Surface grating loaded VCSEL with single mode power of over 80 mW

Abstract

We demonstrate a surface grating loaded VCSEL showing high power, good beam quality and stable single mode operation. In the structure, a single slow light mode propagating laterally along the long cavity of an oxide VCSEL can be selected thanks to the surface Bragg-grating. Experimental results of spectrum, L/I characteristics and beam quality with different device lengths are presented. A single mode power of over 80mW is realized with a narrow diffraction-limited divergence angle of 0.15° for a VCSEL with an oxide aperture of 4μm × 500μm under CW operation. A higher single mode power is expected through extending the device length with the proven scaling law.