波导CO2激光器电光腔倒空特性研究

对影响射频波导激光器电光腔倒空的激光输出脉冲特性的几个主要参数进行了研究。通过改变加在CdTe电光晶体上高压脉冲的不同上升沿时间,以及在不同布氏窗输出反射率等情况下,对腔倒空的脉冲宽度及脉冲峰值功率的变化特性进行了理论分析。在一台用于主动激光成像雷达光源的准折叠高重频腔倒空射频波导CO2激光器上,通过改变CdTe电光晶体的工作参数,获得了20ns到30ns(FWHM)可调输出脉宽。     

CHD/sub 2/OH optically pumped by a waveguide CO/sub 2/ laser: new far-infrared laser lines from the CD/sub 2/ wagging vibrational mode

For the first time, a wide tunability waveguide CO/sub 2/ laser was used to pump the CHD/sub 2/OH molecule for the generation of new FIR laser lines with a large offset. Optoacoustic signals associated with the infrared absorbing transitions of the CD/sub 2/ wagging vibrational mode served as a guide for finding new laser lines. All lines were characterized in wavelength, relative polarization, intensity, optimum pressure of operation, and precise offset measurements.     

声光Q开关波导CO2激光器

用Ge单晶作为声光介质首次研制出声光Q开关波导CO2激光器,Q开关激光脉冲重复频率从0Hz到200kHz任意可调。文中对这种Q开关激光器的性能作了介绍。     

Operating characteristics of CW CO/sub 2/-N/sub 2/O laser

The authors have obtained the emission characteristics of a CW CO/sub 2/-N/sub 2/O laser. The CO/sub 2/ laser lines and N/sub 2/O laser lines vary according to the applied condition. Thus the operating conditions are interpreted.<>     

Continuous-wave erbium-diffused LiNbO/sub 3/ waveguide laser

The first integrated optical laser in LiNbO/sub 3/, doped by an indiffusion of Er/sup 3+/ prior to channel-guide fabrication by Ti diffusion is reported. Pumped by a colour centre ( lambda /sub p/=1.477 mu m), CW operation at lambda =1.532 mu m ( Delta lambda approximately 0.3 nm) with a threshold of approximately 8 mW absorbed power was achieved.<>     

Extremely deep long-period fiber grating made with CO/sub 2/ laser

We report on the realization and tuning of a long-period fiber grating-based filter, which is made in a standard telecom optical fiber, with a resonant attenuation of more than 60dB. This is, to our knowledge, by far the highest published value. The realized filters satisfy requirements of applications which are extremely demanding in terms of the resonant depth or require an exact /spl pi/-phase shift at the resonance.     

Side-wall emitting ZnSe/AlN waveguide CO2 laser

A side-wall emitting ZnSe/AlN waveguide CO₂ laser, which is able to extract the output power from the waveguide wall, is proposed. In the proposed scheme, four polished AlN plates are cemented to form a 16 cm long waveguide with 1.9×1.9 mm² cross section. One of the AlN plates is partially replaced by the ZnSe plate. This part is used as an output window. To confirm the workability of the proposed scheme, a trial laser was constructed and tested. The output power of several milliwatts was observed from the ZnSe waveguide wall.     

电光调QCO2激光器进展

总结了国内外电光调QCO2激光器的发展,介绍了不同激励方式、不同结构的电光调QCO2激光器及其应用,概括了理论研究结果。     

Hybrid Q-switched laser with Ti-indiffused LiNbO/sub 3/ and Er-Yb co-doped glass waveguides

We report the design and characterization of a novel Q-switched laser configuration based on a composite Er/sup +3/-Yb/sup +3/ co-doped ion-exchanged glass and Ti-indiffused LiNbO/sub 3/ waveguides. This 1536 nm Q-switched laser provides stable 200 ns wide optical pulses for a cavity length of 7 m with a peak power of 13.5 W and a pulse energy of 2.7 /spl mu/J at a 2-kHz repetition rate and 180 mW of 980-nm pump power. Also, we examine the dependence of the pulsewidth and peak power on the laser cavity length to estimate the performance of the integrated version of such a laser.     

CO/sub 2/ laser processing of alumina (Al/sub 2/O/sub 3/) printed circuit board substrates

We report the results of an investigation of the laser-material interaction processes involved in laser drilling of alumina, through the use of an enhanced peak power (2.5 kW) CO/sub 2/ laser and novel temporal pulse formats. Peak power was varied from 30 W to 2 kW for pulses of constant energy to observe the effect produced on scribe depth. High-speed videography of hole formation has been combined with microscopic analysis to investigate the key processes involved in laser processing of alumina. Plasma screening was observed for short, high peak power laser pulses, and optimal scribing was achieved in the weakly plasma absorbing regime. A new processing technique for scribing alumina has been developed, which exploits the fast response of the laser to produce novel temporal pulse shapes, which can be modified to generate cleaner holes. Scribe speeds of up to 280 mm/spl middot/s/sup -1/ were obtained for scribe holes >200 /spl mu/m deep and 150 /spl mu/m apart, with no material plugging the hole, in 0.635-mm-thick 96% alumina.     

声光调Q CO2激光器的实验研究

为满足13.5 nm极紫外光刻(EUVL)等领域的应用需求,研制了高重复频率、高稳定性的声光调Q CO2激光器。首先,对声光Q开关的工作原理进行了分析,并实验研究了调制信号电压与衍射效率的关系。接着,研究了调制信号占空比对脉冲波形的影响,通过选择适当的占空比消去了脉冲拖尾。然后,对不同重复频率下的脉冲宽度、功率和脉冲幅值稳定性进行了测量和分析。最后,对激光器的光束指向稳定性进行了测量。实验结果表明:该激光器实现了重复频率1~100 kHz连续可调的脉冲输出,在重复频率1 kHz时,获得最小脉冲宽度252 ns和最大峰值功率7 579 W的激光脉冲输出。通过设计以殷钢管为主体的支撑架,使得激光器的脉冲幅值不稳定性小于3%,光束指向稳定性为46.6 rad。该声光调Q CO2激光器可作为高性能种子源在EUVL等领域中得到应用。     

医用波导CO2激光器

本文报导一种符合医用要求的新型玻璃波导CO2激光器。该器件采用大孔径玻璃波导（d=3～4mm）。提出近场非匹配凹面镜选模的新方法和整体冷却管体的新结构。激光器全长310mm时，能得到输出功率8W左右的稳定基模。连续工作寿命大于1000小时。     

CO2波导激光器在我院临床的应用

随着激光技术在医学科学上的应用日益广泛，近年来研制生产体积小、使用较方便，灵活的CO2波导激光品。我院自1985年以来，采用由国光电子管厂研制提供的BDJ-1型多功能CO2滤导激光治疗机、治疗了皮肤，粘膜线表的各种痣、疣、乳头状唐、鸡眼、毛细血管瘤等32种疾病共492例，取得了满意的疗效，现报道如下，     

Charge trapping and dielectric reliability of SiO/sub 2/-Al/sub 2/O/sub 3/ gate stacks with TiN electrodes

A detailed study on charge trapping and dielectric reliability of SiO/sub 2/-Al/sub 2/O/sub 3/ gate stacks with TiN electrodes has been carried out. Due to the inherent asymmetry of the dual layer stack all electrical properties studied were found to be strongly polarity dependent. The gate current is strongly reduced for injection from the TiN (gate) electrode compared to injection from the n-type Si substrate. For substrate injection, electron trapping occurs in the bulk of the Al/sub 2/O/sub 3/ film, whereas for gate injection mainly hole trapping near the Si substrate is observed. Furthermore, no significant interface state generation is evident for substrate injection. In case of gate injection a rapid build up of interface states occurs already at small charge fluence (q/sub inj/ /spl sim/ 1 mC/cm/sup 2/). Dielectric reliability is consistent with polarity-dependent defect generation. For gate injection the interfacial layer limits the dielectric reliability and results in low Weibull slopes independent of the Al/sub 2/O/sub 3/ thickness. In the case of substrate injection, reliability is limited by the bulk of the Al/sub 2/O/sub 3/ layer leading to a strong thickness dependence of the Weibull slope as expected by the percolation model.     

Optical pumping of CHD/sub 2/OH and CH/sub 2/DOH methanol isotopomers by means of a new pulsed CO/sub 2/ laser: characterization of new far-infrared laser emissions

We have reinvestigated CHD/sub 2/OH and CH/sub 2/DOH methanol isotopomers as sources of far-infrared laser radiation using the optical pumping technique. A new waveguide pulsed CO/sub 2/ laser was used, that delivers high peak powers also in the 10-HP CO/sub 2/ band and has allowed us to observe 19 new far-infrared emissions from CHD/sub 2/OH and 8 new far-infrared emissions from CH/sub 2/DOH. Each of them is characterized in wavelength, pump offset from the center of the exciting CO/sub 2/ line, relative polarization, optimum operating pressure and intensity.     

A tunable waveguide CO2 laser with expanded tuning range

A method of expanding the tuning range of the CW CO₂ waveguide laser making use of a Fabry-Perot type light modulator is proposed. A preliminary experiment has been done to confirm the workability of the proposed scheme.     

复合光栅腔可调谐波导CO2激光器的研究

本文对一级输出方式的复合光栅腔可调谐波导CO2激光器进行了研究，在340mm的放电长度上，获得大于0．5W的谱线61条，其中10p（20）支线的基模功率为3．5W。我们用复合腔的理论说明了光栅一级输出的优越性。     

Tunable electroabsorption modulated laser integrated with a bent waveguide distributed-feedback laser

The fabrication of the first 1.55-/spl mu/m wavelength tunable electroabsorption modulated laser integrated with a bent waveguide distributed-feedback laser is reported. A low-threshold and stable single-mode operation is obtained when the devices were uniformly pumped. A single-mode output power close to 10 mW from a single-mode fiber (40 mW in free space) is obtained with a 0 V bias to the modulator and an extinction ratio of up to 15 dB at 2.5 V. This single mode stability is due to the continuously distributed phase shift implemented in the structure. With a nonuniform injection, it was possible to select one particular mode out of the three neighboring modes inside the broad-reflection band of the reflector. A tuning range of 3.5 mm was obtained while maintaining an output power of more than 2 dBm from each mode.     

矩形波导CO2激光器光栅安装角偏差损耗

稳频调谐矩形波导CO2激光器中采用光栅选支,要求光栅具有精确的安装角度,以避免损耗过大或出现跳支现象。研究了安装角的偏差带来的损耗与偏差角之间的关系。介绍了一种基于三角法并使用铅垂线校准光栅安装角度的方法。计算表明,用该方法安装光栅具有较高的精确度,其安装误差角造成的损耗非常小,而且振荡支线稳定。     

Sol-gel ZnO-SiO/sub 2/ composite waveguide ultraviolet lasers

Random laser action with coherent feedback is realized in ZnO-SiO/sub 2/ composite films, which consists of ZnO clusters embedded in SiO/sub 2/ dielectric matrix prepared by sol-gel technique. The films are deposited on silicon substrate with a SiO/sub 2/ buffer layer to form a waveguide structure. Ultraviolet lasing at room temperature is observed from the composite films with ZnO : SiO/sub 2/ molar ratio varying between 1 : 5 and 1 : 30. The corresponding lasing wavelength and linewidth under 355-nm optical excitation are found to be /spl sim/388 nm and less than 0.6 nm, respectively. Our experiment has shown that the proper control of light confinement inside the random cavities leads to coherent random lasing.