Bruker IFS 125M, User Manual, Page: 120 / 228

120 IFS 125M User Manual Bruker Optik GmbH
Maintenance 6
6.9 Re-adjusting fiber-coupling head
1 It is assumed that the notch of the fiber receptacle is oriented in the direction
of the polarization plane of the laser light. This may not be the case if the
head had been completely disassembled. In this case, proceed as follows:
• Loosen the clamp screw located between the two spring-loaded bolts (5 in
figure 6.9).
• Turn the inner cylindrical part (marked by a yellow circle) until the notch of
the fiber receptacle shows approximately in the same direction as the
polarization plane.
➣
The polarization plane has to be marked at the outer rim of the mount
(where the clamp screw is located). The best way is to check the mini-
mum with the help of a polarizer and place the mark 90° off this position.
2 Measure the laser light power (P
in
) emerging the receptacle with the help of
a power-meter or stand-alone Si-diode, which is placed directly in front of the
receptacle.
3 Mount the fiber alignment tool, and observe
the diffraction pattern on a paper screen posi-
tioned in a distance of 30 cm.
Table 6.31: Readjusting fiber-coupling head
Figure 6.9: Fiber-coupling head