Application of Photoinduced Long-Period Fiber Gratings in Optical Sensors

At present the photoinduced in-fiber Bragg gratings are widely used as a sensitive element of optical fiber sensors. Their operation is based on the vanation of the reflection peak under an outer action. The sensitivity of silica glass to variations of temperature or applied strain is very small, therefore the operation of sensors based on the Bragg gratings are possible only due to the narrowness of the reflection peak. We propose to apply die pholoinduced long-period cladding-mode-coupled fiber grating as a sensitive element of optical fiber sensors The sensitivity of this type of the grating can be increased by its loading in an additional medium.