Multifrequency focusing and wide angular scanning of terajets

Area of Science:

• Physics
• Electromagnetism
• Optics

Background:

• 3D dielectric cuboids can produce high-resolution terajets under plane-wave illumination.
• Terajets are highly localized electromagnetic field enhancements with potential applications in sensing and microscopy.

Purpose of the Study:

• To systematically investigate the harmonic and angular response of terajets generated by 3D dielectric cuboids.
• To demonstrate multifrequency focusing and robust angular response for terajet applications.

Main Methods:

• Numerical simulations and experimental evaluations were conducted using 3D dielectric cuboids.
• Plane-wave illumination was used to generate and analyze terajets at sub-THz frequencies.

Main Results:

• Multifrequency focusing was achieved at the fundamental frequency and two higher harmonics with significant intensity enhancements (∼10, ∼18, and ∼14).
• Experimental validation at sub-THz frequencies showed good agreement with numerical results for terajet generation at fundamental and first harmonic frequencies.
• A wide angular response (0° to 45°) was demonstrated, maintaining focal intensity, indicating potential as a scanning terajet-focusing lens.

Conclusions:

• 3D dielectric cuboids offer a versatile platform for generating terajets with tunable multifrequency focusing capabilities.
• The robust angular response of these terajets makes them suitable for applications requiring wide-angle scanning, such as advanced microscopy and sensor technologies.
• The demonstrated principles are scalable to other frequency bands, including optical frequencies, broadening their potential impact.