Spinning thermal radiation from twisted two different anisotropic materials

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Thermal radiation is crucial for applications like cooling, imaging, and camouflage.
• Chiral metamaterials enable selective emission of circularly polarized waves.
• Controlling thermal emission properties is key for advanced optical devices.

Purpose of the Study:

• To propose and demonstrate spinning thermal radiation from twisted anisotropic materials.
• To achieve broadband and narrowband spinning thermal radiation with high circular dichroism.
• To explore potential applications in biological sensing and thermal detection.

Main Methods:

• Fabrication and characterization of a twisted structure using industrial polymer and biaxial hyperbolic material (α-MoO₃).
• Analysis of thermal emission spectra in the mid-infrared range (13-18 µm).
• Investigation of the underlying physical mechanisms, including polarization conversion and selective absorption, supported by magnetic field distribution analysis.

Main Results:

• Broadband spinning thermal radiation achieved from 13 µm to 18 µm.
• Narrowband spinning thermal radiation with a circular dichroism of 0.9 obtained at 12.39 µm and 18.93 µm.
• Demonstration of enhanced circular dichroism and confirmation of the epsilon-near-zero mode's role.

Conclusions:

• The proposed twisted anisotropic material structure effectively generates broadband and narrowband spinning thermal radiation.
• The study highlights the significant enhancement of circular dichroism, crucial for polarization-sensitive applications.
• The findings pave the way for advanced thermal detection and biological sensing technologies.