Photonic Crystal Power Divider Based On Anisotropic Materials

It is well known that many studies have originated from the assumption of similar phenomena in different fields of nature.Because all things in the universe follow the same rules,even if the appearance is so varied,the inner rules are highly consistent.The production of photonic crystals is also true.It is developed by scientists based on the hypothesis that photons can also have a law that resembles the law of electrons propagating in ordinary crystals.Photonic crystal is a kind of artificial medium material which permittivity or permeability is periodically distributed in space;its most prominent feature is the existence of photonic band gap.The electromagnetic wave which frequency falls in the photonic band gap will not propagate in photonic cryst al.And base on the photonic band gap effect,the introduction of specific defects in the photonic crystal can be realized the manipulation and control of wave.Due to the dielectric constant of the anisotropic material is tensor form,it has unique electromagnetic properties.Its restraining effect on electromagnetic wave is different from ordinary isotropic material.Therefore,when the photonic crystal is composed of anisotropic materials,some very interesting phenomena will occur,which will expand our research ideas.The power splitter is an indispensable passive device in the integrated optical path.It is a very important part of all kinds of optoelectronic integrated components.It can distribute the energy to the output terminals on average or according to the required proportion.In this paper,the photonic crystal power splitter based on anisotropic materials is mainly studied with the key that how to realize the photonic crystal power splitter with small insertion loss,simple structure and polarization independent.The specific contents include:1.The design of some polarization independent photonic crystal power splitters based on anisotropic materials.Most of the current power splitters are designed to achieve power allocation for a certain polarization.The structures of the power splitters are different from the electromagnetic waves with different polarization states,which will not be beneficial to the integration of large-scale optical paths.Therefore,we need to use the same structure to realize the power distribution of the waves with different polarization states in the polarization logic system.In this paper,power allocation control defects are introduced into photonic crystal waveguides.Due to the birefringence property of anisotropic materials,the equivalent refractive index of different polarized waves is different when they pass through anisotropic defects.By artfully designing the structural parameters and material parameters of anisotropic defects,we can use one defect to achieve the power distribution of different polarization states.2.The design of some polarization selection photonic crystal power splitters based on anisotropic materials.Different polarization selection defects are introduced in the input channel,which can make the power splitter has polarization selection function.For the TE power splitter,the TE wave is able to enter and transmit in it,and the TM wave can not be entered;for the TM power splitter,the situation is just the opposite.The power control defect is introduced in the specific cross section of the waveguide,which can make the output power equal or distribute according to the required proportion.Combining the two,the input waves of different polarization states can be isolated and the output power is divided into equal or proportional distribution.