The lasing characteristics of GaN-based vertical-cavity surface-emitting laser with AlN-GaN and Ta/sub 2/O/sub 5/--SiO/sub 2/ distributed Bragg reflectors

Abstract

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 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> --SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> 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.