Raman enhancing structure based on external cavity resonance

Abstract

The invention discloses a Raman enhancing structure based on external cavity resonance. The Raman enhancing structure based on external cavity resonance is divided into a Littrow cavity enhancing structure and a Littman cavity enhancing structure. A gas chamber is placed in a resonance cavity of a laser, that is the gas chamber is placed in an external cavity of an external cavity feedback type semiconductor laser, so that the laser and the gas chamber are combined, the problem that the excitation frequency is reduced due to the fact that the laser is obliquely injected into the gas cavity isavoided, and the problem that the system is more complicated and expensive to be punched in the optical element is avoided. In addition, according to the Raman system adopting the structure, the single-longitudinal mode output of the Raman laser and the tunable wavelength can be realized, and the detection of the multi-wavelength Raman spectrum can be realized.

Description

technical field [0001] The invention relates to a Raman enhanced structure based on external cavity resonance. Background technique [0002] Raman spectroscopy can identify substances at the molecular level and provide molecular "fingerprint" spectral information. And it requires minimal sample preparation, allowing rapid on-site testing. Even if the sample to be tested is placed in a container such as a packaging bag or a glass bottle, it can be detected conveniently. It can detect solids, solutions, and gases. It has a wide range of applications, whether it is in the field of food, drug testing, or environmental monitoring. Raman spectrometers have played an important role. [0003] So far, Raman spectroscopy detection technology has been widely used in food safety, biomedicine, archaeology, public security and other fields, and it is of great value for qualitative analysis, quantitative analysis and molecular structure analysis of substances. However, the signal of Ram...

AI Technical Summary

Problems solved by technology

However, the laser incidence direction of the common intracavity enhancement method is either obliquely incident into the cavity. If the laser is incident from outside the gas cavity into the cavity, then it must be ensured that the incident light is incident into the gas cavity at a certain angle, resulting in the laser in the cavity. The number of reflections within is limited by this angle, which affects the Raman intensity

Or a hole is made on one of the optical components as the entrance of the laser, the purpose is to let the Raman laser enter the cavity, which makes the system complex and expensive, and the number of resonances of the laser in the cavity is limited Or as the number of reflections increases, the power of the laser drops rapidly, and the energy of the laser gradually decreases. The final result is that the magnitude of Raman enhancement is greatly limited.

Existing methods are difficult to achieve greater Raman intensity enhancement. The main reason for this problem is that the Raman laser is separated from the gas cavity.

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