Highly birefringent metamaterial structure as a tunable partial polarizer

Somendu Maurya, Markus Nyman, Matti Kaivola, Andriy Shevchenko
2019 Optics Express  
We consider a highly anisotropic metamaterial structure, composed of parallel metal nanostripes, and show that a thin layer of the material can be used as a tunable partial polarizer. The transmittance of the structure for TE-polarized waves depends strongly on the incidence angle, while for TM-polarized waves, it stays high and essentially constant. In particular, using the structure, the degree of polarization of a partially polarized or unpolarized light can be tuned by changing the
more » ... angle. The TE-wave transmittance drops from, c.a., 1 to 0 when the incidence angle increases by 5 deg only, owing to the presence of an unusual higher-order odd-symmetric TM mode that we have revealed in the structure. The tuning can be made smoother by introducing another layer of a similar metal-nanostripe structure on top of the first one. The new design allows the TE-wave transmittance to decrease gradually towards 0 with the incidence angle increasing from 0 to about 30 deg. Our structures serve as an essential optical component for studies involving partially polarized light. If one of the components vanishes, p becomes equal to 1. Hence, by controlling the intensity of one polarization component without affecting the other one, the degree of polarization can be tuned between 0 and 1. A tunable partial polarizer can be used to achieve this control. Moreover,
doi:10.1364/oe.27.027335 fatcat:hhqe34uj7vdbvch5tefeedmkri