Imprinted terahertz artificial dielectric quarter wave plates

Area of Science:

• Optics and Photonics
• Materials Science
• Terahertz Technology

Background:

• Terahertz (THz) technology requires efficient polarization control components.
• Developing low-loss optical elements for THz frequencies presents significant challenges.
• Artificial dielectric metasurfaces offer a promising route for novel THz devices.

Purpose of the Study:

• To design and fabricate low-loss polymer artificial dielectric quarter wave plates (QWP) for operation at 2.6, 3.2, and 3.8 THz.
• To investigate the use of imprinted gratings on high-density polyethylene (HDPE) for THz wave manipulation.
• To achieve a precise phase retardance of pi/2 for efficient polarization conversion.

Main Methods:

• Fabrication of QWPs using silicon masters for imprinting gratings on HDPE.
• Optimization of grating depth using High Frequency Structure Simulator (HFSS) for desired retardance.
• Utilizing a back-to-back configuration of two plates to achieve high aspect ratio gratings (up to 6.6).

Main Results:

• Successfully developed polymer artificial dielectric QWPs operating at 2.6, 3.2, and 3.8 THz.
• Achieved pi/2 phase retardance using grating depths of 330 µm, 280 µm, and 230 µm for the respective frequencies.
• Demonstrated the feasibility of using imprinted gratings on HDPE for THz polarization control.

Conclusions:

• The developed polymer QWPs offer a low-loss solution for THz polarization control.
• The imprinting technique on HDPE is suitable for fabricating complex grating structures for THz applications.
• These artificial dielectric QWPs have potential applications in THz imaging, sensing, and communication systems.