Single Quantum-Well Transistor Lasers Operating Error-Free at 22 Gb/s

Data are presented showing error-free transmission by a 200-μm-long transistor laser at 15 °C. The device has a threshold current of 30 mA and exhibits a modulation bandwidth of f-3dB = 10.4 GHz at I
_B
= 85 mA and V
_CE
= 1.5 V. At this bias point, the device is able to transmit 27-1 Pseudo Random Binary Sequence (PRBS) data with no errors at 22 Gb/s. The effect of transistor laser input impedance on optical modulation amplitude is discussed and short cavity (200 μm) devices are shown to exhibit a better match to the 50 Ω impedance of the signal generator.