US Patent 7822081 Resonator

This invention relates to a wavelength tunable light source, comprising a main resonator, having a first and a second mirrored end, defining an effective cavity length, i.e. an optical beam path length of a resonant mode of the cavity, an optical gain element, having a first and a second opposing end surface, said second surface being positioned within said main resonator, a mirror element constituting said second mirrored end, and a dispersive focusing resonator element, being positioned along a beam path between said second end surface and said mirror element, whereby said effective cavity length of said main resonator is arranged to be varied.