I am struggling to align the 1550 input on OFC3. We previously solved the problem of have a stable enough test light to align with, but a new problem has arose where the output of OFC2 1550 light is tilted down at a fairly steep angle, enough that the beam is barely on the first intercavity mirror. The mirror mounts do not have enough range to correct for the translation required for the new input beam. After lunch I will attempt some kind of periscoping mirror solution in order to raise the input beam 1-2 inches between the two intercavity mirrors. I believe we have the parts required but am not sure. May need to order a few things.
This problem could easily be solved by touching the intracavity mirrors, but because they are already very well aligned for the 775 path (confirmed via cavity piezo scan), I think it is best to make a periscoping mirror solution work for 1550 light.
I have added about 1.5 inches in height for the 1550 OFC2 output to 1550 OFC3 input via some periscoping mirrors (see this pic and this pic). Will reattempted to align into the cavity now. Note that this work is very close to the output coupler of the amplifier and I bumped it here. This caused all 1550 light at the filter cavities and SHG input to go to zero. Because I knew where this was bumped I was able to simultaenously relign the power distribution sled with the help of these fiber input couplers alignment should be fully recovered. Only noting here if anyone notices a dramatic difference in power anywhere, this would be the cause. It should be fixed though.