Advanced Manufacturing, Electronics and Microsystems: TechConnect Briefs 2015Advanced Manufacturing, Electronics and Microsystems TechConnect Briefs 2015

MEMS & NEMS Devices & Applications Chapter 8

Tip-Tilt-Piston Micromirror with Integrated Large Range Variable Focus for Smart Lighting Systems

J. Morrison, M. Imboden, T.D.C. Little, D.J. Bishop
Boston University, United States

pp. 300 - 303

Keywords: MEMS, optical communications, smart lighting

Modern fabrication techniques are enabling the adoption of micro-opto-electromechanical systems devices in applications never anticipated. Low-cost lighting systems can exploit micromirrors to both enable directed or sculpted light and to support short-range optical communications. The latter application is intended to use visible light as an alternative to the RF spectrum to gain new wireless data capacity under diminishing RF availability. However, optical communication systems are typically limited by line-of-sight obstructions and, in LED-based Smart Lighting systems, low signal to noise ratios (SNR). While SNR can be improved by introducing beamforming techniques, the line-of-sight issue requires multiple access points with integrated beam steering.. We demonstrate a novel MOEMS mirror which integrates variable focus and dynamic beam steering, eliminating the need for multiple microsystems. The mirror provides ±40° optical deflection and a variable focal length which can be tuned from -0.48 mm to +20.5 mm. The mirror can be actuated in a piston mode with a 0.3 mm vertical range. The large optical deflection and variable focus ranges provide unique advantages in Smart Lighting systems, where field of view and dynamic optics are growing in demand due to the high mobility of handheld receivers within the lighting field.