Research On Photonic Crystal Interface Regulation To Realize Light Wave Unidirectional Transmission

The emergence of new things such as cloud computing,online shopping,remote control,etc.has made people's lives easier,and at the same time has dramatically increased the requirements for the speed and capacity of information processing.The integration of traditional integrated circuits is close to saturation,and due to the influence of the Lorentz force when the electrons act,heat loss will occur,and the transmission capacity of information will be low.Researchers have proposed to use photons instead of electrons to solve the current problems.Compared with electrons,photons have the advantages of high speed,low energy consumption,and high capacity.The characteristic of photons is that because there is no interaction between them,a high degree of integration of devices can be achieved.Traditional computers have difficulties in big data processing,information processing,etc.,and optical quantum computers can solve the current computational difficulties by using photon qubits.Therefore,the development of integrated optical circuits is inevitable.The future development trend of science and technology must be towards optical communications and optical quantum computing.Realizing high-efficiency transmission of light is one of the problems faced by integrated optical circuits.High-efficiency transmission of light refers to unidirectional transmission of light and high efficiency for unidirectional transmission.Integrated optical circuits need to achieve high unidirectional transmission efficiency of light.Of micro-nano devices.At present,the main methods to realize the unidirectional transmission of light waves are as follows: 1.Based on the principle of reciprocal light wave unidirectional transmission,the main principle is to realize the unidirectional transmission of light waves by destroying the spatial inversion symmetry of the crystal lattice.However,in practical applications,reciprocal light wave unidirectional transmission devices often have a series of problems such as low forward transmittance and limited to characteristic polarized light due to material limitations and energy gap width restrictions,which seriously restrict the development of integrated optical circuits..2: Based on the anti-scattering characteristics of topological photonic crystals,the transmission of light waves in a single direction can be realized.However,these two methods also have some shortcomings.Micro-nano devices based on reciprocal light wave transmission are often limited in practical applications due to material limitations and energy gap width.The forward transmittance is not high and is limited to characteristic polarized light.A series of problems such as those seriously restrict the development of integrated optical paths;the current research on topological photonic crystals mainly focuses on common symmetrical structures,and the dielectric pillars also have high symmetry.There is no research on low-symmetric or irregular media.Column etc.Therefore,in response to these two problems,this article first proposes a reciprocal unidirectional transmission device based on a total reflection interface: a ring-shaped lattice point photonic crystal heterostructure,which achieves high forward transmittance and is suitable for any polarized light under.Then,for topological photonic crystals,a photonic crystal with low symmetrical elliptical lattice point energy valley based on the optical quantum energy valley Hall effect is proposed,and the unidirectional optical transmission characteristic with topological edge state anti-scattering property is observed at the interface state.It provides new design ideas for the current research of micro-nano photodiode devices.The work content of this article is divided into the following two points:1: A kind of heterojunction ring-hole photonic crystal is designed.After the structure is added to the total reflection interface,the transmittance will be greatly improved,and the scattering will be much reduced.Analyzing the angles of three different total reflection interfaces of 30°,45° and 60°,it is obtained that 45° is the best total reflection interface angle;under the three angles,the unidirectional light can be realized in any polarization state of the forward incident light transmission.When the interface angle is 45°,it can be obtained from the electric field diagram that the forward incident light has a high transmittance in the TE polarization state and the TM polarization state,not only because the total reflection interface reduces the scattering,but also can realize the self-collimation effect.2: Based on the Hall effect of optical quantum energy valley,an all-dielectric elliptical lattice point energy valley photonic crystal is proposed.Using the energy valley degree of freedom,by changing the long axis direction of the elliptical grid point,the center wavelength and width of the energy valley photon forbidden band can be changed.Subsequently,elliptical energy valley photonic crystal structures with different band gaps and central wavelengths are combined in a mirror-symmetric manner to obtain an all-dielectric photonic topological insulator waveguide structure,which realizes anti-scattering robust unidirectional optical transmission.This research has realized topological optical transmission,expanded the energy valley freedom of energy valley photonic crystals,and provided a new idea for unidirectional transmission of micro-nano devices.