Abstract

The BRAQWET (Barrier Reservoir and Quantum Well Electron Transfer) modulator is an interesting alternative to quantum well modulators based on the Quantum Confined Stark Effect and the Wannier Stark Effect. The BRAQWET modulator is based on electrorefraction in a tunable electron-density quantum well. It has excellent high speed potential since it involves only one type of carriers (electrons) and the speed of the refractive index change is not limited by carrier lifetime. Realization of this structure in InGaAsP materials has potential for even higher speeds due to higher electron mobility. However, these materials have a lower bandgap offset, which increases enormously the leakage current of a BRAQWET device (tens of A/cm² at V = 0.5 V).

© 1994 IEEE