LARGE MODULATION DEPTH, SINGLE-MODED QUANTUM-WELL WAVE-GUIDE MODULATOR OPERATING AROUND 1.57 MU

The performance of long wavelength single-mode waveguide modulators suitable for monolithic intergration with a quantum well laser is reported. The device operated between 1.560-mu-m and 1.570-mu-m. The guiding layer was formed by a 0.27-mu-m quaternary layer at the centre of which were four 50 angstrom In0.53Ga0.47As quantum wells separated by 100 angstrom InP barriers. Lateral confinement was obtained by etching ridges in the top InP contact layer. For devices of 500-mu-m length, a modulation depth of 19 dB was obtained at a wavelength of 1.568-mu-m with a reverse bias voltage of only 3 V and an internal loss of 2.5 dB.