关键词: 原子频标, 偏振态, 激光器, 纳米棒结构波片

Abstract: we explore an achromatic wave plate with rectangular silver nanorods structure. Themodulation characteristics of the wave plate on the polarization state of light are analyzed.Silver nanorods were designedbased on silicon dioxide with a length of 250nm,a width of 120nm,a thickness of 40nm and a period of 300nm.The surfaceplasma effect of nanorods is excited,and the surface electric field distribution conforms to the theory. The simulation resultsshow that the circular polarized light can be modulated by excitation of 45 degrees linearly polarized light,which meets theperformance of /4 wave plate. The applicable band is 620nm~668nm,meets the excitation wavelength of calcium atomicfrequency standard,and the transmittance of the wave plate is 40%~48%.In the simulation,the finite difference time domainmethod is used to solve the spatial electromagnetic field distribution,and the trigonometric function method is used to analyzethe polarization state of the beam. Due to the small size,thin thickness and high flexibility of the structure,the application ofthe structure in the optical atomic frequency standard is beneficial to the realization of integration and miniaturization ofoptical modulation. It is also advantageous for laser to modulate highly efficient polarized light.

Key words: Atomic frequency standard, Polarization state , Laser, Nanorod structure wave plate