Terahertz micro-structure polarization sensing system for liquid chiral sample and detection method thereof

Abstract

The invention discloses a terahertz micro-structure polarization sensing system for a liquid chiral sample and a detection method thereof. Sensing detection of a liquid sample is realized by adoptinga reflection system, and the signal intensity and the system signal-to-noise ratio are remarkably improved. Polarizers are arranged in front of and behind the reflection system respectively, the complete polarization state of an emergent wave signal can be detected by rotating the polarizers, a reflection type time domain polarization spectrum (RTDPS) system is formed, and detection of the polarization state and chiral information of a sample is achieved while the detection sensitivity is improved. A single-layer spiral micro-structure is used as a sensor, and the local resonance and artificial chiral response of the micro-structure can greatly enhance the optical response of a natural chiral sample under the condition of oblique incidence of electromagnetic waves. Taking an amino acid sample as an example, the concentration detection precision of the system is 10<-5> g/mL magnitude, and D-type and L-type chiral enantiomers of amino acid can be identified through significant differenceof polarization spectra at characteristic frequency positions.

Description

technical field [0001] The invention belongs to the field of terahertz science and technology, and specifically relates to a high-sensitivity reflective microstructure polarization sensing system for liquid chiral samples, and a specific sensing method thereof. Background technique [0002] Terahertz (THz) waves usually refer to frequencies between 0.1 and 10THz (1THz=10 12 Hz) range, due to its excellent properties such as small photon energy, non-invasive and non-ionization, it has received extensive attention in sensing and detection, and its applications cover various fields such as safety, medical treatment, and biology. Traditional THz sensing is mainly based on time-domain spectroscopy (TDS) systems, which are characterized by the transmission or absorption spectra of samples. Although the TDS system can achieve spectral measurement in a broadband range, this method has strict requirements on the state of the sample, cannot detect liquid (especially aqueous solution)...

AI Technical Summary

Problems solved by technology

[0006] To sum up, on the one hand, the rapid development of terahertz technology and the urgent needs of chemistry, biology and other fields put forward higher performance requirements for THz sensing and detection systems; on the other hand, the existing traditional THz sensing The system has defects such as low sensitivity, limited detection information, and poor applicability.

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