Optical MEMS Corner-Cube Reflector (CCR)
An electrostatic micro CCR: The movable base mirror is tilted
when at rest. Incident light can be modulated by applying
a voltage that pulls the mirror toward the substrate into
a position orthogonal to the other two mirrors. CCRs of this
design have a bandwidth ranging from 0.2 to 2 kHz, with a
driving voltage of 20 to 40 V. Photo courtesy of the UCLA
Department of Electrical Engineering.
The key component of MOICS,
the Tanner optical MEMS communication system, is the MEMS
CCR (the micro-electromechanical systems corner cube reflector).
When its three mirrors are mutually orthogonal, any incoming
radiation is reflected directly back to the source. A CCR
can modulate the signal—and thereby relay information—by tilting
one of its mirrors. Because the area of each CCR mirror will
be less than 0.1 mm2, the remote units will be very small.
Our goal is to develop affordable MEMS CCRs that achieve MOICS
performance specs (e.g., a bandwidth of 100 kHz) and that
can be easily assembled. Check out our
videos of CCR assembly and modulation!
This research has been sponsored by the Defense
Advanced Research Projects Agency (DARPA).