Diploma thesis

kSHG(762.5nm) 14.2703/ µm
kp1(1525nm) 7.01723 / µm
kp2(1525nm) 7.34502/ µm
kΛ=104.17µm 0.0603166 / µm
-0.0313867 / µm
kerr
Table 4.4: Calculated k-vectors of the observed degenerate SHG process
Figure 4.40: Corrected phasematching Figure 4.41: Corrected phasematching 2d
The fit now relies on three data points, instead of one in the two previous section.
This is a great increase in reliability. Still with this one error parameter it is not
possible to move all three degeneracy points in the right places. In addition the kE
parameter is not invariant under the change of waveguides or grating periods. A
fully numerically approach to calculate the effective sellmeier equations may solve
the last discrepancies.
Nevertheless we gained important data. Despite minor quantitative variations
the prognoses are valuable, and as demonstrated in this chapter, have already been
tested successfully.
4.4 PDC experiments
Having evaluated the SHG experiments we decided to use crystal ITI0706-B12 with
a poling period of 104.17 µm. According to our data we should be able to generate
degenerate PDC photon pairs in the range between 1520 to 1560 nm.
The goal was to verify the existence of parametric downconversion in the predicted
frequency regime. To detect the photons we applied the id201 single photon counting
modules, tested in Section 4.1. Great care has to be taken not to confuse PDC with
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