Hansler, Richard | Engineering Papers

NASA NTRS2004

Silicon micromachined broad band light source

A micro electromechanical system (MEMS) broad band incandescent light source includes three layers: a top transmission window layer; a middle filament mount layer; and a bottom reflector layer. A tungsten filament with a spiral geometry is positioned over a hole in the middle layer. A portion of the broad band light from the heated filament is reflective off the bottom layer. Light from the filament and the reflected light of the filament are transmitted through the transmission window. The light source may operate at temperatures of 2500 K or above. The light source may be incorporated into an on board calibrator (OBC) for a spectrometer.

George, Thomas↗

NASA NTRS2001

MEMS Incandescent Light Source

A MEMS-based, low-power, incandescent light source is being developed. This light source is fabricated using three bonded chips. The bottom chip consists of a reflector on Silicon, the middle chip contains a Tungsten filament bonded to silicon and the top layer is a transparent window. A 25-micrometer-thick spiral filament is fabricated in Tungsten using lithography and wet-etching. A proof-of-concept device has been fabricated and tested in a vacuum chamber. Results indicate that the filament is electrically heated to approximately 2650 K. The power required to drive the proof-of-concept spiral filament to incandescence is 1.25 W. The emitted optical power is expected to be approximately 1.0 W with the spectral peak at 1.1 microns. The micromachining techniques used to fabricate this light source can be applied to other MEMS devices.

Tuma, Margaret↗