High-resolution terahertz reflective imaging and image restoration.

Area of Science:

• Optics and Photonics
• Electromagnetism
• Imaging Science

Background:

• Terahertz (THz) imaging offers unique capabilities for non-destructive testing and material analysis.
• Achieving high spatial resolution in THz imaging systems remains a key challenge.
• Continuous-wave THz sources and sensitive detectors are crucial for effective THz imaging.

Purpose of the Study:

• To develop and evaluate a high-resolution continuous-wave terahertz (THz) reflective imaging system.
• To assess the spatial resolution and image quality of the developed THz imaging system.
• To demonstrate the system's performance in imaging various test objects.

Main Methods:

• Utilized a continuous-wave THz gas laser operating at 2.52 THz and a pyroelectric detector.
• Evaluated spatial resolution using the modulation transfer function and resolution targets.
• Employed the Lucy-Richardson deconvolution method for image restoration, informed by knife-edge measurements of the spot profile.

Main Results:

• The developed THz imaging system demonstrated high-resolution reflective imaging capabilities.
• Image quality was significantly improved using the Lucy-Richardson restoration method.
• Successful imaging of diverse test objects confirmed the system's practical performance.

Conclusions:

• The presented high-resolution THz imaging system is effective for detailed object characterization.
• Image restoration techniques are vital for enhancing the quality and interpretability of THz scans.
• The system shows promise for applications requiring precise non-destructive imaging.