Diploma thesis

kSHG(762.5nm) 14.5506/ µm
kp1(1525nm) 7.15375 / µm
kp2(1525nm) 7.48836 / µm
kΛ=104.17µm 0.0603166 / µm
-0.01335 / µm
kerr
Table 4.3: Calculated k-vectors at the degeneracy point
indicates the phasematching peak we measured. Plot 4.35 shows that we should be
able to detect two additional phasematching points at 1629.18 nm where the m=-1
contour again crosses the +45 ◦ slope and at 1089.72 nm. Here the m=+1 contour
cuts the black line. Both points are indicated with green circles in the corresponding
Figures.
Figure 4.35: Corrected phasematching Figure 4.36: Corrected phasematching 2D
Further investigation
As a first step we simplified the setup. It is no longer necessary to monitor the
SHG spectra. We built up the setup drafted in Figure 4.37. The polarization
filter, as always, served to filter any type-I SHG processes. With two different
powermeters, we monitored the SHG power and the OPA power propagating through
the waveguide. Two frequency filters where applied to discard either the pump or
the SHG, in order to get a clean signal in the respective powermeter. The first
spectrometer before the waveguide was kept to monitor the OPA.
Our results can be seen in Figures 4.38 and 4.39 (all measurement data is presented
in Appendix A.4.3). Three phasematching points could be identified at 1138
nm, 1554 nm and 1627 nm, in the first measurement (Figure 4.39) and in the sec-
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