A novel short-cavity laser with deep-grating distributed Bragg reflectors

We have proposed a novel short-cavity laser with deep-grating distributed Bragg reflectors (DBRs). We monolithically fabricated a 0.98 mu m InGaAs/AlGaAs device and 1.55 mu m GaInAsP/InP device using electron beam Lithography and a reactive ion beam etching technique. The lasing operation of both devices was achieved at room temperature. From a comparison of the threshold current from the experimental result with that from the theoretical result, the reflectivity of formed DBRs was estimated to be less than 30%. The theory also predicts that the ideal DBR exhibits a high reflectivity over 97% even with 3 periods of grating. It achieves lasing operation with a threshold current less than 100 mu A using a cavity shorter than 10 mu m. This high performance is realized by reducing the surface roughness and damage to etched sidewalls and improving the reflectivity of the DBR.