DataRay offers a full range of ISO 11146-compliant beam profilers, both camera- and scanning slit-based which provide multiple methods of measuring beam divergence.
Beam divergence is defined in the far-field where the beam divergence is constant. For highly diverging beams the divergence measurement can be made directly in the far-field, but for lower divergence or collimated beams the beam waist and far-field may be inaccessible or difficult to define.
When measuring far-field divergence from the:
- Far-Field (greater than four Rayleigh ranges from the waist)
- Use a BeamMap2 (with appropriate plane spacing) in divergence mode to measure divergence directly in real-time for beam divergences between 1 & 350 mrad (0.02° to 20°). Good for CW and very high rep rate pulsed lasers.
- Use a single plane Beam Profiling Camera or Scanning Slit Beam Profiler on a linear stage to measure the beam diameter along several Z-positions to measure divergence directly.
- Use a single plane Beam Profiling Camera or Scanning Slit Beam Profiler to measure beam diameter at a known distance Z from the source to measure divergence directly with the assumption of a point source.
- Near Field and Far Field – Use a BeamMap2 in M² mode with the beam waist at the zero plane. The first three planes are in the near-field and the last is in the far-field. This provides real-time M2 and divergence measurements.
- Near Field, Far Field or Unknown – See Gaussian Beam Divergence Measurement application note and its associated Excel worksheet. Use with an ancillary lens and appropriate Beam Profiling Camera or Scanning Slit Beam Profiler.
Also refer to M² Measurement & Analysis, as this requires the simultaneous measurement of divergence and beam waist diameter.