Abstract

Mid-infrared laser applications require either coherent sources with narrow linewidths or low divergence output beams. The parameter defining both minimum spectral linewidth and beam quality is the a-factor, also called the linewidth enhancement factor or antiguiding parameter, α-factor is the ratio of the derivatives with respect to the carrier concentration of the real and imaginary parts of the media complex dielectric function. In terms of measurable quantities, it is proportional to the ratio of changes in the refractive index and modal gain with injection current.

© 2002 Optical Society of America