一种光电混合集成有源光双稳器件

本文报道一种光电混合集成的有源双稳态器件,它仅由一只半导体激光器,两只PIN光电探测器及几只电子元器件构成.实验上得到了光学迟滞回线,显示了光开关、光存储、光脉冲整形等功能.文中简述了器件工作原理,光电混合集成制作工艺技术及性能指标.     

基于DFB腔注入锁定效应的可调谐光电振荡器

提出一种基于分布反馈光注入锁定效应的可调谐光电振荡器,其环路主要由马赫曾德尔调制器、光电探测器、环形器、分布反馈激光器和射频放大器顺接而成,分布反馈激光器是系统关键器件,通过分布反馈激光器光注入锁定效应,分布反馈腔在光域实现了微波光子滤波器功能,无需传统光电振荡器必须的射频带通滤波器.同时,由于分布反馈激光器注入锁定提高了环路Q值,因此系统可采用短环路结构,从而降低了光纤因温度敏感对微波信号稳定性的影响并减小了整个系统的尺寸.另外,通过调节注入光波长和功率可改变该微波光子滤波器的中心频率,从而可实现系统的可调谐性.理论分析了该光电振荡器的原理和微波光子滤波器的调谐性,在此基础上开展了实验验证.结果表明该光电振荡器能够产生18.7～21.6 GHz的可调微波信号,在1 kHz频偏处的相位噪声为-90 dBc/Hz.     

Chaotic signal generation and cancellation using a micro ring resonator incorporating an optical add/drop multiplexer

We propose a new design of a chaotic signal generation and cancellation system using an all fiber optic scheme. A system consists of a standard diode laser, a fiber optic micro ring resonator, and an optical add/drop multiplexer. When light from the diode laser is input into the fiber ring resonator, the chaotic signal can be generated by using the selected fiber ring resonator parameters and the diode laser input power. The required signal is obtained in the transmission link via the add/drop device by a specific user at the drop port. Simulation results obtained have shown the potential of application, especially, when the practical ring radius is 10 μm with the optical input power is in the range of the communication standard diode laser, for instance, when the coupling coefficients of the add/drop device are κ₁ = 0.01 and κ₂ = 0.01–0.9. When the add port of the add/drop device is employed, such a system can also be utilized for the multi user applications.     

Frequency doubling of wavelength locked laser diOde with a transmission-type filter in a confocal optical configuratiOn

Direct frequency doubling of a wavelength locked laser diode with an optical bandpass filter in a confocal optical configuration is demonstrated. The wavelength of the laser diode was locked in single longitudinal mode oscillation and tuned to phase-matching wavelength of a quasi-phase-matched second harmonic generation device based on a LiTaO₃ Waveguide. Stable blue light of 4.2 mW was obtained for incident power of 48 mW.     

光耦合理论及其在通信元器件中的应用

运用矩阵光学中变换矩阵的理论,并以重叠面积积分的方法为基础,推导出了普遍适用于计算光在光通信元器件中光耦合效率的理论公式,可通过设置边界条件计算单模光纤、扩束光纤、半导体激光二极管以及光波导等不同光学元器件之间的耦合效率。导出了计算单模光纤之间和单模光纤与扩束光纤之间存在横向偏移、轴向偏移时的耦合效率理论通用公式。阐述了扩束光纤的制作方法及光在扩束光纤中的传播,并根据所推导耦合效率理论公式计算结果与单模光纤间和单模光纤与扩束光纤间的耦合实验数据进行了比较。     

激光雷达系统快速准直的方法和光学装置

 研制了一种能够方便、快速调节激光雷达收发光路准直的光学装置,分析了装置楔角的选取要求、准直误差及其相应的矫正方法。该装置结构简单,主要由两个楔形光学平板组成,通过电机转动两个楔板可使出射光束方向在一定范围内任意改变,该调节范围由楔板的楔角和折射率决定。利用折射定律,严格推导了装置中两个楔形光学平板的旋转角度与出射光束方向之间的关系。提出了将该光学装置插入到激光雷达发射光路,采用螺旋式粗扫、圆形和径向细扫相结合的光束扫描方式实现对激光雷达准直的方法,并给出了系统准直调节过程中的判断准则和具体的准直步骤。     

Efficient noise suppression of an amplified diode-laser by optical filtering and resonant optical feedback

We present the noise suppression of an amplified diode laser by using an optical filter and resonant optical feedback. The intensity noise of the amplified diode laser has been significantly decreased by using the optical filter cavity. It was further suppressed and reached the shot noise limit at 15 MHz by introducing resonant optical feedback from the transmission of the filter cavity. The filter cavity transmits 53% of injection power, and the output power of the filter cavity is more than 200 mW. The observed frequency fluctuations were less than 100 kHz in one minute. This level of noise suppression and output power may allow diode lasers to be utilized in many quantum-optics experiments. PACS 42.55-f; 42.55-Px; 42.50.-p     

基于法布里-珀罗半导体激光器实现高重复频率光脉冲的时钟分频

实验研究了重复速率为6.32 GHz的光脉冲注人法布里-珀罗(Fabry-Perot)半导体激光器实现3.16 GHz光脉冲输出的时钟分频现象,讨论了 Fabry-Perot半导体激光器的偏置电流、注入光功率、注入光光谱以及光谱线宽等因素对时钟分频的影响.利用光注入半导体激光器产生的周期二振荡非线性动力学特性.实现了高重复速率光脉冲的时钟分频.研究表明,当注入光的光谱较窄且锁定Fabry-Perot半导体激光器某一纵模时,在较低的偏置电流和一定的注入光功率时,时钟分频才能发生.采用半导体激光器的速率方程.通过数值模拟,研究了半导体激光器的偏置电流和线宽增强因子以及注入光功率对时钟分频的影响,所得结果与实验结果相吻合.     

Tunable Single-Passband Microwave Photonic Filter Based on Sagnac Loop and Fabry-Perot Laser Diode

A tunable single-passband microwave photonic filter is proposed and demonstrated, based on a laser diode(LD)array with multiple optical carriers and a Fabry-Perot(F-P) laser diode. Multiple optical carriers in conjunction with the F-P LD will realize a filter with multiple passbands. By adjusting the wavelengths of the multiple optical carriers, multiple passbands are merged into a single passband with a broadened bandwidth. By varying the number of the optical carrier, the bandwidth can be adjusted. The central frequency can be tuned by adjusting the wavelength of the multiple optical carriers simultaneously. A single-passband filter implemented by two optical carriers is experimentally demonstrated.     

Design of a Reflective Aspherical Surface of a Compact Beam-Shaping Device

A compact beam-shaping device with a reflective aspherical surface is proposed. The device converts a circular symmetric Gaussian beam from a laser into a uniform distribution on a target plane. The device consists of a laser, a reflective aspherical surface formed on the base plane inclined by 45° against the optical axis, and a spacer. The surface is designed for an optical device used as a transmitter of indoor wireless optical communication, which is one of the promising applications. The designed surface is obtained by approximation using polynomial. Beam shaping of a simulated surface and a uniform intensity distribution on the target plane is obtained. The intensity distribution generated by the surface is numerically simulated and evaluated if the surface is misaligned. It is clarified that the generated distribution is tolerable for the misalignment.     

采用多量子阱器件的无线光通信差拍接收方案研究

研究一种采用光折变多量子阱器件的无线光通信自差拍接收方案。与寻常相干接收方案相比,省去了中频跟踪电子系统;与量子阱器件零拍方案相比,采用中频窄带滤波器,提高了接收端机的输出信噪比。理论上研究了自差拍相干接收方案,从其物理机制出发,结合信噪比分析,探讨了影响相干接收方案的主要因素。建立了该方案的实验系统,并开展了有意义的实验研究。理论分析及实验结果表明,该方案对激光大气传输所引起的诸多不利影响皆有一定的抑制作用,因而有可能应用于卫星地面激光通信和地面无线光通信系统。     

Electrically and Optically Bistable Operation in an Integration of a 1310 nm DFB Laser and a Tunneling Diode

We experimentally demonstrate an In P-based hybrid integration of a single-mode DFB laser emitting at around 1310 nm and a tunneling diode. The evident negative differential resistance regions are obtained in both electrical and optical output characteristics. The electrical and optical bistabilities controlled by the voltage through the tunneling diode are also measured. When the voltage changes between 1.46 V and 1.66 V, a 200-mV-wide hysteresis loop and an optical power ON/OFF ratio of 17 dB are obtained. A side-mode suppression ratio of the integrated device in the ON state is up to 43 dB. The tunneling diode can switch on/off the laser within a very small voltage range compared with that directly controlled by a voltage source.     

激光器型全光波长转换器的小信号分析

当外部光子注入到激光器有源腔中时 ,载流子把被注入光子消耗的一部分放大 ,进而激光器自身的输出功率将降低。基于此 ,可以实现全光波长转换。理论上基于载流子消耗机制 ,对激光器型波长转换器进行了小信号分析 ,给出了频率响应函数。理论分析表明 ,激光器型全光波长转换器的转换速度取决于激光器光子寿命以及激光器腔内的光子密度。     

基于光纤Fabry-Perot滤波器的电光混合光学双稳态

提出了一种新型的电光混合光纤光学双稳装置,它由波长为1.55μm带尾纤的DFB半导体激光器、全光纤可调谐Fabry_Perot滤波器和电光反馈电路构成。实验中通过改变输入光强实现了光学双稳运转。讨论了该双稳器件在激光光强稳定器和光纤传感器方面的应用。     

基于飞秒光频梳的压电陶瓷闭环位移控制系统

利用飞秒光频梳、外腔可调谐半导体激光器和法布里-珀罗干涉仪建立了一套压电陶瓷亚纳米级闭环位移控制系统. 将可调谐半导体激光器锁定至光频梳, 通过精确调谐光频梳的重复频率, 实现了半导体激光器在其工作频率范围内的精密调谐. 利用Pound-Drever-Hall锁定技术将带有压电陶瓷的法布里-珀罗腔锁定至半导体激光器, 进而通过频率发生系统控制压电陶瓷产生亚纳米级分辨率的位移. 实验研究发现锁定至光频梳后可调谐半导体激光器1 s的Allan标准偏差为1.68×10^-12, 将其在30.9496 GHz范围内进行连续闭环调谐, 可获得压电陶瓷的位移行程约为4.8 μm; 以3.75 Hz的步长扫描光频梳的重复频率, 实现了压电陶瓷的450 pm闭环位移分辨率并测定了压电陶瓷的磁滞特性曲线. 该系统不存在非线性测量误差, 且激光频率及压电陶瓷位移均溯源至铷钟频率源. 关键词： 光频梳 压电陶瓷 法布里-珀罗腔 可调谐半导体激光器     

Detection and jamming experiment of optical surveillance device in night equipment transportation北大核心CSCD

针对装备运输过程中可能遭遇侦拍的风险,结合运输安全需求,分析市面上常见的4类消费级侦拍装置(手机、卡片数码相机、单反相机和数码摄像机)的光电可探测性,并实现对各装置的有效干扰。通过搭建“猫眼”激光探测、激光干扰及回波信号接收系统,重点突破典型小口径侦拍装置的探测与识别,以及“猫眼”探测端与目标端的双向成像等理论和关键技术。在此基础上分析不同距离、干扰波长和孔径情况下可见光波段激光对“猫眼”目标的探测及成像干扰效果,并提出一种图像干扰效果评价标准及不同光学侦拍装置的有效干扰阈值。实验结果表明:典型光学侦拍装置在实验距离内具有良好的光电可探测性,并且可被有效干扰;在激光束完全覆盖镜头通光孔径时,目标与装置距离越近,激光束散角越小,波段越接近人眼敏感程度最大波段(555 nm),激光光束产生的非伤害性成像干扰效果越好。     

Bidirectional WDM-PON architecture using a reflective filter and cyclic AWG

We proposed and demonstrated a bidirectional SCM-WDM PON using a reflective filter and cyclic AWG where up/downlink data could be provided using a single optical source. In the proposed scheme, the signal for downstream was modulated by a single CW laser diode and remodulated in the optical network unit as an upstream, the proposed WDM-PON scheme can offer the SCM signal for broadcasting service. In this paper, 1 Gb/s signals both for up- and downstream were demonstrated in 10 km bidirectional optical fiber link.     

外光注入半导体激光器实现时钟分频

从理论和实验上研究了利用光注入半导体激光器对高重复速率光脉冲产生的周期振荡和时钟分频现象.结果表明，光注入半导体激光器引起的二倍周期振荡是使注入脉冲重复频率分频的直接原因.通过耦合速率方程，数值模拟了半导体激光器在外光注入时输出光的时间序列和功率谱，并且分析了激光腔内各种周期振荡的特征.研究表明，当注入光使半导体激光器出现稳定的二倍周期振荡，且注入光的重复频率为此振荡频率的二倍时，时钟分频即可产生实验中，采用重复频率为6.32GHz的光脉冲注入Fabry-Perot激光器，实现了3.16GHz时钟分频信号 关键词： 周期振荡 时钟分频 光谱侧带 光注入     

利用光频梳提高台阶高度测量准确度的方法

提出一种利用光频梳和可调谐半导体激光器提高台阶高度测量准确度的方法. 通过将可调谐激光器锁定至光频梳,可对激光器的输出波长进行精确锁定与测量.基于可调合成波长链原理,利用锁定后的半导体激光器构建了一套台阶高度测量方案,该方案可消除合成波长误差对台阶高度测量不确定度的影响. 采用一台可调谐半导体激光器和光频梳进行了5000 s的连续锁定实验, 结果表明,锁定后的可调谐半导体激光器的频率稳定度达 1.8×10^-12.该方法的理论测量不确定度约为7.9 nm, 且测量结果可溯源至时间频率基准.     

实现20Gbit/s的OTDM孤子信号56km色散位移光纤的传输

在国内最先采用孤子的方式将8×2.5Gb/s的OTDM信号在色散位移光纤中传输了56.1km,对8×2.5Gb/s的OTDM进行解复用后进行了误码测量,系统功率代价为2.9dB.系统采用增益开关半导体激光器作光孤子源,高Q电滤波方式提取时钟,非线性光学环路镜解复用。孤子脉冲最大半宽度为20ps,传输光纤平均色散1.2ps/nm/km。