TEMPERATURE COMPENSATED LONG PERIOD OPTICAL FIBER GRATING FILTER BY USING MULTIPLEX CLADDING STRUCTURE

摘要

PURPOSE: A temperature compensated long period optical fiber grating filter by using a multiplex cladding structure is provided to materialize the temperature compensation by using a multiplex cladding structure and to grow the coupling mode easily even in manufacturing the long period long period optical fiber grating. CONSTITUTION: The temperature compensated long period optical fiber grating filter by using the multiplex cladding structure includes a core, an inner cladding and an outer cladding. The coupling wavelength of the core has the positive wavelength movement according to the temperature increase by the first dopant. The refractive index of the inner cladding is smaller than that of the core. The refractive index of the outer cladding is smaller than that of the inner cladding and has the negative wavelength movement by that the refractive ratio value is increased according to the temperature increase by the second dopant.