PROPERTIES OF A TUNNELING INJECTION QUANTUM-WELL LASER - RECIPE FOR A COLD DEVICE WITH A LARGE MODULATION BANDWIDTH

A new quantum-well laser, in which electrons are directly injected into the lasing quantum well by resonant tunneling, is proposed and demonstrated. The preliminary GaAs-based devices, grown by molecular beam epitaxy, have an 80-angstrom In0.1Ga0.9As active single quantum well and AlAs tunneling barriers. I(th) = 15 mA is measured in a single-mode ridge device, and the differential gain is approximately 2 x 10(-16) cm-2. The principle of operation promises a ''cold'' laser at high injection levels, and therefore Auger recombination and chirp are expected to be suppressed. In addition, tunneling of carriers into the active well has the potential to achieve large modulation bandwidths.