MS750 series Monochromator-spectrograph, perfect imaging

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While choosing a device configuration it is important to select properly the diffraction gratings. A right selection of the diffraction grating allows one to obtain the best combination of high energetic efficiency and spectral resolution.

The basic grating parameters which determine their right choice you can find in the methodical material "Spectral Instrument. Basic Concepts and Characteristics."

We propose a wide range of diffraction gratings to be used in the MS750 Series. Please, choose a necessary grating from the given below list, or consult our specialists.

 
SOL instruments: спектрометр, рамановский микроскоп, эмиссионный спектрометр. dif grating 435x315

Basic parameters for correct selection of diffraction gratings:

In the Table “Selection of diffraction gratings” groove density and blaze wavelength belong to a diffraction grating parameters. Other parameters characterize a spectral device together with a selected grating.

  • Groove density. The diffraction grating has a periodic structure. Such parameters as resolving power and free spectral range are determined by the periodic structure properties of a diffraction grating. The period of grating is the distance through which grooves are repeated. The reciprocal value of a grating period is called the groove density and displays the number of grooves in 1 mm.

  • Blaze wavelength. The reflectivity of a grating depends on the grooves geometry, because the direction to the center of the diffraction maximum is determined by the mirror reflection of the incident beam from the edge of a groove. In spite of rather flat profile of diffraction maximum a blaze wavelength that corresponds to the maximum efficiency of the grating has been adopted as a feature for convenience of calculation.
    When selecting a grating it is useful to determine a blaze wavelength for a required grating on the spectral range of limited wavelengths WL1 and WL2. The blaze wavelength is determined by the ratio:
    WLBlaze = 2 ∙ WL1 ∙ WL2 / (WL1 + WL2).

  • Reciprocal linear dispersion. The light from a grating in the focal plane of a spectral instrument forms a spectrum. Linear dispersion is used for a spectrum characteristic, which is defined as a reciprocal value of the product of angular dispersion of a grating and focal length of a spectral instrument and shows the spectral range that falls on a single linear distance in a focal plane.

  • The spectral resolution. Limiting resolution of a spectral instrument is equal to the minimum half-width of its instrument function. The instrument function is determined by finite sizes of entrance diaphragm, aberrations and also distortions caused by inaccuracy in manufacturing and adjustment of optical elements of instrument. In addition, instrument function, and thus spectral resolution are dependent on lighting method of entrance slit, used aperture and registration system parameters.

  • Operating wavelength range. Energy efficiency range referred to the wavelength region in which grating reflection coefficient is not less than  0.405 of the maximum. In the first order this range is limited by the wavelengths: ⅔ ∙ WLBlaze and 2 ∙ WLBlaze.
    Operating range usually corresponds to a grating energy efficiency. In some cases, for gratings with a high groove density and large blaze wavelength, the long-wave border of operating spectral range of instrument is limited by a maximal rotation angle of a grating which is defined by design of instrument.

 

Table for selection of diffraction gratings

Model Line density,
mm-1
Blaze wavelength, nm  *Reciprocal linear dispersion, nm/mm Spectral resolution,
nm
Operating wavelengths range, nm Spectral range limited by the grating rotation angle, nm
  75 - 0.11
(wavelength 200 nm,
120 order)
0.0024
(wavelength 200 nm,
120 order)
- -
783600 3600 hol 0.33** 0.0064 185 - 450  500
782422 2400 225 0.52 0.01 185 - 450  750 
782427 2400 270 0.51  0.01 185 - 540  750 
782770 2400 400 0.47 0.009 270 - 750  750 
781827 1800 270 0.7 0.014 185 - 540  1000 
781840 1800 400 0.67 0.013 270 - 800  1000 
781840 1800 500 0.63 0.012 335 - 1000  1000 
781875 1800 750 0.51  0.01 500 - 1800  1000 
781225 1200 250 1.08 0.021 185 - 500  1500 
781228 1200 280 1.07 0.021 190 - 560  1500 
781240 1200 400 1.05 0.021 270 - 800  1500 
781250 1200 500 1.03 0.02 335 - 1000  1500 
781260 1200 600 1 0.02 400 - 1200  1500 
781275 1200 750 0.95 0.019 500 - 1500  1500 
780623 600 230 2.19 0.043 185 - 460  3000 
780630 600 300 2.18 0.043 200 - 600  3000 
780640 600 400 2.17 0.043 270 - 800  3000 
780650 600 500 2.16 0.042 335 - 1000  3000 
780660 600 600 2.14 0.042 400 - 1200  3000 
780675 600 750 2.11 0.042 500 - 1500  3000 
7804008 400 800 3.23 0.06 535 - 1600  4500 
7804012 400 1200 3.16 0.06 800 - 2400 4500 
7804017 400 1700 3.03 0.06 1135 - 3400  4500 
7804020 400 2000 2.94 0.06 1335 - 4000 4500 
7804025 400 2500 2.75 0.06 1670 - 4500  4500 
780330 300 300 4.39 0.09 200 - 600  6000 
780335 300 350 4.39 0.09 235 - 700  6000 
780350 300 500 4.38 0.09 335 - 1000  6000 
780360 300 600 4.37 0.09 400 - 1200  6000 
780370 300 700 4.35 0.09 470 - 1400  6000 
7803010  300 1000 4.31 0.08 670 - 2000  6000 
7803015 300 1500 4.23 0.08 1000 - 3000  6000 
7803020 300 2000 4.11 0.08 1335 - 4000  6000 
7803030 300 3000 3.8 0.08 2000 - 6000  6000 
7803035 300 3500 3.59 0.08 2330 - 7000  6000 
780235 200 350 6.6 0.13 235 - 700  9000 
780240 200 400 6.6 0.13 270 - 800  9000 
780250 200 500 6.6 0.13 335 - 1000  9000 
780270 200 700 6.6 0.13 470 - 1400  9000 
7802015 200 1500 6.5 0.13 1000 - 3000  9000 
7802020 200 2000 6.4 0.13 1335 - 4000  9000 
7802025 200 2500 6.3 0.13 1670 - 5000  9000 
7802030 200 3000 6.2 0.12 2000 - 6000  9000 
781547 150 475 8.8 0.17 320 - 950  12000 
781570 150 700 8.8 0.17 470 - 1400  12000 
7815030 150 3000 8.5 0.17 2000 - 6000  12000 
7815045 150 4500 8.1 0.16 3000 - 9000  12000 
780165 100 650 13.2 0.26  435 - 1300  18000 
780170 100 700 13.2 0.26  470 - 1400  18000 
7801010 100 1000 13.2 0.26  670 - 2000  18000 
7801020 100 2000 13.1 0.26  1335 - 4000  18000 
7801025 100 2500 13 0.26  1670 - 5000  18000 
7801030 100 3000 12.9 0.26  2000 - 6000  18000 
7801042 100 4200 12.7 0.25 2800 - 8400  18000 
7801048 100 4800 12.6 0.25 3230 - 9600  18000 
7801055 100 5500 12.5 0.25 3670 - 11000  18000 
7801062 100 6200 12.3 0.24 4130 - 12400  18000 
7801072 100 7200 12 0.24 4800 - 14400  18000 
7801088 100 8750 11.5 0.23 5830 - 17500  18000 
7801097 100 9700 11.1 0.22 6470 - 18000  18000 
7801103 100 10300 10.9  0.21 6870 - 18000  18000 
7875070 75 7000 16.7 0.33 4670 - 14000  24000 
7875095 75 9500 16 0.32 6330 - 19000  24000 
7850010 50 1000 26.4 0.52 670 - 2000  36000 
7850038 50 3800 26.2 0.52 2530 - 7600  36000 
7850063 50 6300 25.8 0.51 4200 - 12600  36000 
7850070 50 7000 25.7 0.51 4670 - 14000  36000 
7850083 50 8300 25.5 0.5 5530 - 16600  36000 
7850124 50 12400 24.6 0.48 8240 - 24820  36000 
7850169 50 16900 23.2 0.46 11270 - 33800  36000 
7850200 50 20000 22 0.43  13330 - 36000  36000 
7837028 37.5 2800 35.1 0.69 18700 - 5600  48000 
7837056 37.5 5600 34.8 0.69 3735 - 11200  48000 
7837093 37.5 9300 34.3 0.68 6200 - 18600  48000 
7837156 37.5 15600 33 0.65 10400 - 31200  48000 
7824116 24 11600 54 1.1 7730 - 23200  75000 
7824144 24 14400 53.6 1.1 9600 - 28800  75000 
7824173 24 17300 53.1 1.1 11530 - 34600  75000 
7824243 24 24300 51.6 1 16200 - 48600  75000 
7824285 24 28500 50.5 1 19000 - 57000  75000 
7824325 24 32500 49.2 1 21670 - 65000  75000 

 

 * at the blaze wavelength

** at the wavelength 255 nm

For blaze wavelength 2000 nm and shorter the data measured by multielement detectors with entrance slit 15 microns.

For the wavelength more than 2000 nm the data obtained by calculation with the entrance slit 15 microns.