Sensing characteristics of a novel two-section long-period grating.

The behavior of a temperature self-compensating, fiber, long-period grating (LPG) device is studied. This device consists of a single 325-microm-period LPG recorded across two sections of single-mode B-Ge-codoped fiber--one section bare and the other coated with a 1-microm thickness of Ag. This structure generates two attenuation bands associated with the eighth and ninth cladding modes, which are spectrally close together (approximately 60 nm).