Patent ID: 7535573

Claim:
A method of making an apparatus for cavity enhanced optical spectroscopy, the method comprising: providing a source of optical radiation capable of emitting source radiation; providing an optical resonator having a lowest order resonator transverse mode and having multiple other resonator transverse modes, wherein the source radiation is coupled to the lowest order resonator transverse mode; providing a detector capable of receiving radiation emitted from the optical resonator; providing a reference optical resonator design having mode frequencies spaced by a small integer fraction of a free spectral range of said reference optical resonator, wherein said small integer fraction is selected from the group consisting of: ⅙, ⅕, ¼, ⅓, ½, 1, 0, ⅖, ⅔, ⅗, ¾, ⅘, and ⅚; deriving a design for said optical resonator by making a predetermined and non-zero deviation away from the reference optical resonator design.