Photon lifetime dependence of modulation efficiency and K factor in 1.3 μm self-assembled InAs/GaAs quantum-dot lasers: Impact of capture time and maximum modal gain on modulation bandwidth

摘要

We studied small-signal modulation characteristics of 1.3 μm InAs/GaAs self-assembled quantum-dot lasers in terms of the modulation efficiency and the K factor as a function of the photon lifetime. We could explain the measured photon-lifetime dependence based on the rate equation model considering explicitly the carrier-capture process and Pauli blocking in quantum dots. Our model shows how the modulation bandwidth of quantum-dot lasers is limited by the carrier-capture time and by the maximum modal gain via the K factor. We present prerequisite designs of quantum-dot active regions for over 10 GHz modulation.