Multi-octave metamaterial reflective half-wave plate for millimeter and sub-millimeter wave applications

Area of Science:

• Optics and Photonics
• Electromagnetics
• Materials Science

Background:

• Quasi-optical modulation of linear polarization at millimeter and sub-millimeter wavelengths typically employs rotating half-wave plates (HWPs).
• Broad operational bandwidths are essential for devices functioning across multiple frequency bands.
• Existing HWPs, including birefringent multi-plates and mesh-based devices, offer bandwidths around 100%.

Purpose of the Study:

• To design and characterize a novel reflective half-wave plate (HWP).
• To achieve operational bandwidths significantly exceeding current technologies (i.e., ~150%).
• To explore a new working principle for HWP realization.

Main Methods:

• Design of a reflective HWP based on differential phase shifts for orthogonal polarizations.
• Utilizing the distinct reflection properties of electric and artificial magnetic conductors.
• Experimental characterization of the reflective HWP's performance across a wide frequency range.

Main Results:

• Demonstration of a reflective HWP with an operational bandwidth of approximately 150%.
• Validation of a novel working principle based on anisotropic reflection.
• The device operates effectively across millimeter and sub-millimeter wavelengths.

Conclusions:

• The novel reflective HWP offers a substantial improvement in operational bandwidth compared to existing technologies.
• This design provides a new pathway for developing advanced polarization modulators for millimeter and sub-millimeter wave applications.
• The device's performance across broad bandwidths makes it suitable for multi-band systems.