Micro Electro-Mechanical Systems (MEMS)-Based Adaptive Optics Systems

Free-space laser communications is an important element of the Translation Communications initiative. However laser communication is inherently limited by atmospheric disturbances and other aberration sources that degrade the quality of the communication link. Adaptive optics systems can reduce signal degradation by rapidly measuring and compensating for these optical aberrations. Sequoia will develop an adaptive optics system for free-space laser comm. The system consist of four elements; the static optical system, the wavefront sensor, the wavefront actuator and the control algorithm. Sequoia will develop a custom adaptive optics control algorithm optimized for the laser communications application. Our advanced control methods directly optimize the signal-to-noise ratio of the communications signal rather than performing brute force phase-conjugation as is done in traditional image recovery adaptive optics control systems. This reduces the sensor requirements of the adaptive optics system resulting in reduced size, weight, and complexity of the overall system. Wavefront correction will be performed using a MEMS-based deformable mirror. MEMS mirrors are an inexpensive and compact alternative to piezoelectric mirrors. Sequoia Technologies will develop a deformable mirror actuator geometry that is optimized for the laser communications application. Pointing of the laser communication system will be performed using Sequoia’s proprietary gyro-stabilized gimbal technology.