Patent ID: 6785444
Filing Date: 2004-08-31
Classification: G02B

Abstract:
An optical fiber grating device in which a long period grating is formed in a core region of an optical fiber comprising the core region having a refractive index n1 and an outside diameter 2a, a first cladding region surrounding the core region and having a refractive index n2 and an outside diameter 2b, and a second cladding region surrounding the first cladding region and having a refractive index n3 and an outside diameter 2c, wherein there is a magnitude relation of n1>n2>n3 among the refractive index n1 of the core region, the refractive index n2 of the first cladding region, and the refractive index n3 of the second cladding region, wherein a relative refractive index difference of the first cladding region to the second cladding region is not less than 0.5%, and wherein a thickness (2c-2b)/2 of the second cladding region with respect to a transmission loss peak wavelength &lgr; is in a range of not less than &lgr; nor more than 10&lgr;.