半导体激光器电吸收调制器和双波导模斑转换器的单片集成

报道了1.6μm的半导体激光器和电吸收调制器以及双波导模斑转换器的单片集成器件.该器件具有良好的单横模特性和准单纵模特性(边模抑制比达25.6dB),3dB调制带宽为15GHz,直流消光比为16.2dB,远场发散角为7.3°×18.0°,和单模光纤的耦合效率达3.0dB.     

CMOS单片光接收机的带宽设计

设计了一个由调节型级联跨阻抗放大器(TIA)和双光电二极管(DPD)构成的光电集成接收机.给出了DPD小信号电路模型和单片集成光接收机的带宽设计方法,给出限制DPD和光接收机带宽的重要因素,分析和模拟了这个光电集成接收机的带宽,用低成本的0.6μm CMOS工艺设计出1.71GHz带宽和49dB跨阻增益的接收机,并给出测试结果.     

连续侧面泵浦Nd:YAG陶瓷激光器被动调Q研究

对比研究了808 nm激光二极管列阵侧面泵浦Nd∶YAG陶瓷与Nd∶YAG单晶激光器在连续和被动调Q运转下的激光输出特性。对于Nd∶YAG陶瓷激光器,在145 W泵浦功率,平平谐振腔20%输出耦合镜透过率时,获得最大44.28 W的1 064 nm连续激光输出,光-光转化效率和斜效率分别为30.5%和38.2%. 谐振腔中插入初始透过率87.89%的Cr⁴⁺∶YAG晶体作为被动调Q开关,在124 W泵浦功率下获得10.03 kHz重复频率,4.62 W平均功率,5.54 kW峰值功率的准连续激光输出。同样实验条件下利用相同尺寸和掺杂浓度的Nd∶YAG单晶进行对比,结果表明Nd∶YAG陶瓷在高功率泵浦下具有广阔的应用前景。     

Theoretical Prediction of Chiral 3D Hybrid Organic–Inorganic Perovskites

Hybrid organic–inorganic perovskites (HOIPs), in particular 3D HOIPs, have demonstrated remarkable properties, including ultralong charge‐carrier diffusion lengths, high dielectric constants, low trap densities, tunable absorption and emission wavelengths, strong spin–orbit coupling, and large Rashba splitting. These superior properties have generated intensive research interest in HOIPs for high‐performance optoelectronics and spintronics. Here, 3D hybrid organic–inorganic perovskites that implant chirality through introducing the chiral methylammonium cation are demonstrated. Based on structural optimization, phonon spectra, formation energy, and ab initio molecular dynamics simulations, it is found that the chirality of the chiral cations can be successfully transferred to the framework of 3D HOIPs, and the resulting 3D chiral HOIPs are both kinetically and thermodynamically stable. Combining chirality with the impressive optical, electrical, and spintronic properties of 3D perovskites, 3D chiral perovskites is of great interest in the fields of piezoelectricity, pyroelectricity, ferroelectricity, topological quantum engineering, circularly polarized optoelectronics, and spintronics.     

Temperature and voltage sensings by mode‐mode interference in polarization‐maintaining optical fibers

Abstract

Two optic fiber sensing systems for temperature and voltage have been developed which utilize the mode‐mode interference of the two orthogonally polarized modes, HE^x _II and HE^y _II, in two commencal polarization‐maintaining fibers (bow‐tie and elliptical core fibers). A package of controlled programs in a Macintosh computer, which can record and process all related data automatically, is established for temperature sensing. The signal drifting problem in voltage sensings has been investigated, and the elimination of signal drifting is obtained by the phase tracking with direct current technology The agreement between the sensing results for temperature and dynamic voltage and those predicted by experimental principles is satisfactory, which confirms the validity of the developed sensing systems.     

指数掺杂透射式GaAs光电阴极表面光电压谱研究

通过求解一维稳态少数载流子扩散方程,推导了指数掺杂和均匀掺杂的透射式GaAs光电阴极表面光电压谱理论方程。利用金属有机化学气相沉积(MOCVD)外延生长了发射层厚度相同、掺杂结构不同的两款透射式阴极材料。通过表面光电压谱实验测试和理论拟合发现指数掺杂结构在发射层厚度和后界面复合速率相同的情况下能够有效提高阴极电子扩散长度,这主要由于内建电场能够促使光生电子通过扩散和电场漂移两种方式向表面运动,从而最终提升阴极的发射效率和表面光电压谱。利用能带计算公式和电子散射理论对这两种不同结构材料的表面光电压谱进行了详细分析。     

激光外差探测中的空间失配问题研究

基于高斯本振光与高斯信号光的激光外差探测系统物理模型,利用数值模拟的方法研究了空间失配角、偏移失配、本振光与信号光的光程差、探测器相对位置以及探测器光敏面直径等因素对外差效率及外差信号幅值的影响.结果表明:外差效率及外差信号幅值受空间失配角和偏移失配的影响较大;并针对实际激光外差探测系统中空间失配角及偏移失配等因素对外...     

4H-SiC 雪崩光电探测器中倍增层参数的优化模拟

应用ATLAS模拟软件,设计了吸收层和倍增层分离的（SAM）4H-SiC 雪崩光电探测器（APD）结构。分析了不同外延层厚度和掺杂浓度对器件光谱响应的影响,对倍增层参数进行优化模拟,得出倍增层的最优化厚度为0.26μm,掺杂浓度为9.0×1017cm^-3。模拟分析了APD的反向IV特性、光增益、不同偏压下的光谱响应和探测率等,结果显示该APD在较低的击穿电压66.4V下可获得较高的倍增因子105;在0V偏压下峰值响应波长（250nm）处的响应度为0.11A/W,相应的量子效率为58%;临近击穿电压时,紫外可见比仍可达1.5×103;其归一化探测率最大可达1.5×1016cmHz ^1/2 W^-1。结果显示该APD具有较好的紫外探测性能。     

大量程折射率仪的研究

利用亚毫米尺度对称金属包覆波导,提出了一种大量程折射率仪的工作原理,这种仪器可测量气体、液体和固体的折射率。原理上,只要待测介质对所用激光波长透明,折射率测量范围不受限制。通过对空气、纯水和LiNbO3晶体的测量,结果表明仪器的测量精度小于3.0 ╳10-3。     

电子科学与技术专业光电子实验室建设

我院根据教学需要,建设了专门为电子科学与技术专业本科教学服务的光电子实验室.本文从实验内容、实验仪器的设计和制作、实验环境的建设和实验教材编写等方面介绍了实验室建设情况.本实验室已经为本校相关专业的教学提供了良好的教学服务.根据实验教学的发展趋势和本校的实际情况,文中提出了下一步实验室建设的思路.