Vertical external cavity surface emitting laser with dielectric film integrated on substrate

Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163 Vertical cavity surface emitting laser (VCSEL) with external cavity which is filled by dielectric materials or air can achieve good beam quality and high power. Aiming at the problem of complex production process and loose structure of the external cavity, a kind of surface emitting laser with the dielectric film integrated on external cavity bottom substrate was designed. Multilayer dielectric insulation films grown on the surface of substrate, N-DBR, and P-DBR composed the coupled cavity structure, and the substrate was served as external cavity of VECSEL. This structure can suppress high order mode, so it can optimize the output spectrum and far-field divergence angle of beam characteristics. Based on the previous theory, we manufactured a VECSEL with active area of 200 μm in diameter and external cavity length of 250 μm. The device is carried out with continuous DC current of 3.4 A at room temperature, and the power is 260 mW, the divergence angle of far field is 3.8°, the full width at half maximum of spectrum is 0.046 nm. Obviously, compared with conventional structure of bottom emitting VCSEL, the beam quality of VECSEL devices is improved.