120MHz射频CO_2波导激光器的调试方法

射频CO_2波导激光器的研制与一般直流、交流、中频激励方法有所不同。它在许多方面具有自己的特点和要求。为此,本文结合射频特性介绍了全晶体管小型化激励源的120MHz CO_2波导激光器的调试方法。内容主要包括:射频电源的保护器件——隔离器的使用方法与要求;击穿电离气体所需触发电压——使用可变长度传输线(移相器)的方法及稳定工作所需阻抗匹配网络的设计与调试方法。     

射频板条CO_2激光器波导耦合损耗的理论研究

射频板条二氧化碳激光器（RFSlabCO2Laser）是最近几年发展起来的一代新型气体激光器，它以优异的性能和光明的应用前景引起国内外研究者极大的兴趣．为获得良好的光束质量，这种激光器普遍采用波导-非稳混和谐振腔，因此如何减小波导与腔镜之间的耦合损耗成为激光器设计中一个关键问题．关于波导激光器的耦合损耗已有较多的理论研究，但大都针对具有介质侧壁的方型、圆型或矩型波导器件．在射频板条二氧化碳激光器中由上下两个大面积金属电极构成了板条型波导腔，它只在垂直于电极平面的方向对光波具有约束作用，故其波导模式与上述介质…     

射频激励全金属波导CO_2激光器的特性研究

全金属波导激光器具有以下优点:成本低、导热性好、可加工性好,并因采用同种材料构成波导,使波导因受热膨胀所造成的变形减小。据报道,这种器件若批量生产,成本约200美元左右,因而有很大的应用前景。本文提出了一种新型二电极射频激励全金属波导CO_2激光器结构,并研究了其输出特性。     

资料简介索引

一、气体激光器5001 在某些应用中CO_2激光器的频率稳定性Frequency stabilization of CO_2 laser in someapplications, Charles Freed, SPIE Vol. 335, PP.59-68 (1982).本文评述了林肯实验室的稳频技术和某些应用。[戎]5002 横向射频波导CO_2激光器放电均匀性改进Improved discharge uniformity for transverseradio frequency waveguide CO_2 laser, G. A. Gri-fith, SPIE Vol, 335, pp. 69-71 (1982).横向射频激励波导激光器存在一种不希望的不均匀气体放电,它与光波导的电气传输线特性有关。当用周期性电感分流时,可以修正电压驻波比,对电气长度超过2/3λ、频率200MHz的激光器,其激光器效率增加4倍。当激光效率为10％时,峰值输出功     

大功率射频板条CO_2激光器电极波导介质膜研究

针对高功率射频板条CO2激光器铜电极表面放电氧化、受射频放电的电子溅射,致使电极表面不光滑,辉光放电不均匀,光波导损耗严重等问题。利用Al2O3波导介质膜具有的反常色散效应、耐高温能力强的特点,采用磁控溅射镀膜技术对激光器电极表面先镀Al,而后阳极氧化获得Al2O3波导介质膜。分析了磁控溅射工艺对膜层结构的影响,测量了镀膜电极对CO2激光的反射率,并进行了放电实验检测。结果表明,溅射功率为250 W时可得到致密的镀膜层结构;厚度6μm的Al2O3薄膜,对波长10.6μm的CO2激光波导反射率最高达75%;电极镀膜后激光器输出功率在占空比为30%时为700 W,占空比为60%时达到了1300 W。     

横向射频激励CO2波导激光器

本文描述了横向射频泵浦的无电极CO2波导激光器。以射频连续波方式激励，激光器在气压为100托时发射功率为0.6瓦。以射频脉冲方式激励，已经在大气压下以重复频率300赫运转，脉冲持续时间为200微秒，峰值功率为几瓦。     

双通道共电极双波长高同步射频波导CO2激光器

研制了双通道、双波长共电极的射频波导CO2激光器,激光器采用双通道共电极结构,每一通道用光栅选频输出,可用压电陶瓷(PZT)控制激光腔长,以调节激光频率以及脉冲激光建立时间。两个通道同时获得了不同波长的脉冲激光输出,通过调节PZT上的电压使双通道输出脉冲激光达到同步,激光器不仅结构紧凑、体积小,而且具有很高的脉冲同步几率。     

射频放电波导CO激光器

射频放电波导CO激光器的结构如图1所示,一对平行平板铝电极,中间以氧化铝陶瓷作为侧壁。放电区的长度为386mm,电极间距为2mm,放电宽度为2～20mm。电极温度的变化范围为20℃～-30℃,由放在电极端口附近的热敏电阻进行监测。冷却的甲醇液体流经上下电极。射频电源频率为125MHz,经由一耦合回路馈入电极。为了使电极上的电压分布均匀以     

射频激励扩散型冷却阵列波导CO2激光器技术

本文介绍了目前国内外研究者们提出的各种射频激励相干阵列波导ＣＯ２激光器技术，讨论了射频激励相干阵列波导ＣＯ２激光器技术的一个研究方向。     

共电极折叠腔窄脉冲射频波导CO2激光器设计分析

报道了共电极折叠腔电光腔倒空射频波导CO2激光器的设计方案,为在限定激光器体积的前提下大幅度地提高激光的输出功率,主振激光采用了Z折叠腔结构以及电光腔倒空方式输出激光.本振通道采用单通道结构.此激光器结构可以提高外差频率稳定度.理论分析了控制电光腔倒空过程激光输出波形的方法.     

Two-dimensional computational model of discharge uniformity in radio-frequency-excited CO/sub 2/ slab lasers with high aspect ratio electrodes

A finite difference scheme for the numerical solution of Maxwell's equations in the time domain is utilized for the optimization of discharge uniformity in radio frequency (RF)-excited CO/sub 2/ slab lasers with high aspect ratio electrodes. The field solver can be coupled to standard RF discharge models. The model may be regarded as a natural generalization of the successful transmission line method to two dimensions.     

Distributed balanced photodetectors for high-performance RFphotonic links

A novel velocity-matched distributed balanced photodetector with a 50-Ω coplanar waveguide output transmission line has been experimentally demonstrated in the InP-InGaAs material system. Distributed absorption and velocity matching are employed to achieve high-saturation photocurrent. A common mode rejection ratio of 27 dB has been achieved. The RF link experiment conducted at 6.48 GHz shows that the laser intensity noise has been suppressed by more than 17 dB     

Compact solid-state waveguide lasers

Glass waveguide lasers will fill an important niche as optical sources in communication, RF photonics, and optical metrology. This is primarily because waveguide lasers benefit from compact size, low noise, relatively high output powers, long upper-state lifetimes, and simple integration with optical-fiber-based systems. Although we do not expect waveguide lasers and amplifiers to ever supplant fiber and semiconductor lasers and amplifiers in every possible communications application, waveguide lasers have a number of advantages over traditional lasers for these uses. Single-frequency waveguide lasers provide narrow linewidth and high output power in a compact, monolithic package. The narrow linewidth is an important advantage over standard semiconductor lasers, and the compact size makes single-frequency waveguide lasers better suited than fiber lasers or extended-cavity semiconductor lasers for many applications.     

旋转波片法测量电光调Q射频波导CO2激光器的内部参数

提出了一种测量电光调 Q射频波导 CO2 激光器内部参数的新方法 ,采用此方法可测量出激光器的小信号增益系数、内部损耗、饱和光强等内部参数 ,并可推广应用到其他种类激光器内部参数的测量。     

射频板条CO_2激光器并联谐振技术的研究

本文利用周期性网络模型计算了射频板条CO2激光器电极的纵向电压分布．探讨了并联谐振技术在板条器件中获得成功运用的原因．提出了利用并联谐振技术进一步提高电压分布均匀性的两个途径．     

太赫兹波导固定衰减器的设计

随着太赫兹技术的迅速发展,太赫兹系统中使用的波导衰减器也成为研究热点。波导衰减器可以对太赫兹信号实现精确衰减和控制功率传输,在解决损耗、辐射和干扰等一系列问题中,具有特殊意义和不可替代的地位。而目前的波导衰减器将衰减片平行于电场放置在矩形波导内,破坏矩形波导传输线,容易造成射频泄露。本文基于吸收式波导衰减器工作原理,提出了一种衰减片垂直于矩形波导电场的波导固定衰减器,通过将衰减片贴在波导内壁,保证传输线完整。使用高频电磁仿真软件HFSS,通过改变衰减片的形状、位置等参数,优化回波损耗、衰减精确度等指标,最终完成110~170 GHz波导固定衰减器的研制。在110~170 GHz频率范围内,衰减器的回波损耗小于-27.5 dB,在20 dB的衰减时,衰减精确度小于±2 dB。     

Analysis of a MEMS transmission line

A microelectromechanical system (MEMS) sound waveguide is considered as a transmission line for RF signals. We analyze a device geometry of a straight one-dimensional microsize silicon rod, where a longitudinal acoustic wave is generated and detected using capacitive transducers. Linear, isotropic, and nondispersive acoustic-wave propagation is assumed. Based on the calculation of the electromechanical impedance, an electrical equivalent model is derived for the acoustic transmission line. A numerical example and a comparison to measured properties of a MEMS-transmission-line resonator shows that the characteristic impedance level of the waveguide is typically high, which causes challenges for matched termination. Solutions to overcome the matching problems are discussed.     

Measurement of RF Transmission Mode in ITER Relevant EC H&;CD Transmission Line

The preliminary results of mode measurement in the ITER relevant 40 m long transmission test line composed from 63.5 mm diameter corrugated waveguides and miter bends are presented. The field patterns were measured by taking temperature profiles on a paper screen placed in front of the waveguide end using an infrared imaging camera. The complex electric field at the waveguide end was retrieved from the measured temperature profiles. As a result, the transmission power includes 87% of HE₁₁ mode and 6% of LP₁₁ odd (HE₂₁+TE₀₁) mode and small ratios of other modes. The mode content had small dependence on length of the transmission line. This result indicated that the higher order mode content generated at the input of the transmission line is conserved and propagated through the transmission line. This suggests that the initial RF coupling to the waveguide is critical since it affects the launcher efficiency.     

Static, dynamic, and noise analysis of multisection DFB lasersusing frequency-domain transmission line model

A novel frequency-domain transmission line model for multisection distributed feedback (DFB) lasers is developed. The characteristic impedances of active periodic structures are derived. A multisection DFB laser is described as a transmission line network, with each section represented by a transmission lint segment with a corresponding characteristic impedance. Static, dynamic, and noise analysis of multisection DFB lasers is demonstrated. The reflections at the junctions between sections are evaluated more accurately. The resonant condition of the equivalent transmission line network, instead of cumbersome Wronskian, is used to reformulate the rate equations. The diffusion coefficient of Langevin noise terms of any two different positions is solved for the first time, resulting in a more accurate noise analysis of multisection semiconductor lasers. Analytical expressions of the dynamic responses and noise properties of multisection DFB semiconductor lasers are derived