Available Photonics Experiments:

P5881-3 Michelson’s laser interferometer III PDF Download page

  • CNC translation stage
  • Definition of length
  • Two mode HeNe-laser
  • Two beam interference
  • Optical homodyne detection
  • Fringe detection, counting
  • Interpolation of interference
  • Calibration of CNC translation stage
Principle of operation
The measuring triple reflector T2 is mounted on top of the movable slide of the translation stage. A stepper motor controlled by a computer drives the sled. The interferometer is counting the fringes which can be converted into the travelled distance. The up and down counter is connected to the computer and the respective data are stored and a plot is generated
  • Examples of investigations and measurements
Set-up a technical interferometer
The setup is done in the same way as the laser interferometer II. Instead of the manual translation stage a stepper motor driven translation stage (12) is used to obtain computer controlled displacements of the measuring triple reflector which is attached to the stage. The stepper motor is connected to its control box (4). The provided with a wired remote control is used for the initial alignment. For the later measurements the control box is connected via its USB box to the computer. In the same way the up and down counter (3) is connected to the computer.
Plotting the translation accuracy
By means of the provided software (17) the stepper motor is driven in such a way that a defined cycle of forward and backward motions are performed and the respective data of the up and down counter recorded.
Based on the set values of the positions and the measured position of the interferometer a deviation plot is created allowing the classification of the accuracy of the motorised translation stage. This way of calibration is the same as performed at CNC machines in industrial applications. Based on its natural fixed wavelength the HeNe laser provides an accuracy of 10-6 or in other words 1 m will be measured with an accuracy of 1 µm by using this set-up. Therefor the HeNe laser is suitable as secondary standard for the meter in a simple way.
  • Technical laser interferometer III (P5881-3) consisting of:
13L-03801BNC connection leads, set of 6
24B-02401Optic cleaning set
3ED-01101Fringe up and down counter FC-01 with quad input
4ED-03001Stepper motor controller, 1 Axis, USB
5LS-01501HeNe Pilot laser Ø30 mm
6MC-02502Profile Rail MG-65, 300 mm
7MC-02601Profile Rail MG 65, 500 mm
8MC-02702Laser adjustment holder, soft ring 30 mm, carrier 20 mm
9PM-00801Triple reflector in click 30 mm
10XM-01501Angle joint mount OCM 650 cross-piece with adjustable prism stage, theta, phi
11XM-04401Beam displacer
12XM-04501Motorised translation unit with triple reflector, travel 50 mm
13XM-04601Fringe detection unit with 4 quadrant photodiodes
14XM-10901Mounting Plate, including carrier 20 mm, C 25
17XS-01031XP-10 Control and evaluation software
 TP-01001Oscilloscope 100 MHz digital, two channel