Quantum-well transistor laser for optical interconnect and photonic integrated circuits

The heterojunction bipolar transistor laser, inherently a fast switching device, operates by transporting small minority base charge densities ~10¹⁶ cm^-3 over nano-scale base thickness (<; 900A) in picoseconds. The insertion of quantum-wells and tilted charge in the short base of a transistor reduces recombination lifetime below 30 ps which is critical for extending the direct modulation bandwidth of the semiconductor laser towards 200 GHz. Three-port operation expands the use of the transistor laser (TL) to optical interconnect and photonic integrated circuits.