Electroabsorption of InAsP/InP strained multiple quantum wells for 1.3 μm waveguide modulators

We report the electroabsorption property of InAsP/InP strained multiple quantum wells (MQWs), grown by gas-source molecular beam epitaxy, for 1.3 μm modulator applications. Very sharp excitonic absorption at room temperature was observed. Electroabsorption measurements performed for a ring-shaped p-i-n diode, consisting of 10-period InAs0.41P0.59(100 Å)/InP(150 Å) strained MQWs, reveal a significant red shift of the absorption peak with increasing reverse biases due to the quantum-confined Stark effect. This large energy shift (e.g., ∼18 meV at an external field of 57 kV/cm) is well accounted for in the ‘‘effective well-width’’ model. The change of the absorption coefficient at a 22 meV detuning is as large as 3510 cm−1 with a small residual absorption, which can be very useful for 1.3 μm waveguide modulators.