Guided terahertz pulse reflectometry with double photoconductive antenna

Area of Science:

• Applied Physics
• Electromagnetics
• Imaging Technology

Background:

• Terahertz (THz) pulse imaging systems are valuable for non-destructive testing and material analysis.
• Existing guided THz reflectometry systems often require complex optical components for focusing and coupling.
• There is a need for simplified and compact THz imaging solutions.

Purpose of the Study:

• To report the development of a guided optics-free terahertz pulse imaging system.
• To evaluate the imaging performance of the developed system.
• To establish a foundation for compact guided THz imagers.

Main Methods:

• Utilized two photoconductive antennas on the same LT-GaAs active layer.
• Employed a silica pipe hollow-core waveguide for guiding THz pulses.
• Operated the system in a pulsed regime without additional focusing optics.
• Assessed imaging resolution using a 1951 USAF resolution test chart.

Main Results:

• Achieved a guided optics-free terahertz pulse imager.
• Demonstrated simplified system implementation compared to previous methods.
• Obtained an image resolution of approximately 0.707 LP/mm over the 400-550 GHz band after 53 mm propagation.
• Validated the system's capability for imaging purposes.

Conclusions:

• The developed system offers a simplified approach to guided terahertz pulse imaging.
• The achieved resolution indicates the system's potential for practical applications.
• This work provides a promising basis for creating compact guided THz imagers for sample inspection.