Abstract

During recent years the intensity noise in semiconductor lasers has received considerable attention. This is mainly due to the theoretical predictions [1] and experimental results [2-7] indicating that sub-shot-noise levels, amplitude squeezing, can be obtained if the pump noise is suppressed using a high impedance injection current. Recent results indicate, however, that multimode operation in semiconductor lasers may render increased noise levels in spite of the low pump noise [4-7]. The intensity noise of vertical-cavity surface emitting-lasers VCSELs has been reported in refs. [8] and [9]. In [8] the polarization stability of GaAlAs-GaAs VCSELs was examined and the effect of mode partition between the two polarizations was observed. However, to the best of our knowledge, measurements where the VCSEL noise is directly compared to the fundamental shot-noise level have not yet been reported.

© 1995 Optical Society of America