Research On The Spectral Characteristics And Sensing Applications Of Photonic Crystal Fiber Grating

Photonic crystal fiber has flexible design and broad range of wavelengths and transmission with no single modal cut-off and so on. Now the photonic crystal fiber grating (PCFG) has been paid more attention. The spectral characteristics of PCFG can be controlled to have a wide rang of application by adjusting the air hole layers, air filling factor and core mode and so on. The strain and temperature senstivity of PCFG have shown great potential in the sensing and communication applications.In this paper the fundamental spectral characteristics and sensing properties of the photonic crystal fiber grating with regular octagonal cladding air holes (O-PCFG) are dicussed from a theoretical point.First, the theoretical research model based on finite element, coupled mode theory and the transmission matrix method of PCF is established.Then the spectrum of O-PCFG is simulated by the transfer matrix method, and the structural parameters of PCF and grating are analyzed, which may affect the spectrum of O-PCFG. And, when phase shift is introduced, the influence to the spectrum of O-PCF-LPG is analyzed. From the resonance conditions of PCFG, the sensing characteristics of temperature and stress are simulated, and the structural parameters that affect on sensitivity are analyzed.The results show that the structural parameters of PCFG affect the resonant wavelength of resonance peak and reflectivity.Temperature and stress sensitivity coefficient of O-PCFG increase as air filling factor, with the core diameter decreases. Finally, a single-parameter sensor based on O-PCFBG is proposed.And the temperature sensitivity coefficient is 0.11941nm/℃.