The Propagation Properties Of Polarized Light In Onedimensional Magneto-optic Photonic Crystals

The magneto-optic materials have magneto-optic effect,by adding magneto-optic materials as defective materials or constituent materials into traditional dielectric one-dimensional photonic crystals,one-dimensional magneto-optic photonic crystals can be formed.When polarized light propagates in one-dimensional magneto-optic photonic crystals,its propagation properties can be controlled by changing the applied magnetic field.In this paper,the modulation characteristics of polarized light propagating in one-dimensional magneto-optic photonic crystals are calculated by using the 4 × 4 transfer matrix method.Under the action of external magnetic field,the relative dielectric constant of magneto-optic materials is changed,showing anisotropy.In order to investigate the propagation properties of linearly polarized light and elliptically polarized light in one-dimensional magneto-optic photonic crystals,according to the theory of electromagnetic field in the medium,the relative dielectric constant of magneto-optic medium and dielectric material are substituted into Maxwell equation,and the 4×4 transmission matrix for calculating one-dimensional magneto-optic photonic crystals is derived.Then,the polarized light is represented as different linear combinations,and the propagation properties of polarized light are studied.Firstly,the propagation properties of polarized light in transmission type one-dimensional magneto-optic photonic crystals are studied.The physical model of transmission type onedimensional magneto-optic photonic crystal is designed.When the linearly polarized light and elliptically polarized light propagate in the crystal,the change of transmission,Faraday rotation angle and polarization state of the transmitted light with the intensity and angle ? of applied magnetic field are studied theoretically.The results show that when the linearly polarized light propagates in the transmission type one-dimensional magneto-optic photonic crystal,with the increase of the intensity of the applied magnetic field,the ?2 in the relative dielectric constant ?M of magneto-optic materials is increased,the transmission and Faraday rotation angle are increased.With the angle ? between the applied magnetic field and the optical axis increases,the transmittance and Faraday rotation angle are decreased.The Faraday rotation angle can be adjusted to 45 degrees by reasonably adjusting the intensity and angle ? of the applied magnetic field.When elliptically polarized light propagates in a transmission type one-dimensional magneto-optic photonic crystal,with the increase of the applied magnetic field strength and angle ?,the transmittance is changed,and the transmission spectrum shape of elliptically polarized light is changed and is no longer symmetrical.By adjusting the intensity and angle ? of the applied magnetic field reasonably,the polarization state of transmitted elliptically polarized light can be controlled.Then,the propagation properties of polarized light in reflective type one-dimensional magneto-optic photonic crystals are studied.The physical model of reflective type one-dimensional magnetooptic photonic crystal is designed.When the linearly polarized light and elliptically polarized light propagate in the crystal,the change of reflectivity,Kerr rotation angle and polarization of the reflected light with the intensity and angle ? of applied magnetic field are studied theoretically.The results show that when the linearly polarized light Propagation in the reflective type onedimensional magneto-optic photonic crystal,with the increase of the intensity of the applied magnetic field,the ?2 in the relative dielectric constant ?M of magneto-optic materials is increased,the reflectivity is increased,and the Kerr rotation angle increases first and then decreases.With the angle ? between the applied magnetic field and the optical axis increases,the reflectivity is decreased and the Kerr rotation angle increases first and then decreases.The Kerr rotation angle can be adjusted by reasonably adjusting the intensity and angle ? of the applied magnetic field.When elliptically polarized light propagates in a reflective type One-dimensional magneto-optic photonic crystal,with the increase of the applied magnetic field strength and angle ?,the reflectivity is changed,and the reflection spectrum shape of elliptically polarized light is changed and is no longer symmetrical.By adjusting the intensity and angle ? of the applied magnetic field reasonably,the polarization state of reflected elliptically polarized light can be controlled.Finally,the propagation properties of polarized light in asymmetric type one-dimensional magneto-optic photonic crystals are studied.The physical model of asymmetric type onedimensional magneto-optic photonic crystal is designed.When the linearly polarized light and elliptically polarized light propagate in the crystal,the change of reflectivity,Kerr rotation angle and polarization of the reflected light with the intensity and angle ? of applied magnetic field are studied theoretically.The results show that one-dimensional magneto-optic photonic crystals with asymmetric structure can achieve Kerr effect without adding reflective layer materials.When linearly polarized light and elliptically polarized light propagate in an asymmetric type onedimensional magneto-optical photonic crystal,the reflectance,Kerr rotation angle and polarization state of the reflected light are changed as the intensity and angle ? of the applied magnetic field change,the variation law is similar to that of the polarized light propagating in the reflective type one-dimensional magneto-optic photonic crystal.However,when polarized light propagates in asymmetric type one-dimensional magneto-optic photonic crystals,its reflectivity is higher,approaching 100%.Under the same external magnetic field,the angle between the reflected polarized light and the incident polarized light is larger,and the polarization state can be controlled more greatly,and the magneto-optical effect is stronger.