Thursday, September 11, 2008

Optics Fun!

The last little while has been really productive. We got the "relay" designed and I got the simulator basically up and running. Fun stuff. The layout should fit in the lab pretty solidly. The open-house is tomorrow so there will be tons of people running around in here... Chaos!!

The 'phase-screen' that simulates atmospheric turbulence. A piece of not-quite-flat plastic is spun in a parallel (collimated) beam to deflect the rays, just like the parallel rays from a star would in hitting the atmosphere.
A random sketch of the layout from the back of the telescope through the system. The light from the telescope is "relayed" by the two lenses (and a fold) to the deformable mirror. The pupil on the DM matches the one at the front of the telescope. That pupil is then imaged by a lens onto the "membrane mirror". That image is then recollimated so the pupil falls on the lenslet array. So, there are images behind the telescope, in between the relay lenses and on the membrane. Pupils are at the front of the scope, at relay lens 1, on the DM and on the lenslets.
My desk at Maikalani.
Swiss Marcus!
Another crate of optics came (with two more on the way). More toys! Mostly electronics and the lasers.
The membrane mirror. There's a flat mirrored space in the middle of a 'resonant cavity'. This thing oscillates back and forth by several millimeters in an image plane. When the membrane is flat, the image is focused. When the membrane is out of place, the image is slightly defocused. By watching the light focus and defocus, you can measure the atmospheric distortion.... This membrane is the key to a 'curvature based' AO system.

For fun, once I had the simulator set up so I got a nice collimated beam off it, I set my camera in the beam to look at the "PSF". Neat laser spots..... All kinds of diffraction and scattered light.


Blogger brian harrington said...

even if i could understand the optics described in your sketch, i wouldn't be able to because of your terrible penmanship. this is me giving you a check minus on your progress report, and don't try and tell your parents that the parent/teacher conference has been canceled. (that last sentence is weird because we are brothers)

7:47 PM  

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