THz wave parametric source with multi-wavelength pulse delay output

Abstract

The invention provides a THz wave parameter source for multi-wavelength pulse delay output. The THz wave parameter source comprises a pump laser, a second crystal, a first crystal and a pump light pulse delay device composed of a reflector and a coupling output mirror. The Sub-ns narrow pulse width pump light is incident into the pump light pulse delay device at a certain small angle to form a sequence of spatially and temporally separated multiple pump light pulses. The pump light pulse sequence is amplified and divided into two beams. The second pump light pulse sequence is coupled through acylindrical lens. Cross-pumped SPS occurs at the second crystal to output pulse delay Stokes optical sequences with different frequencies. The first pump light pulse sequence is coupled into the first crystal through the cylindrical lens to be coupled with the pulse delay Stokes light sequence outputted by the second crystal to generate the pulse delay THz wave output due to parametric conversion. The multi-wavelength output of the THz wave parameter source can be realized without narrow linewidth seed source so as to provide a feasible technical scheme for the THz wave parameter technology to realize real-time spectrum detection.

Description

technical field [0001] The invention relates to the technical field of terahertz wave laser sources, in particular to a THz wave parameter source with multi-wavelength pulse delay output. Background technique [0002] Terahertz (THz) waves refer to electromagnetic waves with a frequency range of 0.1~10 THz. THz waves are between infrared rays and microwaves. They have a series of special properties that many other wave bands do not have. Based on the identification characteristics, two important technical applications of THz wave THz penetration imaging and THz spectrum measurement have been developed. THz waves have a high transmittance in organic macromolecular materials, cloth, wood and ceramics and many other opaque substances in the infrared and visible light bands, and can perform penetrating imaging on them; many macromolecules and polar molecules are in the THz band It has a characteristic absorption spectrum, so that different molecules or substances can be identif...

AI Technical Summary

Problems solved by technology

The THz spectrum system based on multi-wavelength output is-TPG can complete the measurement of multiple spectral components within one pump pulse, which can realize real-time measurement and has wide application prospects, but there are still many problems in this technology: first, multiple seeds The laser wavelength is injected into a single pump pulse, and the multiple THz wave frequency components generated will share the pump energy, which will inevitably cause a decrease in the power of a single frequency THz wave and a decrease in the dynamic range of system measurement; Low, on the order of tens of mW, the four-wave mixing efficiency of the semiconductor optical amplifier is not high, the power of the new wavelength component generated is lower, and the energy difference of each frequency component of the THz wave is large; third, the gain between frequencies Competition leads to poor stability and affects the practical application of the system

In addition, the economic cost of this solution is relatively high, and multiple single-frequency seed sources need to work at the same time

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