Abstract
We present theoretical and experimental results on the quantum noise performances of vertical-cavity-surface-emitting-lasers (VCSELs). Using a semiclassical laser noise approach, we demonstrate that the ratio of the powers in the two polarization modes of the laser is one of the essential parameters governing the VCSELs quantum noise behavior. The generation of amplitude squeezed states of light is only possible for two well-selected cases which are the ideal two-polarization-mode laser and the ideal single-polarization-mode laser respectively. Furthermore, we show that gain suppression, as well as other relevant semiconductor parameters, have also to be taken into account to model realistically the VCSEL’s quantum noise. These theoretical investigations are very well supported by our experimental results. We demonstrate experimentally that indeed there exists a direct link between the parameter M and the shot noise normalized amplitude noise. In a two-polarization-mode laser as, e.g., represented by a large diameter air-post VCSEL, squeezed states could not be generated because of insufficiently low values of M even though a strong anticorrelation between the two modes exists. With a single-polarization-mode laser, as realized with small diameter oxide confined VCSELs, we have been able to demonstrate the generation of single-mode squeezed light with a VCSEL. A squeezing level of 0.9 dB has been measured, which with the detection efficiency corrected, results in 1.3 dB at the VCSEL upper facet.
- Received 10 November 1998
DOI:https://doi.org/10.1103/PhysRevA.60.3284
©1999 American Physical Society