Wavelength tuning in quantum dot semiconductor disc lasers

Conventional optically pumped semiconductor disk lasers (SDLs) are able to produce laser light at a wide range of wavelengths across the visible and near infra-red spectrum with high output power and diffraction limited beam whilst allowing the advantages of various intracavity techniques to be exploited [1]. Recently the SDL architecture has been combined with quantum dots (QDs) based gain materials [2, 3] to explore their advantages provided by three dimensional carrier confinement, like temperature insensitivity and broad gain bandwidth, supported by inhomogeneous broadening [4]. In this paper the gain bandwidth supported wavelength tuning in QD based SDLs is in focus. We report wavelength tuning results of two QD SDLs at 1040 nm and 1260 nm. Broad tunability, of respectively 50 nm and 35 nm is observed. The results show QD based SDLs have wider tunability range than most conventional quantum well (QW) based their counterparts [5, 6] and make QD SDL potentially as a broadly tuneable continuous wave light source.