Linewidth enhancement factor in strained quantum well lasers

The linewidth enhancement factor alpha of strained quantum-well lasers is analyzed by the k-p perturbation method using the effective-mass approximation. It is found that the alpha factor in a strained In/sub 0.80/Ga/sub 0.20/As/InP quantum-well (QW) laser with 1.9% biaxial compression is less than 1.5. For a strained QW laser with p-type modulation doping (MD) of 5*10/sup 18/ cm/sup -3/, the alpha factor is as small as 0.8. It is also demonstrated that the spectral linewidth and wavelength chirping in the strained MD QW laser are significantly less than those in conventional bulk and QW lasers.<
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