We don't yet have all the hardware we need for the M2 test, but we can do a rough-&-ready trial run to check that it'll work as planned...
Here's the test frame carrying the interferometer, fold mirror & null lens. A laser beam's sent out by the interferometer & bounced off the fold mirror that directs it through the plano-concave null lens, up to M2. There the beam's reflected back through the system & returned to the interferometer where, if all goes well, fringes ought to be produced.
A flat paddle mirror on the back of M2 (the same one used to align M5 way back when, although now with a hole added to its centre) is used to get M2 squared up in tip & tilt & aligned in decentre with the optics onboard the test frame.
After making rough measurements of the axial spacings & adjusting the null lens & interferometer to get the despaces right - success!! The first fringes from M2 :) It's too soon to interpret the interferogram as nothing was aligned to anywhere near the proper tolerances - this was, afterall, just the "let's see if we can do this" week...
Great job guys!
No comments:
Post a Comment