Raman spectroscopy was first discovered in 1928 by Indian scientist Raman. A certain frequency of light interacts with matter, in addition to the Rayleigh scattered light with the same frequency as the original frequency, there will also be scattered light of other frequencies on both sides of the frequency, which is called Raman scattering spectrum. Since the difference between the frequency of the Raman scattered light and the frequency of the incident light (ie, the Raman shift) reflects the molecular vibration and rotational energy level, and is independent of the frequency of the excitation light, the Raman effect can be used to identify substances. Under certain conditions or states, different substance molecules have unique molecular structures. It is this characteristic that makes Raman spectroscopy a “fingerprint” for substance identification [2]. In addition, the intensity of the Raman signal is proportional to the intensity of molecular vibration and rotation, so it can also be used for quantitative analysis.
For a long time, large-scale Raman spectrometers have only been used in university laboratories and related research institutes due to large equipment and high prices. With many fields such as environmental testing, food safety and real-time security inspection [3-5], people are paying more and more attention. Abroad, companies such as B&W TEK, Ocean Optics, Thermo Scientific, DeltaNu, etc., have launched highly sensitive, high-resolution portable Raman spectrometers [6-8], and these devices are also widely used in teaching, scientific research and practical testing. Some domestic universities and research institutes have also developed miniaturized Raman spectrometers, but they have not reached the market scale. Miniaturizing the Raman spectrometer, while increasing its sensitivity and resolution as much as possible, is the focus of related research and development at home and abroad. This article will review the application parameters and related components of the portable Raman spectrometer, compare related products at home and abroad, and introduce the function of its structure and the significance of related parameters.
Technological progress
In recent years, for the problem that Raman light is weak and difficult to detect, people have continuously developed new technical means, mainly virtual slit technology, surface-enhanced Raman chip, etc.
- High-throughput virtual slit technology 2. Surface enhanced Raman technology
