近几年来,随着光集成电路的发展,对其重要的组成因素之一的、用电控制激光强度的光调制元件或光开关,也研究出了各种方案并进行了大量实验。其中大多数是以LiNbo_3、LiTaO_3等电光晶体作为基质,通过向装配在晶体表面上的组合电极加电压,或者利用弹性表面波及超声波的传播、在晶体内部形成周期性的折射率分布,然后,被入射到该(周期)范围内的激光束受到相互作用,产生衍射现象。这就是他们的基本工作原理。这些引起衍射现象的周期性折射率分布的周期,因受组合电极的组成条件以及超声波、弹性表面波的激励条件限制、不易缩小。用此现在采用的光强度调制用激光偏转角度,充其量也只有几度,提高作为光调制元件的S/N(信噪)比,尚需付出一定努力,同时,要将其多级配置以构成激光束的 In recent years, with the development of optical integrated circuits, various schemes have been developed and a large number of experiments have been conducted on light modulating elements or optical switches that control the laser intensity by using one of the important components. Most of them are based on LiNbo_3, LiTaO_3 and other electro-optic crystals as a matrix, by the combination of electrodes mounted on the crystal surface voltage, or the use of elastic surface waves and the spread of ultrasonic waves in the crystal to form a periodic refractive index distribution, and then The laser beam incident on this (period) is subjected to an interaction, resulting in a diffraction phenomenon. This is their basic working principle. The period of the periodic refractive index distribution that causes the diffraction phenomenon is not easily reduced due to the compositional conditions of the combined electrode and the excitation conditions of the ultrasonic and the surface acoustic wave. With the present laser light deflection angle for light intensity modulation, at best, only a few degrees are required to improve the S / N (signal to noise) ratio as a light modulating element, and a certain amount of effort is required to be made, and at the same time, Laser beam