Sputtered AlN/Al2O3 distributed Bragg reflectors on amorphous glass

With the sharp increase in the demand for vertical-cavity surface-emitting lasers (VCSELs), the need for high-performance and rapid thermal dissipation distributed Bragg reflectors (DBRs) has become significantly urgent in photonic and optoelectronic devices. In this work, a novel DBR composed of alternating aluminum nitride (AlN) and alumina (Al2O3) has been designed and prepared on an amorphous sodium silicate glass substrate via radio frequency (RF) sputtering technique. The effect of a number of stacks on the reflectance of DBRs has been explored theoretically and experimentally. The results show that AlN/Al2O3 DBRs with 11.5 pairs can achieve 96 % of reflectance. The stopband bandwidth covers from 720 to 880 nm. The surface roughness is around 2.9 nm with an area of 9 μm2. Our sputtering-grown AlN/Al2O3 DBR with high reflectance and low surface roughness has laid a good foundation for the potential application of high-performance and rapid thermal dissipation DBRs in photonic integrated circuits.