In this paper, the transmission-line laser model is modified to model both transverse-electric (TE) and transverse-magnetic (TM) modes so that it is applicable to quantum-well (QW) dual-polarization lasers and polarization-insensitive semiconductor optical amplifiers (SOA's). The effects of carrier transport are also included in the model. The resulting dual-polarization transmission-line laser model is used to study large-and small-signal dynamic behavior of dual-polarization lasers. We find from large-signal simulations that the polarization asymmetry (ratio of the transverse-modal powers) varies on a nanosecond time scale in dual-polarization single-quantum-well (SQW) devices. We show that unequal transverse-modal differential gains and gain nonlinearities are responsible for this temporal polarization asymmetry. In addition, our numerical simulations show that the steady-state polarization asymmetry is a strong function of the gain nonlinearity. Small-signal dynamic simulations show that the modulation response of the polarization-unresolved output of dual-polarization SQW lasers follows that of the transverse mode with the lowest gain nonlinearity coefficient, regardless of the transverse-modal differential gains.
|Number of pages||11|
|Journal||IEEE Journal on Selected Topics in Quantum Electronics|
|Publication status||Published - 1 Apr 1997|
- Dual polarization
- Laser dynamics and modeling
- Quantum well
- Semiconductor lasers