I presented a paper on the W2-AM at SPIE’s Optics + Photonics conference in August 2016. The paper was prepared using a mock-up instrument. The spots were good looking in the paper, but there was some debris on the reticle and in the image. Since then we’ve shipped some units with a red light source and also another with a green light source.
The production instruments have been cleaned up compared to the mock-up used for the paper. This first image is the full frame image from the CC (center-of-curvature) of a silicon nitride tooling ball taken with a Olympus 10x, NA 0.25 PLAN objective. The image is clean.
This next image is a magnified view of the central part of the CC image above.
Finally, silicon nitride tooling balls are nice, but a surface image looks a little different than a CC image. The following picture is of the surface of the same silicon nitride tooling ball used to create the images above. The spots are part of the surface of the ball.
For completeness, here’s a magnified portion of the tooling ball surface image.