Slab-coupled optical waveguide lasers and amplifiers

Slab-coupled optical waveguide lasers (SCOWLs) and amplifiers (SCOWAs) are inherently low-confinement structures with large nearly-circular modes that are easily coupled to optical fibers or collimated for free-space applications. Recently SCOWL powers have increased to 3 W by increasing the cavity length to 1 cm and improving the heat removal. SCOWAs are coherently combined using active phase control to achieve a very high-brightness source. Our coherent beam combining system consists of single-pass amplifiers with angled-facet SCOWAs that suppress feedback. Single-pass, 5-mm long, SCOWAs have now been demonstrated with 1.5 W CW output with only 50 mW seed power. Arrays of 47 SCOWAs have demonstrated a raw power of 57 W with 50 mW of seed power per element. A coherent beam combining demonstration is currently being assembled.