共查询到20条相似文献,搜索用时 109 毫秒
1.
光学相控阵技术是一种灵活、快速和精确的非机械光束定向扫描技术,具有分辨率高,抗干扰和高保密性等优点.综述了电控扫描的光学相控阵技术的应用背景,对以铌酸锂晶体、锆钛酸铅镧陶瓷等电光材料和液晶为移相器材料的光学相控阵技术的最新研究进展进行了详细介绍,讨论了这几种光学相控阵技术的优缺点和适用性,以及光学相控阵器件实用化所需要... 相似文献
2.
基于电光材料的光学相控阵技术研究进展 总被引:6,自引:0,他引:6
综述了基于电光材料的光学相控阵(OPA)的研究进展.介绍了光学相控阵技术的基本原理以及不同电光材料(铌酸锂电光晶体,AlGaAs光波导,液晶和掺镧锫钛酸铅(PLZT)电光陶瓷)光学相控阵技术的基本构想和涉及的关键技术;着重介绍近年来基于PLZT电光陶瓷材料光学相控阵技术的发展情况以及在这方面的最新研究成果,包括单级相控阵、级联相控阵、不同电极结构(表面电极和上下电极结构)相控阵技术等;最后简要介绍了光学相控阵技术在激光雷达等军事领域中的应用. 相似文献
3.
从征 《激光与光电子学进展》1998,35(6):17-18
一种以掺镧钛酸锆酸铅(PLZT)为基础的可编程多通道相位调制器列阵以亚微秒开关速度执行光束的连续控制。这个由圣地亚哥加州大学J.Thomas等人研制的列阵感应波前相位延滞,情况类似于衍射光学元件的效应。这种技术在两维和三维显示器、激光通讯和光雷达方面有应用。加到PLZT上的电压通过电光效应而产生折射率变化。装在PLZT材料片上的电压形成独立可寻址调制器列阵,可以编程,使列阵起着衍射光学相位光栅的作用,使入射光束引起任意相位延迟。经澜改性的钛酸铅酸铅有很大二次电光系统,线性效应较小。它适合可见和红外波长使用,… 相似文献
4.
5.
采用光纤作为传输链路,将光子晶体光纤作为系统的输出阵列,LiNbO3波导作为相位调制器,构建了一种基于光纤光路的光波导光学相控阵。根据光学相控阵理论和LiNbO3波导的电光效应,分析了系统的可行性, 并研究了这种新型结构下的光波导光学相控阵的输出衍射特性和光子晶体光纤阵列结构参数的关系。研究结果表明通过控制施加在LiNbO3波导上的电压可以改变出射光束的附加相位从而实现光束的偏转;光子晶体光纤阵列上的纤芯数量、纤芯间距以及纤芯的排列方式等结构参量会对系统的输出光束的光强分布、半峰值全宽度(FWHM)和归一化的振幅分布产生影响。随着光子晶体光纤制作工艺的不断发展,系统的光束扫描质量将会逐渐提高并且色散特性和传输特性将会获得改善,为今后这种光学相控阵系统的设计提供了理论基础和技术依据。 相似文献
6.
一、前言具有钙钛矿结构的铁电介质和反铁电介质构成了压电陶瓷的基础。工业中使用了以钛酸钡、锆钦酸铅、锆钛酸铅镧、钛酸铅、钦酸铋和另一些具有类似钙钛矿复杂结构的含铋铁电介质、铌锂酸铅以及碱金属为基础的混合物。最广泛采用的以锆钛酸铅为基础的压电陶瓷,是由若干多晶相、非晶相以及充气孔 相似文献
7.
光学相控阵在光束偏转中的应用分析及进展 总被引:1,自引:0,他引:1
与传统光学偏转器件相比,光学相控阵可实现快速、灵活、高精度的光束指向控制。介绍了光学相控阵实现光束偏转的基本原理,并对影响偏转效率及偏转角度的主要因素进行了系统分析,对现有材料可实现的光束偏转性能参数进行了对比分析。针对目前光学相控阵材料只能实现小角度偏转的缺陷,进一步介绍了增加其偏转角度的技术途径。最后对应用光学相控阵技术实现的大角度高精度偏转系统APPLE(adaptive photonic phase-locked elements)进行了介绍,并对其技术先进性与局限性进行了分析。 相似文献
8.
9.
介绍了光学相控阵光束偏转技术的基本原理,根据夫琅和费衍射与傅里叶变换理论建立了光学相控阵模型,针对光学相控阵参数对偏转效率的影响进行了仿真分析。仿真结果表明,相控阵单元数量对偏转效率的影响很小,而增大相控阵填充率,减小相控阵单元总体尺寸,减小偏转角度,则可以有效地提高光学相控阵的偏转效率。 相似文献
10.
利用调制式椭偏仪测量薄膜电光系数 总被引:1,自引:1,他引:0
利用调制式的椭偏仪测量了掺镧锆钛酸铅PLZT薄膜的电光系数.首先用反射椭偏测量的方法得到薄膜的折射率(n)和厚度(d),然后利用透射椭偏在线测量的功能,在样品上加电场(E),得到薄膜的折射率的改变8n.最后用测量得到的厚度,折射率以及折射率的改变来计算薄膜的电光系数.该仪器的灵敏度很高,很适合较薄的膜层材料电光性质的测量. 相似文献
11.
12.
A new deflector device for optical waves is demonstrated in which linear phase modulation due to the electro-optic effect across a multichannel waveguide array is used to deflect optical waves. A preliminary experiment with a 20-channel device made in titanium-diffused LiNbO3 has exhibited deflection through five resolvable spots for an applied voltage of 10 V. 相似文献
13.
提出一种实现二维光码分多址系统编解码的方法.阐述编解码的原理和电光晶体的基本性质,用电光晶体构造编解码器的关键部件电光偏转器和电光开关,对系统的每个部分进行分析,用具体的地址码进行模拟.结果表明,该方法能有效实现二维光码分多址系统的编解码,并且方法简单、控制灵活、系统升级方便,能够在全光网络通信中发挥重要作用.Abstract: A new encoder-decoder scheme of 2-D OCDMA (Optical Code Division Multiple Access) system is proposed.The principles of encoding-decoding and the characteristics of electro-optic crystals are discussed.The key components,electro-optic deflector and switch,were manufactured by electro-optic crystals and each part of this system was analyzed respectively.A simulation was made with 2-D OOC (optical orthogonal code),and the results showed the effectiveness of this technique in realizing encoder-decoder.This system would play an important role in all-optical telecommunications with its simple scheme,flexible control and convenient upgrade. 相似文献
14.
S. N. Antonov A. V. Gerus T. G. Gerus 《Journal of Communications Technology and Electronics》2007,52(4):472-477
A new light deflector is proposed in which different polarizations are deflected in opposite directions by equal angles in the presence of nonuniform transverse mechanical pressure. The characteristics of the deflector are calculated. Light deflection is experimentally studied in a deflector based on TeO2. The experimental deflection angles are in good agreement with the calculated results. On the basis of measurements of light aberrations in crystals of various shapes, the configuration of the deflector that is optimal in terms of sensitivity and the smallness of aberrations is determined. Upon a single pass through the crystal, the deflection angles can be as high as tens of milliradians in the case when mechanical deformations are acceptable and the beam is of relatively high quality. 相似文献
15.
16.
《Photonics Technology Letters, IEEE》1991,3(3):222-224
A ridge-waveguide-type AlGaAs grating surface-emitting beam deflector was fabricated. The deflection is controlled by carrier-induced refractive-index change of the waveguide. The maximum deflection angle change is about 0.6 degrees , which corresponds to about ten resolvable spots. The temperature raising of the active layer was estimated in comparison with the characteristics for direct and pulsed current operation. It was 6.5 degrees C for the injection current (DC) of 20 mA.<> 相似文献
17.
Gefeson Mendes Pacheco Eugenio Scalise Jr. Nori Beraldo 《Journal of Infrared, Millimeter and Terahertz Waves》1993,14(8):1619-1625
The two main constrains on the characteristics of the acousto-optic deflector are the acoustic sound attenuation and velocity. These two parameters will determine the resolution and the radio frequency bandwidth. Due to a double degenerated phase matching condition on a specific acousto-optic deflector configuration, the possibility of an improvement on the resolution of the acousto optic deflector becomes evident. This degenerescence is the result of the action of a D.C. electric field by the electro-optic effect. This configuration presents several advantages upon the early related works based on optical activity of selected materials and enables a wideband interaction in such a way that the number of resolvable channels is kept high. This has implications on the acousto-optic spectrometers for wideband radio astronomy research. 相似文献
18.
19.
20.
A novel electrooptic (EO) beam deflector has been designed through numerical simulation. This stripline lithium tantalate device has the potential to electrooptically modulate the deflection of an optical pulse at unprecedented frequencies. Velocity matching of the optical pulse to a high-frequency transmission line signal is achieved through reflections of the fast optical pulse. An optimal design criterion is formulated for this device. Deflection capability is estimated to be 8/spl deg/. The device is intended for use in deflection-based optical analog-digital (A/D) conversion. 相似文献