitao(2); Zhu, Jihong(3); Tao, Haizheng(1); Zhang, Xianghua(4); Xu, Yinsheng(1)

  Source Title:Journal of Lightwave Technology

  Language:English

  Document Type:Journal article (JA)

  Abstract:An infrared evanescent wave sensor was developed to accurately detect ascorbic acid (vitamin C) in food and drugs. The sensor was fabricated by tapering and bending of As2S3 infrared fibers. Due to the broad transmission range (5000-1500 cm-1) of the infrared fibers, covering the characteristic absorption peak of ascorbic acid (C = O at 1760 cm-1 and C = C at 1690 cm-1), the sensor is capable of accurately identifying and detecting the concentration of ascorbic acid. Experimental results demonstrated that a conically tapered fiber sensor with a waist diameter of 50 μm, waist length of 30 mm, and a radius of 2 mm achieved a maximum sensitivity of 0.1257 (a.u./(mg·ml-1)) and a limit of detection (LoD) of 0.917 mg/ml. Furthermore, the application of this fiber sensor in various vitamin C-containing tablets and juices validated its high accuracy and minimal measurement deviation (as low as 0.19 mg/ml). Compared to traditional detection methods, the sensor not only provides a faster and cost-effective solution to identify the substance but also maintains high accuracy. It offers a new approach to quantitative and qualitative analysis of food and drugs. © 1983-2012 IEEE.

  Affiliations:(1) Wuhan University of Technology, State Key Laboratory of Silicate Materials for Architectures, Wuhan; 430070, China; (2) Chinese Academy of Sciences (CAS), State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Xi'an; 710119, China; (3) Yangtze Optical Fibre and Cable Joint Stock Limited Company (YOFC), State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Wuhan; 430073, China; (4) Institut des Sciences Chimiques de Rennes Umr 6226, Rennes; 35042, France

  Publication Year:2024

  Volume:42

  Issue:9

  Start Page:3494-3500

  DOI Link:10.1109/JLT.2024.3357491

  数据库ID（收录号）:20240615489260
• Record 502 of
  
  Title:Underwater Blue-green Light Weak Signal Detection Based on Adaptive Stochastic Resonance
  
  Author Full Names:Zhang, Jianlei(1); Zhang, Juan(1); Zhu, Yunzhou(2); Yao, Xinyu(1); Wu, Qianqian(1); Yang, Yi(1); He, Fengtao(1)

  Source Title:Guangzi Xuebao/Acta Photonica Sinica

  Language:Chinese

  Document Type:Journal article (JA)

  Abstract:The optical signal is easy to be absorbed and scattered during transmission with Underwater Optical Wireless Communication（UWOC）technology，resulting in serious optical power attenuation and further affecting the signal quality. In order to realize long-distance data transmission，it is very important to recognize，enhance and extract weak light signal under low Signal-to-Noise Ratio（SNR）. Stochastic resonance produces synergistic effect through nonlinear system，weak driving signal and appropriate amount of noise under certain conditions，which not only improves the output signal-to-noise ratio，but also detects useful signals. However，the current parameter selection of stochastic resonance system depends on artificial setting，which is not flexible enough to give full play to the advantages of stochastic resonance signal detection. In this paper，an adaptive stochastic resonance detection scheme based on multi-strategy fusion particle swarm optimization is proposed by analyzing the characteristics of weak underwater light signals and the conditions of stochastic resonance generation. It solves the problem that traditional particle swarm optimization is easy to fall into local optimization resulting in low convergence accuracy and difficult convergence. By introducing adaptive inertia weights to dynamically adjust the local search ability and global search ability of particles，the convergence speed of the algorithm is accelerated. In the process of particle evolution，neighborhood detection is used to strengthen the detection of local extremum location neighborhood，which makes the search radius of the algorithm larger in the initial stage of evolution，and gradually decreases with the increase of iteration times，which increases the refinement ability of the algorithm. Using Cauchy variation and reverse learning interactive strategy to mutate the optimal solution，the local optimal solution in Particle Swarm Optimization is broken，and the ability of the algorithm to escape from local space is effectively improved. In order to evaluate the feasibility and effectiveness of the proposed algorithm，simulation is carried out under the established UWOC weak signal detection system. Considering the special property of pilot signal，that is，some known data is inserted at the sending end and can be accurately extracted at the receiving end，it can be used as a reliable reference signal for parameter estimation. Therefore，this paper selects a specific number of code elements for parameter optimization. By taking the output SNR of the system as the selection index，the optimal system parameter which makes the output SNR maximum is searched and iterated continuously within the preset algorithm parameter range. The optimal system parameters are substituted into the fourth-order Runge-Kutta equation，the output response is obtained by discretization，and the weak light signal is detected. Finally，the error performance of bipolar non-return-to-zero signal with white Gaussian noise is compared under four detection schemes：non-stochastic resonance，fixed parameter stochastic resonance，adaptive stochastic resonance based on particle swarm optimization algorithm and multi-strategy fusion particle swarm optimization algorithm. The simulation results show that the bit error rate performance of the non-stochastic resonance system is worse than that of the other three detection schemes，and the bit error rate performance of the fixed parameter stochastic resonance system has limitations. Adaptive stochastic resonance can significantly improve the bit error rate performance of the system，especially above -6 dB，and the improvement effect is very obvious. Compared with the adaptive stochastic resonance based on particle swarm optimization algorithm，the proposed algorithm has faster convergence speed， more accurate optimization results and less error performance. In order to verify the effectiveness and feasibility of the proposed method， a UWOC experimental system is established. The experimental results show that when the received signal-to-noise ratio is - 1.7 dB，the bit error rate of the proposed algorithm can reach 2×10-4，and its performance is better than that of NO-SR and F-SR， which once again verifies the effectiveness of the proposed algorithm. © 2024 Chinese Optical Society. All rights reserved.

  Affiliations:(1) School of Electronic Engineering, Xi'an University of Posts and Telecommunications, Xi'an; 710121, China; (2) Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an; 710119, China

  Publication Year:2024

  Volume:53

  Issue:3

  Article Number:0301003

  DOI Link:10.3788/gzxb20245303.0301003

  数据库ID（收录号）:20241215774978
• Record 503 of
  
  Title:Ultrafast laser triggering nanocrystallization inside Nd-doped photo-thermo-refractive glass and its application in Q-switched laser
  
  Author Full Names:Wang, Xu(1); Li, Guangying(2); Zhang, Guodong(3); Wang, Jiang(3); Zhang, Yunjie(4); Cheng, Guanghua(3)

  Source Title:Optics Express

  Language:English

  Document Type:Journal article (JA)

  Abstract:Photo-thermo-refractive (PTR) glass doped with rare-earth ions has attracted considerable attention due to its excellent linear photosensitivity and laser performance. This study investigates the nonlinear photosensitive nanocrystallization induced by ultrafast laser irradiation in Nd-doped PTR glass. Phase contrast microscopy reveals that both Gaussian and Gaussian-Bessel beams can modulate the refractive index positively or negatively, depending on specific conditions. Notably, Gaussian-Bessel beams can significantly extend the thickness of the laser-modified layer. Optical spectra indicate the formation of silver nanoparticles, with concentration increasing as pulse energy increases. Furthermore, X-ray diffraction and transmission electron microscopy confirm the precipitation of nanocrystals with the composition of NaF following laser irradiation and thermal treatment, consistent with conventional PTR glass. The nonlinear optical characteristics of the treated sample are evaluated and successfully applied in a passive Q-switched laser, exhibiting both gain characteristics and saturable absorption. This study provides an effective strategy for multifunctional integrated on-chip devices that possess high damage thresholds and enhanced stability. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

  Affiliations:(1) School of Science, Xi’an Shiyou University, Xi’an; 710065, China; (2) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (3) School of Artificial Intelligence, Optics and Electronics, Northwestern Polytechnical University, Xi’an; 710072, China; (4) School of Science, Xi’an Polytechnic University, Xi’an; 710048, China

  Publication Year:2024

  Volume:32

  Issue:22

  Start Page:38931-38941

  DOI Link:10.1364/OE.537472

  数据库ID（收录号）:20244317271267
• Record 504 of
  
  Title:Efficient generation of broadband photon pairs in shallow-etched lithium niobate nanowaveguides
  
  Author Full Names:Fang, Xiao-Xu(1,2); Wang, Leiran(3,4); Lu, He(1,2)

  Source Title:Optics Express

  Language:English

  Document Type:Journal article (JA)

  Abstract:We design and fabricate shallow-etched periodically poled lithium niobate waveguides to realize highly efficient broadband spontaneous parametric down-conversion (SPDC) on nanophotonic chips. The shallow-etched waveguide can tolerate the non-uniformities of waveguide width induced by fabrication imperfections, enabling the generation of photon pairs with high count rate and bandwidth. We demonstrate photon-pair generation with a high brightness of 11.7 GHz/mW and bandwidth of 22 THz in a 5.7-mm-long PPLN waveguide. The generated photon pairs exhibit a strong temporal correlation with a coincidence-to-accidental ratio of up to 16262±850. Our results confirm the feasibility of shallow etching in the fabrication of an efficient SPDC device on the platform of lithium niobate on an insulator, and benefit quantum information processing with a broadband photon source. © 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

  Affiliations:(1) School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan; 250100, China; (2) Shenzhen Research Institute of Shandong University, Shenzhen; 518057, China; (3) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (4) University of Chinese Academy of Sciences, Beijing; 100049, China

  Publication Year:2024

  Volume:32

  Issue:13

  Start Page:22945-22954

  DOI Link:10.1364/OE.519265

  数据库ID（收录号）:20242616354357