High-throughput terahertz spectral line imaging using an echelon mirror

Abstract

This work demonstrates terahertz (THz) line imaging that acquires broadband spectral information by combining echelon-based single-shot THz spectroscopy with high-sensitivity phase-offset electrooptic detection. An approximately 40 dB signal-to-noise ratio is obtained for a THz spectrum from a single line of the camera, with a detection bandwidth up to 2 THz at the peak electric-field strength of 1.2 kV/cm. The spatial resolution of the image is confirmed to be diffraction limited for each spectral component of the THz wave. We use the system to image sugar tablets by quickly scanning the sample, which illustrates the capacity of the proposed spectral line imaging system for high-throughput applications.

Single-shot spatio-temporal measurement of relativistic electron beams by electro-optic sampling

“…A quarter wave plate is put between the analyzer and the ZnTe crystal for a phase offset method. To conduct single-shot temporal measurement, a probe pulse is injected into an echelon mirror, which has a step-like mirror surface, after the reflection, the probe pulses were converted into multiple pulses [27] . Each divided pulse has a time delay defined by the height of the step.…”

Singleshot and high-sensitivity detection of terahertz waveforms using phase-offset electro-optic sampling and an echelon mirror

“…One way to enhance the modulation depth is to use the phase-offset electro-optic sampling method [6,9]. In this scheme, crossed-Nicols polarizers are placed after the echelon mirror and before the camera.…”

“…Another possibility is to use the vertical axis for imaging one dimension rather than just summing up the vertical axis to increase the signal-to-noise ratio [9]. To do that, we image the sample onto the electro-optic crystal and the probe pulses are linearly focused to the same crystal.…”

“…We finally show several demonstrations of the single-shot terahertz time-domain spectroscopy where we can detect the terahertz radiations with high-sensitivity. Single-shot optical-pump terahertz-probe spectroscopy [7], terahertz spectroscopy under pulsed high-magnet [8], terahertz spectral line imaging [9], and the detection of terahertz radiation from laser ablation processes [10] are demonstrated. Those results show that the single-shot techniques using an echelon mirror and the phase-offset electro-optic sampling method shown here opens new possibilities to investigate various types of irreversible phenomena in materials with terahertz radiations.…”

Reflected metasurface carrying orbital angular momentum for a vortex beam in the terahertz region

“…With the aid of the increasingly mature terahertz source alongside detector manufacturing and processing, terahertz technology has developed rapidly [1][2][3]. In 2019, the International Telecommunication Union designated the terahertz band as the sixth generation wireless communication carrier.…”