Monolithically Integrated Semiconductor Optical Amplifier and Electroabsorption Modulator with Dual-Wavelength Expansion-Beam Input

We have demonstrated a semiconductor optical amplifier and electroabsorption modulator monolithically integrated with a novel dual-waveguide beam expander at the input for low-loss coupling to Planar lightguide circuit silica waveguides or cleaved single mode optical fiber. These devices exhibit greater than 10 dB fiber-to-fiber gain, output power of +4 dBm, 3-dB modulation bandwidth of 6 GHz, and Modulator extinction ratios of 20 dB d. c. and 14.4 dB r.f. for a 2.4 V sub (pp) drive.