Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7137458 | Sensors and Actuators A: Physical | 2014 | 8 Pages |
Abstract
A binary micro-mirror array (BMMA) is proposed for speckle reduction in grating light valve based laser projectors. The mirrors are driven by the electrostatic force, and have two states, i.e., '1' state (or 'static/off' state) corresponding to motionless mirrors or mirrors that are released to their zero-bias voltage position and '-1' state (or 'on' state) in accordance to the fully deflected mirrors. The phase modulation depth between the two working states of the mirror is Ï radian. The control electronics of the BMMA is designed by a passive driving scheme derived from a hadamard matrix or a two-level orthogonal array, thus we can avoid using the memory transistors, and number of the control electrodes could be significantly reduced. Performances of the mirrors are analyzed by the analytical model. A proof-of-concept 32 μm pitch BMMA fabricated using aluminum as the mechanical layer is presented, and the proper function of the BMMA is demonstrated with speckle reduction. About 5% speckle contrast ratio can be achieved after compounding the BMMA and a laser diode array.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Zhaomin Tong, Xuyuan Chen,