Abstract
The frequency noise of a laser has a direct influence on the lineshape and the linewidth. We present here the frequency-noise spectrum we obtained with selectively-oxidized Vertical-Cavity Surface-Emitting Lasers (VCSELs) emitting in the range of 850nm. We noticed different parts in the spectrum: a 1/fn part in the low-frequency range, independent of the output power, and a white-noise part in the high-frequency range, inversely dependent of the output power. The link with the laser lineshape is theoretically performed.