title: High-efficiency 20 W yellow VECSEL.
abstract: A high-efficiency optically pumped vertical-external-cavity surface-emitting laser emitting 20 W at a wavelength around 588 nm is demonstrated. The semiconductor gain chip emitted at a fundamental wavelength around 1170-1180 nm and the laser employed a V-shaped cavity. The yellow spectral range was achieved by intra-cavity frequency doubling using a LBO crystal. The laser could be tuned over a bandwidth of ~26 nm while exhibiting watt-level output powers. The maximum conversion efficiency from absorbed pump power to yellow output was 28% for continuous wave operation. The VECSEL's output could be modulated to generate optical pulses with duration down to 570 ns by directly modulating the pump laser. The high-power pulse operation is a key feature for astrophysics and medical applications while at the same time enables higher slope efficiency than continuous wave operation owing to decreased heating.
authors.forename: Emmi
authors.initials: E
authors.lastname: Kantola
authors.forename: Tomi
authors.initials: T
authors.lastname: Leinonen
authors.forename: Sanna
authors.initials: S
authors.lastname: Ranta
authors.forename: Miki
authors.initials: M
authors.lastname: Tavast
authors.forename: Mircea
authors.initials: M
authors.lastname: Guina