混合集成实时声光频谱分析器

采用半导体激光器、微型光学元件、光电接收器列阵和集成光学短程透镜以及导波声光调制器，研制成功了混合集成实时声光频谱分析器，体积为１５６×５６×５６ｍｍ。本文介绍了其工作原理、整体结构和部分实验结果。     

Bi4Ge3O12晶体的声光性质及其应用

锗酸铋（ＢＧＯ）晶体属立方晶系，在０．３－６μｍ波段有良好的透过率，无自然双折射和旋光性，具有良好的光学性能，用ＢＧＯ晶体制得的声光调制器的性能，中心频率８０ＭＨｚ３分贝带宽１２ＫＨｚ，对于驻波型器件，在１Ｗ驱动功率下，零级调制效率可达５７％（６３３ｎｍ）除声光效应外，ＢＧＯ同时具有电光，磁光，光折变和激光等光电子性能，讨论了在ＢＧＯ声光效应的基础上发展新颖复合功能器件如声光调Ｑ／激光，声光锁模，     

声光可调滤光器及其在光谱分析方面的应用

描述了作为色散元件的声光可调滤光器的结构及滤光器的驱动频率ｆａ和衍射光波长λ０的调谐特性。着重对不同物质的吸光谱进行了测试，测试结果表明，不同物质有其不同的吸收光谱，而吸收光谱可反映物质内部的许多信息，这为研究物质内部的微细结构提供了一种有效方法。     

AOM激励器

介绍原子在经激光冷却与囚禁形成原子粘团并上抛过程中所需的“两次调制装置”——声光调制器（ＡＯＭ）的激励器的设计与性能测试。     

红外可调声光滤光器的设计和特性分析

根据声光互作用原理，以TeO2晶体为互作用介质，选取互作用长度为28mm，设计制成近红外声光可调滤光器（AOTF），其衍射波长与超声频率存在对应关系。测试结果表明，该器件的工作波长范围为0.9-2.6μm，驱动频率为40－120MHz，光谱分辨力为7.268nm，6.957nm（对应波长分别为1.5μm，2.4μm）。     

声光滤光器在膜厚测量上的应用

本文对利用声光可调滤光器测量薄膜的光学厚度进行了理论探讨,并在实验中加以证实。     

声光材料及其应用

讨论了表征材料声光性能的主要参量及声光器件对材料的基本要求,介绍了某些常用声光材料的声光性能及其应用。     

声光快速分光装置与微机控制

本文介绍了一个以声光可调滤光器为分光元件的快速分光装置,它具有光波长电调谐,易与微机接口,全固态结构等优点。文章详细讨论了快速分光装置各个单元部份电路设计。在Z—80A CPU控制下,分光装置以5nm波长间隙扫描500～700nm光谱范围只需0.74ms。通过模拟实验,快速分光扫描的结果被证明是正确的。     

宽带声光可调滤光器的设计——一种新型的换能器结构

在设计声增强型声光可调滤光器中 ,首次采用频带分段思想 ,提出梯形倾斜结构的换能器 ,获得了 50 MHz以上的工作带宽     

声光调制器中的热效应探讨

讨论了在声光介质中由于光和声的吸收、换能器损耗引起的热源而致使传声介质内部存在温度梯度,最终引起激光光束通过传声介质时发生偏离．针对大功率声光调制器材料ＪＧＳ１、ＪＧＳ２、ＪＧＳ３进行先偏离测试,分析不同材料的热效应和热饱和特性,综合考虑衍射效率和光束偏离,确定了最佳入射光束位置,并对控制措施（方法）进行了讨论．     

声光快速扫描光谱测试的微机控制与数据处理

本文介绍了一种以声光可调滤光器作色散元件的新型光谱仪——微机控制声光快速扫描分光光度计的设计,并详细阐述了它的设计思想和主要工作特点。     

Radiometers, autocorrelators, and matched-filter receivers by means of acousto-optic spectrum analysis

Acousto-optic spectrum analyzers provide a convenient means of separating wide-bandwidth signals into their frequency components. By a change in the rf input signal into the spectrum analyzer and by the provision of additional digital postprocessing, it is possible to perform radiometry, signal autocorrelation, and matched-filter reception. Although the acousto-optic device has a space-integrating architecture, the matched-filter receiver can be implemented for signals having time durations much longer than the acousto-optic cell. The resulting signal-to-noise ratio improvements from the receiver are consistent with the time-bandwidth product of the waveform, rather than the time-bandwidth product of the acousto-optic device. A mathematical foundation of the processor is presented along with specific receiver implementations. Computer-simulation and experimental results demonstrate key findings. In one experimental example, a linear-frequency-modulated waveform is matched-filter processed to recover a signal that is -24 dB with respect to the input noise floor.     

In-line interferometric time-integrating acousto-optic correlator

A novel, efficient, stable, in-line interferometric, two Bragg cell, acousto-optic architecture is introduced for signal correlation and spectrum analysis. The processor employs an image-inversion technique to produce a correlation output that does not have to be generated on a fast spatial carrier, thus reducing the burden on the required space-bandwidth product on the output time-integrating detector array. The system is particularly suited for wide-instantaneous-bandwidth signal processing and is demonstrated as an autocorrelator for dc-to-10-MHz AM signals on a 100-MHz carrier. A fixed-spatial-carrier outputbased correlator and spectrum-analyzer architecture that is particularly limited in the wideband mode is demonstrated for comparison purposes with the proposed flexible-spatial-carrier-design-based in-line acousto-optic correlator.     

Acousto-optic cyclostationary signal processing

Cyclostationary signal-processing techniques implemented by means of acousto-optics are considered. Cyclic-processing methods are reviewed and motivated, such as the cyclic correlation and the cyclic spectrum. It is shown that the cyclic correlation can be computed at cycle frequencies of interest by use of one-dimensional time-integrating correlators in additive or multiplicative configurations. Detection of cycle frequencies is briefly considered, and a one-dimensional acousto-optic spectrum-analysis approach is described that is effective for amplitude-modulated signals. The problem of computing the two-dimensional cyclic correlation for all cycle frequencies and lags is then considered. This is accomplished by means of an acousto-optic triple-product processor configured in a manner similar to that used for ambiguity-function generation. The cyclic spectrum can be obtained in a postprocessing step by Fourier transformation of the cyclic correlation in one dimension. Higher-order extensions of the cyclic correlation are also discussed, and it is shown how a two-dimensional slice of the three-dimensional cyclic triple correlation can be computed by use of an acousto-optic four-product processor.     

熔锥型光纤声光可变衰减器

利用耦合模理论对光纤熔锥声光器件进行了数值模拟,得到了全光纤声光衰减器传输谱和可调谐性。分析了带宽与声波长、耦合长度的关系。数值分析结果表明,声波在光纤熔锥中引起的轴向电介质微扰、耦合长度和工作波长都会对器件的传输谱产生影响,选择合适的设计参数可以制作较为理想的声光衰减器。实验上获得了损耗小于0．2dB,带宽大于200nm,动态范围为20dB的单模光纤熔锥可变衰减器,所得结果与理论分析相符合。这种器件可用于光纤通信及光纤传感。     

Programmable ultrashort optical pulse delay using an acousto-optic deflector

We present an optical pulse delay (OPD) for delaying ultrashort optical pulses that uses an acousto-optic deflector as an active component. The OPD is designed to correct for chromatic dispersion caused by the significant color spectrum of ultrashort pulses. It is intended to be used as one of the components in a three-dimensional memory system based on pulse-collision addressing in two-photon materials. Calculations show that the OPD should be able to provide 65 arbitrary delays with a random access time of ? 1 μs for 100-fs pulses. The power efficiency of the OPD can be as high as 85% and hence permits two units to be cascaded to provide more than 4000 distinct delays. The number of delays and the access time can be optimized such that a fewer number of delays are obtained with a shorter access time, which favors high-speed operations. We provide experimental results that use a Michelson interferometer to measure three different delays, approximately 1 mm apart (equivalent to ?3-ps time delay), obtained with 130-fs pulses. In addition we include an analysis of the performance of acousto-optic devices for both monochromatic light and ultrashort pulsed lasers. Finally, we provide the design of the optical pulse-delay system for a three-dimensional memory application.     

Considerations for the Use of Semi-Transparent Metallic Thin Films as Potential Transmittance Standards in Spectrophotometry

Various characteristics of evaporated metal-on-fused silica filters are discussed in relation to their optical transmission properties. Special metal holders provided with shutters were designed to be used with these filters, and are described in detail. Transmittance measurements, performed in various conditions, are reported and indicate that the evaporated metal-on-fused silica filters might present an acceptable material as transfer standards in spectrophotometry.     

硅微声光传感特性的实验研究

硅微声光传感器是一种由硅微列阵簧片和光纤组合成的新型传感器，这种传感器在完成声光转换的同时对声频信号进行了并行滤波处理，可用作神经网络的并行输入，是一种光机电一体化的传感系统。本文中叙述通过纤反射强度调制技术检测硅簧片振动信号的方法；通过实验研究，完成了对声光调制信号的探测和预处理，并给出了实测数据及其分析。为实现音频编码和振动信号的实时分析，本文中还给出了采用人工神经网络对阵列传感器的输出信号进     

Effect of r.f. sputtering parameters on ZnO films deposited onto GaAs substrates

In order to compensate the piezoelectrical property of GaAs-based material for monolithic integrated acousto-optic circuit applications, a ZnO film with a highly preferred orientation should be deposited. R.f. sputtering was employed to deposit ZnO films with various technological parameters. The optimal conditions to deposit high quality ZnO film onto GaAs-based substrates were deduced and investigated. Low loss surface acoustic wave devices fabricated on ZnO/GaAs wafers were obtained. The total insertion loss measured at a centre frequency of 25.37 MHz was 20 dB.