Enhancement of terahertz reflection tomographic imaging by interference cancellation between layers

Area of Science:

• Applied Physics
• Imaging Science
• Signal Processing

Background:

• Terahertz reflection tomographic imaging is crucial for non-destructive evaluation.
• Small gaps between layers in a sample cause signal interference, degrading image quality.
• Upper-layer reflections contaminate lower-layer signals in tomographic reconstructions.

Purpose of the Study:

• To develop a method for enhancing terahertz reflection tomographic imaging.
• To mitigate interference caused by reflections from adjacent layers.
• To improve the quality of tomographic images, particularly for lower layers.

Main Methods:

• Proposing an interference cancellation technique for terahertz imaging.
• Estimating the upper-layer reflection signal using system modeling.
• Eliminating the estimated upper-layer signal from the acquired data.

Main Results:

• Successfully reduced interference between layers in terahertz tomographic imaging.
• Provided a corrected lower-layer reflection signal.
• Demonstrated improved quality of the lower-layer tomographic image.
• Validated the method with both simulated and real terahertz reflection data.

Conclusions:

• The proposed interference cancellation method effectively enhances terahertz reflection tomographic imaging.
• Accurate estimation and removal of upper-layer reflections are key to improving lower-layer image fidelity.
• This technique offers a significant advancement for applications requiring high-resolution subsurface imaging.