Transistor laser with simultaneous electrical and optical output at 20 and 40 Gb/s data rate modulation

A single quantum well transistor laser (cavity length L = 300 μm) has been designed and fabricated that operates with threshold ITH = 18 mA at 15 °C and 14 mA at 0 °C. Due to the “fast” base recombination lifetime (τB < 29 ps), the transistor laser demonstrates reduced photon-carrier resonance amplitude (<4 dB) over its entire bias range and a modulation bandwidth f-3dB = 9.8 GHz at 15 °C for IB/ITH = 3.3 and 17 GHz at 0 °C for IB/ITH = 6.4. Under the same bias conditions, simultaneous electrical and optical “open-eye” signal operations are demonstrated at 20 and 40 Gb/s data rate modulation.