Imai Tadayuki, Ueno Masahiro, Sasaki Yuzo, Sakamoto Tadashi
Appl Opt. 2017 Sep 1;56(25):7277-7285. doi: 10.1364/AO.56.007277.
The potassium tantalate niobate (KTN) optical beam deflector is an electro-optic deflector without any moving parts that works at frequencies higher than 200 kHz. In this paper, we discuss the performance parameters of this deflector. Optical beams are bent by the spatial distribution of the refractive index in the KTN crystal block used in this deflector. In addition to the deflection function, the index distribution operates as a cylindrical convex lens. Therefore, the deflector is often used with glass cylindrical lenses to cancel out the lens function. We analyzed optical rays curving in the block based on the graded index lens theory. We describe the way in which performance parameters, such as the deflection angle, change, depending on both the choice of the compensating lenses and the parameters of the KTN block, namely its size and charge density. We concentrate especially on methods designed to improve the resolvable spot number, which is the most important figure of merit for optical deflectors. One way to achieve improvement is to input a collimated beam or a slightly converging beam into the KTN block.
钽铌酸钾（KTN）光束偏转器是一种无任何移动部件的电光偏转器，其工作频率高于200kHz。在本文中，我们讨论了这种偏转器的性能参数。光束通过该偏转器中使用的KTN晶体块内折射率的空间分布而发生弯曲。除了偏转功能外，折射率分布还起到柱面凸透镜的作用。因此，该偏转器常与玻璃柱面透镜一起使用，以抵消透镜功能。我们基于渐变折射率透镜理论分析了光线在晶体块中的弯曲情况。我们描述了诸如偏转角等性能参数如何根据补偿透镜的选择以及KTN晶体块的参数（即其尺寸和电荷密度）而变化。我们特别关注旨在提高可分辨光斑数量的方法，这是光学偏转器最重要的品质因数。实现改进的一种方法是将准直光束或略微会聚的光束输入到KTN晶体块中。
