Terahertz polarization-maintaining subwavelength filters.

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Terahertz (THz) polarization-maintaining waveguides are crucial for polarization-sensitive THz systems.
• Developing functional THz devices requires advanced polarization control platforms.

Purpose of the Study:

• To propose and analyze a novel THz grating based on a subwavelength rectangular polymer waveguide.
• To demonstrate simultaneous filtering of two polarization states using the proposed grating.

Main Methods:

• Numerical simulations were employed to characterize the proposed THz grating.
• The grating's performance was analyzed for its filtering capabilities across different polarization states.

Main Results:

• The proposed THz grating exhibits two transmission dips with an extinction ratio (ER) over 20.9 dB and a full-width half-maximum (FWHM) of approximately 21.1 GHz.
• A π-phase shift enables the grating to function as a polarization-maintaining narrow bandpass filter with ER > 12.3 dB and FWHM < 1.7 GHz.

Conclusions:

• The developed waveguide-based THz grating offers a new method for steering polarized THz radiation.
• This technology has potential applications in THz polarization-sensitive imaging, sensing, and wireless communication systems.