Lineshape and frequency noise of a vertical cavity surface emitting laser

Summary form only given. VCSELs are very original semiconductor lasers from different points of view, namely the short, high Q cavity; several transverse modes and gain guiding. with possible linewidth enhancement; different current injection mechanisms, for which the current noise can strongly influence the effective cavity length; strong thermal effects. For all these reasons, an accurate study of the frequency noise and of the lineshape of VCSELs is very interesting. We have performed such a study on a air-post VCSEL with an emission wavelength of 770 nm. We have recorded the lineshape at different injection current levels by heterodyne with a narrow linewidth extended cavity laser while the frequency noise spectrum is investigated using a Fabry-Perot cavity and frequency discriminator.