Research On Optical Intensity And Phase Modulator Based On Zero-Refractive Index Materials

In the modern information society,taking advantage of electromagnetic waves to transmit messages is an indispensable means of communication.It can be realized by materials with special optical properties such as graphene,transparent metal oxides,or artificial structures constructed from these electromagnetic materials,such as optical waveguides and light modulators to transmit and manipulate this signal.Epsilon-near-zero(ENZ)photonics is an important field to study the interaction of light and matter in recent years.Zero-refractive-index materials(ZIMs),as a singularity in optical materials,will lead to significant development in the field of integrated photonic devices and have broad prospects in high-performance integrated photonic chips.Based on the theory of ZIMs,this paper introduced the development process and research status of ZIMs,and also illustrated the basic properties of this metamaterial and several common construction methods.The applications in the field of photoelectric modulation devices such as gratings are briefly summarized.The specific research work of the full text is as follows:(1)Based on the electro-optic properties of graphene and the equivalent medium theory,an anisotropic zero-refractive-index metamaterial waveguide structure was designed.Taking advantage of the properties of the waveguide structure,a two-output port symmetric optical modulator is also proposed.Simulation results show that the device has an extinction ratio of 14.8d B,and the maximum transmittance of light passing through the modulator is 96.7%,which is about 1.8% higher than the previous work.In addition,the device is more flexible in the port selection and can be manipulated at will,and its maximum energy can reach about 62% of the incident wave.Such ultra-compact optics could open up a new frontier in highly integrated photonic circuits,especially on nanochips.(2)Based on the electro-optic properties of ITO and the related theory of metasurfaces,a phase-regulating metasurface structure based on the zero refractive index property of indium-tin-oxide was designed.The metasurface is composed of a periodic grating structure.By increasing the applied voltage,the dielectric constant of the indium tin oxide depletion layer is changed,and the surface plasmon resonance is excited to realize the modulation of the reflected light phase.The structural parameters are optimized through simulation experiments,and the optimal phase modulation effect is controlled within the wavelength range of incident light around 1550 nm.The function of beam deflection of incident light by a metasurface composed of 13 structures is simulated,and the results show that the reflected light will be deflected by 10 degrees for every 16.1degrees of phase difference.The potential value of such optical phased arrays will have important guiding significance for the development of beam steering devices,and polarimeters.