Microfabricated incandescent lamps

A silicon filament vacuum sealed incandescent light source has been fabricated using IC technology. The incandescent source consists of a heavily doped p(+) polysilicon filament coated with silicon nitride and enclosed in a vacuum sealed ( approximately 80-mT) cavity in the silicon chip surface. The filament is electrically heated to reach incandescence at a temperature near 1400 K. The power required to achieve this temperature for a filament 510 x 5 x 1 microm(3) is 5 mW yielding a total optical power of 250 microW with a peak distribution wavelength near 2.5 microm. The radiation emitted by this source approximately follows Lambert's cosine law. The energy conversion efficiency is 5%.