新型大尺寸电磁驱动MEMS光学扫描镜的研制

设计并制作了一种结构新颖的镜面尺寸为6mm×4mm的电磁驱动MEMS光学扫描镜.这种背面为微型铜驱动线圈的MEMS硅基扭转镜面沉浸在由包含永磁体的磁回路产生的磁场中,当电流信号通过驱动线圈时,MEMS光学扫描镜绕着扭转梁发生了大角度的扫描运动.采用MEMS体硅加工工艺和电镀技术制作的器件显示出了优良的性能,实验获得的扫描镜静态转角斜率为0.03°/mA,当器件进行动态扫描时,在381Hz的谐振频率下获得了最大±10.2°的光学扭转角度,空气中的Q因子为221,相应的功耗为13μW,与此同时MEMS光学扫描镜具备了出色的镜面粗糙度、光学反射率和镜面平整度.实验证明该器件完全适合于微型光谱仪和可调光滤波器的应用.

A Novel Large-Scale Electromagnetically Actuated MEMS Optical Scanning Mirror

A novel configuration of an electromagnetically actuated MEMS optical scanning mirror with a large mirror area of 6mm×4mm is designed,fabricated,and characterized.This optical scanning mirror based on a silicon plate,in which a set of micro-coils for actuation are adhered to the back side of the mirror using the electroplating technique,is immersed in the magnetic field produced by the magnetic circuit,including a permanent magnet.The mirror rotates around one pair of torsion bars when the driving current signal is applied on the driving coils.This device,fabricated using silicon bulk processing and the electroplating technique,shows excellent performance.The slope of optical steering deflection of this device is 0.03°/mA,the optical deflection angle is 1e2. under a resonant frequency of 381Hz at a lower power consumption of ＜1mW,and theQfactor in air is 221.Additionally,the MEMS scanning mirror as a precise optics element presents good surface roughness of mirror and high reflectivity,so it can be applied in scanning systems such as high speed micro-spectrometers and optical tunable filters in optical communication.