Gain Coupling of Class A Semiconductor Lasers (Postprint)

Abstract : We report on the development of a gain-coupled class A semiconductor laser for dual-wavelength generation via optical switching. A vertical external cavity surface emitting laser (VECSEL) structure is used, because it provides a flexible platform for high-power, high-brightness output in the near-IR and visible ranges. For the first time (to our knowledge), two VECSEL cavities sharing a common gain region are studied. Because the cavities are in competition for common carriers, birefringent filters in the external cavity control the laser cavity thresholds; this configuration demonstrates the possibility of switching between the two cavities, which can operate at different wavelengths. However, in this Letter we also show, numerically and experimentally, that with the consideration of spontaneous emission, it is possible to maintain simultaneous lasing in each cavity at a different wavelength.