Study On The Modulation Characteristics Of One-dimensional Photonic Crystal Based On Ferroelectric Materials In The Terahertz Band

Terahertz modulator and optical switch are one of the research hotspots in terahertz wavefield.In order to study the dynamic modulation characteristics of photonic crystals,this paper discusses the ferroelectric lead zirconate titanate by terahertz time-domain spectroscopy(PbZr_0.52Ti_0.48O₃)modulation with illumination changes,analyzes its micro mechanism,and taking the lead zirconate titanate as a defect layer,design parameters and study the modulation ability of photonic crystal terahertz region.The main contents are as follows:1.Various modulation modes of ferroelectric materials are analyzed,and the modulation principle of ferroelectric materials is studied by using the damping harmonic oscillator model.The transmission matrix model of one dimensional photonic crystal is derived in detail,and the transmission coefficient and reflection coefficient are obtained,and the program is written by MATLAB software.2,the preparation of lead zirconate titanate thin films b y terahertz time-domainspectroscopy,through parameter extraction,get the external light field,carrier film internal redistribution,the formation of a field,resulting in silicon based lead zirconate titanate thin film refractive index and dielectric constant changes with the variation of the external light field intensity.The real part of the refractive index modulation amplitude of up to 99.3%,the real part of permittivity modulation range to 698.5%.3.Two properties of photonic crystal are discussed:photonic band gap and defect mode.A study of photonic crystal defect free layer,the medium cycle number,center frequency,incident angle and the refractive index modulation effect on photonic band gap;two,the use of lead zirconate titanate as defect photonic crystal,studied the modulation effect of the thickness of defect layer on the defect mode,the lead zirconate titanate with light according to the modulation effect,get the lead zirconate titanate with different refractive index,the characteristics of one-dimensional photonic crystal dynamic modulation.