FABRY-PEROT ETALON, WAVELENGTH MONITOR AND WAVELENGTH VARIABLE LIGHT SOURCE WITH BUILT-IN WAVELENGTH MONITOR

摘要

PROBLEM TO BE SOLVED: To provide a Fabry-Perot etalon, which can obtain two signals by a simplex and is physically stable and to enable a wavelength monitor over a broad band with high resolution, and to recognize wavelength changing direction, too.;SOLUTION: The Fabry-Perot etalon 21 is formed by inclining one surface 212 to another surface 211, having a reflecting film so that respective amplitude periods of rays which are transmitted through the Fabry-Perot etalon 21 and then are divided to two, are relatively deviated by a phase difference of π/2. The Fabry-Perot etalon 21 is used as a wavelength discriminating part of the wavelength monitor. That is, rays transmitted through the Fabry-Perot etalon 21 are branched and reflected in the inclined direction of the Fabry-Perot etalon 21 by a knife edge mirror 22. Then the branched rays are respectively received by a first PD23 and a second PD24 to detect the signal, depending on the wavelength.;COPYRIGHT: (C)2002,JPO