Quantum cascade laser (QCL) phase-locked system using solid-state semiconductor source harmonic as reference source

Abstract

The invention discloses a quantum cascade laser (QCL) phase-locked system using a solid-state semiconductor source harmonic as a reference source. The QCL phase-locked system comprises a first wave beam separator, a second wave beam separator, a band-pass filter, a terahertz frequency mixer, an intermediate-frequency amplification unit and a phase-lock unit which are connected sequentially, wherein a terahertz QCL outputs a signal to the first wave beam separator, and a solid-state semiconductor source higher harmonic outputs a signal to the second wave beam separator; the first wave beam separator and the second wave beam separator couple the output signal of the terahertz QCL and the signal of the solid-state semiconductor source higher harmonic to the terahertz frequency mixer respectively, and the frequency mixer uses the solid-state semiconductor source higher harmonic as a phase-lock reference; an intermediate-frequency signal obtained after the frequency mixing of the terahertz frequency mixer is amplified via the intermediate-frequency amplification unit at first, and then conveyed to the phase-lock unit; and the phase-locked performs phase-lock processing on the intermediate-frequency signal, so as to realize the phase lock of the terahertz QCL.

Description

technical field [0001] The invention relates to a terahertz signal source phase-locked system, in particular to a terahertz quantum cascade based on a high-sensitivity superconducting thermal electron mixer and a low-frequency signal source (such as a solid-state semiconductor source) high-order harmonics as a reference source Laser lock-in system. Background technique [0002] Commonly used signal sources in the terahertz frequency band mainly include solid semiconductor sources (such as Gunn oscillators and frequency multiplier combinations), vacuum tube signal sources (such as return wave tube oscillators), far-infrared gas lasers, and quantum cascade lasers. Except for far-infrared gas lasers, the operating frequencies of the above-mentioned commonly used terahertz signal sources are generally affected by external conditions. For example, the operating frequencies of free-running Gunn oscillators and terahertz quantum cascade lasers are affected by ambient temperature fl...

AI Technical Summary

Problems solved by technology

Such reference signal sources, such as solid semiconductor sources, have sharply reduced output power at higher frequency bands (above 1.5 THz), and are very difficult to prepare, while superlattice harmonic generators increase with the harmonic order in the THz high frequency band. The output power is also sharply reduced, which will be greatly limited in practical applications

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