Active planar optical waveguide made from luminescent silicon nanocrystals

We show experimentally that a layer of silicon nanocrystals, prepared by the Si-ion implantation ~with the energy of 400 keV! into a synthetic silica slab and exhibiting room-temperature red photoluminescence, can serve simultaneously as a single-mode planar optical waveguide. The waveguide is shown to self-select guided transverse electric and transverse magnetic modes from the broad photoluminescence emission of the nanocrystals resulting in a substantially narrower emission spectrum for these modes. We further report on an investigation of optical gain in a sample implanted to a dose of 4310 cm. Despite the occurrence of strong waveguiding, results of the variable stripe length method turned out not to be able to give unambiguous evidence for optical gain. © 2003 American Institute of Physics. @DOI: 10.1063/1.1544433#