Highly coherent modeless broadband VECSEL

摘要

l'Agriculture, Montpellier, France $3Laboratoire de Photonique et de Nanostructures, Marcoussis, France; We report on the highly coherent modeless broadband continuous wave operation of a semiconductor vertical-externalcavity-surface-emitting laser. Its design is based on a frequency-shifted-feedback scheme provided by an acoustooptic frequency shifter inserted into the cavity. Chirping the optical wave inside the cavity leads to the elimination of the traditionnal spectral resnonances occuring in usual laser cavities, leading to a wideband (>330GHz here) continuous spectrum. The light is of high coherence concerning the transverse mode and the polarisation state, as well as in the time domain (time coherence ≈ 19μs, like a 1MHz DFB) in spite of its wideband emission.