Visible GaN laser diodes: From lowest thresholds to highest power levels

More and more applications are using GaN laser diodes. Visible blue laser devices are well established light sources for converter based business projection of several thousand Lumens. Additional laser-based concepts like near-to-eye projection push device requirements above heretofore limits. In 2017, threshold currents of 10 and 20mA were reported for single mode blue and green laser, respectively. We will present a drastic reduction of laser threshold of green R&D laser samples by more than a factor of 2 down to 10mA. We also will discuss turn-on delay as a limiting factor for modulation speed and spatial resolution of flying spot projection. On the other side, new applications may occur in the near future. We will present research data on blue laser bars as a possible component for industrial applications like for materials processing. LIV characteristics are measured up to power levels of 107W. We observe power conversion efficiencies of 44% at 60W output power for our best samples.