Monochromator-spectrograph MSO520


Monochromator-spectrographs MSO520 series has a unique combination of high-intensity, accuracy and spectral resolution. 
The large angle of the grating rotation allows using Echelle grating, providing extremely high spectral resolution (up to 0.002 nm), as well as extended operating wavelength range for the other gratings.

MSO520 are completely automated spectral devices with a focal length of 520 mm and an F-number of 5.4.

Model MSO5201i and model MSO5204i  have astigmatism-corrected optics what makes these devices applicable in multichannel spectroscopy.

Automated four-grating turret (model MSO5204 and model MSO5204i ) provides fast switching of gratings with high repeatability of the set wavelength.

In model MSO5201 and model MSO5201i a single-position holder is used for easy manual switching of gratings.


Optical system

 Optical scheme

Czerny-Turner (astigmatism–compensated in model MS5201i and model MS5204i)

1 input, 2 outputs

 Wavelength range

185 nm – 60 μm (depends on the type of grating)

 F-number (entrance)

 Focal length (output)

520 mm

 Scanning range (limited
 by grating rotation angle)

0 – 1500 nm (grating 1200 l/mm)

 Main mirrors


 Stray light

1 х 10-6

 Focal plane

28 х 10 mm


 Horizontal magnification 


 Vertical magnification 

1.29 (for MSO5201i and MSO5204i only)

 Vertical spatial resolution (minimal distance between the edges of the two nearby tracks

< 20 μm (for MSO5201i and MSO5204i only)


 Motor type

stepper, with fractional steps




0.22 arc seconds


± 1 step

 Max. speed

10 000 steps/s


 Number of ports 

1 input, 2 outputs

 Output port repeatability (automated mirror)

± 0.03 nm (for grating 1200 l/mm, wavelength 546 nm)

 Switching time (output port)

4 s


 Diffraction grating 1200 l/mm, λ = 546 nm Echelle 75 l/mm, λ = 200 nm, 120 order
 Reciprocal linear dispersion  1.55 nm/mm 0.11 nm/mm
 Spectral resolution:    
  • PMT (slit width 10 µm)

0.028 nm

0.0020 nm

  • digital cameras (12 µm pixel)

0.034 nm

0.0024 nm

 Wavelength repeatability 

± 0.007 nm

± 0.0009 nm

 Wavelength accuracy 

± 0.034 nm

± 0.0044 nm

 Average scanning step

0.0017 nm

 Scanning step at 200 nm

2.25 x 10-4 nm



80 х 70 х 10 mm


About the center of the grating working surface


Automated 4-grating turret (models MSO5204, MSO5204i)

Positioner for 1 manually changeable grating (models MSO5201, MSO5201i)
 Grating positioning repeatability:  
  • wavelength (For grating 1200 l/mm, wavelength 546 nm)

± 0.02 nm

± 0.05 nm

  • vertical image position 

± 50 μm

± 75 μm



on-board CPU



 External interface



 Overall sizes (LхWхH)

635 х 339 х 270 mm


25 kg (may vary, depends on the configuration)

All characteristics were measured for grating 1200 l/mm, slit width 15µm, wavelength 546 nm.
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