Bench Alignment: Perturbations of Optics

Picking up where Mark left off on March 4th.

The following image compares a 'surface plot' of the best focus image (where the ring of the first minimum is about five pixels or 27μm in diameter) with a Zemax Huygens PSF plot (where the same ring is about 10μm in diameter.)


Now we try perturbing various optics to observe the effects of those perturbations on the image of the laser beam at the focus following the KBR lens.

First we move the fiber tip in three translations: up, down motions are transverse to the beam - longitudinal motion is along the beam. No change was made in the size or location of the iris that creates the ~f/35 beam coming out of the fiber, nor was any change made to the angle of the beam (so these translations of the fiber tip do not exactly mimic different field points.)

Source (transverse and longitudinal) motions are roughly 1mm increments at the source.
Motion for Image #3 was down, #5 up.
Motion for Image #7 was horizontal toward outside edge of table.




Here is a Zemax spot diagram of these field points:



Next we move the ellipsoidal foreoptic mirror.


Ellipse motions were in roughly 1mm increments (see sketch of ellipse motions.)
Motions for Images #15, 16, 18 & 19 were in the plane of incidence - 15 & 16 in +X direction, 18 & 19 in -X direction.
Motions for Images #21, 22, 24 & 25 were normal to plane of incidence - 21 & 22 in +Y direction, 24 & 25 in -Y direction.