40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Wed Feb 6 20:19:52 2013, Manasa, Update, Optics, G&H and LaserOptik mirrors 
    Reply  Thu Feb 7 14:10:25 2013, Manasa, Update, Optics, LaserOptik - AR Reflectivity - Bad data SN6_R.pngSN6_R.png
       Reply  Fri Feb 8 21:14:52 2013, Manasa, Update, Optics, G&H - AR Reflectivity  pr2.png27_1044419003.bmp
          Reply  Fri Feb 8 22:49:31 2013, Koji, Update, Optics, G&H - AR Reflectivity  
             Reply  Fri Feb 8 23:04:40 2013, Manasa, Update, Optics, G&H - AR Reflectivity  
          Reply  Sat Feb 9 19:34:34 2013, rana, Update, Optics, G&H - AR Reflectivity  
          Reply  Mon Feb 11 19:55:47 2013, Manasa, Update, Optics, G&H - AR Reflectivity  
             Reply  Wed Feb 13 09:28:56 2013, Steve, Update, Optics, G&H - HR plots 
Message ID: 8045     Entry time: Fri Feb 8 21:14:52 2013     In reply to: 8023     Reply to this: 8046   8051   8063
Author: Manasa 
Type: Update 
Category: Optics 
Subject: G&H - AR Reflectivity  

 Hours of struggle and still no data 

I tried to measure the AR reflectivity and the loss due to flipping of G&H mirrors

 With almost no wedge angle, separating the AR reflected beam from the HR reflected beam seems to need more tricks.


The separation between the 2 reflected rays is expected 0.8mm. After using a lens along the incident beam, this distance was still not enough to be separable by an iris.

The first trick: I could find a prism and tried to refract the beams at the edge of the prism...but the edges weren't that sharp to separate the beams (Infact I thought an axicon would do the job better..but I think we don't have any of those).

Next from the bag of tricks: I installed a camera to see if the spots can actually be resolved.

The camera image shows the 2 sets of focal spots; bright set to the left corresponding to HR reflected beam and the other from the AR surface. I expect the ghost images to arise from the 15 arcsec wedge of the mirror. I tried to mask one of the sets using a razor blade to see if I can separate them and get some data using a PD. But, it so turns out that even the blade edge is not sharp enough to separate them.

If there are any more intelligent ideas...go ahead and suggest! 



ELOG V3.1.3-