Rare-Earth-Ion-Doped Channel Waveguide Lasers on Silicon

This paper reviews the recent developments in rare-earth-ion-doped channel waveguide lasers. Optical gain in rare-earth-ion-doped waveguides has been increased by two orders of magnitude to ∼1000 dB/cm and waveguide lasers with extremely high slope efficiencies and output powers exceeding the Watt level have been demonstrated. Of particular interest in integrated optics is the recent integration of rare-earth-ion-doped channel waveguide lasers in amorphous materials directly deposited on a silicon substrate. Remarkable performance with respect to slope efficiency, output power, and laser linewidth has been achieved.