Wideband and low voltage waveguide modulators with asymmetric coupled QWs beyond 40 Gb/s

A prerequisite for ultrafast modulators in 80 or 160 Gb/s TDM optical fiber communications will be that modulating voltages should be as low as possible. This is because the driving capability of electronic devices such as HBTs and HEMTs is rapidly decreasing at higher frequencies. A wideband wavelength range of operation is also very important for extension to DWDM systems. The Mach-Zehnder modulator with a multiple quantum well (MQW) waveguide is a promising candidate because of its low chirp and adjustable chirp modulation characteristics.