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Femtosecond Laser Filaments for Use in Sub-Diffraction-Limited Imaging and Remote Sensing
Published on: April 25, 2019
Scanning laser terahertz near-field imaging system.
Kazunori Serita1, Shori Mizuno, Hironaru Murakami
1Institue of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan. serita-k@ile.osaka-u.ac.jp
Optics Express
|June 21, 2012
Summary
We developed a new scanning laser terahertz (THz) near-field imaging system for high-resolution, high-speed measurements. This system achieves sub-wavelength spatial resolution, enabling detailed imaging of small samples.
Area of Science:
- Terahertz (THz) Imaging
- Near-Field Optics
- Laser Spectroscopy
Background:
- Traditional THz imaging systems often face limitations in spatial resolution and imaging speed.
- Developing advanced THz imaging techniques is crucial for various scientific and industrial applications.
Purpose of the Study:
- To propose and develop a novel scanning laser terahertz near-field imaging system.
- To achieve high spatial resolution and high-speed THz imaging capabilities.
Main Methods:
- Utilized a 1.56 μm femtosecond fiber laser for THz wave generation.
- Employed a 2D THz emitter plate (DASC) scanned by a galvanometer for 2D image acquisition.
- Integrated THz time-domain spectroscopy (THz-TDS) for amplitude detection of transmitted THz pulses.
Main Results:
- Successfully obtained THz transmission images of millimeter-sized metal sheets and human hair samples.
- Achieved a spatial resolution of approximately 27 μm (sub-wavelength order, ~λTHz/28).
- Demonstrated high-speed imaging with a capture rate of ~47 seconds per 512 x 512 pixel image.
Conclusions:
- The developed scanning laser THz near-field imaging system offers significant improvements in spatial resolution and imaging speed.
- This system provides a powerful tool for high-resolution characterization of various materials at THz frequencies.
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