Patent ID: 7411991

Claim:
An apparatus, comprising: a tunable laser cavity, wherein said laser cavity comprises at least three mirrors, at least one filter and a plurality of crystals, wherein said at least three mirrors are substantially arranged in a folded linear cavity lambda configuration, said at least one filter comprises a birefringent filter and an etalon, at least one of said plurality of crystals comprises a Coloquiriite crystal, and at least one of said plurality of crystals comprises a nonlinear crystal, wherein said at least three mirrors, said at least one filter, and said plurality of crystals are configured for providing electromagnetic radiation of an approximately single frequency; and at least one electromagnetic radiation source being coupled to the laser cavity, wherein said at least one electromagnetic radiation source is capable of providing electromagnetic radiation having an approximately particular wavelength to said laser cavity, wherein at least one of said plurality of crystals is configured to, in operation, alter one or more properties of said electromagnetic radiation provided by said electromagnetic radiation source, wherein said at least one filter is configured to filter at least a portion of the electromagnetic radiation altered by at least one of said plurality of crystals, wherein the at least one filter is adjustable to tune the frequency of the electromagnetic radiation altered by the at least one of said plurality of crystals, wherein at least one filter comprises a quartz birefringent filter, wherein said quartz birefringent filter further comprises three plates of quartz birefringent.