Microsecond pulsed yellow emission by intracavity doubled optically pumped two-chip VECSEL

A quasi-continues-wave (QCW) 100 mu s pulsed yellow laser at 589 nm, based on intracavity frequency doubling (ICFD) of identical two-chip vertical-external-cavity surface-emitting laser (VECSEL) with bow-tie configuration, is demonstrated. Each VECSEL chip is optically QCW-pumped by an 808 nm laser diode, emitting a fundamental wavelength around 1178 nm. A birefringence filter is inserted in the laser cavity to select the linear p-polarized oscillation and tune the operation wavelength. Using a lithium-triborate (LiB3O5) as the frequency doubled crystal, a total frequency doubled output power of 264 mW at 589 nm is achieved, operating at a pulse duration of 194 mu s and a pulse repetition rate of 1 kHz. A good beam quality factor is measured to be M (2) = 2.15. These results represent a novel scheme for the QCW multiple gain chips VECSEL ICFD system, opening up a new perspective for the realization of impact long pulse 589 nm laser for sodium guide-star.