Semiconductor laser with curved deep-etched distributed Bragg reflectors supporting a planar Gaussian mode

A compact integration-compatible semiconductor laser supporting a planar Gaussian mode is demonstrated. Curved deep-etched distributed Bragg reflectors (DBR's), contouring the phase front of the Gaussian wave, act as feedback elements. The DBR's are 0.5 microm deep and have two first-order air gaps separated by a third-order semiconductor spacer. Low-threshold current (10 mA) is achieved for a 90-microm-long laser with a waist of 2 microm. Lasing in a planar Gaussian mode is observed up to 1.7 times the threshold current, whereas at higher currents the mode behavior degrades because of spatial hole burning.