Intensity noise correlations in vertical-cavity surface-emitting lasers

We compare experimental results concerning the intensity noise of vertical-cavity surface-emitting lasers (VCSELs) operating with only one longitudinal and transverse mode above threshold to the predictions of a full quantum model. Our theoretical predictions are compared to the experimental results obtained with VCSELs. Our sample has several VCSELs with different active medium diameters on the same chip. The operation wavelengths range from 820 to 850 nm and the emitted optical power can be varied from 1 to 5 mW. High reflectivity Bragg reflectors constitute the cavity mirrors. The cavity length, of the order of the wavelength, ensures single longitudinal mode operation of all lasers in the sample but not single transverse mode operation. To obtain single mode operation, the driving current must not be too high. We keep the driving current below five times the threshold current. We check with a monochromator that only one mode is above threshold. With a Glan polarizer (extinction ratio 10/sup -4/) we observe that this mode (TEM/sub 00/) is linearly polarized.