Effect of shorter section length on the performance of bisection gain lever transistor laser

The effects of different shorter to longer section length ratio on the performance of dual section transistor laser is analyzed numerically by solving the coupled rate equations. Dual section transistor laser is configured in common emitter configuration and biased in the active region. The DC and gain levering characteristics of bisection transistor laser is analyzed for different shorter to longer section length ratio ranging from 3:97 to 30:70. The shorter and longer section threshold current are found increase with increase in the shorter to longer section length ratio. A minimum shorter section threshold current of 3 µA is estimated for longer section bias current of 1.6 mA with shorter to longer section length ratio of 3:97. Higher slope efficiency is observed between an optical power and bias current of bisection transistor laser. A maximum gain lever of 9.87 dB is predicted for the shorter to longer section length ratio of 3:97 and gain levering decreases for increase in the ratio.