All-optical, high contrast GaAlInAs multiple quantum well asymmetric reflection modulator at 1.3 μm

A high contrast, low intensity GaAlInAs/AlInAs multiple quantum well asymmetric Fabry–Perot reflection modulator for operation at 1.3 μm has been demonstrated. The reflection modulator takes advantage of the large absorptive and refractive nonlinearities associated with saturating the heavy-hole exciton resonance. We achieve an on/off contrast ratio in excess of 1000:1 (30 dB) and an insertion loss of 2.2 dB at a pump intensity of 30 kW/cm2, corresponding to a carrier density of 4.5×1017 cm−3. The modulator was demonstrated to have a large operating bandwidth, achieving an on/off contrast ratio of greater than 100:1 over a 5 nm optical band. The operating speed of the modulator was measured and found to approach 1 GHz.