Available Photonics Experiments:

P5829 Interference of light PDF Download page

  • Coherence
  • Interference
  • Fresnel's mirror
  • Fresnel's zone plate
  • Newton's rings
  • Fabry-Perot's optical cavity
  • Examples of investigations and measurements
Newton’s rings, interference of thin plates
To demonstrate the famous Newton’s rings a combination of glass plate and plano-convex lens is used. Typically the lens has a fairly long focal length of about 2 to 4 m. If one uses a coherent light source the radius of curvature of the lens can be smaller resulting in a shorter focal length which is more practically. In this assembly a lens with 100 mm focal length is applied providing excellent Newton's ring when illuminated with the provided “green” laser (11).
The beam of the laser is expanded by a factor of 6 with the beam expander (6) which is mounted into a mounting plate for C25 mounts. The resulting image pattern is imaged by means of the biconcave lens (2) to the white screen (13).
Fresnel mirror (15)
Two mirrors are arranged in such a way that they can simultaneously illuminated by an expanded laser beam. On of the mirror is slightly tilted with respect to the other providing the required phase shift to observe the interference fringes. Both mirrors can mounted onto adjustment holders allowing the azimuthal and elevational alignment.
Fresnel's zone plate (5)
A fresnel plate designed for 532 nm, 99 fringes and a focal length of 100 mm is mounted into a “click 25” holder fitting into the mounting plate XM-1090. The fresnel plate is made from a computer graph which has been exposed to a black and white film.
Fabry Perot cavity (6)
Two glass plates are mounted into a click 25 optics holder with a spacing of 3 mm. Each plate is coated for 50% transmission on one side. These sides are facing each other forming a coplanar resonator.
The click 25 optics holder is placed into the adjustment holder (XM-1130) which can be tilted in two angles by means of two precision fine pitch screws. To mount the click holder a 2 mm hexagon key is needed.
The adjustment holder is attached to a 20 mm carrier which will be placed onto the provided optical rails.
  • P5829 Interference of light consisting of:
12B-11341Optical screen with XY scale on block
24B-00401Plano-convex lens f=40 mm, C25 mount
34B-01001Biconcave lens f=-20 mm, ø 10 mm, C25 mount
44B-04701Half wedge plate, C25 mount
54B-04801Half lens f=100 mm, C25 mount
64B-04901Fresnel zone plate, C25 mount
74B-05101Fabry Perot insert, C25 mount
84B-07201Beam expander magnification 6x
94B-09101Newton's rings optics
10ED-00101Adaptive power supply APS-05
11LS-00101LED white C25
12LS-01101DIMO diode laser module, 532 nm
13MC-01001Screen holder on carrier 20
14MC-02601Optical rail MG 65, 500 mm
15XM-07601Fresnel mirror assembly
16XM-10904Mounting plate C25 with carrier 20 mm
17XM-11101Adjustment holder, 4 axes, carrier 20 mm
18XM-11301Adjustment holder 40 mm on carrier 20 mm