title: Bragg gratings in rectangular microfiber for temperature independent refractive index sensing.
abstract: We present fiber Bragg grating fabricated in rectangular microfiber for temperature-independent refractive index (RI) measurement. The grating has two Bragg peaks due to the high geometrical birefringence of the rectangular microfiber. The two peaks present different RI responses because the modes along the orthogonal polarizations have different energy fractions in terms of evanescent field outside the silica microfiber and hence the light/liquid interaction strength are different. In contrast, they exhibit identical temperature sensitivities because most mode energy is confined in the microfiber and the thermal-optic effect of silica dominantly determines the temperature response. As a result, temperature-independent RI sensing can be realized by monitoring the wavelength separation between the two peaks.
authors: Institute of Photonics Technology, Jinan University, Guangzhou 510632, China.
authors: Yang
authors: Y
authors: Ran
authors: Long
authors: L
authors: Jin
authors: Li-Peng
authors: LP
authors: Sun
authors: Jie
authors: J
authors: Li
authors: Bai-Ou
authors: BO
authors: Guan
mesh_terms: D055100:Optical Fibers; D055620:Optical Phenomena; D013696:Temperature