Electro-optical effects in strain-compensated InGaAs/InAlAs coupled quantum wells with modified potential

摘要

We design and experimentally report strain-compensated InGaAs/InAlAs coupled quantum wells with modified potential. At a lower applied electric field (F=50  kV/cm), the calculated blueshift of the lowest excitonic peak is 40.6 meV. In the room-temperature photocurrent experiments, a maximum upward shift of the apparent peak position of more than 35 meV is observed with an external reverse bias of −4 V. Furthermore, a lower absorption loss (α=9.8 cm−1)and a large negative refractive index change (Δn=−0.0095)are obtained at 1.55 μm. This indicates that the strain-compensated InGaAs/InAlAs coupled quantum wells with modified potential have a great potential for application to reflection type electro-optical switches.