High-speed InGaAlAs/InAlAs multiple quantum well electrooptic phase modulators with bandwidth in excess of 20 GHz

High-speed phase modulation (in the frequency bandwidth of 20 GHz, the highest yet reported for multiple quantum well (MQW) phase modulators) for waveguided InGaAlAs/InAlAs MQW optical modulators is reported. The modulator successfully operates at a long wavelength of 1-55 mu m with a low required voltage for phase shift (V pi =3.8 V), small intensity modulation depth below 1.5 dB, and without any modulation bandwidth degradation up to 20 GHz under high input optical power of 0 dBm in single-mode fiber.<>