Fibonacci terahertz imaging by silicon diffractive optics

Area of Science:

• Optics and Photonics
• Terahertz (THz) Imaging
• Diffractive Optics

Background:

• Terahertz imaging offers unique capabilities for non-destructive analysis.
• Conventional imaging systems often face limitations in achieving multifocus capabilities and high spatial resolution simultaneously.

Purpose of the Study:

• To experimentally demonstrate Fibonacci or bifocal terahertz imaging.
• To evaluate the performance of a silicon diffractive zone plate for multifocus THz imaging.
• To compare the Fibonacci lens with conventional phase zone plates.

Main Methods:

• Utilized a silicon diffractive zone plate in continuous wave mode.
• Performed terahertz imaging experiments at 0.6 THz.
• Analyzed spatial profiles and focal depth at frequencies ranging from 0.3 to 0.6 THz.

Main Results:

• Successfully demonstrated simultaneous imaging in two different planes at 0.6 THz.
• Achieved spatial resolution at the scale of the wavelength.
• Showcased the multifocus imaging capability of the Fibonacci lens.
• Observed good agreement between experimental data and simulation results.

Conclusions:

• The demonstrated Fibonacci lens is effective for bifocal terahertz imaging.
• The silicon diffractive zone plate enables high-resolution, multifocus THz imaging.
• The performance of the Fibonacci lens is superior to conventional phase zone plates in multifocus applications.