Laserful

Researchers at ETH Zurich in Switzerland have created an optically-pumped vertical-external-cavity surface emitting laser (OP-VECSEL) that emits more than 20W of continuous-wave (CW) average output power in the fundamental mode at 960 nm. (Optics Letters 33 2719)

The result is achieved by improved thermal management. The key to making this happen was to grow the VECSEL's semiconductor gain structure in reverse order, solder it directly onto a diamond heat spreader and remove the GaAs substrate using a wet-chemical etching procedure.

Via: Optics.org