Micro-cavity lasers with directional emission

Micro-cavity lasers with directional emission are getting more and more attention in the optoelectronic device and application field. In this paper, we presented two kinds of micro-cavity with the limason and triangle shape cavity for the directional emission application. By using quantum cascade material, the two kinds of micro cavity lasers are compared about output emission characteristics such as the far-field patterns, light output and the threshold current. The two kinds of micro-cavity lasers show good directional emission, and the limason cavity laser can reach about 30° on the main lobe of the far-field pattern with about 4.3mW peak power and the triangle can show a large one lobe with about 110° on the one side emission pattern. From the measurement result of the threshold current of the two lasers, the cavity quality factor Q finally has been obtained.