M² Measurement & Analysis

M², M2, or M-squared, is an important beam quality metric. In short, it defines how a beam compares to a perfect single-mode Gaussian. For a given wavelength, there is a relationship between far-field divergence and beam waist diameter that determines M². For the same far-field divergence, M² values greater than 1 produce a beam waist diameter of M² times the theoretical beam waist diameter of a perfect single-mode Gaussian beam.

DataRay's products offer multiple ways to measure M²: measurements to ISO 11146 may be made using a Beam Profiling Camera or Beam'R2, mounted on an M2DU translation stage.

The software also supports manual M² measurements of any of these instruments mounted on a third-party translation stage, with the user entering the sequential stage positions.

ISO-11146 Compliant M² Measurement

You can use this Excel spreadsheet to model your M² measurement and help ensure you choose the correct lens accessory.

If you are unsure as to which is most suitable for your application, please contact us or filter by your application criteria.

Figure 1: Results of an automated M² measurement using a WinCamD series camera and M2DU-50 stage

 

Real-time relative M² measurements with lower absolute accuracy can be made using a BeamMap2 multiple Z plane scanning slit beam profiler. This can be a great option for real-time M² optimization.

Figure 2: The real-time relative M² curve calculated by a BeamMap2

 

If you are unsure as to which is most suitable for your application, please contact us or filter by your application criteria.