0.98 /spl mu/m multiple quantum well tunneling injection lasers extrapolated

We have recently demonstrated that hot-carrier effects can be substantially reduced in single quantum well tunneling injection (SQW-TI) lasers. In this paper, we demonstrate the operation of a multiquantum well TI laser for the first time and a measured maximum intrinsic modulation bandwidth of 84 GHz for the device at a wavelength of 0.98 /spl mu/m. The active region consists of four In/sub 0.2/Ga/sub 0.8/As quantum wells, so designed that each of the four wave functions in the quantum wells is not localized in an individual well but distributed in the multiple quantum wells. Carriers injected into the active region by optical phonon assisted tunneling are uniformly distributed in the MQW, resulting in a high differential gain.