共查询到19条相似文献,搜索用时 234 毫秒
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为了提高光谱成像系统的通光能量,该文介绍了一种可见光波段的大孔径(20 mm×20 mm)声光可调滤光器,与常用声光可调滤光器(光孔径10 mm×10 mm)相比,其光通量提高了3倍。该文还首次推导了包含声波衰减系数、工作频率、光到换能器距离的声光可调滤光器衍射效率公式。根据这个公式可以更准确地计算出声光可调滤光器的衍射效率。实验表明,这种双换能器声光可调滤光器工作带宽接近0.95个倍频程,滤光范围为0.4~0.9μm,衍射效率大于60%,光谱分辨率小于10 nm。 相似文献
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在可调谱声光滤光器基础上研制了一种新型单色仪_声光扫描单色仪.工作波长范围4000-7500A,光谱分辨率6A,单色光衍射光强0.14mW,自动扫描速度0.02ms-250s/cycle。该仪器可用于快速光谱扫描、多光谱成象和透明材料的微细结构分析等。 相似文献
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TeO2是声光可调滤波器主要成像晶体,由于晶体本身在分光成像时会产生色差,漂移等问题,文中从基础理论出发,研究了TeO2 晶体的旋光性对其作为声光可调滤波器时分光特性的影响,进而对其基本参数作了优化。首次对比分析了I.C.Chang理论体系与P.A.Gass修正理论体系,通过对比分析方法,得出在红外波段,两种理论体系对于超声波频率协调关系的计算结果差异较大,作者认为是I.C.Chang理论忽略晶体旋光特性所引起,因此,以P.A.Gass理论作为基础的声光可调滤波器设计方法适用于红外波段,当入射光极角小于30时,其旋光特性对分光性能的影响较小。通过对比分析可知,设计的入射光极角应小于54.7,这样可以保持较高的声光优值和较低水平的超声波频率;在红外波段,设计的入射光极角应小于39.2,两频率协调关系偏差f较小。 相似文献
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The performance of a fiber grating interrogation system using an acousto-optic tunable filter (AOTF) is analyzed. An equivalent linear circuit is presented to describe the system, which tracks the wavelength of a fiber Bragg grating (FBG) sensor in a FBG sensor array. From the model, the tracking resolution of a shot-noise-limited system has been determined for both transmissive and reflective interrogation of FBGs. An optimum ratio between the bandwidths of the FBG and the AOTF has been derived. Experimental results of a tracking system are presented to validate the theoretical predictions. The theory should also be suitable for interrogation systems using other forms of tunable bandpass filters for tracking the FBG wavelength 相似文献
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Min-Yong Jeon Hak Kyu Lee Joon Tae Ahn Dong Sung Lim Do Il Chang Kyong Hon Kim Seung Beom Kang 《Electronics letters》2000,36(4):300-302
An electronically wavelength tunable modelocked fibre laser operating over a 50 nm range using an all-fibre acousto-optic tunable filter is presented. The tuning range is 1557-1607 nm, for a 70 m long erbium-doped fibre (EDF) with a 270 ppm concentration 相似文献
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An acousto-optic tunable filter is employed to flatten the gain spectrum of an erbium-doped fibre amplifier. A relatively flat gain spectrum of 15 nm in bandwidth with variations of less than 1 dB is obtained by simultaneously applying eight closely-spaced RF signals to the acousto-optic tunable filter.<> 相似文献
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在集成声光可调谐滤波器(IAOTF)的基础上,提出了一种新型的集成光学波导型声光光通道监测仪(OCM).介绍了该OCM的工作原理及其基本结构,对它的插入损耗、响应时间、波长范围、波长分辨率和波长精度等性能指标进行了分析与计算,并对制成的集成光学声光OCM进行了实验研究.理论分析和实验结果表明,该OCM能够对密集波分复用(DWDM)系统多路光信道的工作波长和功率同时进行监测,其插入损耗小于3 dB,响应时间小于7μs,波长监测范嗣达174 nm,波长分辨率可达0.3 nm、波长精度可达±30 pm. 相似文献
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偏振超光谱成像技术是一个新兴的交叉技术领域,探索该技术在航天、民用等领域的应用已经成为国内外的重点研究课题,特别是基于声光可调谐滤波器(AOTF)的光谱成像仪,与传统仪器相比,在工作机制和仪器设计上都有着众多的优点。通过研究AOTF的工作原理,分析实验中AOTF偏振光谱成像仪的工作过程,制定了相应的数据采集系统设计方案,并且详细论述了系统基于LabVIEW平台的设计流程,同时给出了各模块的LabVIEW程序设计框图。经过实测实验对系统的功能进行了验证,结果表明:系统能够高效可靠地完成对图像数据的采集与相应仪器的控制,具有一定的研究价值和实用价值。 相似文献
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We present a novel design scheme based on the Gel'fand-Levitan-Marchenko inverse-scattering method for an acousto-optic tunable filter having an almost-ideal bandpass spectrum. We find that the ideal filter characteristics of flat-top with unity transmission and no side-lobes are in principle asymptotically possible in a properly designed codirectional Bragg filter. We propose physical schemes of achieving such characteristics in the acousto-optic tunable filter design. Filters having this desirable characteristic are of immense importance in improving the crosstalk performance in optical networks employing the wavelength-division-multiplexing scheme. We then discuss design specifics and simulated performances, and present a new optimization formula 相似文献
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声光可调谐滤波器(AOTF)是一种利用各向异性介质中的声光作用工作的快速可调谐的分光元件,通过调节所加载的超声波频率可实现对出射光波长进行灵活、快速地调节.光谱分辨率是评价声光可调滤波器性能的主要指标之一.以二氧化碲非共线声光可调滤波器为研究对象,基于声光作用基本原理,系统推导了非共线声光可调滤波器光谱分辨率公式,并分... 相似文献
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A time-dependent analysis of acousto-optic tunable filters (AOTF's) for multiwavelength optical-switching operations is presented, it explains the reason for the observed nonlinear behavior such as passband-pulling and quantifies the associated crosstalk performance degradation. The degradation of the filter performance is found to be due to copresence of the acousto-optic interaction profiles for different channels. Along with extensive Poincare-sphere analysis, the model also reveals time-dependent fluctuation of switching spectral responses, which calls for attention to the worst instances in the fluctuation for the wavelength division multiplexer (WDM) optical-switch application 相似文献