a CREOL, The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816-2700, USA b OptiGrate, 3267 Progress Drive, Orlando, FL 32826, USA
Abstract:
Incoherent combining of multiple laser beams with offset wavelengths into a single near-diffraction-limited beam is an effective solution to increasing energy brightness and scaling output power of high-power lasers. Volume Bragg gratings (VBGs) recorded in photo-thermo-refractive (PTR) glass allow spectral beam combining with a remarkably high spectral density of channels. Spectral beam combining (SBC) of five channels within 1-2 nm bandwidth around 1064 and 1550 nm into a single near-diffraction-limited beam with absolute efficiency 92-94% is demonstrated. Scaling of this technique to multi-kW power level is discussed.