基于AOTF的在线红外光谱测量系统

介绍了一种新型的红外光谱测量系统，它由准直发射系统和聚焦接收系统两大部分组成，以声光可调谐滤光器（AOTF）为色散元件，连续改变AOTF的驱动频率就能实现快速波长扫描，达到实时测量目的。该系统具有结构简单、测量快速等特点，可用于在线有害气体检测和红外光谱分析。实验表明，系统光谱测量范围2．5－5μm，光谱分辨力为10nm。     

一种新型农药浓度荧光测量系统的研究

根据声光可调滤波器（Acousto-Optic Tunable Filters，AOTF）的分光原理研制了一种新型的农药浓度荧光俭测系统，系统以高压短弧氙灯为激发光源，以AOTF为分光元件，利用光纤探测传输荧光，采用数据采集卡实现数据接收和A／D转换，由微机进行数据存储和显示，并且利用该系统实现了对西维因农药浓度的荧光持性的测量。结果表明：系统测量光谱范围为230nm～750nm，光谱分辨率为10nm，在激发波K319nm、荧光波长650nm、西维因溶液浓度为0．0～120．0μg／L时系统具有较好的线性关系，线性相关系数r为0．9991，该系统达到了荧光检测的指标。     

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，     

红外声光滤光器与压电换能器设计方法

本文讨论了红外声光滤光器的设计方法,并着重讨论了压电换能器的设计,认为对于声光滤光器、换能器设计的关键是增透膜及1/ω_0C_0值的选取。为了提高换能器的电声转换效率,可以适当选取电极面积,使1/ω_0C_0>R_((?)0)。设计制作了波长2～5μm的红外声光滤光器,在现有条件下对其性能进行了估测。     

一种以AOTF为核心的农药荧光检测系统

提出了一种将 AOTF 技术用于农药含量检测的荧光光谱系统。该系统分别采用以α-Quartz,TeO2 晶体作为声光介质的激发和发射色散元件 AOTF,以高压短弧氙灯为激发光源,利用光纤探测并传输荧光,由数据采集卡进行数据接收和 A/D 转换。该系统通过声光调制产生单色光,由超声射频的变化实现光谱扫描,没有机械调谐部件,故波长切换快、结构简单。西维因农药的荧光特性测量结果表明,系统的荧光波长范围为 500-750nm, 光谱分辨率为 10nm。当激发光波长为320nm,荧光波长为 647nm,西维因溶液浓度为 0.0-120.0μg/L 时,系统具有较好的线性关系,线性相关系数 r 为 0.9991。它可用于对粮食作物中的农药残留的检测和荧光光谱分析。     

LD抽运Nd:GdVO41.34μm激光器及其倍频特性

采用直线腔激光二极管（LD）抽运Nd：GdVO4晶体1，34μm激光器。在泵浦功率为8W的情况下，获得连续波输出为1．91W。激光器光-光转换效率为23．9％，斜效率为29．1％。采用声光调Q，重复频率为10kHz时，得到最短脉宽、最大单脉冲能量分别为78ns和20．1μJ，最大平均输出功率为253mW。采用Nd：GdVμ4晶体KTP腔内倍频激光器，在泵浦功率为6.7W时，得到单向连续红光输出为50．7mW，光-光转换效率为1．5％。     

10.6微米高效率声光调制器

利用 Ge 单晶良好的机械、声光性能,研制出工作中心频率为 70MHz、波长为 10.6ìm 的锗声光调制器。该器件采用高品质因数 Ge 单晶(III)作为声光介质, y36°切铌酸锂晶体作为压电换能器。由于锗器件对热变化特别敏感,所以设计了环绕结构和背面结构两种不同的吸热系统,测试表明,采用环绕结构比采用背面结构时衍射效率可提高 10%以上,而且光斑质量也明显变好。用 13W高频驱动功率驱动锗晶体声光调制器,其最大峰值衍射率达到 68%。     

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。     

声光频谱分析技术研究

介绍利用我们研制的以声光滤光器（ＴＡＯＦ）作为色散元件的声光频谱分析装置［１－４］，对若干透明固体和液体的频谱进行测试的结果。实验表明，各种物体所固有的声光（ＡＯ）频谱是不相同的，这可作为对物体的微细结构分析的一种鉴别方法。     

彩色合成中AOM设计分析

利用铌酸锂晶体为压电换能器，熔石英为声光互作用介质，研制出调制速度为32MHz、工作频率为180MHz、渡越时间为15ns、用于RGB彩色合成中的的声光调制器，文中主要讨论和分析了Q参数与调制器中心工作频率、换能器长度的关系；讨论了R参数对衍射光束形状的影响及与衍射效率的关系，还讨论并确定了换能器最佳尺寸，经测试，高速率声光调制器衍射效率为47％，并测试了调制速度。     

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。     

应力对多层薄膜窄带滤光片透射特性的影响

利用薄膜应力公式和弹性力学的小挠度弯曲理论,分析了多层薄膜应变与薄膜厚度变化的关系,建立起基片曲率与薄膜厚度变化关系的理论模型,提出了多层薄膜各层厚度不均匀变化的关系式。膜厚均匀变化只影响中心波长的漂移,而这种膜厚不均匀变化不仅引起中心波长也引起光谱的退化。在基片由10mm厚减薄到1．0mm时,对100GHz的窄带滤光片的模拟结果为中心波长减小0．977nm;0．5dB带宽减小0．19nm。引入膜厚随机误差的模拟结果为中心波长减小1．066nm;纹波增加0．36dB;峰值插损增加0．32dB,光谱进一步退化了。说明了基片曲率变化引起的光学薄膜厚度变化的不均匀性是引起这种窄带干涉滤光片光谱退化的主要原因之一。     

中波红外短波通滤光片的设计与镀制技术研究

研究了中波红外宽光谱短波通滤光片优化设计和镀制,论述了设计该种滤光片的原则和方法。根据等效折射率理论,以周期性对称膜系为基础,使用部分膜层优化方法,设计了中波红外宽光谱短波通滤光片,在2 300～4 700 nm透射波段范围上的平均透射率设计值大于90%,在5 000～6 300 nm截止波段范围上的平均透射率小于1.00%。采用"会聚光红外光学系统"和等离子体辅助沉积工艺实验制备了滤光片。实验表明,在透射波段范围上的平均透射率约为83%,截止波段的平均透射率约为0.45%。结果表明,部分膜层优化方法设计的膜系,膜层结构简单,有利于膜层厚度的监控。     

新型体全息窄带滤光器的光学特性研究

用紫外/可见分光光度计测定由DCG记录的透射式体全息窄带带阻滤光器的光谱特性,分析其滤波特性。测量结果分析表明,滤光器有较窄的带宽,其半宽度小于13nm,1/10宽度小于19nm。在400-800nm可见光区域,对其主谱线的相对透过率小于2%,其它谱线的相对透过率大于85%。对半导体泵浦激光器主谱线532.0nm有优良的滤光特性。     

Wide wavelength range tunable guided-mode resonance filter based on incident angle rotation

A wide wavelength range tunable guided-mode resonance filter (GMRF) with high peak efficiencies, narrow linewidths, and low sidebands is experimentally demonstrated. The resonance wavelength can be tuned under TM polarized light illumination by rotating the angle of incidence. The GMRF composed of a one-dimensional grating layer and two waveguide layers on a glass substrate is designed with rigorous coupled-wave analysis. The grating structure of the GMRF is patterned by interference lithography with two ultraviolet laser beams. The reflection colours of fabricated GMRF can be shifted from blue to red by rotating the angle of incidence. The measured full width at half-maximums of the reflection peaks located at 450.6, 500.9, 551.0, 601.1, and 651.3?nm are 3.1, 3.9, 4.3, 3.8, and 4.1?nm, respectively. The corresponding sidebands of measured spectra are below 0.2. Compared with previous experimental studies on tunable structures, the narrow linewidths and low sidebands of the proposed GMRF are remarkably improved.     

Thermal effect on the output transmission of single-core fiber Comb filter

We propose and experimentally demonstrate switchable and tunable transmission characteristics of a single-core comb filter based on thermal operation. Its temperature characteristics are investigated to reveal a shift in the peak wavelength position from 0.15 to 0.41 nm/°C and a tunable range of wavelength spacing of 1.18–1.38 nm for maximum and minimum effective lengths, respectively. This configuration provides the unique advantages of an all-fiber structure, tunable wavelength spacing, switchable spectral peaks, independent tuning of the center wavelength and wavelength spacing of the spectral peaks, and low polarization sensitivity. It is relatively simple to fabricate and is expected to have applications in temperature fiber optic sensors and multiwavelength fiber laser sources.     

Collinear guided wave to leaky wave acoustooptic interactions in proton-exchanged LiNbO(3) waveguides

The results of a detailed theoretical study on collinear guided wave to leaky wave acoustooptic (AO) interactions in proton-exchanged LiNbO(3) (PE:LiNbO(3)) planar waveguides are presented. The guided-to-leaky mode conversion for an input optical beam at the wavelength of 632.8 nm by the induced diffraction grating from a collinear surface acoustic wave (SAW) is analyzed using a generalized multimode formulation of the coupled mode theory. Mode conversion efficiency and AO bandwidth have been calculated as functions of acoustic frequency, interaction length, guiding layer thickness, and acoustic drive power density for three cuts of the LiNbO(3) substrate. High performance configurations that are desirable for application to demultiplexing and switching in optical communication systems are identified, and the corresponding channel capacity and frequency resolution are determined. For example, it was shown that the X-cut configuration features the highest mode conversion efficiency. However, a relatively small AO bandwidth is associated with this configuration. Both high mode conversion efficiency and large AO bandwidth can be accomplished at the guiding layer thickness of 1.0 mum. A TM(o)-->TE(nu) mode conversion efficiency as high as 42% together with an AO bandwidth of approximately 70 MHz can be achieved in the Z-cut waveguide at the guiding layer thickness of 1.0 mum, acoustic drive power density of 50 mW/mm, interaction length of 40 mm, and acoustic frequency of 460 MHz. The corresponding channel capacity and frequency resolution are 745 and 0.09 MHz, respectively. Measured mode conversion efficiencies as high as 90 and 78% obtained at the acoustic frequencies of 107 and 367 MHz using the X-cut substrate and the Y-propagation SAW have verified the theoretical prediction on the mode conversion efficiencies.     

Acousto-optic tunable filter as a polychromator and its application in multidimensional fluorescence spectrometry.

Acousto-optic tunable filter (AOTF) is an electronically driven dispersive device which operates on the principle of acousto-optic interaction in an anisotropic medium. Incident white light will be diffracted by the AOTF into a specific wavelength when a specific rf is applied to it. The diffracted light needs not be a monochromatic light. Multiwavelength light can be diffracted from the AOTF when several rf signals are simultaneously applied into the filter. Compared to conventional polychromators, advantages of this electronic AOTF polychromator include its ability to individually amplitude-modulate each wavelength of the diffracted multiwavelength light at different frequency. This is accomplished by individually and sinusoidally modulating each applied rf signal at the desired frequency. This feature makes it possible to develop a novel AOTF-based multidimensional fluorimeter in which the sample was simultaneously excited by two different wavelengths (514.5 and 488.0 nm) whose amplitudes were sinusoidally modulated at two different frequencies (100 and 66 Hz). Multicomponent samples, e.g., mixtures of rhodamine 6G and rhodamine B, were successfully analyzed using this novel fluorimeter and the developed data analysis.