Laser interferometer

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Laser interferometer

• Su-Jin Kim, GNU
• Xiaoyu Ding

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Laser Interferometer
Xiaoyu Ding

• Whats laser interferometer?
• The principle of standard interferometer
• Types of interferometers
• Applications

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Whats a Laser Interferometer
Xiaoyu Ding

• Laser Interferometer
• the instrument used for high precision
  measurements (distance, angles. etc.)
• it uses interferometry as the basis for
  measurement.
• it uses the very small, stable and accurately
  defined wavelength of laser as a unit of measure.

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Physics Review
Xiaoyu Ding

• Diffraction

Diffraction is a sure sign that whatever is
passing through the hole is a wave.
Diffraction of Water Waves
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Physics Review
Xiaoyu Ding

• Diffraction of Light

Light, just like a water wave, does spread out
behind a hole is the hole is sufficiently
small. Light is a electromagnetic wave.
Diffraction of light Wave
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Physics Review
Xiaoyu Ding

• A Double-Slit Interference Experiment

Color pattern
Visible light
Interference of Light
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Principle of Michelson Interferometer
Xiaoyu Ding

• Albert Michelson (18521931)
• the first American scientist to receive a Nobel
  prize, invented the optical interferometer.
• The Michelson interferometer has been widely used
  for over a century to make precise measurements
  of wavelengths and distances.

Albert Michelson
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Principle of Michelson Interferometer
Xiaoyu Ding

• Michelson Interferometer

1. Separation
2. Recombination
3. Interference

A Michelson Interferometer for use on an optical
table
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Principle of Michelson Interferometer
Xiaoyu Ding

• Analyzing Michelson Interferometer
• The central spot in the fringe pattern alternates
  between bright and dark when Mirror M2 moves.

If we can know the spacing distance of M2 between
two sequent central bright spots and the number
of central bright spots appeared, then we can
calculate how long M2 moved.
?/4 -gt bright to dark
Photograph of the interference fringes produced
by a Michelson interferometer.
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He Ne

• 632.8 nm wave length is used.

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Applications
Xiaoyu Ding

• Measurement of Distance
• 1) frequency stabilized He-Ne laser tube
• 2) combination of beam-splitter and
  retroreflector
• 3) a moving retroreflector
• 4) detection electronics

Aerotechs LZR3000 Series Laser Interferometer
System
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Applications
Xiaoyu Ding

• Other Applications
• Measure angles, flatness, straightness, velocity
  and vibrations, etc.

Rearrangements of the light paths
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Resolution
Xiaoyu Ding

• XL-80 Laser Measurement System

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References
Xiaoyu Ding

• http//www.aerotech.com/products/engref/intexe.htm
  l
• http//www.renishaw.com/en/interferometry-explaine
  d--7854
• http//en.wikipedia.org/wiki/Michelson_interferome
  ter
• http//en.wikipedia.org/wiki/Interferometry
• PHYSICS FOR SCIENTISTS AND ENGINEERS, Randall D.
  Knight, 2003.

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Laser interferometer

• Su-Jin Kim
• Gyeongsang National University

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Linear Distance Measurement

• The positioning accuracy is measured by comparing
  the position value displayed by machine with the
  actual position.

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Rectangularity Measurement

• Measurement of the rectangularity between the
  x-axis and z-axis.

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Straightness Measurements

• Straightness and parallelism measurements with
  moving board up to 20 mm.

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Reference

• http//www.youtube.com/watch?vVyePASErr5Q Theory

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Renishaw

• http//www.youtube.com/watch?v41Auhp1RTP0