Low-voltage superlattice asymmetric Fabry-Perot reflection modulator

A normally off transverse superlattice asymmetric Fabry-Perot modulator that has a contrast ratio of more than 26:1 at the Fabry-Perot resonance, and a reflection change of 33% at a wavelength of approximately 20 degrees AA away from Fabry-Perot mode for an operating voltage swing of <3 V is discussed. The structure contains an active region of 52 periods of a 30 AA GaAs-30 AA Al/sub 0.3/Ga/sub 0.7/As superlattice, embedded between top and bottom quarter-wave grating mirrors. The modulation is achieved by reducing the cavity loss at the Fabry-Perot resonance through the field-induced effective absorption edge blue-shift in the superlattice.<>