Beamwidth approximations for the fundamental mode in symmetric double-heterojunction lasers

The beamwidth for the fundamental TE
0
mode in symmetric DH lasers is approximated within 4 percent by analytical formulas covering wide ranges of cavity thickness and refractive index steps. By using a Gaussian approximation for near-field distributions, and numerically calculated beamwidth curves, we find a Gaussian beam-like expression for the beamwidth, over the range
1.5 < D < 6
, where
D
is the normalized guide thickness. In the nonGaussian region
0 < D < 1.5
, the beamwidth is estimated by using a corrected Dumke-like asymptotic approximation.