Research On Optical Transmission And Group Velocity Control Based On Synthetic Photonic Lattice

Light controlling usually refers to the regulation and control of light field parameters such as the amplitude,frequency,and group velocity dispersion et al.,which is one of the research hotspots in optics.Because it is simple and fast to control light-field by inserting electro-optic,acousto-optic,and magneto-optic modulators in the optical fiber loops.The synthetic photonic lattice based on the optical fiber loops has attracted great interest,which is a discrete optical system composed of the average length cycle number and the length difference cycle number of the fiber loop as the vertical and horizontal coordinates.In recent years,many novel optical phenomena have been observed in the synthetic photonic lattice,such as the one-way invisible transmission,defect state scattering phenomenon,and Berry curvature effect.Different from previous work,the Hermitian and non-Hermitian synthetic photonic lattices are used as platforms to control light in this paper,and we study the spatial evolution of light pulses and the changes of group velocity systematically combined with the theories of gauge potential and the non-Hermitian quantum mechanics.We discovered total reflection,dynamic localization,and asymmetric localization of light pulses.The specific research contents are as follows:In the first chapter,we first introduced the basic concepts such as the physical model of the synthetic photonic lattice and described the typical optical phenomena of light pulses in such systems.Secondly,we introduced the related gauge potential,group velocities,non-Hermitian optical theories,and the corresponding typical optical phenomena.Finally,the research content of this paper was briefly described.The second chapter first studied the non-mirror-symmetric synthetic photonic lattice and the corresponding kinetic equation.The system’s transmittance and group velocity dispersion was analytically solved,and the diffractionless transmission conditions were analyzed.Finally,the propagation evolution of optical pulses was studied by numerical simulation,focusing on the reflection of light at the interface.We found that there exists an effective magnetic field interface at which the total reflection of light-wave occurs.The discovery provides a new way to implement optical switches and optical diodes.In the third chapter,we firstly studied the construction of the physical model of the longitudinally modulated synthetic photonic lattice.Then,the dynamic equation of the light was established,and the corresponding dispersion relation was solved.On this basis,we studied the evolution of the group velocity of optical pulses and found that the group velocity increases and decreases periodically.In addition,we also studied the spatial propagation of the optical field by using simulation and found the longitudinal dynamic local phenomena of the optical field.Our research presents a new method to realize dynamic localization of light-wave and group velocity oscillation in the synthetic photonic lattice,which has specific guiding significance for the field of optical switching and optical signal processing.In Chapter 4,we constructed the anti-PT symmetric synthetic photonic lattice first.Then,we analyzed the dispersion relations of the system.Combined with the coupling and the group velocity dispersion,we studied the propagation phenomenon of the light wave in the anti-PT symmetric synthesis photonic lattice by numerical simulation.The results indicate the asymmetric transmission of light waves in the anti-PT symmetric synthetic photonic lattice.When the coupling efficiency is 0 and there is no diffractionless transmission,the asymmetric local phenomenon will appear.The realization of optical asymmetric local phenomena provides a new idea for obtaining optical switches.The fifth chapter is the summary and prospect of this paper,which mainly summarizes the main work and innovative points of the paper and puts forward some ideas for future work.