Testing results for the optic labeled “C”
Hello again,
I’m going to break this page into several sections as follows:
- General Synopsis of the test results
- Impression of the optical surface and performance predictions
- Detailed Robo Foucault results and images
- Detailed Interferometry results and images
Section #1 Synopsis
- Optical Diameter = 151mm (6”)
- Radius of Curvature = 1642mm (64.65”)
- Focal Ratio = F/5.44
- 15 zone Robo Foucault Knife edge results: (@550nm)
- Axis 1 Horizontal
i. P-V Wave Front Error = 1/10.7
ii. Surface RMS Error = 8.8nm
iii. Strehl Ratio = 0.961
iv. Slightly under corrected, Best fit conic constant = -0.918
- Axis 2 horizontal
i. P-V Wave Front Error = 1/9.97
ii. Surface RMS Error = 7.3nm
iii. Strehl Ratio = 0.972
iv. Slightly under corrected, best fit conic constant = -0.949
- Reduction of 16 fringe image interferometric data (@550nm)
- P-V Wave Front Error = 1/2.76
- Surface RMS Error = 17.06nm
- Strehl Ratio = 0.859
- Slightly over corrected, best fit conic constant = -1.041
Section #2 Impression of the optical surface
- Sample Images
- A seen in the sample images, the surface is fairly smooth, but appears to have a slight micro-ripple, which appears to be the result of machine polishing.
- Also seen in the sample images is the appearance of a slightly turned down outer zone, however the edge itself does not appear to be turned down, although it doesn’t have the “balanced diffraction edge” effect.
- The limiting factors for this optic are two fold
- The slight turned down outer zone
- The ¼ P-V wave front of Primary astigmatism (@550nm)
- Based on these limiting factor, I’d expect this optic to still perform very well, perhaps in the 40-50 power per inch range.
Section #3 Detailed Robo Foucault results and images
- Below are the screen captures of the 15 zone Robo Foucault results as reduced by FigureXP
- Axis 1 Horizontal
- Axis 2 Horizontal
- The results can also be downloaded as one of three file types:
- A Figure file for use in Figure45 or FigureXP
- A Sixtests file for use in Jim Burrows’ Sixtests reduction program
- A plain text file for entry into any Foucault data reduction program
- In addition t the numerical results, you can also browse or download the generated knife edge images obtained during each test
- Axis 1 Horizontal
ii. Download Images (25Meg zip File)
- Axis 2 horizontal
ii. Download Images (26Meg zip file)
Section #4 Detailed Interferometry Report and Images
- Here is the final Interferometry on this optic, from a total of 15 interferograms over two test orientations:
- The original interferograms are available for either browsing or downloading
- Axis 1 Horizontal Interferograms
ii. Download Axis 1 Images (3.7Meg zip file)
- Axis 2 Horizontal Interferograms
ii. Download Axis 2 images (3.8Meg zip file)
- Axis 2 Horizontal and ROTATED to match axis 1’s orientation!
i. Browse Axis 2 rotated images
ii. Download axis 2 rotated images (3.8Meg zip file)
This completes my analysis of Mirror C. Any questions or comments are welcomed!
James Lerch