Font Size: a A A

Investigation Of The Properties Of Photonic Crystal Fibers And Their Sensing Applications

Posted on:2011-03-04Degree:DoctorType:Dissertation
Country:ChinaCandidate:Q ShiFull Text:PDF
GTID:1118330332972773Subject:Optics
Abstract/Summary:PDF Full Text Request
Photonic crystal fibers (PCFs, also known as microstructured fibers) have attracted great interest in the scientific and industrial community because of their unique characteristics and advantages over conventional optical fibers. The past decade has witnessed a remarkable progress in the fabrication and commercialization of PCF, and in particular, functional optical devices have become global research focus, especially in the field of PCF sensing.The research work in this thesis is supported by the National Key Basic Research and Development Program of China (Nos.2003CB314906 and 2010CB327605), the National Natural Science Foundation of China (Nos.10774077, 50802044 and 60677013) and Australian Research Council's (ARC) Discovery Project scheme. Based on the insight study on the theoretical analysis approach, different unique properties, selective filling techniques of photonic crystal fiber, and acoustic-induced photonic crystal fiber grating, PCF-based novel sensing technology has been theoretically and experimentally studied. Main content of the research work in this thesis includes:1. Investigation of the F-P interferometric sensing technology based on hollow-core photonic bandgap PCFThe environmentally stable in-line F-P interferometric strain sensor is developed. The proposed sensor has several advantages such as short length of just 0.2 mm, diameter equivalent to conventional single-mode fiber, bend and temperature insensitive and strain sensitivity of 1.55 pm/με.Moreover, the multiplexing and demodulation schemes of hollow core PCF F-P interferometric strain sensor has been studied from the theoretical and experimental aspects as well. And finally, a strain sensing system based on the hollow core photonic bandgap fiber has been set up.2. Investigation of the tuning peroperties of photonic bandgap fiber acoustic grating in terms of electric, temperature and refractive index. Based on the detailed numerical simulation and analysis of the guided modes in the solid-core photonic bandgap fiber filled with liquid, long-period grating was inscribed in the low-index contrast photonic bandgap fiber through electric-induced acoustic wave, furthermore, its electrical tenability of wavelength and intensity has been investigated.By synthesizing the speedy tenability of the acoustic grating, the bandgap tenability of photonic bandgap fiber, and the dispersion properties of the PCF, a highly sensitive refractive index sensor was proposed. Relevant experimental results are in good agreement with the theoretical analysis. The parameters of the sensor are as follows:temperature sensitivity of 6.94 nm/℃, refractive index sensitivity of 1.79×104 nm/RIU, detection limit of 8.4×10-6 RIU. To the best of our knowledge, above parameters are the best ones for the same type sensors ever reported by far.3. Investigation of the hybrid guided birefringence photonic crystal fiber and its applicationsBy selective filling liquid into the air hole of PCF, novel hybrid guided birefringent PCF is proposed. The properties of the hybrid guidance mechanism are studied and a new type of fiber Sagnac interferometric filter is presented. Its fringe spacing changes with wavelength, and the notch could be tuned by temperature, refractive index, etc., which could be applied for multi-parameter sensing measurements.4. Investigation of tunable narrowband filter and sensor based on double materials polymer PCF.The fabrication technique and properties of double-material polymer PCF have been investigated, and the above mentioned fiber has been drawn out. Based on modes coupling theory and selective filling technology, we have developed a narrowband filter and refractive index senor for the fluid with the slight refractive index difference from background material. The temperature sensitivity reaches 2 nm/℃, and refractive index sensitivity achieves 2.81×103 nm/RIU for the optimized operation wavelength for the polymer fiber at 800 nm.5. Design of new types all-solid photonic crystal fiber with the unique characteristics. All-solid square-lattice photonic bandgap fiber with larger effective mode area has been designed. Simulation results demonstrate that the proposed effective mode area of all-solid square-lattice photonic bandgap fibers is 1.25 times larger than triangular lattice ones.The birefringence property of the photonic bandgap fiber with rectangular high index rods cladding has been studied. The simulation results demonstrated that the phase birefringence and the group birefringence reach 1×10-3 and 4×10-2, respectively.
Keywords/Search Tags:Photonic crystal fiber, acousitic grating, selective filling, mode coupling, sensing devices, fiber devices
PDF Full Text Request
Related items