Product information：

Optical path structure of Raman probe:

★ the laser signal from the fiber laser changes into a parallel laser through the collimating lens;

★ the laser irradiates the dichroic chip, so that the incident laser is reflected to the collimator group at an angle of 45 degrees, and then focused on the measured target;

★ the Raman signal generated by the measured sample returns to the original optical path, changes into a collimated beam through the collimator group, and then passes through the dichroic chip. At this time, 95% of the elastic scattered light is filtered out;

★ the Raman light signal in the optical signal after passing through the dichroic plate passes through the filter group unimpeded (transmissible above 790nm), and the laser signal above 0d10 is filtered;

★ the Raman signal light is focused to the slit of the spectrometer through the focusing lens group for the next spectroscopic measurement.

Optical path structure of spectrometer:

★ the spectrometer is composed of slit, collimating mirror, grating, imaging mirror, cylindrical lens and detector;

★ the Raman probe focuses the signal light on the slit to realize spatial filtering;

★ the signal light passing through the slit is incident on the collimating mirror inside the spectrometer at a divergent angle;

★ the signal light collimated by the collimator is diffracted by the grating, and the light of different wavelengths has different diffraction angles;

★ diffracted light of all wavelengths is reflected and focused by the focusing mirror and reaches the detector surface to realize spectroscopic detection.

Principle of Raman technology:

Sir chandrasekhara venkata Raman won the 1930 Nobel Prize in physics for the discovery of Raman effect. When light passes through the medium, it can be observed that the frequency and phase of light change irregularly due to light scattering. This phenomenon is called Raman effect.

The scattering molecule was originally in the ground state. When foreign photons incident on the molecule, the molecule absorbs a photon, transitions to the virtual energy level, and immediately returns to the ground state to emit photons. This is Rayleigh scattering. If the molecule transitions to the virtual energy level and does not return to the original ground state, but falls to another higher energy level to emit photons, the emitted new photon energy HV 'is obviously less than the incident photon energy HV, which is the Stokes line Δ E=h(u0- Δ U) Conversely, anti Stokes lines are generated Δ E=h(U0- Δ U) , Stokes lines and anti Stokes lines are generally called Raman lines. Usually, most molecules are in the ground state of vibrational energy level, so the intensity of Stokes lines is much stronger than that of anti Stokes lines.

Δ U is the difference between the scattered light and the scattered light frequency due to the Raman shift Δ U only depends on the molecular structure and has nothing to do with U0, so Raman spectrum can be used as molecular fingerprint spectrum. The abscissa of Raman spectrum is generally Raman shift, expressed in wave number Δ U = us-u0, where US and U0 are Stokes displacement and excited light wave number respectively, and the ordinate is Raman intensity.