Erbium-doped phosphate glass waveguide on silicon with 4.1 dB/cm gain at 1.535 mu m

Erbium-doped multicomponent phosphate glass waveguides were deposited by rf sputtering techniques. The Er concentration was 5.3x10(20) cm(-3). By pumping the waveguide at 980 nm with a power of similar to 21 mW, a net optical gain of 4.1 dB at 1.535 mu m was achieved. This high gain per unit length at low pump power could be achieved because the Er-Er cooperative upconversion interactions in this heavily Er-doped phosphate glass an very weak [the upconversion coefficient is (2.0+/-0.5)x10(-18) cm(3)/s], presumably due to the homogeneous distribution of Er in the glass and due to the high optical mode confinement in the waveguide which leads to high pump power density at low pump power. (C) 1997 American Institute of Physics.