Author Affiliations
Abstract
1 DTU Electro, Department of Electrical and Photonics Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
2 Jiaxing Key Laboratory of Photonic Sensing & Intelligent Imaging, Jiaxing 314000, China
3 Intelligent Optics & Photonics Research Center, Jiaxing Research Institute Zhejiang University, Jiaxing 314000, China
An optical phased array (OPA), the most promising non-mechanical beam steering technique, has great potential for solid-state light detection and ranging systems, holographic imaging, and free-space optical communications. A high quality beam with low sidelobes is crucial for long-distance free-space transmission and detection. However, most previously reported OPAs suffer from high sidelobe levels, and few efforts are devoted to reducing sidelobe levels in both azimuthal (φ) and polar (θ) directions. To solve this issue, we propose a Y-splitter-assisted cascaded coupling scheme to realize Gaussian power distribution in the azimuthal direction, which overcomes the bottleneck in the conventional cascaded coupling scheme and significantly increases the sidelobe suppression ratio (SLSR) in the φ direction from 20 to 66 dB in theory for a 120-channel OPA. Moreover, we designed an apodized grating emitter to realize Gaussian power distribution in the polar direction to increase the SLSR. Based on both designs, we experimentally demonstrated a 120-channel OPA with dual-Gaussian power distribution in both φ and θ directions. The SLSRs in φ and θ directions are measured to be 15.1 dB and 25 dB, respectively. Furthermore, we steer the beam to the maximum field of view of 25°×13.2° with a periodic 2λ pitch (3.1 μm). The maximum total power consumption is only 0.332 W with a thermo-optic efficiency of 2.7 mW/π.
Photonics Research
2023, 11(4): 659
Author Affiliations
Abstract
1 Department of Physics, College of Liberal Arts and Sciences, National University of Defense Technology, Changsha 410073, China
2 DTU Fotonik, Technical University of Denmark, Lyngby DK-2800, Denmark
3 School of Electrical Engineering, Yanshan University, Qinhuangdao 066004, China
4 e-mail: xjli@nudt.edu.cn
5 e-mail: xgua@fotonik.dtu.dk
Microring resonators (MRRs) with ultracompact footprints are preferred for enhancing the light-matter interactions to benefit various applications. Here, ultracompact titanium dioxide (TiO2) MRRs with sub-10-μm radii are experimentally demonstrated. Thanks to the large refractive index of TiO2, the quality factors up to 7.9×104 and 4.4×104 are achieved for TiO2 MRRs with radii of 10 μm and 6 μm, respectively, which result in large nonlinear power enhancement factors (>113) and large Purcell factors (>56). The four-wave mixing (FWM) measurements indicate that, compared to the large MRR, the FWM conversion efficiency of the ultracompact TiO2 MRRs can be greatly improved (e.g., -25 dB versus -31 dB), a harbinger of significant superiorities. Demonstrations in this work provide more arguments for the TiO2 waveguides as a promising platform for various on-chip photonic devices.
Photonics Research
2021, 9(7): 07001416
作者单位
摘要
西北核技术研究所,陕西 西安 710024
漫反射非接触测量方法是测量入射激光功率密度分布的有效手段。但强激光长时间辐照漫反射金属靶板,材料上升到一定温度表面反射率将显著下降,影响测量效果。基于有限元方法,结合热源抖动和风速对流,对镀金膜的铝板进行了强激光辐照条件下的温度变化模拟,结果表明材料表面能量吸收率是决定温度升高的关键因素。通过粗糙度设计可实现与光滑表面吸收率接近的漫反射表面,有效降低靶板温度,为优化漫反射金属靶板设计提供参考。
激光技术 功率密度 金属靶板 温度分布 表面粗糙度 
中国激光
2015, 42(s1): s102001
作者单位
摘要
State Key Laboratory for Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, Zhejiang Provincial Key Laboratory for Sensing Technologies, Zhejiang University, Hangzhou 310058, China
plasmonics hybrid silicon nanowire integration 
Frontiers of Optoelectronics
2014, 7(3): 300–319
Author Affiliations
Abstract
Northwest Institute of Nuclear Technology, Xian 710024, China
We simulate the integrated effects of atmospheric aberration, atmospheric turbulence, thermal blooming, random jitter of laser's intensity and phase, speed of wind, direction of wind, absorption of air, kinetic cooling of CO2 and N2, speed of target, output power and beam quality of laser, wavelength, focus length, and the launch altitude of laser to accurately simulate the transmission loss of the laser's energy, concentration of laser's power and other beam quality parameters of the laser propagating to the dynamic target. And we evaluate the efficiency of laser's irradiation on the target more accurately for the optical link of ground-to-airspace. We also investigate influences of characteristics of dynamic parameters (Strehl's ratio, RMS of wave-front, spatial distribution of intensity on the target, the real focus on the optical link and the peak intensity along the propagation path) including speed of wind, direction of wind, speed of target and the kinetic cooling effect of air, especially. We conclude that the higher speed of wind and target weakens the thermal blooming of atmosphere and improves the beam quality and efficiency of laser's irradiation on the target. The kinetic cooling effect of air is more remarkable to improve the beam quality irradiating on the target at the initial part of the propagation path of the laser. The changed direction of wind weakens the atmospheric aberration and directs to better beam quality and higher efficiency of laser's irradiation on the target.
010.1290 Atmospheric optics 010.1300 Atmospheric propagation 010.1330 Atmospheric turbulence 
Chinese Optics Letters
2014, 12(s2): S20101
作者单位
摘要
西北核技术研究所, 陕西 西安 710024
采用激光主动照明技术,是对远距离暗目标进行成像、定位和跟踪的重要手段。但由于激光在大气路径中传输,受到大气湍流等因素的影响会造成辐照在目标上的激光光强分布不均匀,同时激光波前会产生畸变,从而降低目标的成像质量,影响对目标的高精度跟踪能力。基于激光照明大气传输模型,对中等湍流、弱湍流和不同光束数情况下的激光照明结果进行了数值模拟,分析了照明激光光强和波前对远距离目标成像的影响。计算结果表明:照明光强起伏方差优于0.5,波前畸变标准误差优于0.2 λ,可满足约1μrad量级的目标分辨能力。
激光技术 激光主动照明 大气湍流 激光传输 成像分辨率 
光学学报
2014, 34(s1): s101004
作者单位
摘要
1 浙江大学现代光学仪器国家重点实验室, 浙江 杭州 310027
2 西北核技术研究所, 陕西 西安 710024
为了研究白宝石在纳秒激光辐照下表面损伤的特性,利用有限元方法对脉冲激光作用下白宝石的温度场进行仿真,分析白宝石中Cu杂质在不同激光能量密度下的温升变化,以及杂质尺寸对温升的影响,并采用波长1064 nm、脉宽6 ns的激光对两种不同尺寸白宝石晶体材料进行实验,对材料的损伤阈值、损伤位置分布、不同激光能量密度对损伤面积的影响以及损伤增长特性进行了分析。结果表明,杂质吸收机制可以较好地解释白宝石在纳秒激光脉冲辐照下的损伤过程,且仿真结果与实验结果吻合较好,当“1-on-1”辐照时,材料表面的损伤面积随着激光能量密度的增大呈线性增长,当“s-on-1”辐照时,材料后表面的损伤面积随脉冲次数增大呈指数增长。
激光技术 激光诱导损伤 损伤实验 白宝石 表面损伤特性 
中国激光
2014, 41(s1): s106008
作者单位
摘要
西北核技术研究所, 陕西 西安 710024
根据简单饱和增益模型建立的氧碘化学激光器功率模型,理论分析了氧碘化学激光器功率稳定性影响因素。结合氧碘化学激光器实际监测参数,研究了氯气压力和碘文氏管压力对氧碘化学激光器功率稳定性的影响。实验结果表明,在1~6 s时间段内,随着出光时间的变长,氯气压力和碘文氏管压力的均方根(RMS)值变小,同时,较小的氯气压力和碘文氏管RMS值,相应的出光功率的RMS值也会较小,这说明提高氯气压力和碘文氏管压力的稳定性可以提高氧碘激光器出光功率的稳定性。
激光器 功率稳定性 氯气压力 碘文氏管压力 
光学学报
2014, 34(s1): s114004
作者单位
摘要
西北核技术研究所 激光与物质相互作用国家重点实验室, 西安 710024
对高功率半导体泵浦固体激光器(DPL)系统的可靠性进行了分析, 根据GO法的原理构建了DPL系统的GO图; 利用GO法计算公式, 得到了系统故障率和平均无故障工作时间等重要可靠性指标。结果符合实验室经验值。最后分析了各部件的故障率的重要度, 讨论了改善高功率DPL系统可靠性的措施, 对系统的使用和维修等工作具有参考意义。
GO法 半导体泵浦固体激光器 可靠性 故障率 维修率 GO methodology diode-pumped solid-state laser reliability failure rate repair rate 
强激光与粒子束
2014, 26(2): 021005
作者单位
摘要
1 中国科学院 光电技术研究所, 成都 610209
2 中国科学院大学, 北京 100039
3 西北核技术研究所, 西安 710024
对空间目标实际探测过程中,光电系统的探测能力不仅与其可探测信噪比有关,还与其所成图像的质量有关,即空间分辨能力有关。针对现有光电系统探测能力分析不足,提出了一种基于调制传递函数下的信噪比探测模型(MSNR),给出了基于MSNR下的系统极限探测能力综合评估方法,实现可定量分析大气、像差、目标运动等对系统探测能力的影响;利用实测数据完成对MSNR模型的完善,对不同条件下光电系统的极限探测能力进行了仿真,仿真结果表明: 大气条件、系统像差、目标运动等条件对系统的探测能力影响明显,目标运动导致探测能力降低近1.0等星;该方法实现定量对光电系统的探测能力进行综合评估,可为系统优化设计与实际工作开展提供一定的科学依据。
探测能力 调制传递函数 信噪比 空间目标 detecting ability modulation transfer function signal-to-noise ratio space target 
强激光与粒子束
2014, 26(1): 011013

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