Available Photonics Experiments:

P5837 LED and diode laser
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  • Principle of semiconductor
  • Electroluminescence
  • LED and laser diode
  • Emission properties
  • Spatial distribution
  • Polarisation properties
  • Spectral properties
  • Examples of investigations and measurements
OX General set-up
For a comprehensive study of the properties of LED and laser diodes the setup comes with four different light sources. One diode laser (12) having a wavelength of 630 nm and three high brightness LED emitting white (9), red (10) and blue (11) radiation. The respective light source is plugged into the four axes adjustment holder (17) and connected to the adaptive power supply (8). The internal microprocessor recognises the connected type of light source and sets the electrical parameters accordingly. One lens (4) is used for the beam collimation and lenses (4) and (5) are cylindrical lenses for transforming the elliptical beam of the laser diode (12) into an almost circular one.
OX Spatial and polarisation properties of LED and laser diode
The to be characterised light source is plugged into the holder (17) besides the XY and angular tilting adjustment screws the light source can be rotated around its axis. The rotation is read by means of the attached scale. The entire holder is moved towards the swivel unit (15). A photodetector (2) is attached to the swivel arm and measures the intensity of the emitted light. The photocurrent is displayed by the provided digital meter which is switched to the µA mode. By rotating the swivel arm the angle resolved intensity distribution is measured. Additional rotation of the light source in its holder allows the recording of the three dimensional intensity distribution. By using the polarisation analyser (1) attached to the swivel arm the polarisation of the respective light source is measured with respect to the injection current.
OX Spectral properties of LED and laser diode
The grating (7) is placed into the fixed part of the swivel unit (15) and serves in conjunction with the swivel arm and photodetector as spectrometer. For each of the provided light sources the spectrum is recorded. Especially for the LED an influence of the maximum emission wavelength will be observed for different values of the injection current.
  • P5837 LED and Laser Diode consisting of:
12B-03601Polarisation analyzer 40 mm
22B-05401Photodetector for pivot arm
32B-11341Optical screen with XY scale on block
44B-00401Plano-convex lens f=40 mm, C25 mount
54B-01101Cylindrical lens f=25 mm, C25 mount
64B-01201Cylindrical lens f=80 mm, C25 mount
74K-T6001T - grating 600 l/mm
8ED-00101Adaptive power supply APS-05
9LS-00101LED white in C25 housing
10LS-00201LED red in C25 housing
11LS-00501LED blue in C25 housing
12LS-01301Dimo diode laser module, 630 nm (red)
13MC-02501Profile Rail MG-65, 300 mm
14TP-00301Digital multimeter 3 1/2 digits
15XM-02101Triple swivel unit
16XM-10903Mounting plate C25 with carrier 20 mm
17XM-11141Adjustment holder, 4 axes, rotary insert , C20