Timeline for Lens metrology: How to measure a double-sided thick aspherical lens optically?
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 7, 2018 at 2:47 | vote | accept | WDC | ||
| May 6, 2018 at 17:13 | answer | added | JB2 | timeline score: 1 | |
| May 1, 2018 at 1:10 | comment | added | WDC | @S.McGrew A good proposal. You are right. I would imagine theoretically it works but the inaccuracy might amount up. It also depends on the thickness. If references it would be better. But the info now is helpful already. | |
| May 1, 2018 at 0:57 | comment | added | S. McGrew | Don't know if there is a straightforward way to measure the curvature of both surfaces by sending a beam all the way through the lens. Possibly it could be done by using several different incident beams (e.g., collimated, diverging, and converging by known amounts), measuring the resulting wavefront for each, and solving the parallel equations made by plugging in the wavefront values to a thick-lens equation. It could be a messy calculation. | |
| May 1, 2018 at 0:47 | comment | added | WDC | @S.McGrew Thanks for the hint. And it seems to be the way it mentioned in many places. I just wonder how would lens metrology guys think about this issue. Is it unavoidable for single surface measurements? | |
| May 1, 2018 at 0:42 | comment | added | S. McGrew | There are probably several different ways to do that, but I would do it by measuring the wavefront of a collimated beam reflected off the front surface, then measure the wavefront of a collimated beam reflected off the back surface. One surface at a time makes it MUCH simpler. | |
| May 1, 2018 at 0:39 | comment | added | WDC | @S.McGrew I would like to measure the actual shape of each side of the lens. | |
| May 1, 2018 at 0:39 | comment | added | S. McGrew | What do you want to measure? Do you want to know the curvature of each surface? | |
| May 1, 2018 at 0:32 | comment | added | WDC | @probably_someone Unfortunately not. The lens assumes to be a freeform, an asymmetric one. And could you hint more on the "normal approach"? | |
| May 1, 2018 at 0:29 | comment | added | probably_someone | Is the lens assumed to be mirror-symmetric? That could allow the normal approach to work. | |
| May 1, 2018 at 0:24 | history | asked | WDC | CC BY-SA 3.0 |