Research On Design And Application Of Novel Microstructured Optical Fibers

The works of this thesis are supported by National Basic Research Program of China (2010CB327600), National Natural Science Foundation of China (61077049), Program for New Century Excellent Talents in University of China (NCET-08-0736), Chinese Universities Scientific Fund (BUPT2009RC0410) and the 111 Project of China (B07005).Microstructured optical fibers (MOFs) show us an amazing and promising application potentiality for their special properties, such as dispersion, nonlinearity. In recent years, the design, fabrication and application of MOFs have attracted a lot of attention. The novel applications of surface plasmon resonance (SPR) sensors based on MOFs and dispersion flattened microstructured optical fiber with high nonlinearity which could generate broad and flattened supercontinuum spectrum at 1.55μm, are studied both theoretically and experimentally. The major achievements are as follows.1.This thesis theoretically analyzes how MOF structural parameters and metalized nanolayer influence the performance of surface plasmon resonance sensors by using FEM (finite element method). In the simulation, we use Drude-Lorentz model to accurately describe the metal dielectric constant, propose two novel types of surface plasmon resonance sensors based on MOFs.(1) Surface plasmon resonance sensors based on Ag-metalized nanolayer in microstructured optical fibers have been proposed. The numerical results show that the sensitivity of Ag-metalized SPR sensor could reach 1167nm/RIU (refractive index unit) and corresponding resolution is 8.57×10-5 RIU, the performance of Ag-metalized sensor is higher than that of traditional Au-metallized sensor. In addition, the SNR and Q factor of Ag-metallized sensor are higher than Au-metallized sensor. We believe it is instructive for the further research of MOF-based SPR sensors.(2) A surface plasmon resonance sensor based on Au-metalized nanolayer in 6 big-holes MOF has been proposed. The numerical results show that the sensitivity of Au-metalized surface plasmon resonance sensor can reach 1200nm/RIU and the corresponding resolution is 8.33×10-5 RIU.2.Experimentally studies how to accemble nanoscale functional materials into microstructured optical fibers.Try to assemble functional materials such as nanowires and colloidal gold nanoparticles into airholes of MOF. From the SEM testing of the MOF samples, we can see the functional materials have been assembled into airholes of MOF. Furthermore, we adopt a new approach of silver-ammonia solution reduction by water bath heating, and successfully deposit Ag nanopaticles on the inner surface of airholes in MOFs.3.One dispersion flattened MOF with high nonlinear coefficient and low confinement loss is designed by utilizing the finite-difference beam propogation method(FD-BPM), which is suitable for flat broadband supercontinuum (SC) generation in 1.55μm region. The properties of optimized MOF are as follows. The ultraflat dispersion with a value between -1.65 and -0.335ps/nm/km is obtained ranging from 1375 to 1625 nm. The nonlinear coefficient of proposed MOF is 33.8W-1km-1 and the confinement loss is in 10-4dB/km scale at the wavelength of 1550nm. In addition, the proposed MOF have some other advantages, such as less structural parameters and moderate d/A value.Theoretically studies the SC generation in proposed MOF by solving the generalized nonlinear Schrodinger equation using the split-step Fourier method. The results show that the 3-dB bandwidth of the SC is 125nm (1496nm～1621nm), with the full width at half maximum (FWHM)TFWHM=1-6ps, the fiber length of 80m, and the corresponding input peak power is 43.8W. Amplitude noise is considered related to the SC generation.For practical fabrication, the influence of random imperfections of airhole diameters on dispersion and nonlinearity is discussed to verify the robustness of our design.