Abruptly autofocusing terahertz waves with meta-hologram

Area of Science:

• Optics and Photonics
• Metamaterials
• Terahertz (THz) Technology

Background:

• Ring-Airy beams exhibit unique self-focusing and accelerating properties.
• Traditional methods for generating such beams can be complex and limited in control.
• Terahertz (THz) wave applications require advanced beam manipulation techniques.

Purpose of the Study:

• To demonstrate an abruptly autofocusing ring-Airy beam in the THz waveband.
• To utilize a meta-hologram for precise phase and amplitude modulation of THz waves.
• To investigate the potential of meta-holograms for beam generation in other wavebands.

Main Methods:

• Design and fabrication of a meta-hologram composed of gold C-shaped slot antennas.
• Modulation of phase and amplitude of incident THz waves using the meta-hologram.
• Utilizing a THz holographic imaging system to measure the generated ring-Airy beam.

Main Results:

• Successful demonstration of an abruptly autofocusing ring-Airy beam in the THz waveband.
• Observation of an abrupt focus following a parabolic trajectory.
• Generation and investigation of THz ring-Airy beams with varying parameters.

Conclusions:

• Meta-holograms offer a powerful platform for generating complex beam profiles in the THz waveband.
• The demonstrated method provides precise control over beam focusing and trajectory.
• This approach is extendable to other wavebands, potentially replacing traditional holography.