Very fast optical beam steering and wave front correction can be achieved by employing phased arrays of lightweight High Contrast Grating (HCG) MEMS mirror etalons. The etalons provide a large phase shift for a small displacement, 100x more than traditional reflective mirror elements. Operating such etalon arrays requires exquisite control of the MEMS mirror displacements. Our aim is to use in-situ stroboscopic interferometric imaging of the etalons to ensure phase accuracy and combat long term-drift, while employing feed-forward electrical input shaping to achieve fast settling time and precise phase tracking in a power-efficient way.
- Mischa Megens
- B.-W. Yoo, M. Megens, T. Chan, T. Sun, W. Yang, C. J. Chang-Hasnain, D. A. Horsley, and M. C. Wu, “Optical phased array using high contrast gratings for two dimensional beamforming and beamsteering,” Optics Express, vol. 21, no. 10, p. 12238, May 2013.
- T. K. Chan, M. Megens, B.-W. Yoo, J. Wyras, C. J. Chang-Hasnain, M. C. Wu, and D. A. Horsley, “Optical beamsteering using an 8 × 8 MEMS phased array with closed-loop interferometric phase control,” Opt. Express, vol. 21, no. 3, pp. 2807–2815, Feb. 2013.