大功率TEA CO2激光器的电磁辐射测试及屏蔽方舱设计

为了抑制大功率TEA CO<,2>激光器对其他电子设备的电磁干扰,在测量并分析激光器的近场电磁辐射特性的基础上,设计了电磁屏蔽方舱并进行了实验验证.根据大功率TEA CO<,2>激光器的工作原理,分析了激光器工作过程中的主要电磁辐射源;结合电磁辐射理论与激光器的实际结构,确定了电磁辐射测试的主要部位为火花开关、主回路、...     

Use of 13CO2 in high-power pulsed TEA lasers

The use of 13CO2 in carbon dioxide lasers enhances the available spectral range very significantly but is prohibitively expensive if gas flow through the laser is required. A TEA CO2 laser equipped with a gas recirculation system is described. This reduces gas costs to negligible levels even for expensive isotopic mixtures.     

Novel CO(2)/N(2)O waveguide laser

We present a new design for a waveguide laser which is easily constructed from readily available materials. We have demonstrated its operation for CO(2) (8.5-W output) and N(2)O (1.5-W output).     

Compact CO2 laser for infrared heterodyne radar

A compact CO(2) laser has been developed for field use as part of an infrared heterodyne radar. The laser, which contains a separate local oscillator, transmits 10.5 W cw or 7 W average in the electrooptically Q-switched mode at a repetition rate of 50 kHz. The applicability of this laser to active imaging is discussed.     

Digital feedback stabilization of a single-axial-mode CO2 TEA laser

We have achieved long-term stability in producing high-power single-axial-mode CO2 laser pulses with a hybrid oscillator (TEA laser + low-pressure section) by using a novel digital feedback system that electronically adjusts cavity length.     

Compact flowing gas system for CO(2) lasers

A miniature air-actuated vacuum pump has been utilized to effect gas flow at partial atmospheric pressures for waveguide CO(2) lasers. Implications are that flowing gas laser systems can be acceptable for many applications requiring miniaturization of components.     

高功率TEA CO2激光器的双波长免调切换结构

为在一台激光器上切换输出10.6/9.3μm两种波长高能激光,采用输出镜镀膜选支方法获得了9.3μm单谱线输出,其脉冲能量与原10.6μm波长基本相当.设计出双波长密闭免调切换输出结构,利用有限元分析软件MSC.Patran/Nastran对该结构的切换移动平台组件进行了静力学、热应力及热力耦合分析,并基于Matlab...     

A TEA CO2 laser with a peak radiation power of 100 MW

A high-power pulse-periodic TEA CO₂ laser is used as a component of a long-range mobile differential absorption lidar. In order to reach the ultimate peak generation power, a system for laser excitation with a supply voltage of ±40 kV and efficient preionization was developed, allowing the laser to operate at high pressures of gas mixtures of various compositions. Energy, time, and spatial characteristics of laser radiation were studied. Laser pulses with an energy of >10 J and FWHM duration of ≈30 ns were obtained. The ultimate peak laser radiation power is 100 MW, and the maximum efficiency with respect to the discharge-consumed energy is 12.6%.     

A Multichannel TEA N2 Laser for Visualizing Pulsed Plasma in the Nanosecond Range

The choice of a UV nanosecond TEA N₂ laser ( = 337 nm, _l 3 ns) for the multiframe probing of a dense pulsed plasma is justified and the influence of elements of its structure on the lasing efficiency is considered. The parameters of laser radiation were studied under various conditions of the formation of a space discharge and the methods for increasing the energy deposition were analyzed. Based on an optimized design of the laser module, a multichannel light source with a simple design has been built that allows all the channels to be triggered from a common spark gap and ensures the flexible changing of pulse delays within a range of t = 1–100 ns.     

Generation of high-power laser light with Gigahertz splitting

We demonstrate the generation of two high-power laser beams whose frequencies are separated by the ground state hyperfine transition frequency in (87)Rb. The system uses a single master diode laser appropriately shifted by high frequency acousto-optic modulators and amplified by semiconductor tapered amplifiers. This produces two 1 W laser beams with a frequency spacing of 6.834 GHz and a relative frequency stability of 1 Hz. We discuss possible applications of this apparatus, including electromagnetically induced transparency-like effects and ultrafast qubit rotations.     

高功率CO_2激光对远场HgCdTe探测器的干扰实验

理论分析和实验研究了高功率CO2激光对远场光导型长波红外HgCdTe探测器的干扰损伤。采用激光辐照探测器的温升理论模型,根据实验参数,讨论了高功率激光对长波红外探测器的损伤机理,计算了温升与辐照时间和功率的关系,并和CO2激光器在距离15km处辐照光导型长波红外HgCdTe探测器的实验结果进行对比分析。实验结果表明,2.5kW连续CO2激光经过大气衰减后在15km处激光功率密度可达0.161W/cm2,计算可知此时会聚到探测器靶面处的功率密度为140W/cm2;靶面处功率密度为20.5W/cm2时,对探测器产生干扰;靶面处功率密度为110W/cm2时,达到损伤,计算此时探测器表面温度已达到Hg析出温度,这一实验现象和理论计算预期结果相吻合。实验结论对研究探测器的激光防护和激光干扰星载探测器技术具有指导意义。     

Versatile, isotopically specific hydrogen halide TEA pin laser

A practical, easily constructed design for a laboratory hydrogen/deuterium halide chemical TEA laser is presented. Typical output energies in excess of 50 mJ/pulse broadband and 5 mJ/pulse on single lines are easily obtained. Isotopically specific oscillation on the v=1-->0 band of single isotopes of H35Cl-H37Cl, D35Cl-D37Cl, H79Br-H81Br, and D79Br-D81Br is demonstrated. The ease of conversion from one laser species to the next and the flexible design provide a highly versatile device for laboratory problems in chemical and physical dynamics. Major advances in the development of laboratory HCl and HBr chemical TEA lasers are also reviewed.     

基于透射式非稳腔的单纵模TEA CO_2激光器

为了获得TEA CO_2激光器高质量的单纵模输出,对种子注入锁定的TEA CO_2激光器进行了研究。首先,本文提出了一种透射耦合输出的虚共焦非稳谐振腔方案,利用Glad软件的Prony法对腔模的演化进行了仿真分析,并实验记录了近场与远场的光斑光强分布。仿真结果与实验结果吻合,验证了此腔型方案的合理性。其次,在此腔型的基础上进行了腔外种子注入锁定实验,实验结果显示:自由振荡时存在频率为195 MHz的拍信号,当种子注入锁定成功后,输出激光拍频消失,波形变光滑,峰值功率降低48.6%,脉冲产生时间缩短20ns。实验结果与已有成果吻合,验证了此种透射式非稳腔的TEA CO_2激光器具有输出高质量单纵模的能力。     

大功率激光二极管列阵的硅基微通道热沉研制

为了提高大功率激光二极管列阵的散热效率以便提高其寿命和波长稳定性,研制了一种封装集成度较高的屋脊式硅基微通道热沉.将田口稳健设计方法用于微通道热沉的优化设计,利用正交试验和信噪比分析实现了参数的稳健优化.以(110)单晶硅作为基片,采用KOH各向异性刻蚀和硅-玻璃-硅三层阳极键合方法制作出了通道宽度约为50 μm的微通道热沉,通道壁面粗糙度优于0.1 μm.采用激光二极管芯片对样品进行了封装和测试,利用砷化镓激光波长的温度漂移系数估算出了中间激光二极管的有源区温升,从而计算出了热沉的热阻.测试结果表明,该微通道热沉的单位面积热阻约为0.070 cm2·K/W,与有限元分析结果基本一致.     

Monitoring of high-power CO2 laser cutting by means of an acoustic microphone and photodiodes

Laser cutting is nowadays a well-established sheet metal processing method. The cutting of thick plates (>15 mm) is, however, still characterized by more narrow process windows compared to those for thin sheets. Therefore good cutting quality cannot always be guaranteed. The development of a monitoring system that can measure the cut quality on-line could form a solution to this problem. In this study, the determination of an appropriate monitoring system is dealt with. The applicability for monitoring purposes of two types of sensors is investigated: the microphone and the photodiode. For both types, correlation between the sensor output and the cut quality is investigated. Besides contour cutting, piercing is also covered in the study. The full break-through of the piercing can be monitored by both sensors. Furthermore quantitative relations between cut quality parameters and photodiode signal parameters could be determined.     

Compact High-Power Subnanosecond Repetitive-Pulse Generators (Review)

This review presents the results of investigations, design work, and tests of generators of subnanosecond pulses with amplitudes exceeding 100 kV. These generators were developed at the Institute of Electrophysics on the basis of compact nanosecond repetitive-pulse RADAN generators. Relatively long pulses (2–5 ns) were transformed into shorter ones (down to 150–200 ps) with the use of systems based on high-pressure sharpening and cutting gas spark gaps. This ensured stable operating modes for the generators at repetition frequencies of up to 100 Hz. Such spark gaps were utilized in systems of additional energy compression for enhancing the peak power of output subnanosecond pulses, as well as in devices producing high-power bipolar pulses. Some applications of short (<1 ns) powerful voltage pulses are considered.     

Negative differential resistance in high-power InGaN/GaN laser diode

Negative differential resistance in InGaN/GaN ultraviolet laser diodes is demonstrated. Switching between the lower and upper branches of the S-shaped current-voltage characteristic leads to a change in the optical emission power by six orders of magnitude as the current increases from 3 to 15 mA. The occurrence of a negative differential resistance is explained by superlinear injection of charge carriers of the same sign into the high-resistance InGaN quantum well.     

Er3+/Yb3+共掺双包层光纤的高功率L-band 光纤激光器的实验研究

采用端面泵浦的方式,用尾纤输出波长为976 nm的高亮度多模半导体激光器, 包层泵浦的铒镱共掺双包层大模面积光纤,非球面镜组耦合系统,进行了共掺双包层光纤的高功率L-band光纤激光器的研究,泵浦耦合效率达到了62%以上,并在F-P激光振荡腔中实现了高效的连续激光输出。在光纤长度为30 m、入纤功率为 13.41 W时,首次报道输出连续功率达到了4.3 W。激光器的斜率效率为44％, 激光输出中心波长1 603 nm。     

高功率半导体激光器直接调制特性的实验研究

本文介绍了一种具有自动功率控制(APC),自动温度控制(ATC)及 调制输入接口的半导体激光光源,并对其低频调制特性进行了深入的实验研 究。给出了用高速光电探测器探测到的调制信号波形,并进一步分析了调制 频率与闭值电流之间的关系,以及调制频率与平均输出功率之间的关系。     

用于大功率激光二极管列阵的硅基微通道热沉研制

将田口稳健设计方法用于面向大功率激光二极管列阵的硅基屋脊式微通道热沉的优化设计,利用正交试验和信噪比分析实现了参数的稳健优化。采用激光二极管条对样品进行了封装和测试。利用砷化镓激光波长的温度漂移系数估算出了中间的激光二极管条的有源区温升。测试结果表明,该微通道热沉的单位面积热阻约为0.070 K&#8226;cm2/W,与有限元分析结果基本一致。