COHERENCE LENGTH AND NOISE PROPERTIES OF GAALAS BROAD-BAND SOURCES.

The coherence length of two types of GaAlAs broadband sources has been measured as a function of current. The noise properties of these devices were also measured in interferometers with short path-length differences. The coherence length of the envelope of the longitudinal modes was found to be 30 mu m for both devices, whereas the individual mode coherence lengths were between 1 and 7 mm. The noise properties of these devices were determined in a michelson interferometer and were found to be essentially intensity-noise limited at 1kHz for small path-length difference (< 2 cm).