CN207816830U - Become wavelength excitation and the adjustable Raman spectrometer of spectral region - Google Patents

Abstract

The utility model proposes a Raman spectrometer with variable wavelength excitation and adjustable spectral range, including a laser, and the Raman light generated by the laser beam emitted by the laser to excite the sample is scattered to the incident slit, and the Raman light passes through the first plane in turn After being reflected by the reflector and the first concave reflector, the parallel beams are transformed into parallel beams incident on the surface of the plane blazed grating. The plane blazed grating is fixed on the rotating platform, and the plane blazed grating can be rotated through the rotating platform; the reflected light after being split by the plane blazed grating Focusing on the surface of the detector after passing through the second concave reflector and the second plane reflector, the detector is connected with the signal processing system, and the signal processing system is also connected with the display. Because the angle of the plane blazed grating is adjustable, the above-mentioned Raman spectrometer can use a variety of lasers with different wavelengths as the excitation light source; for a specific laser wavelength, a wide range of Raman can be realized by adjusting the angle of the plane blazed grating Spectral measurement.

Description

Raman spectrometer with variable wavelength excitation and adjustable spectral range

technical field

The utility model relates to a Raman spectrometer, in particular to a Raman spectrometer with variable wavelength excitation and adjustable spectral range.

Background technique

Raman spectrometers are increasingly used in chemical, biological, agricultural, food, geological and mining fields. According to actual applications, common excitation light sources generally use single-frequency solid-state or semiconductor lasers. Excitation wavelengths include 266nm, 355nm, 405nm, 450nm, 466nm, 485nm, 532nm, 785nm, 1064nm, etc. At present, most Raman spectrometers can only use a single-frequency laser as the excitation source. In order to ensure high spectral resolution, the wavenumber measurement range is generally limited to 2500cm ^-1 -4000cm ^-1 . Since there are often different optimal excitation wavelengths for different samples, multiple Raman spectrometers are often required to be used together in order to detect different samples, which increases the cost of detection and the complexity of operation.

Utility model content

In order to solve the problems existing in the prior art. The utility model provides a Raman spectrometer with variable wavelength excitation and adjustable spectral range.

In order to achieve the above object, the utility model proposes a Raman spectrometer with variable wavelength excitation and adjustable spectral range, including a laser, the laser can be a solid, gas or semiconductor laser, the emission wavelength is variable, and the laser emits The Raman light generated by the sample excited by the laser beam scatters to the incident slit, and the above-mentioned Raman light is reflected by the first plane reflector and the first concave reflector in turn, and then transformed into a parallel beam incident on the surface of the plane blazed grating. The blazed grating is fixed on the rotating platform, and the planar blazed grating can be rotated through the rotating platform; the reflected light after the splitting of the planar blazed grating passes through the second concave reflector and the second planar reflector in sequence, and then focuses on the detector. On the surface, the detector is connected with a signal processing system, and the signal processing system is also connected with a display.

Preferably, the laser beam emitted by the laser is incident on the sample directly or through an optical fiber.

Preferably, the Raman light generated by exciting the sample with the laser beam emitted by the laser is directly incident or incident into the incident slit through an optical fiber.

Preferably, the detector adopts a line array or area array imaging device.

Preferably, the detector adopts CCD or CMOS device.

The beneficial effect of this scheme of the utility model is that the above-mentioned Raman spectrometer with variable wavelength excitation and adjustable spectral range, because the angle of the plane blazed grating can be adjusted, so a variety of lasers with different wavelengths can be used as the excitation light source; for a specific The laser wavelength can also be adjusted by adjusting the angle of the planar blazed grating to achieve a wide range of Raman spectrum measurement. The Raman spectrometer with variable wavelength excitation and adjustable spectral range involved in the utility model has the advantages of compact structure and small volume.

Description of drawings

Fig. 1 shows a schematic structural diagram of a Raman spectrometer with variable wavelength excitation and adjustable spectral range involved in the present invention.

Reference signs: 1-laser, 2-sample, 3-incident slit, 4-first flat mirror, 5-first concave mirror, 6-plane blazed grating, 7-rotary platform, 8-rotary knob, 9-the second concave mirror, 10-the second plane mirror, 11-the detector, 12-the signal processing system, 13-the display.

Detailed ways

Below in conjunction with accompanying drawing, the specific embodiment of the present utility model is described further.

As shown in Figure 1, the Raman spectrometer with variable wavelength excitation and adjustable spectral range involved in the utility model includes a laser 1, and the laser 1 can be a solid, gas or semiconductor laser, whose emission wavelength is variable, and the laser 1 can be replaced according to the excitation wavelength requirements of different samples. The Raman light generated by the laser beam emitted by the laser 1 to excite the sample 2 is scattered to the incident slit 3. In this embodiment, the laser beam emitted by the laser 1 It is incident on the sample 2 directly or through an optical fiber; the Raman light generated by the laser beam emitted by the laser 1 to excite the sample 2 is directly incident or incident on the incident slit 3 through an optical fiber.

The above-mentioned Raman light is reflected by the first plane reflector 4 and the first concave reflector 5 in sequence, and then converted into a parallel light beam incident on the surface of the plane blazed grating 6. The plane blazed grating 6 is fixed on the rotating platform 7. The platform 7 can make the plane blazed grating 6 rotate. Specifically, the rotating platform 7 can be rotated by electric control or manual control. In this embodiment, the rotating platform 7 can be rotated by manual control. Specifically, A rotary knob 8 is provided on the rotary platform 7 , and the rotation of the rotary platform 7 can be controlled by manually rotating the knob 8 .

The reflected light after being split by the planar blazed grating 6 passes through the second concave reflector 9 and the second planar reflector 10 in turn, and then focuses on the surface of the detector 11. Due to the spectroscopic effect of the planar blazed grating 6, light rays of different wavelengths are focused At different positions on the surface of the detector 11, the detector 11 is connected to the signal processing system 12, and the calculation and analysis are performed through the signal processing system 12 to output spectral data; the signal processing system 12 is also connected to the display 13 , the spectral curve is displayed by the display 13 . In this embodiment, the detector 11 can use a linear or area array imaging device, and specifically the detector 11 can use a CCD or CMOS device; the signal processing system 12 and the display 13 are all prior art, I won't go into details here.

The Raman spectrometer with variable wavelength excitation and adjustable spectral range involved in the utility model, because the angle of the plane blazed grating 6 can be adjusted, so multiple lasers with different wavelengths can be used as the excitation light source; for a certain specific laser wavelength, also By adjusting the angle of the planar blazed grating 6, a wider range of Raman spectrum measurement can be realized. The Raman spectrometer with variable wavelength excitation and adjustable spectral range involved in the utility model has the advantages of compact structure and small volume.

There is a corresponding relationship between the wavenumber of the spectral measurement and the pixel point of the spectrometer detector, and the wavenumber ν and the pixel position x satisfy the functional relationship of the polynomial ν=a+bx+cx ² +dx ³ +... In this embodiment, a linear quasi- Combined to meet the error requirements, that is, using ν = a + bx. The specific method for calibrating and splicing the Raman spectrometer with variable wavelength excitation and adjustable spectral range includes the following steps:

Step 1. Using a laser 1 to excite a sample 2 with a known Raman spectrum.

Step 2. Adjust the rotary knob 8 to rotate the flat blazed grating 6 so that the laser interference is just outside the display of the Raman spectrum. Determine the wavenumber range of the Raman spectrum at this time as the position of the first segment of the Raman spectrum, and record the position at this moment The position of the rotary knob 8 is the first position.

Step 3, utilize two Raman peaks of the sample 2 of known Raman spectrum in step 2, i.e. v and x of these two Raman peaks are all known, obtain parameter a and b in v=a+bx , so as to determine the wavenumber of each point position in the first section of the Raman spectrum curve acquired in step 2, the wavenumber and intensity of the first section of the Raman spectrum curve are derived from a data table (such as an EXCEL form), and are recorded as the first data table.

Step 4. Adjust the rotary knob 8 to move the Raman peak obtained in step 2 to the left, so that the initial value of the wave number increases. At this time, the value of parameter b remains unchanged, and the value of parameter a changes to a ₁ . The wavenumber range of the Mann spectrum is determined as the position of the second segment of the Raman spectrum, and the position at which the knob 8 is rotated at this moment is recorded as the second position.

Step 5, using a Raman peak of the sample 2 whose Raman spectrum is known in step 4, that is, the ν and x of the Raman peak are known, and obtain the parameter a ₁ in ν=a ₁ +bx, so as to determine the step The wave number of each point in the second segment of the Raman spectrum curve obtained in 4, and the wave number and intensity of the second segment of the Raman spectrum curve are exported to a data table, which is recorded as the second data table.

Step 6, splicing the first data table obtained in step 3 and the second data table obtained in step 5, and then generating a spliced Raman spectrum graph.

If you want to splice multiple Raman spectrum curves, the principle is the same as above, so I won’t go into details here. The Raman spectrum of the laser 1 of a certain emission wavelength of the Raman spectrometer has been calibrated by the above method, and if the laser 1 is replaced, recalibration is required. When the user purchases a Raman spectrometer that has been calibrated to measure a sample with an unknown Raman spectrum, he can directly adjust the rotary knob 8 to the corresponding mark position, and then splice the two obtained data tables to generate a spliced The Raman spectrum curve.

Claims (5)

1. a kind of change wavelength excitation and the adjustable Raman spectrometer of spectral region, it is characterised in that：Including laser, the laser Solid, gas or semiconductor laser can be selected in device, and launch wavelength is variable, and the laser beam of the laser transmitting excites sample Generated Raman light scattering is to entrance slit, and above-mentioned Raman light is successively by the first plane mirror, the first concave mirror It is changed into parallel beam incident after reflection to plane balzed grating, surface, the plane balzed grating, is fixed on rotating platform, Plane balzed grating, can be made to rotate by the rotating platform；Reflected light after plane balzed grating, light splitting is passed through successively The surface of detector, the detector and signal processing system are focused on after second concave mirror and second plane mirror It is connected, the signal processing system is also connected with display.

2. change wavelength excitation according to claim 1 and the adjustable Raman spectrometer of spectral region, it is characterised in that：It is described The laser beam of laser transmitting is incident on sample directly or by optical fiber.

3. change wavelength excitation according to claim 1 and the adjustable Raman spectrometer of spectral region, it is characterised in that：It is described Raman light is directly incident caused by the laser beam excitation sample of laser transmitting or is incident on entrance slit by optical fiber.

4. change wavelength excitation according to claim 1 and the adjustable Raman spectrometer of spectral region, it is characterised in that：It is described Detector is using linear array or face battle array image device.

5. change wavelength excitation according to claim 4 and the adjustable Raman spectrometer of spectral region, it is characterised in that：It is described Detector uses CCD or cmos device.