Available Photonics Experiments:

P5828 Diffraction of light PDF Download page

  • Huygens' principle
  • Diffraction single and dual slit
  • Diffraction by circular aperture
  • Diffraction by a wire
  • Babinet's principle
  • Diffraction of:
    White Light
    Monochromatic light
  • Examples of investigations and measurements
Diffraction of white light
In this setup the diffraction of white light is demonstrated and measured. As diffraction objects a set of 4 different patterns are used (5, 6, 7, 8), circular holes, single and double slit and finally a fine mesh gauze to demonstrate two dimensional diffraction.
The selected diffraction probe is placed into the holder (14) of the swivel unit. The diffraction pattern is imaged on the screen (2) which is mounted to the swivel arm. By means of the photodetector (1) and the digital multimeter (13) the intensity distribution can be measured.
To obtain sufficient light the collimator (3) is provided for an almost parallel beam of the white LED.
OX-08 Diffraction of monochromatic light
The white light source is substituted by a “green” laser (11) emitting a wavelength of 532 nm. The beam is expanded by means of the beam expander (4) by a factor of 6 resulting in a beam diameter of about 9 mm.
The beam is directed to the selected diffraction probes (5, 6, 7, 8) and the resulting diffraction pattern is imaged onto the screen (2). The angular resolved intensity distribution is measured by using the photodetector (1).
The reading of the light intensity is done by a digital meter (13) which is switched into the µA mode to obtain a linear relation of the light intensity and photo current.
White light source
The white light source (10) consists of a high brightness LED. The spectrum of the lamp is shown in the figure on the left. Beside a peak at 440 nm a broad range from 500 to 700 nm is available.
The light source is connected to the adaptive power supply (9) which allows the variation of the injection current and that way the intensity of the emitted light.
The divergent radiation is collimated by means of a lens (3) having a focal length of 40 mm.
  • P5828 Diffraction of Light consisting of:
12B-05401Photodetector for pivot arm
22B-11341Optical screen with XY scale on block
34B-00501Plano convex lens f=40 mm, ø 22.4 mm, C25 mount
44B-07201Beam expander magnification 6x
54K-CA031Circular apertures
64K-M3001Gauze 300 mesh
74K-S0011Single slit 0.06 mm
84K-S0021Double slit
9ED-00101Adaptive power supply APS-05
10LS-00101LED white C25
11LS-01101DIMO diode laser module, 532 nm
12MC-02501Profile Rail MG-65, 300 mm
13TP-00301Digital multimeter 3 1/2 digits
14XM-02101Triple swivel unit
15XM-10901Mounting plate C25 with carrier 20 mm
16XM-11101Adjustment holder, 4 axes, carrier 20 mm