A Raman spectroscopy detection method based on the principle of polarization difference

Abstract

The invention relates to a Raman spectrum detection method based on the principle of polarization difference. The existing Raman signal is weak, the sensitivity is low, and the requirements for the materials to be detected are high. The invention combines the polarization difference principle with the Raman enhancement effect of the core-shell nanoparticle layer, and focuses light fields in different polarization states to the core-shell nanoparticle area. The core-shell nanoparticle includes a metal nanoparticle core and an inert material shell. The detected substance is located in the detected area near the core-shell structure nanoparticle layer. Based on the excitation of different polarization states and the strong electromagnetic field enhancement effect of the core-shell structure nanoparticle, the enhanced Raman signal of the detected substance is obtained. Based on the adjustable polarization state , the multi-enhanced Raman signals in the polarization dimension are processed with polarization differentiation information to obtain high-information Raman signals. The invention has the characteristics of high sensitivity, high signal-to-noise ratio, various forms and substances of detected objects, rich polarization-related characteristics, high information content, wide application range, easy function expansion and the like.

Description

technical field [0001] The invention belongs to the field of optical technology, and relates to a Raman spectrum detection method, in particular to a Raman spectrum detection method based on the principle of polarization difference, which is mainly used in material analysis, environmental monitoring, resource exploration, food safety, biological research, life Raman spectroscopy detection in the fields of science, medical treatment, process control, national defense and security. Background technique [0002] The Raman spectrum detection method is a scattering spectrum detection method developed based on the Raman scattering effect discovered by the Indian scientist C.V. Raman (Raman). Molecular vibration and rotation information has developed rapidly after the invention and use of lasers, and is widely used in material analysis, environmental monitoring, resource exploration, food safety, biological research, life science, medical treatment, process control, national defens...

AI Technical Summary

Problems solved by technology

Raman spectroscopy detection technology exists in the prior art, which is called tip-enhanced Raman spectroscopy technology, (see paper B. Pettinger, et.al. Nanoscal probing of absorbed species by tip-enhanced Raman spectroscopy. Phys. Rev. Lett. 2004 , 92, 096101), although it has certain advantages, there are still essential deficiencies, because only a small needle tip plays a strengthening role, resulting in weakened Raman signal, and the needle tip is easily contaminated, and the detection signal is easily interfered, so the detection The signal is easy to deviate from the true value, the sensitivity is not high, and the needle tip affects the flexibility of the detection system construction, which is essentially unable to provide information related to the polarization of the light field; there is a needle tip enhanced Raman spectroscopy technology in the prior art, (see US Patent , patent name: High contrast tip-enhanced Raman spectroscopy, inventors: Alexei P. Sokolov, Alexander Kisliuk, Disha Mehtant, Ryan D. Hartschuh, Nam-Heui Lee, patent number: US7656524B2, patent authorization time: February 2, 2010 Japan), although there are certain characteristics, but there are still essential deficiencies, it has not fundamentally avoided the deficiencies of the original tip-enhanced Raman spectroscopy technology, and the flexibility of excitation light polarization adjustment is poor, the system construction flexibility is low, and the polarization Raman information In addition, this detection method has essential requirements on the material properties of the detected object, which limits the scope of application

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