Differential gain, refractive index, and linewidth enhancement factor in high-speed GaAs-based MQW lasers: influence of strain and p-doping

The addition of strain and p-doping in high-speed GaAs-based MQW lasers are assessed experimentally in terms of their potential for both increasing the differential gain, /spl part/g//spl part/N, and reducing the modulus of the differential refractive index, |/spl part/n//spl part/N|, in order to decrease the linewidth enhancement factor, /spl alpha/. The increased differential gain with strain alone is found to be offset by a corresponding increase of |/spl part/n//spl part/N|. The further addition of p-doping, on the other hand, simultaneously increases /spl part/g//spl part/N and decreases |/spl part/n//spl part/N|, yielding a substantial reduction in /spl alpha/.>