Terahertz reflection imaging system based on zero order Bessel wave beams

Abstract

The invention discloses a Terahertz reflection imaging system based on zero order Bessel wave beams. The system comprises a Terahertz emission source, a collimating lens, a silicon chip, a diffractionelement, a focusing lens, a Terahertz detector, a sample table, a sample table moving device, a lock phase amplifier and a control module, wherein the collimating lens, the silicon chip, the diffraction element and the sample table are in sequential arrangement in a direction along the transmission direction; the center of the silicon chip is positioned in the center axial line of the transmission wave beams; an included angle between the silicon chip and the center axial line is 45 degrees; the main optical axes of the collimating lens and the diffraction element are positioned in the centeraxial line of the transmission wave beams; through the diffraction element, the transmission wave beams become the zero order Bessel wave beams; the main optical axis of the focusing lens is positioned on a reflection light path and is vertical to the center axial line of the transmission wave beam; the Terahertz detector is positioned on the focal plane of the focusing lens and is connected withthe lock phase amplifier; the control module is respectively connected with the sample table moving device and the lock phase amplifier. The Terahertz reflection imaging system can simultaneously provide high imaging quality and large depth of field.

Description

technical field [0001] The invention belongs to the technical field of terahertz imaging, and more specifically relates to a terahertz reflection imaging system based on zero-order Bessel beams. Background technique [0002] Terahertz Wave (THz wave for short) refers to a section of electromagnetic wave with a frequency between 100 GHz and 10 THz (wavelength 30 μm to 3 mm), which is located between infrared waves and microwave bands. Terahertz waves have some unique properties compared to electromagnetic waves in other bands. Because the terahertz wave is located between the infrared wave and the microwave, it has the characteristics of two wave bands: it has the penetration ability similar to the microwave and the directionality similar to the light wave on the macroscopic level, and has quantum characteristics on the microscopic level. It is equivalent to the rotational energy level of the molecule. Terahertz waves have good penetration to many dielectric materials and n...

AI Technical Summary

Problems solved by technology

[0004] Overall, existing terahertz reflection imaging systems cannot simultaneously provide high imaging resolution and large depth of field

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