1 / 5

Color correction in WFS

Color correction in WFS. Dichroic beamsplitter only. Dichroic beamsplitter + compensator plate. 0.6-1.0µm through-focus spots at membrane mirror Dichroic – silica, 10mm thick Compensator added to remove chromatic effects – silica, 10mm thick, @90 deg to dichroic

york
Download Presentation

Color correction in WFS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Color correction in WFS Dichroic beamsplitter only Dichroic beamsplitter + compensator plate • 0.6-1.0µm through-focus spots at membrane mirror • Dichroic – silica, 10mm thick • Compensator added to remove chromatic effects – silica, 10mm thick, @90 deg to dichroic • Off-axis angles in WFS re-optimised to account for changed input aberrations • Strehls at membrane mirror are ‘unchanged’

  2. Position of compensator plate in relay

  3. Changes in WFS due to added compensator plate in relay Cam2 Cam 2 • Tilt of camera mirror 2 increases from 9.5 to 14.0 degrees • Position of elements following cam 2 changes slightly • No changes in focal lengths and element sizes

  4. Mapping deformable mirror onto lenslet array • AO modeling (Rigaut) shows that lenslet array (LA) element must be aligned within 3% of its corresponding electrode position on deformable mirror (DM) • At 51.7mm diameter DM this translates into a position tolerance of 0.16mm • Mapping determined using Zemax raytrace macro ‘raygrid.zpl’ coded by Turner (FocusSoft) and provided to us by Jim Oshman

  5. Mapping deformable mirror onto lenslet array • Due to off-axis angles in relay and WFS there are anamorphic magnification effects in imaging DM onto LA • Raytraced magnifications of LA onto DM : x-axis = 1.72, y-axis = 1.84 • Tilting steering mirror to bring off-axis stars into center of DM results in small relative rotation of pupils. Largest rotation is for 4 corner positions (±9.32 arcsec, ±9.32 arcsec). Rotation is 0.44 degrees, equivalent to a linear translation of 0.19mm at edge of DM (compared to tolerance of 0.16mm). Acceptable • For smaller off-axis angles movements are all less than 0.16mm • Since it is easier to change electrode pattern on DM we will keep LA circular and use raytraced x and y translations to position electrodes on DM

More Related