A low quantum defect and power scalable Yb-doped glass waveguide laser

We present a continuous wave laser action in ytterbium (Yb)-doped phosphate glass buried channel waveguides. The 25 mm long waveguides were fabricated by the standard ion exchange method. When pumped with a 976 nm laser diode, the waveguide laser emits at 982.4 nm, yielding an ultralow quantum defect of 0.66 %. The impact of coupling and pump power variation on the laser emission wavelengths is demonstrated. Furthermore, the results of pulsing using a monolayer graphene as a saturable absorber (SA) are presented and a pulse train with a repetition rate of 1 MHz and a pulse width of 700 ns was obtained.