Diffraction gratings

Long-focus IMAGING monochromator-spectrographs of MS750 series

Monochromator-spectrographs of MS750 series are long-focus devices with a large flat focal field, combined with a high-intensity, accuracy and spectral resolution. They are completely automated spectral devices with focal length of 750 mm and F-number of 1/8.9, which can be used both as monochromators and as spectrographs.

High-quality optics and wide choice of diffraction gratings provide devices operation in a wide range from 185 nm up to 60 µm (depending on the selected grating).

MS750 series monochromator-spectrographs are based on Cherny-Turner asymmetric scheme, aberrations are minimized and re-reflections from diffraction gratings and mirrors are excluded.

Model MS7501i and model MS7504i have the astigmatism-corrected optics what makes these devices applicable in multi-channel spectroscopy.

Automated four-grating turret (model MS7504 and model MS7504i) provides a fast switching of gratings with high repeatability of the set wavelength and the vertical image.

In MS7501 and MS7501i models a single-position holder is used for easy manual switching of gratings.

A wide choice of changeable gratings gives the best combination of high energetic efficiency and maximal spectral resolution for different spectrum areas.

Monochromator-spectrographs of MS750 series have one input port and two output ports. Installation of an output port is realized with an automated mirror.

Extremely high spectral resolution – better 0.02 nm for grating 1200 grooves/mm and better 1 pm for echelle grating – makes monochromator-spectrographs of MS750 series the ideal devices for high resolution spectroscopy: Raman spectroscopy, laser-induced breakdown spectroscopy, multi-channel spectroscopy (models MS7501i and MS7504i provide extremely high spatial resolution along the slit height).

Benefits of MS series monochromator-spectrographs
Long-focus IMAGING monochromator-spectrograph MS750
Optical scheme of MS7501 and MS7501i with one diffraction gratingOptical scheme of MS7504 and MS7504i with four diffraction gratings

Models of monochromator-spectrographs of MS750 series

Diffraction unitSingle-position holder for manually changeable gratingsSingle-position holder for manually changeable gratingsFour-grating turretFour-grating turret
OpticsStandardAstigmatism-compensated (Imaging)StandardAstigmatism-compensated (Imaging)
  • Model MS7501:
    diffraction unit = single-position holder for manually changeable gratings; optics = standard.
  • Model MS7501i:
    diffraction unit = single-position holder for manually changeable gratings; optics = astigmatism-compensated (Imaging).
  • Model MS7504:
    diffraction unit = four-grating turret ; optics = standard.
  • Model MS7504i:
    diffraction unit = four-grating turret ; optics = astigmatism-compensated (Imaging).

In MS750 monochromator-spectrograph models with the standard optics (modifications MS7501 and MS7504) a flat entrance deflecting mirror is used, and in the astigmatism-compensated devices (modifications MS7501i and MS7504i) a cylindrical mirror is used as an entrance deflecting.

As well as in all Czerny-Turner design spectral devices, in monochromator-spectrographs of MS750 series an axis of the diffraction gratings rotation goes through the center of grating operating surface and coincides with the direction of grooves. This fact provides the stability of the geometry of the beams for formation of a flat and fixed focal field. The image quality in the whole flat focal field is optimized due to the use of an asymmetric scheme and use of a focusing large-size mirror allows one to use the whole focal field width without vignetting. Besides, Cherny-Turner asymmetric scheme provides a low level stray light and light re-entrance from the optical elements and detectors can be avoided.

In MS7504 and MS7504i models the gratings rotation axes are arranged perpendicular to the spectrum scanning axis, providing a high repeatability of wavelength setting at replacing of gratings.

SOL instruments methodical materials: