Available Photonics Experiments:

P5886 Laser beam analysis
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  • Diode laser
  • DPSS laser
  • Gaussian beams
  • Beam expanding
  • Beam shaping
  • Beam intensity distribution
  • Computerised recording
  • Examples of investigations and measurements
Principle of operation
A precise knife edge is moved through the cross-section of the laser beam. As the blade moves across the beam, it is cut from reaching the photodetector. The timely change of the signal is differentiated to obtain the beam profile. When the path to the detector is fully opened the entire intensity is measured and used as calibration value.
To increase the resolution of the measurement the number of knife edges is increased whereby the blades are differently orientated providing more information about the cross section. In this set-up a device with of seven knife edges are used. The collection of the data is performed by a PC with the provided software. For this purpose extra PCI board is built into the PC which controls the beam analyser, collects and stores the data on the hard disk. Based on the recorded data a 2D and 3D graphical presentation of the intensity profile is displayed on the monitor or can be printed out.
OX Beam parameter of a visible (635 nm) laser diode
The laser diode (6) emits a divergent elliptical beam. By means of a spherical focusing lens (9) the beam is made almost parallel and the intensity distribution measured. In addition two cylindrical lenses are provided.
One has a focal length of 20 mm (2) and the other one 80 mm (3). The goal is to achieve an almost round diode laser beam which is controlled by the beam profiler (8). In this setup the objective (9) is used to focus the round beam and the smallest beam waist is measured.
OX Beam parameter of a DPSSL 532 nm
A diode pumped solid state laser (DPSSL) with second harmonic generation (5) emits an almost perfect round laser beam.
Firstly the intensity distribution of the beam without extra optics is measured.
In a next step the diameter of the beam is increased by means of the beam expander (1). The beam is than focused with the objective (9) and the smallest beam waist is measured. This will be done with and without the beam expander to verify the Rayleighs law for the properties of Gaussian beams.
  • P5886 Laser beam analysis consisting of:
14B-07201Beam expander magnification 6x
24B-07301Collimating cylindrical lens f = 20 mm
34B-07401Collimating cylindrical lens f= 80 mm
4ED-00101Adaptive power supply APS-05
5LS-01101DIMO diode laser module, 532 nm
6LS-01301Dimo diode laser module, 630 nm (red)
7MC-00051Profile rail MG-65, 500 mm
8TP-02401Beammaster BM-7S, PC card and software
9XM-00361Module B - Collimating optics on carrier
10XM-10901Mounting plate C25 with carrier 20 mm
11XM-11101Adjustment holder, 4 axes, carrier 20 mm
 Required Options:  
 TP-02001Personal computer, X86