Optically pumped rare-earth-doped Al2O3distributed-feedback lasers on silicon [Invited]

This paper reviews recent progress in the field of optically pumped rare-earth-doped channel waveguide lasers, with a focus on operation utilizing distributed-feedback resonators on silicon wafers. Rare-earth-doped amorphous aluminum oxide thin films have been deposited onto silicon wafers by RF reactive co-sputtering from metallic Al and rare-earth targets, the spectroscopy and optical gain of Er 3+ , Yb 3+ , Nd 3+ , and Tm 3+ ions has been investigated, and the near-infrared laser transitions near 1 μm in Yb 3+ , 1.5 μm in Er 3+ , and 2 μm in Tm 3+ and Ho 3+ have been demonstrated. Output power between a few μW and hundreds of mW have been achieved in different waveguide geometries, and ultranarrow-linewidth laser operation has been demonstrated.