Terahertz band imaging objective lens with high relative aperture and large field of view

Abstract

The invention discloses a terahertz band imaging objective lens with a high relative aperture and a large field of view, and belongs to the technical field of optical lens imaging. The object of the invention is to provide a terahertz band imaging objective lens with a high relative aperture and a large field of view, to realize the high relative aperture and large imaging field of view. The terahertz band imaging objective lens comprises a terahertz filter, a first lens, a diaphragm and a second lens. The first lens and the second lens are both convex lenses and both have positive focal power. The first lens and the second lens are both made of plastics having an absorption coefficient of less than 0.5 cm-1 in a less than 0.5THz band and a refractive index 1.3 to 2. Both the first lens and the second lens have high-order aspheric surfaces as the front surfaces, the image quality of the whole field of view is well corrected, and the high relative aperture and large imaging field of view are realized. The invention is applicable to an objective lens for terahertz imaging.

Description

technical field [0001] The invention belongs to the technical field of optical lens imaging, and relates to an imaging objective lens with high relative aperture and large field of view in the terahertz band. Background technique [0002] Terahertz (Terahertz, abbreviated as THz, 1THz=10 12 Hz) generally refers to electromagnetic waves with frequencies in the 0.1-10THz band, located between infrared and microwave, and in the transition stage from macroelectronics to microphotonics. Because this band has important characteristics such as wide spectrum, narrow pulse width, coherence, low energy, perspective, fear of water, fingerprint absorption spectrum, etc. , terahertz technology plays an increasingly important role. [0003] In the field of human security inspection, terahertz waves have high penetrability and can detect dangerous and prohibited items hidden in clothing without causing ionizing radiation hazards to the human body. Therefore, the use of terahertz waves f...

AI Technical Summary

Problems solved by technology

However, the terahertz band high relative aperture and large field of view imaging objective lens for security imaging is blank, and no mature products have yet been introduced to the market

Some research institutions simply combine multiple single lenses to form an imaging objective lens. Due to the lack of a complete design optimization process, it is difficult to obtain high-quality imaging results

Images