High power multiwavelength light source

In accordance with the invention, a multiwavelength light source comprises a length of optical waveguide amplifier, a multiwavelength reflector for reflecting a plurality of different spectrally separated wavelengths optically coupled to one side of the amplifier and a low reflection output coupled to the other side. A broadband source is provided for passing broadband light to the multiwavelength reflector. In the preferred embodiment, the reflector is a plurality of reflective Bragg gratings, the waveguide amplifier is a length of rare-earth doped fiber (e.g. EDF) and the broadband source is the amplifier pumped to generate ASE. In operation, broadband light is transmitted to the gratings. Light of wavelength channels corresponding to the reflection wavelengths of the gratings is reflected back through the amplifier for further amplification before it arrives at the output. Optionally one or more transmission filters can be disposed between the reflector and the amplifier (or at the output) ASE source to control the relative magnitudes of the selected channels.