Available Photonics Experiments:

P5864 Red Second harmonic generation option
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  • Nd:YAG laser, 1.3 µm operation
  • InGaAs photodetector
  • Nd:YAG rod 1.3 µm coating
  • KTP crystal 1.3 / 0.66 µm
  • Second harmonic generation
  • Bright red 660 nm radiation
  • Examples of investigations and measurements
Principle of operation
Within the same setup as XP-07 the Nd:YAG rod is replaced by a rod with a high reflectivity at 1.320 µm. In the same way the cavity mirror M2 is replaced against one with also a high reflectivity at 1.320 µm. The diode pumped Nd:YAG laser is now operating at this wavelength. A KTP crystal which is cut under such an angle with respect to its optical axis so that the phase matching condition for the second harmonic generation to 660 nm is obtained. The result is a bright red laser output.
OX Generation of “red” second harmonic radiation
After aligning the basic set-up in the same way as already shown in XP-06 the Nd:YAG rod and the mirror SHG 100 are exchanged against the components coated for 1.3 µm. The system will operate immediately provided the basic setup was already aligned. The laser operation at 1.3 µm is verified with the IR card behind the RG1000 filter. Now the KTP crystal is inserted inside the cavity and already red laser emission should be visible on a piece of white paper. Turning the KTP inside the adjustment holder results in best phase matching indicated by highest red output power. Four fine pitch adjustment screws are used to align the crystal with respect to the optical axis of the laser cavity for further increase of the red light intensity. The intensity of the second harmonic is measured as function of the fundamental power and the injection current of the pump laser respectively. The evaluation of the data will show the expected quadratic behaviour.
  • P5864 Upgrade kit for SHG 660 nm (XP-0660) consisting of:
14B-03121 Nd:YAG rod 1.3 µm in mirror holder
24B-03141 Mirror SHG 1.3 µm
34F-00401Coloured glass filter KG5, 50 x 50 x 3 mm
4XM-00941Red SHG Crystal in holder