2024

• Record 229 of
  
  Title:A 4×112 Gb/s Ultra-Compact Polarization-Insensitive Silicon Photonics WDM Receiver With CMOS TIA for Co-Packaged Optics and Optical I/O
  
  Author(s):Xue, Jintao(1,2); Wang, Binhao(1,2); Chen, Yihan(2,3); Chen, Sikai(2,3); Wu, Jinyi(1,2); Cheng, Chao(1,2); Bao, Shenlei(1,2); Qi, Nan(2,3); Zhang, Wenfu(1,2)
  Source:Journal of Lightwave Technology
  Volume: 42  Issue: 17  DOI: 10.1109/JLT.2024.3402053  Published: 2024  
  Abstract:We present a four-channel polarization-insensitive silicon photonic (SiPh) wavelength division multiplexing (WDM) receiver, incorporating a polarization splitting grating coupler, dual-ring filters and bidirectional photodiodes. This design achieves an ultra-compact footprint of 1 mm × 0.2 mm with a polarization dependent loss (PDL) of 0.58 dB or less. Four clearly open eye diagrams at a data rate of 112 Gb/s PAM4 are obtained. Furthermore, we demonstrate the hybrid integration of the SiPh chip with a 28 nm CMOS transimpedence amplifier (TIA), resulting in an impressive energy efficiency of 1.34 pJ/bit at a data rate of 100 Gb/s PAM4. Sensitivities of -13.4 dBm and -5.6 dBm are achieved at data rates of 50 Gb/s NRZ and 100 Gb/s PAM4, respectively, under KP4 forward error correction (FEC) threshold. © 1983-2012 IEEE.
  Accession Number: 20242116124309
• Record 230 of
  
  Title:Enhanced secondary electron emission properties of sputter-deposited MgO–Au composite film via Cr doping
  
  Author(s):Liu, Li(1); Li, Jie(1); Xia, Zhangcong(1); Liu, Biye(1); Liu, Hulin(3); Wu, Shengli(1,2); Hu, Wenbo(1,2)
  Source:Vacuum
  Volume: 229  Issue:   DOI: 10.1016/j.vacuum.2024.113545  Published: November 2024  
  Abstract:High and stable secondary electron emission yield (SEY) is essential for thin film materials used for electrical signal amplification in electronic devices. To enhance the secondary electron emission (SEE) capability of MgO–Au composite film, Cr-doped MgO–Au film was prepared by magnetron sputtering and the effect of Cr doping on the SEE properties of MgO–Au film was intensively investigated. It was confirmed that the doped Cr element is distributed through the whole composite film in a form of Cr2O3. Compared to the conventional MgO–Au film, the Cr-doped MgO–Au film with a Cr/(Cr + Mg) atomic ratio of 0.71 % achieves a SEY of 7.1 with a 4.4 % rise at the primary electron energy (Ep) of 300 eV and a maximum SEY of 10.9 with a 10.1 % increase at the Ep of 800 eV, and it also has a reduction of 49.2 % in SEE decay rate under continuous electron bombardment. For this novel composite film, the SEY ascension mainly attributes to the MgO grain enlargement and chemical stability enhancement, and the decreased SEE decay rate is associated with the improvements of resistance to electron bombardment and electric conductivity induced by Cr doping. © 2024 Elsevier Ltd
  Accession Number: 20243416901796
• Record 231 of
  
  Title:Low self-starting threshold polarization-maintaining Er-doped fiber optical frequency comb
  
  Author(s):Gao, Yanwei(1); Cheng, Haihao(2); Hu, Xiaohong(2); Li, Yongqi(1); Liu, Hao(1); Yang, Yanzhao(3); Pan, Ran(2); Wang, Yishan(2); Wu, Shun(1)
  Source:Optics and Laser Technology
  Volume: 177  Issue:   DOI: 10.1016/j.optlastec.2024.111092  Published: October 2024  
  Abstract:We report the development of an all-fiber polarization maintaining (PM) optical frequency comb using a mode-locked figure-9 laser with a low self-starting pump threshold. We have achieved self-starting mode-lock for repetition rates (fr) from 70 MHz to 109 MHz. At a repetition rate of 109 MHz, mode-locking can be achieved for a pump power ranging from 187 mW to 880 mW. To the best of our knowledge, this is the lowest pump power reported for PM figure-9 erbium fiber lasers with repetition rate over 100 MHz. By optimizing the pump power to 238 mW, we have achieved an output power of 5 mW, center wavelength of 1566.2 nm, and 3-dB spectral bandwidth of 20.5 nm. The repetition rate has a high signal-to-noise ratio of 95 dB at a resolution bandwidth of 300 Hz. We have studied the spectral characteristics of the laser under different cavity lengths and pump powers. Additionally, we have stabilized the repetition rate using a GPS-Rb disciplined RF reference. The fractional instability of the repetition rate is measured to be 4.67×10-12 at 1 s and 9.22×10-13 at 10 s over a measurement of 11 h. Our findings demonstrate that the developed figure-9 comb is robust, compact and has the advantage of high stability and low power consumption. It offers a cost effective solution for future outdoor comb applications. © 2024
  Accession Number: 20241916030777
• Record 232 of
  
  Title:Tunable chalcogenide solid-core anti-resonant fiber polarization filter based on SPR effect
  
  Author(s):Zhang, Zhenlong(1); Li, Jianshe(1); Guo, Haitao(2); Xu, Yantao(2); Wang, Ruiduo(2); Li, Shuguang(1); Zhang, Hao(2); Chang, Yanjie(2); Zhao, Yuanyuan(1)
  Source:Optics and Lasers in Engineering
  Volume: 181  Issue:   DOI: 10.1016/j.optlaseng.2024.108371  Published: October 2024  
  Abstract:Based on surface plasmon resonance (SPR), we proposed a tunable chalcogenide solid-core anti-resonant fiber (SC-ARF) polarization filter. The purpose of introducing the SPR, which is excited by coating the inner wall of the cladding tubes with a gold film, is to achieve a discrepancy between the confinement loss of two polarized fundamental modes (FMs). The full-vector finite element method (FV-FEM) evaluates the impact of fiber core radius, cladding tube radius, cladding tube wall thickness, and gold film thickness on the polarization filter characteristics. The results show that when the thickness of the gold film is 30 nm and the fiber length is 4 mm, the filter bandwidth can simultaneously cover the S + C + L optical communication band and reach 248 nm, and the extinction ratio (ER) value reaches -377.46 dB. Moreover, we also confirmed the tuning effect of the gold-coated cladding tube wall thickness on the resonance wavelength. The proposed fiber polarization filter has potential application value in optical fiber communication and transmission. © 2024 Elsevier Ltd
  Accession Number: 20242616352254
• Record 233 of
  
  Title:Numerical simulation of dynamics behavior of pulsed-DC helium plasma jet confined by parallel magnetic field at atmospheric pressure
  
  Author(s):Liu, Yinghua(1,2); Yin, Peiqi(1,2); Xu, Boping(1,2); Liu, Dawei(3); Pi, Liangwen(2,4); Fu, Yuxi(2,4); Wang, Yishan(1,2); Zhao, Wei(1,2); Tang, Jie(1,2)
  Source:Physical Review Research
  Volume: 6  Issue: 3  DOI: 10.1103/PhysRevResearch.6.033028  Published: June 2024  
  Abstract:A two-dimensional axisymmetric fluid model is used to simulate the dynamics behavior of an atmospheric-pressure helium plasma jet in the presence of a parallel magnetic field. The plasma jet is generated in a coaxial dielectric barrier discharge (DBD) driven by pulsed direct-current voltage. Comparative analysis of the plasma jet with and without the parallel magnetic field indicates that a slightly thinner plasma sheath inside the tube is present with the parallel magnetic field as a result of the decreased accumulated electrons on the inner surface of dielectric tube. After the streamer propagates outside the tube, a little more concentrated electron distribution in the annular wall is observed by applying the magnetic field because of the reduced electron diffusion in the radial direction and the confinement effect of the magnetic field on the electrons in the avalanche heads. The tiny reduction in the length of plasma jet is attributed to the E × B drift of charged particles. These results demonstrate that the parallel magnetic field has no apparent effect on the propagation of the plasma jet, and it contributes little to the performance improvement of the coaxial DBD, which agrees well with the previous experimental observations. This little impact of the parallel magnetic field on the coaxial DBD plasma jet may result from negligible contribution of the memory effect to the sole discharge pulse as well as the weak confinement effect of the applied magnetic field on the surface electrons that moves along the magnetic field lines under electrostatic repulsion. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
  Accession Number: 20242916699818
• Record 234 of
  
  Title:Non-Ambiguous Range Extension by a Frequency Scanning Soliton Microcomb
  
  Author(s):Shi, Wenqi(1,2); Wang, Yang(3); Wang, Weiqiang(3,4); Chen, Kairong(1,2); Cao, Yulian(1,2); Zhang, Wenfu(3); Liu, Jianguo(1,2)
  Source:Journal of Lightwave Technology
  Volume: 42  Issue: 20  DOI: 10.1109/JLT.2024.3415161  Published: 2024  
  Abstract:Laser based range measurement system plays an important role in both scientific and industrial areas. Soliton microcomb (SMC) based dispersive interferometry (DPI) method has shown the advantages of high speed, high precision, and compact size in ranging systems. However, due to the high repetition rate of SMCs, it results in a small non-ambiguous range (NAR), which impacts the practical application of SMC based ranging systems. Furthermore, when the measured distance is close to N times NAR, it is difficult to extract the distance information including the delay time and direction. Here, we introduce frequency scanning and prime number algorithm to an SMC based DPI ranging system. The frequency of SMC can be scanned over one free spectral range (FSR) by sweeping the pump frequency and the resonance of the microresonator synchronously. The interference spectra are recorded when the frequency is scanned every 1/im(im = 2, 3, 5, 7..., a list of primes) FSR, and the NAR can be extended by ∼ √ 2∏im times through interpolating the recorded interference spectra. We experimentally verify the feasibility of the proposed ranging system, and the NAR is extended by 3 times. Furthermore, we extract a small delay time of 6.859 fs with a standard deviation of 1.128 μm, which cannot be determined by the SMC with original repetition rate. The proposed ranging system can extend the NAR without any auxiliary rough measurement systems, and the detectable distance over the full range can be achieved. © 1983-2012 IEEE.
  Accession Number: 20242616301799
• Record 235 of
  
  Title:Low noise operation of an all polarization-maintaining figure-9 Er:fiber laser with near-zero cavity dispersion
  
  Author(s):Cheng, Haihao(1,2); Zhang, Zhao(1,2); Hu, Xiaohong(1); Zhang, Ting(1,2); Pan, Ran(1,2); Jia, Jing(1,2); Wang, Yishan(1,2); Wu, Shun(1,3)
  Source:Optical Fiber Technology
  Volume: 87  Issue:   DOI: 10.1016/j.yofte.2024.103892  Published: October 2024  
  Abstract:We demonstrate the low noise operation of a figure-9 1.5-μm Er:fiber laser constructed by all polarization-maintaining (PM) fiber and fiber components. Starting from the original rate equations and nonlinear Schrödinger equation, the cavity roundtrip evolution toward stable mode locking state is present. The radio frequency spectrum shows a 94.6-MHz fundamental repetition rate with up to 100 dB high signal-to-noise ratio. The net dispersion is tailored to near zero by incorporating and optimizing the length of PM dispersion-compensating fiber in the cavity. As a result, an integrated root-mean-square relative intensity noise of 0.0026 % [1 Hz, 1 MHz] and 10.8-fs timing jitter [100 Hz, 1 MHz] at the fundamental repetition rate are measured. We also lock the fundamental repetition frequency to a stable radio frequency reference and an in-loop relative stability of 2.1 × 10−12 at 1-s gate time is obtained. © 2024 Elsevier Inc.
  Accession Number: 20242616509154
• Record 236 of
  
  Title:Process optimization of infrared chalcogenide glass based on the scattering detection
  
  Author(s):Tang, Yuxin(1,2); Xu, Yantao(1,2); Cui, Xiaoxia(1,2); Zhang, Jinchang(1,2); Li, Man(3); Xiao, Xusheng(1,2); Yan, Mengmeng(3); Guo, Haitao(1,2,3)
  Source:Ceramics International
  Volume: 50  Issue: 5  DOI: 10.1016/j.ceramint.2023.12.020  Published: March 1, 2024  
  Abstract:Chalcogenide glasses with less optical losses are highly demanded as optical materials for micro lense, waveguide and fiber devices. However, it is still challengeable to reduce the optical losses in infrared chalcogenide glasses with opaque visible light. Herein, an improved 3D distribution of scattering sources is established in this study to test and compare the concentration and distribution of defects in As38S62, Ge28Sb12Se60 and As40Se60 chalcogenide glasses. Furthermore, by comparing the scattering images of serial As40Se60 glass prepared under various melting, quenching and annealing temperatures, the preparation process was optimized to reduce its scattering loss. In addition, this study introduced a scheme that could be widely applied to optimize processing of other infrared glasses and devices glass to reduce their scattering losses. © 2023 Elsevier Ltd and Techna Group S.r.l.
  Accession Number: 20235215279498
• Record 237 of
  
  Title:Numerical simulation of dynamics behavior of pre-ionized pulsed-DC helium plasma jets at atmospheric pressure
  
  Author(s):Liu, Yinghua(1,2); Yin, Peiqi(1,2); Xu, Boping(1,2); Liu, Dawei(3); Pi, Liangwen(2,4); Fu, Yuxi(2,4); Wang, Yishan(1,2); Zhao, Wei(1,2); Tang, Jie(1,2)
  Source:Physics of Plasmas
  Volume: 31  Issue: 9  DOI: 10.1063/5.0215614  Published: September 1, 2024  
  Abstract:A two-dimensional axisymmetric fluid model was established to investigate the dynamic behavior of pre-ionized pulsed-direct-current helium plasma jets at atmospheric pressure. Our simulation results show that, at a relatively low pre-ionization level, the electron number density is reduced and the streamer propagation is decelerated before the plasma jet is ejected from the tube, which is attributed to the inhibitory effect of a recombination process between the positive ions in the streamer and the seed electrons near the anode. As the pre-ionization reaches a relatively high level, the electron number density is larger than that without pre-ionization before the plasma jet is ejected from the tube, which originates from the promotion effect of decreased breakdown voltage. These two competing mechanisms jointly dominate the dynamic behavior of gas discharge in the presence of pre-ionization. After the plasma jet is ejected from the tube, the enhanced discharge power is responsible for the strengthened electric field in the streamer head, augmented total ionization rate, accelerated streamer propagation, and increased number density of electrons and active species, whatever the pre-ionization density is. With the increase in pre-ionization density, the plasma jet length, streamer propagation speed, discharge power, and discharge energy exhibit the initial increase and subsequent decrease variation trend. The optimal enhancement effect is obtained at the pre-ionization density of 6 × 1012 m−3, with the plasma jet lengthened by 28.4% and the energy deposition efficiency enhanced by 28.1%. © 2024 Author(s).
  Accession Number: 20244117184058
• Record 238 of
  
  Title:Power-Guided Asymmetrical Vector Dissipative Soliton Molecules in a Compact Fiber Resonator
  
  Author(s):Huang, Xiangzhen(1); Li, Xiaohui(1); Chen, Enci(2); Pan, Zhiwen(1); Guo, Penglai(3); Sun, Liaoxin(4); Wang, Yishan(5); Zhao, Wei(5)
  Source:IEEE Journal of Selected Topics in Quantum Electronics
  Volume: 30  Issue: 5  DOI: 10.1109/JSTQE.2023.3319342  Published: September 1, 2024  
  Abstract:Vector dissipative soliton molecules (VDSMs) can be promising for polarization multiplexing transmission applications. We report a nonlinear polarization rotation (NPR) vector dissipative soliton molecule laser. The laser realizes three-type vector dissipative soliton molecules of directly generated '1+2' type, '2+2 type, and outer-cavity projected super-position '2+'2+2'' type just by changing the pump power. It's proved that the different generated methods of vector soliton molecules in Hamiltonian systems can also be realized in dissipative systems. This is also the first time that multiple different generated methods of vector dissipative soliton molecules are realized in a fiber resonator based on NPR. The results proved the VDSMs' structures can be controlled, which can be potentially applied in optical frequency comb, optical communication systems, optical logic processing, optical detection, etc. © 1995-2012 IEEE.
  Accession Number: 20234114860851
• Record 239 of
  
  Title:Research on Rough Road Detection Link Model
  
  Author(s):Yang, Yi(1); Zhang, Leilei(1); Ruan, Chi(2); He, Fengtao(1); Zhao, Zixuan(1); Jiao, Liang(1)
  Source:Guangzi Xuebao/Acta Photonica Sinica
  Volume: 53  Issue: 7  DOI: 10.3788/gzxb20245307.0712005  Published: July 2024  
  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.
  Accession Number: 20243116788002
• Record 240 of
  
  Title:On chip broadband and high extinction ratios Mach-Zehnder interferometer for DPSK signal demodulation
  
  Author(s):Shao, Wen(1,2,3); Jia, Shuaiwei(1,2,3); Gao, Duorui(1,2,3); Huang, Long(1,2,3); Xie, Zhuang(1,2,3); Wang, Yang(1,2,3); Yao, Bin(1,3); Xie, Ningbo(1,3); Wang, Wei(1,3); Wang, Weiqiang(4); Xie, Xiaoping(1,2,3)
  Source:Optics Communications
  Volume: 569  Issue:   DOI: 10.1016/j.optcom.2024.130813  Published: October 15, 2024  
  Abstract:Differential phase shift keying (DPSK) signals are widely employed in optical communication systems due to the high sensitivity and simple self-delay interference demodulation scheme. In this paper, we demonstrate a broadband on-chip Mach-Zehnder interferometer (MZI) for multiple channel DPSK signal demodulation. The chip is constructed using a single-mode high-index doped silica glass waveguide with fiber-to-fiber insert loss less than 3 dB and small second-order dispersion. The MZI interference fringe extinction ratio is over 25 dB in the range of C- and L-bands. The MZI is employed to demodulate four parallel DPSK signals simultaneously with similar performance, indicating that the broad bandwidth MZI is suitable for a receiver of massive parallel optical communications. © 2024
  Accession Number: 20242616422171