Enter Mon Dec 14 10:32:49 2020

Met with Shruti and finalized the fiber components we want to order.

Alignment procedure has apertures on the E beam path, one before the mixing BS and one after.

1. Use apertures to determine a path for the E beam
2. Place the PD such that signal from the E beam is maximized
3. Align W path to the PD using the penultimate aperture. Because the penultimate aperture and PD position are shared with the E beam, the beams should be copropagating.
4. Add short focal length lens before the PD.
5. adjust alignment to maximize beat note.
   1. maximize DC level for E and W with the other path blocked.
   2. maximize beat
   3. repeat

W path laser is down to 25 uW at the PD. Also noticed that the y-alignment depends sensitively on the position of the final lens. The PD height is not the same as the height of the apertures, or the lens is off-center.

Exit Mon Dec 14 15:36:59 2020