Integrated Al2O3:Er3+ ring lasers on silicon with wide wavelength selectivity.

Integrated Al(2)O(3):Er(3+) channel waveguide ring lasers were realized on thermally oxidized silicon substrates. High pump power coupling into and low laser output power coupling from the ring is achieved in a straightforward design. Output powers of up to 9.5 microW and slope efficiencies of up to 0.11% were measured while lasing was observed for a threshold diode-pump power as low as 6.4 mW for ring lasers with cavity lengths varying from …