Continuous-wave broadband emitter based on a transition-metal-ion-doped waveguide.

We demonstrate the suitability of a simple continuous-wave-pumped transition-metal-ion-doped waveguide as a broadband light source in the wavelength region 600-1000 nm for interferometric applications. Spatially coherent (single mode in the confined direction), spectrally broadband (~130-nm FWHM) luminescence with output powers of several hundreds of microwatts is obtained from a Ti:sapphire planar waveguide with incident pump powers from an Ar-ion laser of up to 1 W. This result represents an increase in power by several orders of magnitude from previously reported simple broadband light sources in this wavelength range.