| As a new type of special fiber,microstructure optical fiber has many special features.It not only restricts in the continuation of the road of the traditional optical fiber in optical communication field,but also has begun to be widely used in the field of optical fiber sensing.Recently,photodynamic research rises gradually.It mainly focuses the dynamic characteristics of the material in the complex optical field,and then extends to the actual application fields,such as microelectromechanical application,bioscience applications.With the demand of the development of novel fiber optic sensor application,the study on the microstructure of fiber for photodynamic technology is particularly important.This thesis proposed three kinds of microstructure optical fiber devices.The common feature of these three kinds of fiber optic components is that the external shapes and internal structures have been changed to produce special optical fields,and the special light field is mainly used for signal transmission or mechanical influences on tiny objects.1.The photodynamic research of miroparticle had been carried out based on four-core fiber optical tweezers probe.(1)It was proposed for the first time that the two kinds of four-core fiber optical tweezers probe,which have transversal dual-optical tweezers and axial-dual-optical tweezers Systematic research had been implemented,including how to perform preparation,how to inject the input light,and how to change the fiber core beams' paths.(2)According to the theory of beam propagation method and the angular spectrum method,the simulation of the output combination field had been carried out.(3)Based on the model of geometric beam tracing,the force distributions of the particle in the combination of light fields were calculated,and through the langevin equation of motion,the movement of particle in the liquid medium characteristics was determined.Results showed that the periodic driven of the particle is a low frequency motion process,and frequency would not be higher than 100 Hz.The results can be applied to study biological activity of the particles,and the application fields such as transportation,optic-mechanical integration device preparation.2.The Research on special Airy fiber and related mechanical properties of the particle were carried out.(1)The Airy and gaussion filed transformation mechanism was discussed based on fiber coupled-mode theory.(2)This thesis first proposed a multi-core airy optical fiber which has custom symmetric airy function distribution,and we calculated the output field of the optical fiber based on the beam propagation method,and discussed the response characteristics of the wavelength.Results showed that the ouput field of the central main lobe will be split into multiple main lobes,the beams still have free acceleration and self-healing characteristic,and non-diffraction characteristics,and the wavelength modulation will cause beam free acceleration changes.This kind Airy fiber can be used in various applications such as a micro beam splitter.(3)It was for the first time proposed the ring core optical fiber with annular Airy function distribution.And similar to the former,the response characteristics of wavelength was calculated,and also the simulation of the mechanical property of mirco size particles was conducted in the symmetrical ring core Airy fiber.Results showed that the airy fiber has symmetrical circular Airy distribution,and remains the long range without the diffraction transmission.And the features of free acceleration form the focal point,this can be used for micromachining or particles' trapping.And particles can have different paths to complete transport guiding under the action of the output field,or linear transport,or bending transport.3.The surface plasmon polaritons fiber and related particles of light dynamic characteristics had been studied.(1)It was proposed the surfaces plasmons(SPPs)fiber based on the nanotubes and gold nanowires for the first time.(2)By using the finite element method,the model number of the SPPs fiber was calculated based on the nanotubes and gold nanowires.Results showed that when the gold nanostructures are small,the optical fiber has only two transmission modes,short-range and long-range mode,respectively.And dispersion characteristics analysis showed that the gold nanotube structure optical fiber mode number increases when the wall decrease.(3)The transmission loss characteristics of the long-range mode and the mode field width were analyzed.It indicated that the long-range transmission distance of optical fiber can get 30 mm,but the mode field width and transmission distance is not a simple inverse relationship.(4)The simulation analysis of the nano particles near the optical fiber end surface and movement characteristics was analyzed,the results showed that nanoparticles are captured by the force,which pulled the nanoparticles to the fiber structure of gold center and pushed them away.Because different particles have difference forces,the particles can be sorted in conjunction with the micro flowing.To sum up,the researches in this thesis expand the application fields of micro structure fiber.Due to the advantages of high integration,and low cost etc,the microstructure optical fiber will have great potential applications,and the particle photodynamic research based on optical fiber is important to the optical fiber sensing,bioscience,photodynamics application fields... |
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