Keita, Jennie W
Keita and I worked out the distance behind SRM we have to place the AUX launcher to match the beam radius the IFO beam normally has on SRM on its way into the OFI.
This is based on measurements of beam profile Keita made in the optics lab with the aux laser mounted with a collimator on it.
The code used to do this is saved in ligo/home/jennifer.wright/ModeMatching/beam_diverg.py
The graph attached shows the measured points in orange and the fitted points in blue.
Beam waist, w0 is 0.916 mm
Beam waist position in relation to front of launcher , z0 is -1.423 m
Rayliegh range for beam, z_R is 2.477 m
Move launcher 3.986 m away from SRM
Distance between OM1 and SRM is 3.646 m