The lasing characteristics of GaN-based vertical-cavity surface-emitting laser with AlN-GaN and Ta2O5--SiO2 distributed Bragg reflectors

The characteristics of a GaN-based vertical-cavity surface-emitting laser (VCSEL) with 25 pairs AlN-GaN distributed Bragg reflector (DBR) and eight pairs Ta
₂
O
₅
--SiO
₂
DBR was investigated and analyzed under the optical pumping at room temperature. The GaN-based VCSEL emits a blue wavelength at 448 nm with a linewidth of 0.17 nm with a near-field emission spot diameter of about 3 μm. The laser beam has a near linear polarization with a degree of polarization of about 84%. The laser shows a high spontaneous emission coupling efficiency of about 5×10/sup -2/ and a high characteristic temperature of about 244 K.