Superconducting heterodyne integrated receiver with terahertz quantum-cascade laser as local oscillation source

Abstract

The invention discloses a superconducting heterodyne integrated receiver with a terahertz quantum-cascade laser as a local oscillation source. The superconducting heterodyne integrated receiver comprises the terahertz quantum-cascade laser, a frequency mixer, a first intermediate frequency amplifier, a second intermediate frequency amplifier, a spectrometer, a convex lens and a wave beam splitter. Local oscillation reference signal wave beams output by the terahertz quantum-cascade laser are shaped by the convex lens, then the local oscillation reference signal wave beams and detected signals are coupled to the frequency mixer through the wave beam splitter wave beam splitter, the first intermediate frequency amplifier and the second intermediate frequency amplifier amplify intermediate frequency signals output by the frequency mixer, and the spectrometer analyzes output signals of the second intermediate frequency amplifier. The terahertz quantum-cascade laser, the convex lens, the wave beam splitter, the frequency mixer and the first intermediate frequency amplifier are arranged in a low-temperature vacuum environment which is 4K in temperature and achieved by the same vacuum dewar, any adjustable optical element for coupling the output signals of the terahertz quantum-cascade laser to the superconducting electronic frequency mixer is not needed, the structure is simple and compact, and integration and miniaturization are facilitated.

Description

technical field [0001] The invention relates to a superconducting heterodyne integrated receiver, in particular to a superconducting heterodyne integrated receiver suitable for a terahertz high-frequency band (1.5-5.0 THz) and using a terahertz quantum cascade laser as a local oscillator reference source. Background technique [0002] The terahertz (THz) frequency band is between the microwave and far-infrared frequency bands, and this frequency band is one of the important frequency bands in modern astronomy. There are abundant molecular rotational spectral lines and fine-structure atomic spectral lines in the terahertz frequency band. High-resolution observations of these molecular and atomic spectral lines can study the chemical properties and kinematic characteristics of celestial objects. High-resolution observations of molecular rotation lines and fine-structure atomic lines in the terahertz band are of great significance for understanding the evolution of the early un...

AI Technical Summary

Problems solved by technology

Two 4 K vacuum dewars make the structure of the superconducting heterodyne mixing receiver very complicated. Considering that the water vapor in the earth's atmosphere seriously attenuates the terahertz high-frequency signal, the high-resolution observation of molecular or atomic spectral lines in the terahertz high-frequency band Generally based on space or balloon telescopes, superconducting heterodyne mixer receivers with complex structures are difficult to apply in actual astronomical observations

For this reason, in 2008, the German DLR team proposed a superconducting heterodyne integrated receiver. They used the terahertz quantum cascade laser and the superconducting thermal electron mixer to work respectively in vacuum Dewar 40 K and 4 K cold stages (ie Provide a low temperature environment with a temperature lower than 4K), but the superconducting heterodyne integrated receiver requires the terahertz quantum cascade laser to work at a relatively high temperature, and at the same time, the vacuum dewar requires tunable optical elements to couple the terahertz quantum cascade The output signal of the laser is sent to the superconducting thermal electron mixer, which also brings difficulties to the actual astronomical observation

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