Patent ID: 6982998

Claim:
A laser source comprising: a laser medium having a back facet and a front surface, wherein said laser medium emits a laser beam through said front surface into an external cavity; a cavity end mirror that defines a length of said external cavity and reflects said laser beam back towards said laser medium, wherein said cavity end mirror is curved; a wavelength tunable filter arranged between said laser medium and said cavity end mirror and being tunable to a wavelength of said laser beam to provide a resonant beam within said external cavity; a focussing optics that focuses said laser beam on said cavity end mirror, wherein said laser medium, said wavelength tunable filter, said focussing optics and said cavity end mirror are arranged in a spatially linear cavity structure substantially in a line without angular redirection of said laser beam in said external cavity, and wherein at least one of said laser medium or said cavity end mirror is movable in a linear direction of said spatially linear cavity structure to adjust an optical oath length of said external cavity commensurate with a tuning of said wavelength by said wavelength tunable filter.