Monolithic integration of InGaAsP-laser with transferred-electrondevice as fast laser driver

A monolithically integrated laser driver circuit has been fabricated incorporating an InGaAs-transferred electron device (TED) and an InGaAsP mushroom stripe laser emitting at 1.3-μm wavelength. The TED provides a large-signal modulation of the laser diode along with a pulse shaping of the optical output signal. A threshold current of 18 mA of the integrated laser has been obtained. The modulation of the optical output signal by the TED has been demonstrated. For practical application of the circuit under dc-bias conditions the thermal resistance of the TED's has been calculated and an optimum device structure is proposed. The possibility of triggering the circuit optically will be discussed     

CO2激光测距机用智能化计数逻辑及控制电路

本文介绍了一种CO2激光测距机用智能化计数逻辑及控制电路,该电路也可用于一般脉冲式激光测距机。     

车载激光侦察告警系统的研究

简述了激光告警器的发展和现状，介绍了车载激光告警器的系统组成、工作原理和特点，并着重对激光探测头和信息处理器设计进行了分析、说明。探测头中的光电探测器采用InGaAsPin光电二极管。信息处理器没有阈值电路，脉宽甄别，二次反射信号抑制等数字化电路，在确认是激光信号后，首先将激光信号数字化，经运算术出激光入射方向，进而通过威胁类型和等级判断电路判别是激光测距信号还是激光制导信号，并根据数据库中存储的数据判断其威胁等级。告警系统具有灵敏度高、响应时间快、动态范围宽等特点，与烟幕施放装置连为一体，实现了激光探测与烟慕干扰的有机结合，并预留了与其他控制设备的通讯接口，便于系统扩展。     

A new bistable laser diode configuration for all optical switching

A new bistable laser diode configuration for all optical switching has been suggested and its equivalent circuit model is developed. For switching the device to the high state (set) a TE mode optical pulse is required, which is the oscillating mode of the laser, whereas a TM mode pulse is used to bring the output to a low state (reset). But the wavelength of the set and reset pulses are the same as that of the lasing wavelength of the device. The static and dynamic characteristics are studied by simulating the equivalent circuit model using the circuit simulation program PSPICE. It is found that as the carrier lifetime τ_a of the absorption section increases, the width of the optical pulse required for reset increases nonlinearly. The rise and fall times are found to be 0.15 and 0.16 ns, respectively, for a τ _a, of 3 ns     

激光近距离动态探测系统发射电路设计研究

从激光器和激光器驱动电路两方面对激光近距离动态探测系统发射电路进行了研究。对国内外脉冲半导体激光器状况进行了分析,对探测系统发射电路设计原理进行了论述,在不同的设计背景和要求下,讨论了发射电路对激光器和器件的选择。同时,对探测系统发射电路设计注意事项进行了总结,并指出电路板布局布线的关键所在。最后分析了激光近距离探测系统发射电路的现状和发展。     

便携式脉冲调制型医用半导体激光器的驱动电源及光学透镜系统的设计

针对脉冲激光器穴位照射治疗的特点,对半导体激光二极管（LD）的驱动电路及光学镜头系统的设计进行了研究。本文设计了一款新型的锂电池供电便携式脉冲医用激光器,介绍了采用脉冲调制恒流驱动的原理以及采用透镜组和电路调整的方法改变激光照射功率密度的光学镜头的设计方法。该款脉冲激光器适用于激光体外穴位照射,对激光临床应用有一定的意义。     

新型的半导体激光器保护电路

根据半导体激光器的特性,设计了一套新型的保护电路系统,利用有效的滤波电路、防浪涌保护电路、慢启动电路、过流过压保护电路及精密温控电路,较大地改进了半导体激光器电源的可靠性,提高了半导体激光器的输出稳定性,延长了激光器的使用寿命。该保护系统具有性能可靠、结构简单、成本低廉等优点。     

基于功率晶体管窄脉冲激光驱动设计

激光的高功率、窄脉冲是提高激光引信系统精度,提高引信抗干扰能力的重要手段。为实现小体积的高频、高功率、窄脉冲激光发射,采用大功率晶体管正反馈设计出晶闸管开关应用于高频脉冲激光测距窄脉冲激光发射电路,用钳位二极管抑制激光器反向击穿。通过对RLC充放电回路、晶体管开关电路、晶闸管器件的分析,设计SCR电路,分析放电回路的三个步骤,运用pspice仿真程序对驱动电路进行了参数仿真。制作了印刷电路板,得到峰值电流12 A,脉宽8 ns的脉冲电流。     

激光告警装置背景光干扰消除方法及实现

为了有效抑制周围环境背景光对光谱型非成像类脉冲激光告警器的干扰,在采取滤光、滤波、比较器阈值限制等方式进行背景光噪声消除后,针对近距离、大能量的背景闪光干扰情况,根据背景闪光与脉冲激光在时间长度上的相异性,采用高速可编程逻辑器件对告警器的入射光时间进行了计时并判断,对背景闪光干扰进行了消除。经过实际测试,应用该方法后,告警装置12h内由太阳光引起的虚警次数为0,采用多种方式模拟近距离、大能量背景闪光干扰,告警装置均无虚警情况出现。结果表明,该方案可为由背景光引起的激光告警装置虚警问题的解决提供较好的实例和实验方案,其时长判断方法仅通过一片复杂可编程逻辑器件即可实现,硬件电路集成度高、程序编写简单,具有较好的应用价值。     

S2激光器泵浦源的设计

S2激光器产生的蓝—绿激光波长范围为430—520nm,根据理论计算,采用放电泵浦S2双原子分子的泵浦电流脉宽应小于30ns．以Blumlein电路作为泵浦源,设计合理的电路结构,传输线采用宽带引线,减小回路的寄生电感,实现了稳定的快脉冲放电,满足了对放电电流的要求,为放电激励是激光器产生激光提共了条件。     

自同步自扫描固体激光器电源

本文描述了一种自同步自扫描固体激光器电源。提出了一种新的自扫描控制电路，该电路使扫描脉冲与可控硅所加电压完全同步。此外，还报导了电源整机的原理、性能以及具休工作电路技术指标等。     

激光雷达测距系统光源驱动设计

脉冲式激光雷达探测性能与激光光源发出的光脉冲密切相关,而激光二极管(LD)驱动电路性能直接决定了光脉冲的优劣。基于激光雷达系统要求,选用超快速金属氧化物半导体场效应管(MOSFET)作为开关器件,建立驱动电路模型,对驱动电路设计与分析,经过多次试验,成功设计出最小脉宽10 ns,上升沿3.5 ns,重复频率可达50 kHz的LD驱动电路。驱动LD峰值功率将近60 W,成功用于激光雷达光源部分,测距精度达到3 cm/10.77 m,满足激光雷达系统要求。     

倍压磁脉冲开关在准分子激光器中的应用

本文提出了将磁脉冲压缩开关结合LC反转倍压电路应用于高重复率紧凑型准分子激光器的技术。对磁脉冲压缩开关应用的原理及结合LC倍压方法在准分子激光器高压快放电激励电路中的工作过程进行了分析 ,并给出了一种实用型的准分子激光器电源放电电路     

Design optimization of a hyperbolic unstable-resonatorsemiconductor laser

A semiconductor laser with a hyperbolic unstable resonator has been investigated through numerical simulations. The laser has an integrated focusing grating outcoupler. The complete device, including the resonator, outcoupler, and free-space propagation, has been modeled. Propagation in the resonator and the outcoupler grating has been modeled using a beam-propagation method that accounts for anti-guiding and thermal effects. The work has been aimed at optimizing the resonator layout for suppressed filamentation and wavefront distortion, i.e., to design a laser that produces an injection-independent focused spot. We show that small changes in the resonator layout can have a large effect on the laser performance and characteristics of the focused spot. We conclude that thermal effects, rather than anti-guiding effects, limit the performance of the device     

激光目标回波模拟器能量标定装置研究

为了解决激光目标回波模拟器输出脉冲激光能量无法现场标定的问题, 采用模拟积分原理, 通过光电探测组件参数优化设计和积分组件电路结构设计, 建立了激光目标回波模拟器能量标定装置, 并设计相应实验对标定装置的测量能力进行验证。结果表明, 激光目标回波模拟器能量标定装置可实现对脉冲宽度为10ns~100ns脉冲激光能量值的准确测量, 其能量测量范围为10fJ~1pJ, 包含因子k=2时, 测量不确定度为13.8%。该研究可满足激光目标回波模拟器输出脉冲激光能量测量与标定的需求。     

Enhancing IC repairs by combining laser direct-writing of Cu and FIB techniques

The aim of this work was to demonstrate the combination of laser direct-writing of Cu and FIB techniques. Preliminary electrical resistivity measurements and a comparison between the pros and cons of both methods have been carried out. Some IC repair cases are presented where an FIB device has been used in combination with the laser deposition device developed in the microelectronics laboratory. Also, particular attention has been given to problems which are insoluble by the FIB technique but readily resolved by the laser system.     

Multipulse operation of a high average power, good beam qualityzig-zag dye laser

A laser pumped zig-zag dye laser operating at 568 nm with a pulse length ~2 μs has been sealed to high power using a MOPA configuration. Pulse energies in excess of 7 J with beam quality <2 XDL have been achieved under repetitively pulsed, 10 Hz operation. RMS jitter was measured as 0.12 of a 1 XDL spot. The device has operated with over 70 W output for runs up to 5 s. Substantially longer run times and output powers are possible. This device represents an advance in dye laser capabilities. Improvement in pointing accuracy of better than an order of magnitude have been demonstrated. In addition, an improvement in beam quality by about an order of magnitude has been achieved compared to other dye lasers operating in this power range     

AlGaAs heterostructure injection laser s.c.r.

The operation of a gate-controlled p-n-p-n injection laser device has been demonstrated. The switching is accomplished by an electrical control signal. The threshold current of the laser incorporated into the device is about 100 mA, and its optical properties are similar to those of the Be-implanted laser reported recently.     

Controlled timewise redistribution of laser energy

An electronic feedback circuit is described which has been used in a Nd:glass high-power laser system for converting the spiky light emission into a smooth near-rectangular output of adjustable intensity and duration. The feedback circuit is also capable of converting the laser emission into a stroboscopic output of frequency of several hundreds of kilohertz or into aQ-switched high-intensity output. The attractive feature of the system is that the change from one type of laser operation into the other does not require any modification to the circuit, but only a simple readjustment of a few control knobs. The feedback system incorporates a high-current fast photodiode, a Pockels-cell shutter, and a pulser. The main innovation of the present electronic feedback circuit over previously proposed systems is the ability to set the Pockels cell at any point of its transmission curve. This feature will be demonstrated to be of decisive importance in smoothing out the laser emission and in converting the spiky light output into a series of periodic light pulses.     

大功率半导体激光器驱动电源

根据半导体激光二极管的工作特性，设计了一种以VICOR电源为功率模块，以绝缘栅双极晶体管（IGBT）为大功率变换器件的大功率激光二极管驱动电源，该驱民源电路简单，能有效地抑制电源的浪涌冲击，保证了激光二极管不受外界的电干扰。在线保护机制可实时对半导体激光器工作监控，半导体激光器的慢启动电路、温控电路保证了半导体激光器安全工作。该电源已应用于机载激光雷达样机系统中，通过一年多的使用，半导体激光二极管工作正常，性能稳定可靠。