Nonlinear Transmission Properties Of Dissipative Solitons And Fabrication Of Highly Nonlinear Polymer Optical Fibers

With the development of fiber technology and laser technology,the combination of low-loss fiber and high-energy,ultra-short pulses has promoted the rapid development of nonlinear fiber optics,and has become a research hotspot.Researchers have paid much attention to some novel phenomena after ultrashort pulses are transmitted in optical fibers,such as the dispersive wave,Raman self-frequency shift,supercontinuum generation,etc.For dissipative soliton pulses,researchers have been studying how to improve the pulse energy of dissipative solitons.Few studies have been devoted to the unique spectral evolution of dissipative solitons.For this reason,we have carried out experimental and numerical studies on the nonlinear transmission characteristics of dissipative soliton pulses in SMF.Compared with solid-core optical fibers,hollow core fiber are not only an excellent pulse transmission medium,but its flexible design of air hole structure also becomes an ideal carrier for material filling,filling functional materials with different physical properties into hollow core fiber.Air holes have been used in nonlinear fiber optics,fiber optic sensing,chemistry,bio-detection,random laser devices,etc.,and have become a research hotspot in fiber optic photonic devices in recent years.Based on this,we carry out experimental research on hollow-core fiber filled with photopolymer.The main contents of this paper are as follows:(1)In the study of the nonlinear propagation characteristics of ultrashort pulses in fiber,the spectral polarization dependence of the pulses propagated in single-mode fiber is studied experimentally and theoretically by using the dissipative soliton pulses from the Yb-doped large-mode-area photonic crystal fiber laser amplification system.Experimentally,because the M-shaped spectrum produced by dissipative solitons has two sharp peaks and steep edges,the two sides of the M-shaped spectrum can evolve into valleys with larger modulation depth during pulse propagation.By changing the polarization of the incident pulse,the modulation depth of the two valleys can be tuned.In theory,the mechanism is fully explained by simulation and attributed to the cross-phase modulation effect caused by nonlinear birefringence.At the same time,After a segment of fiber propagation,the input pulse can be reproduced using a bandpass filter to filter out the spectrum between the two deep valleys.(2)In the experimental study of photopolymer filled hollow-core fiber,firstly,through the filling method of the existing literature reported,the complete filling and selective filling of hollow-core fiber with different air hole structure were fabricated.Secondly,the photopolymers were used to fill the capillaries with different pore diameters.The problem of discontinuity and non-uniformity of filling during filling was overcome,then the photopolymer was uniformly and continuously in the hollow-core fiber.It achieved high optical output efficiency.Finally,white-light supercontinuum source was coupled into different inner diameter capillaries filled with photopolymer.Some novel experimental phenomena were found in the experiments,and preliminary analysis of the results were carried out.This work laid a good experimental foundation for our subsequent experimental research on composite fibers integrating multiple functional materials.