Influence of free carrier plasma effect on carrier-induced refractive index change for quantum-well lasers

The influence of the free carrier component due to the plasma effect on carrier-induced refractive index change and its dependency on polarization for multiple-quantum-well (MQW) and bulk lasers are experimentally studied. The ratios of the component to the total index change, R/sub fc/, are 0.6, 0.4, and 0.1 for 1.3- mu m MQW, 1.3- mu m bulk, and 0.8- mu m MQW lasers, respectively. The TM/TE polarization ratios of the component, R/sub TM/TE/, are 0.8 and 0.3 for 1.3- mu m MQW and 0.8- mu m MQW lasers. The relationship between the index change and the carrier overflow (to barrier and separate confinement heterostructure layers) for MQW lasers is also discussed. Large R/sub fc/ and R/sub TM/TE/ for the 1.3- mu m MQW laser result from the carrier overflow.<
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