A new type of spectrometer, with no movable parts, no optical sources, and no precision engineering, is demonstrated by the use of computer interpretation of interference patterns. Currently it has a resolution sufficient to determine the optical spectrum of a two-moded distributed-feedback laser with 2-nm mode spacing. The spectrometer operates by transmitting the laser light through two pinholes to generate an interference pattern in the far field. The interference pattern is captured with an infrared camera and is transferred to a computer. The spectrum of the light is extracted from this interference pattern by the maximum-entropy method of spectral estimation.
© 1995 Optical Society of America
D. D. Marcenac and J. E. Carroll, "Maximum-entropy optical spectrum analyzer," Opt. Lett. 20, 1074-1076 (1995)