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Terahertz single-pixel near-field imaging based on active tunable subwavelength metallic grating
- Source :
- Applied Physics Letters. 116:241106
- Publication Year :
- 2020
- Publisher :
- AIP Publishing, 2020.
-
Abstract
- Terahertz (THz) single-pixel near-field imaging, producing images by introducing a scene with a series of spatially resolved subwavelength patterns while recording the correlated intensity on a single-element detector, is a promising technology for imaging applications. Spatial light modulator (SLM) is one of the key devices in THz single-pixel near-field imaging. Combined with a Digital Micromirror Device to shape the optical pump beam, a photo-induced tunable high-efficiency, ultra-thin, and fast THz SLM is presented by integrating designed subwavelength metallic grating into silicon on sapphire. In the experiments, the SLM is demonstrated with an over 60% THz peak amplitude modulation depth and broad bandwidth under a relative low pump fluence (80 μJ/cm2). The measurements, simulations, and calculations agree well with each other. Meanwhile, sub-nanosecond decay time extracted by fitting the |ΔT| curve suggests a fast response device. A two-dimensional grating is also explored, and the polarization-independent feature makes it easier to use. Finally, an imaging demonstration is conducted to verify the usability of the designed device. These results demonstrate the feasibility of realizing super-resolution and even real-time imaging simultaneously.
- Subjects :
- 010302 applied physics
Spatial light modulator
Materials science
Physics and Astronomy (miscellaneous)
business.industry
Terahertz radiation
Detector
Physics::Optics
02 engineering and technology
Grating
021001 nanoscience & nanotechnology
01 natural sciences
Digital micromirror device
law.invention
Amplitude modulation
Optical pumping
Optics
Silicon on sapphire
law
0103 physical sciences
0210 nano-technology
business
Subjects
Details
- ISSN :
- 10773118 and 00036951
- Volume :
- 116
- Database :
- OpenAIRE
- Journal :
- Applied Physics Letters
- Accession number :
- edsair.doi...........4a7035cd39ecf50013b02a35f51f1605