The influence of distributed rare earth dopant on the performance of waveguide lasers fabricated by the femtosecond laser direct-write technique

The development of an Yb-doped distributed Bragg reflector (DBR) waveguide laser fabricated in phosphate glass using the femtosecond laser direct-write technique is reported. The laser has the slope efficiency of 31% with the output power up to 81 mW at a pump power level of 378 mW. A theoretical model for the waveguide laser (WGL) is presented which gives emphasis to transverse integrals to investigate the energy distribution in a homogenously doped glass which is opposed to the fiber laser. The model was validated with experiments comparing a DBR WGL, and then used to study the influence of distributed rare earth dopants on the performance of such lasers. Approximately 15% of the pump power was absorbed by the doped "cladding" in the femtosecond laser inscribed Yb doped WGL case.7 page(s