| Record 1 of 15 | | Title: Optical frequency comb generation based on spectral broadening of a phase locked dual-wavelength microcavity laser | | Author(s): Wang, T (Wang, Ting); Wu, JL (Wu, Jiliang); Yang, YD (Yang, Yuede); Xiao, JL (Xiao, Jinlong); Huang, YZ (Huang, Yongzhen) | | Source: JOURNAL OF PHYSICS D-APPLIED PHYSICS Volume: 56 Issue: 5 Article Number: 054003 DOI: 10.1088/1361-6463/acae2f Published: FEB 2 2023 | | Abstract: A highly coherent optical frequency comb (OFC) based on spectral broadening of a phase-locked dual-wavelength microcavity laser is presented. By directly modulating the microcavity laser to generate multiple sidebands, the cross-injection locking of the dual modes is achieved and the beat-signal linewidth is improved from 13.5 MHz to less than 100 Hz. Subsequently, 21 flat comb teeth in a +/- 3 dB power variation are achieved by combining a phase modulator. Finally, an OFC with a bandwidth of 16 nm is successfully realized by narrowing the optical pulse and spectral broadening in a commercial nonlinear optical fiber. The repetition rate has a low phase noise of -102 dBc Hz(-1) at 10 kHz offset, demonstrating the generated OFC has a high degree of coherence. | | Accession Number: WOS:000916763900001 | | ISSN: 0022-3727 | | eISSN: 1361-6463 |
| Record 2 of 15 | | Title: Lightweight real-time stereo matching algorithm for AI chips | | Author(s): Liu, Y (Liu, Yi); Wang, WH (Wang, Wenhao); Xu, XT (Xu, Xintao); Guo, XZ (Guo, Xiaozhou); Gong, GL (Gong, Guoliang); Lu, HX (Lu, Huaxiang) | | Source: COMPUTER COMMUNICATIONS Volume: 199 Pages: 210-217 DOI: 10.1016/j.comcom.2022.06.018 Published: FEB 1 2023 | | Abstract: AI chips have developed rapidly and achieved remarkable acceleration effects in the corresponding algorithm field in recent years. However, deep learning algorithms are changing rapidly, including many operators that AI chips and inference frameworks cannot use in the short term. To solve the problem that it is challenging to deploy a stereo matching algorithm based on binocular vision on AI chips, this paper proposes a multi-stage unsupervised lightweight real-time depth estimation algorithm for AI chips called TradNet. TradNet combines the traditional matching algorithm with a convolutional neural network and uses convolution directly supported by AI chips to realize the structure of the traditional matching algorithm. TradNet is composed of operators directly supported by current AI chips, which reduces the computational complexity of the algorithm, and greatly improves the compatibility of the stereo matching algorithm with existing AI chips. Compared with the deep learning-based multi-stage binocular disparity algorithm AnyNet, the accuracy is improved by 5.12%, and the inference speed is only 12.7%. Compared with the matching-based binocular disparity algorithm BM, the accuracy is improved by 25.24%, and the inference speed is only 48.7%. Our final model can process 1280x720 resolution images within a range of 60-80 FPS on an NVIDIA TITAN Xp. It achieves 28FPS on a 1TOPS (Tera Operations Per Second) custom AI chip, and the power consumption is 0.88 W. | | Accession Number: WOS:000916921000001 | | ISSN: 0140-3664 | | eISSN: 1873-703X |
| Record 3 of 15 | | Title: Ultrastretchable Triboelectric Nanogenerators Based on Ecoflex/Porous Carbon for Self-Powered Gesture Recognition | | Author(s): Zhao, J (Zhao, Jiang); Xiao, Y (Xiao, Yu); Yang, W (Yang, Wei); Zhang, SC (Zhang, Shaochun); Wang, HN (Wang, Huining); Wang, Q (Wang, Qiang); Sun, ZY (Sun, Zhaoyang); Li, WJ (Li, Wenjie); Gao, M (Gao, Min); Wang, ZF (Wang, Zefeng); Xu, Y (Xu, Yun); Chen, HM (Chen, Huamin); Wang, J (Wang, Jun) | | Source: ADVANCED MATERIALS TECHNOLOGIES DOI: 10.1002/admt.202201769 Early Access Date: JAN 2023 | | Abstract: Stretchable triboelectric nanogenerator (STENG) has become the research hotspots in flexible power supply, which is indispensable in intelligent wearable electronics. In this work, an ultrastretchable Ecoflex/porous carbon-based STENG (EP-STENG) is presented for gesture recognition application. Due to the ultrahigh stretchability of Ecoflex (570%) and high conductivity of porous carbon, the EP thin film acts as an excellent stretchable electrode under various deformations. In addition, the output performance of the EP-STENG can enhance by adjusting the concentration of porous carbon. At a mass fraction of 0.28 wt%, the EP-STENG reaches the optimal output performance. This is due to the appropriate conductive networks and strong trapping effect. Surprisingly, the performance of the EP-STENG still remains 70% at a stretching strain of 177%, which makes it a promising wearable sensor for human-machine interaction. Finally, the EP-STENG-based stretchable sensor array can acquire gesture signal of the fingers, which can control the mechanical hand to make corresponding actions. The proposed ultrastretchable EP-STENG can promote the development of intelligent wearable system and flexible electronics. | | Accession Number: WOS:000919028000001 | | ISSN: 2365-709X |
| Record 4 of 15 | | Title: Advanced Optoelectronic Devices for Neuromorphic Analog Based on Low-Dimensional Semiconductors | | Author(s): Wang, XY (Wang, Xiaoyu); Zong, YX (Zong, Yixin); Liu, DY (Liu, Duanyang); Yang, JH (Yang, Juehan); Wei, ZM (Wei, Zhongming) | | Source: ADVANCED FUNCTIONAL MATERIALS DOI: 10.1002/adfm.202213894 Early Access Date: JAN 2023 | | Abstract: Neuromorphic systems can parallelize the perception and computation of information, making it possible to break through the von Neumann bottleneck. Neuromorphic engineering has been developed over a long period of time based on Hebbian learning rules. The optoelectronic neuromorphic analog device combines the advantages of electricity and optics, and can simulate the biological visual system, which has a very strong development potential. Low-dimensional materials play a very important role in the field of optoelectronic neuromorphic devices due to their flexible bandgap tuning mechanism and strong light-matter coupling efficiency. This review introduces the basic synaptic plasticity of neuromorphic devices. According to the different number of terminals, two-terminal neuromorphic memristors, three-terminal neuromorphic transistors and artificial visual system are introduced from the aspects of the action mechanism and device structure. Finally, the development prospect of optoelectronic neuromorphic analog devices based on low-dimensional materials is prospected. | | Accession Number: WOS:000919118600001 | | ISSN: 1616-301X | | eISSN: 1616-3028 |
| Record 5 of 15 | | Title: Effects of pressure on GaN growth in a specific warm-wall MOCVD reactor | | Author(s): Niu, HD (Niu, Huidan); Yao, WZ (Yao, Weizhen); Yang, SY (Yang, Shaoyan); Liu, XL (Liu, Xianglin); Chen, QQ (Chen, Qingqing); Wang, LS (Wang, Lianshan); Wang, HH (Wang, Huanhua); Wang, ZG (Wang, Zhanguo) | | Source: CRYSTENGCOMM DOI: 10.1039/d2ce01678h Early Access Date: JAN 2023 | | Abstract: A horizontal warm-wall metal-organic chemical vapor deposition (MOCVD) reactor was designed for growing high-quality gallium nitride (GaN) films. The reactor features a Mo reflector screen above the ceiling stabilizing the temperature field, which can realize a ceiling temperature of 790 degrees C and a temperature gradient within 6 degrees C mm(-1) above the substrate. The pressure-dependent phenomenon of the reactor is explored from 50 to 150 Torr for studying the growth rate and thickness uniformity of GaN films grown on a 4 in. c-plane sapphire. The growth rate of the GaN sample at 150 Torr is slowed, because higher pressure leads to parasitic reactions consuming a lot of precursors. High crystal quality and smooth surface morphology of GaN films are achieved simultaneously using the warm-wall MOCVD. The photoluminescence (PL) spectra have few yellow luminescence (YL) bands derived from gallium vacancies, carbon impurities and related point defects, due to the conducive trimethylgallium (TMG) decomposition in the warm-wall MOCVD reactor. Moreover, the chemical reaction mechanism has been studied for the warm-wall MOCVD system, where promoting the pyrolysis reaction in the gas phase is helpful to reduce the concentration of point defects in GaN films. This work provides a practical case for epitaxial nitride materials and plays an important role in promoting the development of MOCVD equipment. | | Accession Number: WOS:000919736300001 | | eISSN: 1466-8033 |
| Record 6 of 15 | | Title: Phonon-Assisted Upconversion Photoluminescence of a Self-Trapped Exciton in the Rb2CuCl3 Single Crystal | | Author(s): Xu, KX (Xu, Kai-Xuan); Zhou, ZR (Zhou, Ziren); Zhang, J (Zhang, Jun) | | Source: JOURNAL OF PHYSICAL CHEMISTRY LETTERS Volume: 14 Issue: 1 Pages: 32-37 DOI: 10.1021/acs.jpclett.2c03514 Published: JAN 12 2023 | | Abstract: Phonon-assisted upconversion photoluminescence (UCPL) plays an important role in a wide range of fields such as optical refrigeration, sensitive optical thermometry, quantum state control, and upconversion optoelectronics. High photoluminescence quantum yield (PLQY) and strong electron-phonon coupling are two basic prerequisites of efficient UCPL materials. The self-trapped exciton (STE) system with the above-mentioned advantages hints that it may be a good candidate for phonon-assisted UCPL. Here, we synthesized Rb2CuCl3 single crystals (SCs) which yield a high PLQY of the STE emission at 400 nm, and an efficient phonon-assisted UCPL was demonstrated at room temperature. By exponentially fitting the intensity of temperature -dependent UCPL spectra, we obtained an optical thermometry sensitivity of SCs up to 6 mK at 295 K. We also propose that net cooling would be possible if the PLQY is improved up to 91.5% with 345 nm excitation. Our results open a new door to explore laser cooling in STE systems. | | Accession Number: WOS:000918921700001 | | PubMed ID: 36563108 | | Author Identifiers: | | AuthorWeb of Science ResearcherIDORCID NumberZhang, Jun 0000-0002-9831-6796 | | ISSN: 1948-7185 |
| Record 7 of 15 | | Title: Dual-band MWIR/LWIR superlattice infrared focal plane arrays for simultaneous detection | | Author(s): Zhou, XC (Zhou, Xu-chang); Huang, JL (Huang, Jianliang); Wang, HP (Wang, Haipeng); Kong, JC (Kong, Jincheng); Li, JB (Li, Junbin); Mu, YC (Mu, Yingchun); Zhang, YH (Zhang, Yanhua); Ma, WQ (Ma, Wenquan); Ren, H (Ren, Hai); Li, DS (Li, Dongsheng); Jiang, Z (Jiang, Zhi); Sun, H (Sun, Hao); Zhao, CB (Zhao, Canbing) | | Source: INFRARED PHYSICS & TECHNOLOGY Volume: 128 Article Number: 104539 DOI: 10.1016/j.infrared.2022.104539 Early Access Date: JAN 2023 Published: JAN 2023 | | Abstract: We have demonstrated dual-band infrared focal plane arrays (FPA) using type II InAs/GaSb superlattice photodetector with simultaneous detection in both the mid-and the long-wavelength (MW/LW) atmospheric windows of 3-5 lm and of 8-12 lm. The material comprises two back-to-back photodiodes sandwiched in be-tween two N-type contacts and separated by a common P-type ground contact, with the structure of MW and LW channel optimized separately. The three-terminal architecture was used to realize the simultaneous and spatially coincident detection of the MW and LW signal. The temporal noise equivalent difference of the 384 x 288 FPA is 17 mK for MW channel with 4.9 lm cut-off wavelength, and 19 mK for LW channel with 9.7 lm cut-off wavelength at 78 K. The camera with this T2SL FPA shows high quality dual-band imaging capability. | | Accession Number: WOS:000919320200001 | | ISSN: 1350-4495 | | eISSN: 1879-0275 |
| Record 8 of 15 | | Title: Room-temperature high-speed mid-infrared quantum cascade laser with pi-shape metal contact | | Author(s): Gao, X (Gao, Xu); Yang, K (Yang, Ke); Zhu, YX (Zhu, Yi-xuan); Liu, JQ (Liu, Jun-qi); Zhai, SQ (Zhai, Shen-qiang); Liu, SM (Liu, Shu-man); Zhuo, N (Zhuo, Ning); Zhang, JC (Zhang, Jin-chuan); Wang, LJ (Wang, Li-jun); Liu, FQ (Liu, Feng-qi); Wang, XH (Wang, Xiao-hua); Wei, ZP (Wei, Zhi-peng) | | Source: ELECTRONICS LETTERS Volume: 59 Issue: 2 Article Number: e12704 DOI: 10.1049/ell2.12704 Published: JAN 2023 | | Abstract: The authors demonstrate a high-speed 8.5-mu m quantum cascade laser (QCL) with room temperature continuous wave (CW) operation. The maximum output power of 141 mW is obtained at 20 degrees C. The parasitic capacitance of the device is decreased from 36.6 to 7.1 pF by monolithic integrating a pi-shape metal contact electrode. This results in an increase in the -3 dB RF modulation bandwidth from 870 MHz to 4.5 GHz compared with the conventional electrode configuration. | | Accession Number: WOS:000918992000001 | | ISSN: 0013-5194 | | eISSN: 1350-911X |
| Record 9 of 15 | | Title: Photonic Generation of Background-Free Phase-Coded Microwave Pulses with Elimination of Power Fading | | Author(s): Guan, MY (Guan, Mengyuan); Wang, L (Wang, Lu); Li, FP (Li, Fangping); Chen, XY (Chen, Xiaoyu); Li, M (Li, Ming); Zhu, NH (Zhu, Ninghua); Li, W (Li, Wei) | | Source: PHOTONICS Volume: 10 Issue: 1 Article Number: 66 DOI: 10.3390/photonics10010066 Published: JAN 2023 | | Abstract: We report a novel photonic scheme to generate background-free phase-coded microwave pulses with elimination of power fading by cascading a dual-polarization dual-parallel Mach-Zehnder modulator (DP-DPMZM) and a polarization modulator (PolM). The DP-DPMZM is driven by a radio frequency (RF) signal to generate two first-order optical sidebands with an orthogonal polarization state, while the PolM is driven by a three-level electrical coding signal. By properly adjusting the polarization state, a series of background-free frequency-doubled phase-coded microwave pulses can be generated after optical-to-electrical conversion. Benefiting from the carrier-suppressed single-sideband (CS-SSB) modulation, the proposed signal generator can suppress the chromatic-dispersion-induced power-fading effect, which has excellent potential for long-distance fiber transmission. In addition, the system can directly generate phase-coded microwave signals in pulse mode by truncating continuous wave (CW) microwave signals. Moreover, the microwave signal generator has wideband tunability since no optical filter is involved in our scheme. The proposed method was theoretically analyzed and experimentally verified. Phase-coded microwave pulses centered at 14 GHz and 19.2 GHz with a bit rate of 0.5 Gb/s were successfully generated. | | Accession Number: WOS:000916286100001 | | eISSN: 2304-6732 |
| Record 10 of 15 | | Title: GRPAFusion: A Gradient Residual and Pyramid Attention-Based Multiscale Network for Multimodal Image Fusion | | Author(s): Wang, JX (Wang, Jinxin); Xi, XL (Xi, Xiaoli); Li, DM (Li, Dongmei); Li, F (Li, Fang); Zhang, GX (Zhang, Guanxin) | | Source: ENTROPY Volume: 25 Issue: 1 Article Number: 169 DOI: 10.3390/e25010169 Published: JAN 2023 | | Abstract: Multimodal image fusion aims to retain valid information from different modalities, remove redundant information to highlight critical targets, and maintain rich texture details in the fused image. However, current image fusion networks only use simple convolutional layers to extract features, ignoring global dependencies and channel contexts. This paper proposes GRPAFusion, a multimodal image fusion framework based on gradient residual and pyramid attention. The framework uses multiscale gradient residual blocks to extract multiscale structural features and multigranularity detail features from the source image. The depth features from different modalities were adaptively corrected for inter-channel responses using a pyramid split attention module to generate high-quality fused images. Experimental results on public datasets indicated that GRPAFusion outperforms the current fusion methods in subjective and objective evaluations. | | Accession Number: WOS:000915585300001 | | PubMed ID: 36673310 | | Author Identifiers: | | AuthorWeb of Science ResearcherIDORCID NumberWang, Jinxin 0000-0003-4205-7673 xi, xiao li 0000-0002-7242-5695 | | eISSN: 1099-4300 |
| Record 11 of 15 | | Title: High Optical Feedback Tolerance of a Detuned DBR Laser for 10-Gbps Isolator-Free Operation | | Author(s): Yang, QL (Yang, Qiulu); Lu, D (Lu, Dan); He, YM (He, Yiming); Zhou, DB (Zhou, Daibing); Zhao, LJ (Zhao, Lingjuan) | | Source: PHOTONICS Volume: 10 Issue: 1 Article Number: 38 DOI: 10.3390/photonics10010038 Published: JAN 2023 | | Abstract: The optical feedback tolerance (OFT) of a distributed Bragg reflector (DBR) laser was investigated experimentally. The static and modulation performance of the DBR laser under optical feedback was examined by evaluating its relative intensity noise (RIN) and bit error rate (BER). It is shown that the OFT of the DBR laser is closely related to its peak wavelength detuning relative to the Bragg wavelength. A high tolerance to optical feedback was demonstrated, both in the continuous wave (CW) and the direct modulation (DM) states, when the DBR laser was red-detuned relative to the Bragg wavelength. The excess RIN induced by optical feedback was well suppressed to a level of -140 dB/Hz at a feedback level of -9 dB in the CW state. In a 10 Gbps direct modulation state, bit error rates (BER) below 1 x 10(-9) and 3 x 10(-7) were obtained under a feedback level of -15 dB and -9 dB, respectively, for the case of back-to-back transmission. After 20 km fiber transmission, the BER still maintained below 1 x 10(-7) under a feedback level of -15 dB, with a power penalty of less than 1 dB. | | Accession Number: WOS:000915966000001 | | eISSN: 2304-6732 |
| Record 12 of 15 | | Title: Influence of the lattice parameter of the AlN buffer layer on the stress state of GaN film grown on (111) Si | | Author(s): Zhang, ZZ (Zhang, Zhen-Zhuo); Yang, J (Yang, Jing); Zhao, DG (Zhao, De-Gang); Liang, F (Liang, Feng); Chen, P (Chen, Ping); Liu, ZS (Liu, Zong-Shun) | | Source: CHINESE PHYSICS B Volume: 32 Issue: 2 Article Number: 028101 DOI: 10.1088/1674-1056/ac6b2b Published: JAN 1 2023 | | Abstract: GaN films grown on (111) Si substrate with different lattice parameters of the AlN buffer layer by metal-organic chemical vapor deposition are studied. The stress states obtained by different test methods are compared and it is found that the lattice parameter of the AlN buffer layer may have a significant effect on the stress state in the initial stage of subsequent GaN film growth. A larger compressive stress is beneficial to improved surface morphology and crystal quality of GaN film. The results of further orthogonal experiments show that an important factor affecting the lattice parameter is the growth rate of the AlN buffer layer. This work may be helpful for realizing simple GaN-on-Si structures and thus reducing the costs of growth processes. | | Accession Number: WOS:000918175900001 | | ISSN: 1674-1056 | | eISSN: 2058-3834 |
| Record 13 of 15 | | Title: A Microwave Photonics True-Time-Delay System Using Carrier Compensation Technique Based on Wavelength Division Multiplexing | | Author(s): Zhao, YR (Zhao, Yiru); Wang, CQ (Wang, Chaoquan); Zhao, ZP (Zhao, Zeping); Zhang, WJ (Zhang, Weijie); Liu, JG (Liu, Jianguo) | | Source: PHOTONICS Volume: 10 Issue: 1 Article Number: 34 DOI: 10.3390/photonics10010034 Published: JAN 2023 | | Abstract: A novel microwave photonic true-time-delay (TTD) system using carrier compensation technology is proposed and experimentally demonstrated. Wavelength division multiplexing combines ten lasers into a single beam. We separate one channel from the laser as a compensating carrier, and the compensation carrier is combined with the time-delayed optical signals to be detected. Meanwhile, sideband signals are amplified effectively thanks to carrier-suppressed double-sideband (CS-DSB) modulation. Therefore, the power of both the central optical carriers and sidebands is guaranteed, which produces a better beat frequency result than the TTD system without carrier compensation. The simulation results confirm that the signal amplitude has an order of magnitude improvement due to the compensation. With employing the delay fibers based on multiple-fiber Bragg gratings (MFBGs), the experimental delay and response time reach 90.160 mu s and 160.80 ns. The proposed technique can find applications in time-delay beamforming of phased array antennas (PAAs). | | Accession Number: WOS:000918838900001 | | eISSN: 2304-6732 |
| Record 14 of 15 | | Title: Nonlinear dynamics of a semiconductor microcavity laser subject to frequency comb injection | | Author(s): Wang, T (Wang, Ting); Yang, YD (Yang, Yue-De); Hao, YZ (Hao, You-Zeng); Zhang, ZN (Zhang, Zhen-Ning); Shi, Y (Shi, Yang); Xiao, JL (Xiao, Jin-Long); Huang, YZ (Huang, Yong-Zhen) | | Source: OPTICS EXPRESS Volume: 30 Issue: 25 Pages: 45459-45470 DOI: 10.1364/OE.475651 Published: DEC 5 2022 | | Abstract: The nonlinear dynamical behaviors of a semiconductor microcavity laser with frequency comb injection have been experimentally and numerically investigated. The microcavity laser is harmonically locked to a unit fraction of the comb spacing due to the undamped relaxation oscillation at certain conditions, creating additional comb lines with reduced frequency spacing. The stability maps indicating various locking states are obtained based on rate equations, which demonstrates that the locking regions are closely related to the relaxation oscillation. Moreover, the microcavity laser with comb injection leads to spectral broadening of the original comb and the number of comb lines raises from 3 to 13. Owing to the large modulation bandwidth of the microcavity laser, the comb lines and the frequency spacing can be tailored over a wide range by varying the injection parameters.(c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement | | Accession Number: WOS:000917130000010 | | PubMed ID: 36522951 | | Author Identifiers: | | AuthorWeb of Science ResearcherIDORCID NumberHuang, Yong-Zhen 0000-0002-0529-4947 | | ISSN: 1094-4087 |
| Record 15 of 15 | | Title: Quantum phase transitions driven by sliding in bilayer MnBi2Te4 | | Author(s): Ren, Y (Ren, Yi); Ke, SS (Ke, Shasha); Lou, WK (Lou, Wen-Kai); Chang, K (Chang, Kai) | | Source: PHYSICAL REVIEW B Volume: 106 Issue: 23 Article Number: 235302 DOI: 10.1103/PhysRevB.106.235302 Published: DEC 2 2022 | | Abstract: Layered material MnBi2Te4 has bridged the fields of topology, magnetism and two-dimensional (2D) van der Waals materials, and attracted tremendous interest recently. Based on the first-principles calculation, we find that the topological, magnetic and ferroelectric properties of MnBi2Te4 bilayer can be engineered by interlayer sliding. By sliding bilayer MnBi2Te4, the interlayer exchange interaction can be tuned between ferromagnetic and antiferromagnetic, enabling the transition from ferromagnetic insulators to Chern insulators, and the charge transfer would lead to coexistence with antiferromagnetic and ferroelectric phases. Our work paves a different mechanical way to engineer quantum phases in 2D magnetic materials. | | Accession Number: WOS:000918963100002 | | ISSN: 2469-9950 | | eISSN: 2469-9969 |
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