METHOD FOR MANUFACTURING FIBER BRAGG GRATING, SENSOR AND FILTER

摘要

PROBLEM TO BE SOLVED: To provide a method to easily manufacture an FBG having accurate reflected wavelengths with good reproducibility and to provide a sensor and a filter which use the FBG. SOLUTION: A first FBG 16 is preliminarily manufactured in an optical fiber 10. Since the grating period of a second FBG is determined by the pitch of a phase mask 25 and by the tension of the optical fiber 10, the reflection wavelength by the first FBG 16 is measured and used as the index to control the tension of the optical fiber 10 by a tension applying drum 23. Then the optical fiber 10 is irradiated with UV rays 26 through a phase mask 25 to manufacture the second FBG. Since the reflection wavelength of the FBG 16 and the tension of the optical fiber 10 are in the proportional relation and the tension can be measured and controlled with good accuracy, the second FBG can be manufactured with good accuracy and reproducibility.