Yesterday we took a scatter measurement of AlGaAs mirror #143. Instead of one bright scattering center, we saw 3.
The procedure is identical to the procedure used for mirror #137, although the exposure settings and choice of angles are a bit different (see the attached plot). Also, we used 20 mW of incident power instead of 10 mW.
Total integrated scatter from 14° to 82° is 80(8) ppm.
Data, images, and plot-generating code are on the SVN at CTNlab/measurements/2014_07_28.