Development of an optical beam manipulator based on micromachine technologies

本研究的目的是利用基于集成电路的微机械加工技术来制作用于光束的切换、斩波、定向和扫描的微型光学机械装置。我们已经建立了由切割板、微镜和微执行器组成的微光机械装置。利用光刻、刻蚀等半导体技术实现了许多高度超过100微米、精度达到1微米的微结构。一种装置是一种光学斩波器，由带有狭缝的切割板和驱动该切割板的压电致动器组成。另一种装置是由微镜阵列组成的矩阵光束开关，每个微镜由细长的扭转光束悬挂，在静电力的作用下可以弯曲90度。获得的结果如下：(1)以各向异性刻蚀单晶石英衬底，建立了驱动器，在2.7 kHz处产生超过100微米的共振位移。该驱动器已成功应用于光束斩波器中。另一种类型的执行器在端板上连接的多折叠悬架在很高的共振模式下处于共振振动时，在端板上产生50-100微米的静态位移。将该驱动器应用于光学开关中。(2)在硅衬底上制作了微镜阵列。每个镜子由两个扭杆悬挂，在静电力的作用下，它可以弯曲多达90度。通过在特定位置插入微镜，改变了来自准直光束光纤的光束方向。利用该器件实现了矩阵光开关，其插入损耗为9.6分贝，通断比和串扰小于-60分贝。

The purpose of this research is to fabricate micro miniature optomechanical devices for switching, chopping, directing and scanning optical beams by IC-based micromachining technology. We have built micro optomechanical devices composed of chopping plates, micromirrors and microactuators. Semiconductor technologies such as photolithograph and etching were utilized to realize many microstructures which were more than 100mum in height and had accuracy of 1mum. One device is an optical chopper composed of a chopping plate with slits and piezoelectric actuators to drive the plate. Another device is a matrix optical beam switch composed of arrays of micromirrors ; each mirror is suspended by thin and long tortioal beams and can be bent 90 degrees by electrostatic force.Following results have been obtained :(1) A single cristal quartz substrate was anisotropically etched to build a actuator which produces displacement over 100mum in resonance at 2.7 kHz. The actuator was successfully applied to an optical beam chopper. Another type of actuator produced 50-100 mum static displacement at the end plate when the multi-folded suspention attached to the plate was in resonant vibration at very high resonant mode. The actuator was applied to an optical ON-OFF switch.(2) Arrays of micromirrors were fabricated on silicon substrate. Each mirror was suspended by two tortion bars and it could be bent as much as 90 degrees by electrostatic force. Directions of optical beams from collimated beam fibers were changed by inserting micromirrors at certain locations. A matrix optical switch was realized by using the device ; the insertion loss was 9.6 dB and ON-OFF ration and cross talks were less than -60 dB.