CN-122016710-A - Vertical-reverse terahertz hair extension integrated probe

CN122016710ACN 122016710 ACN122016710 ACN 122016710ACN-122016710-A

Abstract

The vertical-reflection terahertz receiving and transmitting integrated probe comprises a photoconductive transmitting antenna, a first collimating lens, a half-reflection half-lens, a focusing objective lens, a reflecting prism, a second collimating lens and a photoconductive receiving antenna, wherein the photoconductive transmitting antenna, the first collimating lens, the half-reflection half-lens and the focusing objective lens are sequentially arranged into one row, the photoconductive receiving antenna, the second collimating lens and the reflecting prism are sequentially arranged into another row, and the two rows are arranged in parallel and are positioned on the same side of a target to be measured. The optical axis of the transmitting antenna and the optical axis of the receiving antenna are arranged in parallel on the same side, so that compared with an inclined-to-back type split probe, the volume of the probe is effectively reduced, and the probe has the characteristics of portability, light weight and the like.

Inventors

CHEN JIGANG
LIU JUNFENG
YUAN YINGHAO
ZHU QING
MAO ZHIYONG
NI BO

Assignees

上海航天技术基础研究所

Dates

Publication Date: 20260512
Application Date: 20260302

Claims (10)

1. The vertical-reflection terahertz receiving and transmitting integrated probe is characterized by comprising a photoconductive transmitting antenna, a first collimating lens, a half-reflection half-lens, a focusing objective lens, a reflecting prism, a second collimating lens and a photoconductive receiving antenna; The photoconductive receiving antenna, the second collimating lens and the reflecting prism are sequentially arranged in another row, and the two rows are arranged in parallel and are positioned on the same side of the target to be measured.
2. The vertical-reflection terahertz integrated transmitting and receiving probe as claimed in claim 1, wherein the optical axis of the photoconductive transmitting antenna is perpendicular to the first collimating lens and the focusing objective lens, the optical axis of the photoconductive transmitting antenna forms an included angle of 45 degrees with the semi-reflecting semi-transparent lens, the optical axis of the photoconductive receiving antenna is parallel to the optical axis of the photoconductive transmitting antenna and forms an included angle of 180 degrees with the optical axis of the photoconductive transmitting antenna, the optical axis of the photoconductive receiving antenna is perpendicular to the second collimating lens, and the optical axis of the photoconductive receiving antenna forms an included angle of 45 degrees with the reflecting prism.
3. The vertical-back terahertz receiving and transmitting integrated probe of claim 1, wherein the photoconductive transmitting antenna transmits terahertz waves, the first collimating lens shapes divergent terahertz waves transmitted by the photoconductive transmitting antenna into parallel beams, the parallel beams positively penetrate the half-reflecting half-lens, the focusing objective lens has a focusing function and converges the parallel beams penetrating the half-reflecting half-lens to a target surface to be detected, terahertz echo paths reflected by the target surface to be detected return, are reversely transmitted into the half-reflecting half-lens, are reflected by the half-reflecting half-mirror and then are transmitted into the reflecting prism, are reflected by the reflecting prism, change the propagation direction, and are detected by the photoconductive receiving antenna after passing through the second collimating lens.
4. The integrated vertical-back terahertz hair-extension probe of claim 1, further comprising a housing, wherein the photoconductive transmitting antenna, the first collimating lens, the half-back half-lens, the photoconductive receiving antenna, the second collimating lens and the reflecting prism are all disposed in the housing, and wherein the focusing objective lens protrudes out of the housing and is fixedly connected with the housing.
5. The integrated vertical and reverse terahertz receiving and sending probe of claim 4, wherein the photoconductive transmitting antenna is connected with a femtosecond laser optical fiber line and a bias voltage line, the photoconductive receiving antenna is connected with the femtosecond laser optical fiber line and a weak current signal output line, the shell is provided with a through hole, and the femtosecond laser optical fiber line, the bias voltage line and the weak current signal output line extend out of the shell through the through hole and are connected with external equipment.
6. The integrated vertical and horizontal terahertz hair extension probe of claim 4, further comprising a lens clamp, wherein the first collimating lens and the second collimating lens are fixedly connected with the shell through the lens clamp, the lens clamp is in an omega-shaped structure, a round hole is reserved in the middle, and the first collimating lens or the second collimating lens is placed in the round hole and fixed through 502 glue.
7. The integrated vertical and reverse terahertz hair extension probe of claim 4, further comprising a plane mirror clamp, wherein the half-reflecting and half-reflecting lenses and the reflecting prism are fixedly connected with the shell through the plane mirror clamp, and the plane mirror clamp is in a concave structure, and the half-reflecting and half-reflecting lenses or the reflecting prism are placed in the grooves and fixed through 502 glue.
8. The vertical-back terahertz integrated transmitting and receiving probe as in claim 4, further comprising an antenna clamp, wherein the photoconductive transmitting antenna and the photoconductive receiving antenna are both fixedly connected with the shell through the antenna clamp, the antenna clamp is of a hollow omega-shaped cylinder structure, and the photoconductive transmitting antenna or the photoconductive receiving antenna is placed in the hollow omega-shaped cylinder structure and is fastened by using a screw at the top of the antenna clamp.
9. The vertical and reverse terahertz integrated probe of claim 1, wherein the photoconductive transmitting antenna is made of GaAs material as a substrate, the terahertz wave band generated by cylindrical design is a low-frequency band, the surface of the reflecting prism is coated with a gold film to increase the reflectivity to 96%, the focusing objective lens can perform small-range displacement to change the focal length, and the materials of the first collimating lens and the second collimating lens are 4-methylpentene.
10. The integrated vertical and reverse terahertz hair extension probe of claim 4, wherein the housing is made of indium steel.

Description

Vertical-reverse terahertz hair extension integrated probe Technical Field The invention relates to a terahertz probe of terahertz time-domain spectroscopy equipment, in particular to a vertical and horizontal terahertz receiving and transmitting integrated probe. Background Terahertz waves are relatively blank fields in the field of electromagnetic wave research due to their special frequency and wavelength ranges. The terahertz electromagnetic radiation frequency is between (0.1-10) THz terahertz (corresponding to the wavelength of 0.03-3 mm), in the electromagnetic spectrum, the electromagnetic radiation frequency is just between communication microwaves and optical infrared rays, and the window is positioned in a region where the electronic and photon characteristics are fused. Terahertz waves have higher frequency, wider bandwidth and smaller beam scattering angle compared with microwaves, so that information can be transmitted with wider signal bandwidth when the terahertz waves are used for communication, and the information transmission quantity is greatly improved. Compared with infrared rays, the terahertz wave has stronger penetrating power, can easily penetrate most nonmetallic and nonpolar compounds, and is convenient for imaging the internal structure of an object and acquiring related key information. The terahertz time-domain analysis system is divided into a host part and a probe part, wherein the host is used for carrying out time-domain analysis on received terahertz echoes, the probe is used for transmitting terahertz waves and receiving terahertz echo signals, and the probe is connected with the host for carrying out data analysis. Terahertz probes are mainly divided into three basic types, namely transmission type, oblique type and vertical type. The design of the conventional terahertz probe has obvious defects, the transmission type probe detection target is designed to be in a split mode aiming at a nonmetallic substrate material, the transmission type probe is large in size, terahertz waves are required to be aligned during use, the operation is troublesome, and the inclined-reflection type terahertz probe is designed integrally, but has two optical paths of incident waves and echoes, so that more optical devices are required to be added during design, and the attenuation of the energy of the terahertz waves is represented by adding one optical device. Thus, a large number of researchers began to design an integrated lightweight vertical-type terahertz probe. Patent CN202122698531.0 discloses a terahertz probe with a vertical incidence type terahertz detection system, which is the most visible terahertz probe in the market, and has the structure that the optical axis of a transmitting antenna and the optical axis of a receiving antenna are mutually perpendicular, so that the number of times of the turn-back change of a designed optical path is minimum, but the whole volume size is greatly increased. Patent CN202323452395.2, a vertical incidence terahertz detection device for eliminating multiple reflections, discloses a novel optical path structure, and improves terahertz receiving quality by adding parabolic mirrors and wedge plate designs. Disclosure of Invention The invention aims to provide a vertical and reverse terahertz integrated probe, wherein the optical axis of a transmitting antenna and the optical axis of a receiving antenna are arranged on the same side in parallel, so that miniaturization, light weight and portability are realized. In order to achieve the purpose, the invention provides a vertical-reflection terahertz hair-extension integrated probe which comprises a photoconductive transmitting antenna, a first collimating lens, a half-reflection lens, a focusing objective lens, a reflecting prism, a second collimating lens and a photoconductive receiving antenna, wherein the photoconductive transmitting antenna, the first collimating lens, the half-reflection lens and the focusing objective lens are sequentially arranged into one row, the photoconductive receiving antenna, the second collimating lens and the reflecting prism are sequentially arranged into another row, and the two rows are arranged in parallel and are positioned on the same side of a target to be measured. The vertical-reflection terahertz receiving and transmitting integrated probe is characterized in that the optical axis of the photoconductive transmitting antenna is perpendicular to the first collimating lens and the focusing objective lens, an included angle of 45 degrees is formed between the optical axis of the photoconductive transmitting antenna and the semi-reflecting semi-transmitting lens, the optical axis of the photoconductive receiving antenna and the optical axis of the photoconductive transmitting antenna are parallel to each other and form an included angle of 180 degrees, the optical axis of the photoconductive receiving antenna is perpendicular to the second collimating lens, and