Ultrahigh speed performance of a quantum well laser at cryogenic temperatures

We have systematically studied the high speed performance of a 1.55 μm InGaAsP multiple quantum well laser diode at cryogenic temperatures from 10 to 300 K. We show that the maximum modulation bandwidth of the laser diode increases from 10 GHz at room temperature to over 27 GHz at the vicinity of 100 K. Our analysis indicates that this bandwidth is mainly limited by the device parasitics above 100 K and carrier transport below it.