有源-吸收分段式脊型波导半导体激光器的光双稳激射特性

本文报道了一种脊型波导有源-吸收分段结构半导体激光器中的光双稳输出特性的实验研究结果及其理论分析.给出了实验中发现的获取最大光滞回线宽度(Hysterisis)、所对应的器件结构参数以及电注入水平.此外,一种光线近似理论模型被采用来求解光输出特性从而得到了与实验近似一致的结果.     

Semiclassical theory of optically bistable laser by output-feedback pumping scheme

Steady-state solutions of the output-feedback pumped bistable laser(OFPBL)have been obtained using the semiclassical laser equations.A linear-stability of the solutionshas been analysed.The results tell us that width of the hysteresis loop and the laser output in-tensity vary widely with the pump intensity and the intensity of input optical signal and thefeedback coefficient of the laser output as well as the other parameters.It shows that this typeof bistable laser is a kind of active optical bistable device which can be adjusted and controlledconveniently.     

Current-driven state-bistability and power-bistability in a DFB semiconductor laser subject to optical injection

In this paper, current-driven state-bistability and power-bistability in a distributed feedback (DFB) semiconductor laser (LD) subject to external optical injection have been investigated experimentally. The results show that, by sweeping the bias current of slave LD along different routes nearby the threshold, both the power-bistability and the state-bistability between locking and bimodal regime can be observed under the suitable injection power, but these bistable phenomena will disappear under much large injection power. Additionally, the dependence of the width of the state-bistablility loop on the injection power has been discussed.     

Bistable Optical Devices Using Laser Diodes Coupled to Interference Filters

A bistable optical device was demonstrated by using the longitudinal mode hopping of the laser diode and the narrow transmission spectrum of an interference filter. The device is capable of converting changes in the wavelength of the laser diode into changes in intensity by transmitting it through the filter. Exclusive OR operation was observed with the use of triple signal outputs. In addition, an optical switch-off phenomenon was confirmed by directly injecting a pulse 500 ps wide into an external dye laser.     

Controlling Chaos of a Delayed Optical Bistable System

High-dimensional chaos was controlled with the occasional proportional feedback technique in a delayed optical bistable system which consists of a laser diode interferometer with a delayed opto-electronic feedback loop. Both the experiment and the numerical simulation showed that a large number of periodic orbits can be stabilized by controlling the chaotic attractor. The transient state of the trajectory under control was demonstrated.     

端面抽运Tm，Ho：YLF激光器双稳特性的理论分析与实验研究

报道了波长为792nm激光二极管端面抽运Tm,Ho：YLF连续激光器的双稳输出特性.在考虑能量传递上转换和基态对2μm激光重吸收的前提下,建立了Tm,Ho：YLF双稳激光器准三能级速率方程理论模型.通过对Tm,Ho：YLF激光器速率方程的求解,理论预见了Tm,Ho：YLF激光器双稳输出的特性,并分析了其产生的机理.进行了激光二极管端面抽运Tm,Ho：YLF激光器双稳输出的实验研究,当激光晶体温度为253K时,双稳区的宽度可达1.6W,跃变点输出功率的跃变量可达82.5mW.通过对比发现理论结果与实验结果比 关键词： 端面抽运 Tm Ho：YLF晶体 连续输出 光学双稳     

Bistable operation of a GaAs-AlGaAs diode laser coupled to an external resonator of narrow spectral bandwidth

The influence of an external dispersive resonator on the emission properties of a double heterostructure semiconductor laser operating at room temperature has been investigated. The proper design of the external resonator (frequency selectivity and efficient back-coupling of the radiation leaving the diode) demonstrates that a laser with optical feedback can show bistability and hysteresis phenomena. The dispersive bistability has its origin in the dependence of the refractive index on carrier density, temperature and optical power. Hysteresis curves have been measured by changing the injection current or by tuning the dispersive element. We have found a threshold in the injection current for the onset of the hysteretic behaviour. Moreover, a theoretical model has been established to explain the essential features of the experimental results. Hysteresis cycles for different experiments have been calculated.     

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     

Speckle-pattern contrast of semiconductor laser propagating in a multimode optical fiber

Speckle patterns produced by coherent light from a GaA1As double-hetero-structure laser diode that has been transmitted through a multi-mode optical fiber are experimentally studied by analyzing the average contrast. It has been found that the speckle contrast observed in the far-field region is significantly lowered when the spectral width of a laser diode is as broad as a few tens of Angstroms.     

Optical bistability effects in a Tm,Ho:YLF laser at room temperature

We demonstrate strong optical bistability in a 2 microm continuous-wave Tm,Ho:YLF laser pumped by a 792 nm laser diode near room temperature. The bistable region is as much as 100 mW wide at 283 K and can be controlled by the temperature of the laser crystal. The influence of crystal temperature on the characteristics of optical bistability is obtained. The influence of the pump-to-mode ratio on the bistable characteristics of the laser is also discussed. To our knowledge this is the first report of optical bistability effects in Tm,Ho:YLF lasers.     

Frequency dynamics of semiconductor lasers with atomic absorbers: theory and experiments

In this paper we discuss the spectral behavior of monomode semiconductor laser systems whose output amplitude is constant, but whose frequency may be bistable, multistable, locked or present instabilities. The explored configurations are: (i) a laser diode (Fabry-Pérot) under orthogonal filtered optical feedback; and (ii) an extended-cavity diode laser with an intracavity strongly-saturated resonant vapor. Starting from rate equations for the carrier density and for the radiation field oscillating in the cavity of these systems we describe spectral features which are in very good quantitative agreement with experimental observations.     

Analysis of fringe locking in a laser diode interferometer under injection-current modulation

A theoretical analysis has been performed that explains a fringe-locking phenomenon observed in a two-beam interferometer in which a laser diode was subjected to optical feedback and modulation of its injection current. The dependence of wavelength change on the injection-current variation is calculated by use of a model of coupled resonators consisting of the laser cavity and the interferometer. The fringe phase change caused by modulation of the injection current is derived from this model and has proved to be suppressed within much less than 2pi in excess of an integer multiple of 2pi if the path difference of the interferometer is longer than 10 mm. The calculated phase fluctuation agrees well with those observed in experiments.     

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     

A Narrow Line Width Tunable Diode Laser System

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BILED／BILD组合回路的光学逻辑运算

利用激光二极管或发光二极管混合双稳态回路(BILD/BILED)的组合,得到了光学多稳态,光学异或逻辑门和光学R-S触发器.这种光电子学的逻辑回路与大规模集成技术完全相容,因此有希望应用于光学信息处理,光通信和光计算.     

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.     

End-pumped optical bistability Tm,Ho:YLF laser

We experimentally demonstrate strong optical bistability in a 2 μm continuous wave Tm,Ho:YLF laser with a bulk crystal. The laser is end-pumped by a 792 nm fiber-coupled laser diode. The bistable region is as wide as 1.6 W and the jump power at the turning point is as high as 82.5 mW when the temperature of the laser crystal is kept at 253 K. The influences of the cavity length and the transmission of the output coupler on the characteristics of optical bistability are obtained. The theoretical analysis shows that the bistable output in the Tm,Ho:YLF lasers comes from the combined effects of the nonlinear saturation of ground state reabsorption, the energy transfer upconversion, and the excited state absorption.     

基于延时光电反馈控制两段式半导体激光器的双稳及自脉动特性

提出一种将延时光电反馈引入两段式双稳半导体激光器（TBLD）的吸收区，从而达到控制其双稳及自脉动特性的方案.利用速率方程模型，分析了反馈增益及延迟时间对TBLD双稳及不稳定特性的控制作用.数值模拟的结果表明：TBLD的稳定区域随延迟时间呈周期性变化；双稳区域随延迟时间的增大而变窄；在一定的取值范围内，增大延迟时间有利于增强双稳的稳定性；负反馈更容易出现不稳定性. 关键词： 两段式双稳半导体激光器 动态双稳 自脉动 延时光电反馈     

基于SOA的环形腔激光器在全光信号处理中的应用

半导体光放大器（SOA）因其具有良好的光光互作用特性,包括交叉增益调制、交叉相位调制、交叉偏振调制以及四波混频等,在全光信号处理技术中已经获得了广泛的应用。利用SOA与光纤反馈可构成环形腔激光器S_FRL。在S—FRL中将SOA的光一光互作用特性与反馈条件相结合,可以改变孓FRI．的起振、抑制、选频等多种状态,从而构成不同功能的全光信号处理器件。在分析S—FRL激光振荡原理的基础上,提出了双环耦合的S-FRL,并以此为基础构成一种双环耦合的双稳态触发器,进而构成一种同步脉冲展宽器;还提出了一种级联的S-FRL,由此构成一种基于负逻辑的全光判决器。