Charge control analysis of transistor laser operation

The authors report the calculation of the minority carrier distribution in the base region of the transistor laser (TL) employing the relevant continuity equations and experimental carrier lifetimes, spontaneous and stimulated, extracted from the transistor $I-V$ characteristics. A charge control model of the TL is developed, consistent with the short recombination lifetime of the quantum-well base (which competes with the short emitter-to-collector transit time). The absence of carrier-photon resonance of a TL is demonstrated with the $3dB$ bandwidth $(IB∕IB,th=1.5)$ estimated to be $30GHz$ for a $400μm$ long laser cavity length and $70GHz$ for a $150μm$ cavity.