Compact 1/8 Meter Double Monochromator

• Compact size - Only 5-1/4"x6-1/4"x3-1/4" • Connects to any computer via RS232. • Scans in both directions. Programmable in angstroms, nanometers, microns, wavenumbers, or eV. • Dual double-grating turrets with automatic grating change allows for broad spectral range coverage. • Subtractive dispersion mode minimizes image distortion and pulse spread, with sub-picosecond residual broadening versus nanosecond pulse broadening of regular monochromators. • Additive mode gives increased dispersion and low stray light for Raman and fluorescence studies. • May be configured as a monochromator or a spectrograph. • Monochromator may be factory configured for right angle or straight through beam path.

Focal Length 240 mm
f/# 3.9
Wavelength Precision
and Reproducibility
0.007 nm(with 1200 g/mm grating)
Wavelength Accuracy ±0.30 nm standard(with 1200 g/mm grating)
Scan Speed > 1 - 1200 nm/min(with 1200 g/mm grating)
Stray Light < 0.01% @ 220 nm(NaI)
Slit Width - 10 - 3000 μm
Height - 2 - 20 mm
Reciprocal Resolution 3.2 nm/mm(with 1200 g/mm grating)
Max Resolution 0.06 nm(with 1200 g/mm grating)
Grating One to two gratings(68 X 68 mm, 68 X 84 mm optional)
must be purchased. See Appendix A for options
Power 100-240 V, 50/60 Hz, 60 W
Computer Interface RS232
Warrenty One year
Options DKBS - Bi-lateral slits
DKGPIB - IEEE-488 communication interface(internal)
DK2401 - Hand-held controllers for local control
IR240 - Gold Optics
DKPURGE - Purge port

The Digikröm CM112: Much More than a Monochromator

The CM112 is two single monochromators in series. The exit slit of the first monochromator is the entrance slit of the second. The two monochromators act as a double filter with the rejection of stray light being almost the square of the single monochromator value.

The CM112 may be factory configured as an additive or subtractive dispersion double monochromator. As an additive instrument, the first grating spreads the spectrum over an angular range; the second grating then doubles this dispersion. The result is twice the resolution of a single 1/8 meter monochromator. As a subtractive instrument, the first monochromator selects a bandpass, the second monochromator then removes the temporal and angular aberrations introduced by the angular spectral dispersion in the first monochromator.

The CM112 offers a solution to practical problems in monochromatic imaging. Selecting a monochromatic image with an ordinary monochromator fails because multiple wavelengths in the bandpass create multiple, overlapping images. In the CM112, the second subtractive monochromator recombines these multiple images, creating a clear image. Finally, the CM112 is a unique solution to practical problems in the spectroscopy of pulsed sources. An ordinary monochromator has a spread in the internal optical path lengths that will introduce a 25 to 100 picosecond broadening in light pulses that are passed through the monochromator. In the subtractive dispersion CM112, the second monochromator equalizes the optical path lengths so that broadening is reduced to a minimum.

ㅣ Software ㅣ Manual ㅣ Catalog ㅣ ▶  Download

Series Options and Accessories


Hand-held control module, 2 line x 20 character LCD display.
Allows local operation of CM110/112 monochromators and CMSP110/112 spectrographs.


IEEE-488/GPIB option for parallel interface operation of CM110/112
monochromators and AB300 Series automatic filter wheels.

CMGPIB- 220V (220Vac input)

IEEE-488/GPIB option for parallel interface operation of CM110/112
monochromators and AB300 Series automatic filter wheels.


Attachment to allow CMSP Spectrograph to operate as a monochrometor.


Single filter carrier that mounts directly between CM unit and accessories.


For use with CM110. Infrared (gold) coatings on CM110 mirrors.
Enhances transmission by up to 40% between 600 and 1100 nm.
Not suitable for work below 600 nm.


Same as above, for use with CMSP110.


For use with CM 112. Infrared (gold) coatings on CM112 mirrors.
Enhances transmission by up to 80% between 600 and 1100 nm.


Same as above, for use with CMSP112.


RS232 Cable for AT style computer


RS232 Cable for PS2 style computer


RS232 Cable for MAC style computer

Special Slit Sizes

DKFS010 : Pair, 10µm slits
DKFS020 : Pair, 20µm slits
DKFS025 : Pair, 25µm slits
DKFS050 : Pair, 50µm slits

CM Standard Ruled Gratings   Size = 30 X 30 mm

SP Part # Ruling
Peak(nm) Range(nm)
Peak %T
AG2400-00240-303 2400 240 180-680 70
AG1200-00200-303 1200 200 180-450 65
AG1200-00300-303 1200 300 200-750 72
AG1200-00500-303 1200 500 330-1000 83
AG1200-00600-303 1200 600 400-1500 80
AG1200-00750-303 1200 750 480-1500 85
AG0600-00500-303 600 500 350-1300 80
AG0600-01200-303 600 1200 800-3000 85
AG0300-00500-303 300 500 310-1100 80
AG0300-02500-303 300 2500 1500-6000 88
AG0150-00500-303 150 500 320-980 72
AG0150-04000-303 150 4000 2500-9000 93
AG0075-01700-303 75 1700 1100-2800 85
AG0075-08000-303 75 8000 5000-15000 82
AG0045-01750-303 45 1750 1100-3000 78