High power quantum cascade lasers

We concentrate on recent exciting results on quantum cascade (QC) microlasers with “chaotic laser resonators” obtained by deforming the circular shape of a whispering gallery cylinder laser into a quadrupolar shape. Conventional microdisk lasers, despite their low thresholds, have suffered so far from negligible output power. We have found that the output power increases near exponentially with increasing deformation and that for low deformations the emission can be interpreted as arising form chaotic whispering gallery rays which collide with the boundary at a varying incidence angle and escape refractively when the latter is below the critical angle for total internal reflection