实现圆偏振光非对称传输的完全光子禁带光波导异质结构的设计

Design of Optical Waveguide Heterostructure with Fully Photonic Bandgap for Asymmetric Transmission of Circularly Polarized Light

从理论上提出了一种可以实现圆偏振光波非对称传输的器件设计。该器件是由锗、硅以及空气孔洞构成的具有完全光子禁带的二维光子晶体异质结构。本研究通过在光子晶体中引入线缺陷,构成能够实现高正向透射的光波导结构,同时设计可将光波发散的微腔结构并结合全反射原理抑制反向入射光,实现圆偏振光非对称传输,最终实现了圆偏振光在光通信波段(1550 nm)附近的高正向透射率(可达0.726)的非对称传输。圆偏振是具有固定相位差(π/2)的任意正交线偏振光的线性叠加,本研究设计的结构同时可以实现任意线偏振光的非对称传输,因此具有广泛的应用前景,其应用领域包括量子通信、信息处理、集成光学。

This paper theoretically studies the design of a device for achieving asymmetric transmission of circularly polarized light.The device is a two-dimensional(2D)photonic crystal(PhC)heterostructure with a fully photonic bandgap,which is with triangular lattice air holes embedded in the germanium and silicon.Here,a line defect is introduced in the 2D PhC to form an optical waveguide structure that can achieve high forward transmittance.At the same time,a microcavity structure is designed to diverge the light,which is combined with the total reflection principle to suppress backward incident light,and therefore the asymmetric transmission of circularly polarized light is achieved.As a result,the asymmetric transmission of circularly polarized light at the telecommunication wavelength(1550 nm)with high forward transmittance(up to 0.726)is realized.As the circularly polarized light is a linear superposition of two orthogonally linear polarization lights with a fixed phase difference(π/2),the structure designed in this study can realize asymmetric transmission of arbitrarily linearly polarized light at the same time.Therefore,it has a wide range of applications,including quantum communication,information processing,and integrated optics.