Polarization dependence of linewidth enhancement factor in InGaAs/InGaAsP MQW material

Measurements and calculations on the differential gain, the differential refractive index, and the linewidth enhancement factor have been performed for unstrained quantum-well (QW) material. The differential refractive index is considerably lower for the transverse magnetic (TM) polarization than for the transverse electric (TE) polarization, which is ascribed to absence of the plasma effect for the TM polarization. This has implications for the linewidth enhancement factor and thus linewidth and chirp in QW lasers.<
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