/ A Sagnac tunable optical drop/pass filter system for WDM

摘要

PURPOSE: A Sagnet-type tunable optical drop/pass filter system for WDM(Wavelength Division Multiplexing) communication is provided to pass all of the inputted signals to the next node without reinserting the signals extracted at a node by configuring a WDM tunable selector using a brag diffraction grating. CONSTITUTION: The first optical signal add/drop multiplexer(30) distributes an optical signal(s1), inputted through a fiber-optic or plane optical waveguide(21) from an optical signal generator(10) generating many wavelengths, into two optical signals(s2,s3). One(s2) of the two optical signals is outputted to the second optical signal add/drop multiplexer(60) through a fiber-optic or plane optical waveguide(23). The other distributed optical signal(s3) is outputted to a pass part(50) through a fiber-optic or plane optical waveguide(24). The optical signal(s2) inputted to the second optical signal add/drop multiplexer(60) is distributed into a clockwise optical signal(s4) and a counterclockwise optical signal(s5) again. The distributed signals(s4,s5) are inputted to a wavelength selector(80), which reflects only a specific wavelength, and fed back clockwise and counterclockwise respectively. The optical signal(s6,s7) fed back from the wavelength selector(80) are combined by the second optical signal add/drop multiplexer(60) and outputted to the second receiving part(70).