The Preparation Research Of Hollow-core Photonic Crystal Fibers

Hollow-core photonic crystal fiber is spreading the light through the air fiber core, so ithas a lot of new features; extremely low loss and nonlinearity effect ensure that the signalcan transmit for long distance, which it has potential advantages and application in fibercommunication and laser transmission; Variable refractive index and controllable dispersioncan be applied in the optical sensing and the dispersion compensation field; the low bendingloss in biological medical aspects also has certain applications. Therefore, it has importantscientific research and application value to research the HC-PCF of theory and preparation.This thesis is systematic studying the HC-PCF of guide light mechanism, characteristics andapplication, the photonic band gap and preparation technology, the main contents are asfollows:(1) Summing up the research process on the application of HC-PCF, includes itsrelevant background and research status, and then the basic characteristics of HC-PCF arebrief summarized. On the basis of this, its applications are introduced in each field.(2) HC-PCF of unique guide light mechanism is introduced, explain the out of planephotonic band gap theory, and understand that HC-PCF can produce the photonic band gaponly out of plane. Then analyze and compare all kinds of theoretical analysis method forphotonic crystal fiber, and confirm the plane wave expansion method and the full vectorfinite element method as the analysis methods in the thesis.(3) Using the plane wave expansion method calculate the HC-PCF photonic band gap,and analyze each structure parameters of influencing the HC-PCF band gap, then theHC-PCF mode field distribution is simulated by the finite element method. After that, westudy on the influence of fiber core structure on photonic band gap and transmission loss forHC-PCF with a fixed duty ratio, and give the structure parameters at a wavelength of1.55μm. This result not only can eliminate surface mold loss, but also suitable for thepreparation of process.(4) According to the characteristics of HC-PCF, combining with the condition of thelaboratory, we choose the proper technology to prepare and make HC-PCF. Then, theexperiments are made for six times, only one result of the experiment is better, this fiberstructure is integrity, and calculate the band gap scope for3.53μm~3.99μm of the fundamental mode. So in the next experiment, the method of proper increasing the thicknessof the annular tubes will be used. While ensure that air share can’t diminish, reduce the sizeof the cladding pitch. This will result in that the position of band gap move to the short wavedirection.