NEW ELECTROABSORPTIVE DEVICE WITH NEGATIVE-RESISTANCE BASED ON A LOW-RESPONSIVITY GAAS ALAS MULTIPLE-QUANTUM-WELL/

We propose and demonstrate a novel electroabsorptive device which poss esses N-type negative resistance. The device consists of a low respons ivity GaAs/AlAs multiple quantum well modulator on top of a GaAlAs pho todetector. The structure has a larger photocurrent contrast ratio in the negative resistance region (approximately 3:1 as the voltage chang es from 0 to 15 V) than conventional self-electro-optic effect devices (SEEDs). The characteristics of the device change only a little up to high illumination levels (2 mW continuous wave in a 2.8 mum/1e2 diame ter spot). We discuss the possible applications of this element as an improved bistable reflection-mode SEED and as an optically controlled microwave oscillator.