Membrane external-cavity surface-emitting laser emitting in bi-frequency operation through micromachining of cavity mirror

Abstract

We present continuous wave bi-frequency operation in an optically pumped membrane external-cavity surface-emitting laser (MECSEL). A laser ablation system utilising a digital micromirror device is used to define areas of intra-cavity loss by removing Bragg layers from the surface of the cavity mirror in a crosshair pattern with an undamaged central area. Our MECSEL simultaneously operates on two Hermite-Gaussian spatial modes, the fundamental and a higher order mode, by aligning the laser cavity to be centred on a masked area. We demonstrate bi-frequency operation with a wavelength separation on the order of 5 nm around 1005 nm.