Compact Circular Multipass Cell



Optical path length 349 cm / 137"
Input-output beam angle 28 degree horizontal
  3 degree vertical
Beam alignment tolerance ± 0.002 degree horizontal
  ± 0.1 degree vertical
Ideal numerical aperture (NA)  0.027
Input hole diameter  4 mm / 0.157"
Fringe level  <2.0 x 10-4 rms @ λ = 4.3 µm
Wavelength range NIR / mid-IR / THz
Gas volume 38 ml
Gas fittings Swagelok 6 mm or 1/4" or whitworth G 1/8"
Absolute pressure range 0-1 bar / 0-750 torr
Leak rate <1 x 10-7 bar x l/s
Mirror surface Gold
O-Ring material NBR
Absorption mask material Teflon, others on request
Window material options BaF2, CaF2, Al2O3, N-BK7, others on request
Dimensions 10 cm diameter, 3.3 cm height (excluding gas connectors)
Mounting 3 x M6


Keeping track of trace gas levels is of critical importance in a wide range of applications. For low abundance trace gases, small absorptions can be observed by increasing the optical path length. This is achieved using multi pass cells.

With the IRcell, we offer a multi pass cell consisting of only a single, circular mirror. The cell body is at the same time the mirror reflecting the optical beam.

The advantage of such a configuration lies in its robustness towards mechanical stress such as vibrations or temperature changes. With this design, we offer an optical path of 3.5 m.


Adam Perry
Your direct line to our expert

Data sheets

Ordering information

  • Product Code
  • IRcell

+49 89 189166 0

Menlo Systems, Inc.
+1 973 300 4490

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