RealTime 5Axis Profiling Speeds Beam Measurement

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Real-Time 5-Axis Profiling Speeds Beam
Measurement Adjustment

• Dr. Andrew D MacGregor
• V-P Sales Marketing, DataRay Inc.
• Peter Bura Laser 2000 GmbH

DataRay Inc. Boulder Creek, CA
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The Problem

• How do I measure and adjust
• Beam Profile
• Beam Focus Position
• M2
• Collimation
• Divergence
• Pointing
• in real time?

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Beamwaist M2 formulae
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Multi-plane Scanning Principles

• A rotating puck carries multiple slits.
• The slits are precisely located in planes
  separated in z in the focal region.
• The puck is inside a rotatable head with
  electronic angle readout.
• Typical puck has XY slits in four separate
  planes. Three or five plane versions also
  available.
• Minimum plane spacing is 25 ?m, maximum is 10 mm,
  with a total front-to-back of 25 mm.
• Standard plane spacings are 25, 50, 10, 250
  500 ?m and 5 10 mm

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Case Study 1 Refocused fiber coupled beam

• A fiber output is refocused to form a waist in
  space.
• Waist position is to be measured adjusted in
  x,y z to better than a few microns. For
  multiple assemblies, the time to make a
  measurement is critical.
• A puck with 100 mm spacing was appropriate for
  this application.
• The display shows the beam profile in five planes
  in z, the individual profiles (center plane scale
  is different), the plotted beamwaist curve the
  results.
• Results M2 10.9 Waist diameter 26
  mm Corresponding to Rayleigh Range
  59 mm
• By fitting a beamwaist hyperbola to the measured
  points, it is possible to calculate z0, the
  distance of the beamwaist from the zero plane of
  the profiler.
• Set the instrument against a reference assembly.
  If the zero plane is set in the desired beamwaist
  plane, then it becomes a simple matter to adjust
  the beam waists of all assemblies to the same xyz
  position.
• Measurement of the beamwaist diameter and the M2
  simplifies the comparison of multiple assemblies.

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Real-time XYZ Focus Position Measurement
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Case Study 2Telecom Optical Switching Assemblies
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Real-time Divergence Pointing Measurement

• A singlemode fiber output is collimated forming
  a waist of a few hundred mm .
• The Collimation (Divergence) Pointing of the
  beam are to be measured in realtime. For multiple
  assemblies, the time to make a measurement is
  critical.
• A puck with 5, 5, 5 and 15 mm spacing was
  appropriate for this application.
• The display shows the beam profile in four planes
  in z, the plotted beamwaist curve and the
  results.
• Results M2 1.0 Waist diameter
  131, 129 mm Far field divergence 12.7, 12.7
  mr Pointing 2.3 mr, -9.8 mr
• By fitting the beamwaist hyperbola to the
  measured points, it is possible to calculate all
  necessary parameters.
• Set the instrument against a reference assembly.
  If the pointing of the reference assembly is
  defined as 0, 0 mr., then the relative pointing
  of other assemblies can be measured.

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Real-time Divergence Pointing Measurement
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Conclusions I

• High volume production needs
• Patented multi-plane scanning
• High speed PCs
• has led to a new generation of highly efficient
  beam measurement tools.

DataRay Inc. Boulder Creek, CA
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Conclusions II

• Multiplane beam profiling offers significant
  advantages over single plane processing.
• It enables five-axis beam measurement rather than
  the two-axis measurement of conventional single
  plane profiling.
• It can lead to dramatic time and cost savings in
  beam measurement and adjustment

DataRay Inc. Boulder Creek, CA