Near-UV laser diodes for external cavity lasers

We develop (Al,In)GaN laser diodes on free standing GaN substrates in the wavelength range from 390 nm to 425 nm for external cavity lasers. By varying the indium content in the InGaN active region we tailor the emission wavelength for specific applications. For usage in an external cavity laser module, the internal Fabry-Perot-modes of the laser diode have to be suppressed to provide good stability and tunability of the emission wavelength and avoid mode-hopping. Therefore we apply an antireflective coating with a reflectivity below 1% to the front facet of the laser diode.