Carrier dynamics in high-speed (f_{-3 dB} > 40 GHz) 0.98-μm multiquantum-well tunneling injection lasers determined from electrical impedance measurements

Carrier capture times in InGaAs-AlAs-GaAs 0.98-μm multiquantum-well tunneling injection lasers with f_{-3 dB} ∼ 43-48 GHz have been determined from analysis of high frequency electrical impedance measurements. The capture times range from 14 ps, at biases around threshold, to about 1 ps, at 50-mA bias. The small capture times agree well with tunneling times obtained directly from pump-probe measurements. The impedance measurements also suggest that the carrier lifetime in the well is much less than the escape time from the well, consistent with the cold carrier distribution associated with a tunneling injection mechanism.