Ultrahigh-speed all-optical modulation using intersubband transition quantum well waveguide and its application

All-optical modulation over ultra-wide wavelength range using intersubband transition (ISBT) quantum well will be presented. This is based on cross-phase modulation (XPM) through the intersubband transition in an InGaAs/AlAsSb coupled quantum well using a linearly polarized pump wave. Optical millimeter wave at 76 GHz has been generated over a wavelength range of 1330 - 1620 nm using sinusoidal-intensity modulated pump. Pumping at a higher modulation rate could be possible, which will have potential application in coherent millimeter to THz wave generation, optical sampling, as well as in optical communications.