Abstract:

Using quantum cascade lasers with a two-dimensional metallic aperture-grating structure defined on the facet the authors demonstrate a collimated laser beam with small divergence angle perpendicular and parallel to the laser waveguide layers (2.7 degrees and 3.7 degrees, respectively). These values represent a reduction by a factor of similar to 30 and similar to 10, respectively, compared to those of the original 8.06-mu m- wavelength laser without plasmonic collimation. The devices preserve good room temperature performance with output power as high as 53% of that of the original unpatterned lasers.