Ultralow-threshold-current lasing in inversion channel lasers

A new regime of semiconductor laser operation was observed in quantum-well inversion channels of double heterostructure optoelectronic switches. The quantum-well active region operated with substantial excess negative charge imbalance due to the proximity of a high-density depleted donor charge sheet. Threshold current densities as low as 15 A/cm/sup 2/ in as-cleaved 400- mu m-long devices were measured, and unusual high-frequency operation under low power operation was observed. These qualities may be of great significance for optical interconnections and optoelectronic integrated circuits.<
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