Patent ID: 6546028
Filing Date: 2003-04-08
Classification: H01S

Abstract:
A wavelength reference apparatus for use in calibrating a tunable Fabry-Perot filter or a tunable VCSEL to a precise, absolute frequency on a target frequency grid, the wavelength reference apparatus comprising:a fiber etalon wherein the fiber etalon is chosen so as to have a FSR significantly less than the target frequency grid, whereby when monotonic light is swept through the fiber etalon, the transmission peaks established by the fiber etalon will surround, and have much less spacing, than the target frequency grid; a detector for detecting the transmission peaks established by the fiber etalon; identifier means for identifying an accurate single frequency among the fiber etalon's transmission peaks; and comparator means for determining a correspondence between transmission peaks generated by the fiber etalon and the target frequency grid so as to tune the tunable Fabry-Perot filter or the tunable VCSEL to the precise, absolute frequency grid once the accurate single frequency is known in the fiber etalon's transmission peaks.