High contrast ratio self-electro-optic effect devices based on inverted InGaAs/GaAs asymmetric Fabry–Perot modulator

We demonstrate a new class of ‘‘normally off’’ high contrast ratio asymmetric Fabry–Perot (ASFP) reflection modulators based on a blue-shift of the Fabry–Perot mode under bias. The negative differential resistance (NDR) exhibited by the photocurrent-bias behavior was exploited to implement self-electro-optic devices (SEED) using as the load (a) a photodiode (D-SEED), and (b) a phototransistor (T-SEED). In the D-SEED scheme, a contrast ratio of ∼50:1 with ∼20% throughput was realized. The T-SEED configuration was found to offer nearly as high contrast ratio but with a ∼200:1 gain from the control light beam. Moreover, the ASFP modulators used belong to the inverted configuration which offers considerable convenience in device integration and optical interconnections.