Cylinder lens alignment in the LTP

Peter Z. Takacs

doi:10.1117/12.621202

15 September 2005 Cylinder lens alignment in the LTP

Peter Z. Takacs

Proceedings Volume 5921, Advances in Metrology for X-Ray and EUV Optics; 592105 (2005) https://doi.org/10.1117/12.621202
Event: Optics and Photonics 2005, 2005, San Diego, California, United States

Abstract

The Long Trace Profiler (LTP) is well-suited for the measurement of the axial figure of cylindrical mirrors that usually have a long radius of curvature in the axial direction but have a short radius of curvature in the sagittal direction. The sagittal curvature causes the probe beam to diverge in the transverse direction without coming to a focus on the detector, resulting in a very weak signal. It is useful to place a cylinder lens into the optical system above the mirror under test to refocus the sagittal divergence and increase the signal level. A positive cylinder lens can be placed at two positions above the surface: the Cat's Eye reflection position and the Wavefront-Matching position. The Cat's Eye position is very tolerant to mirror misalignment, which is not good if absolute axial radius of curvature is to be measured. Lateral positioning and rotational misalignments of the lens and mirror combine to produce unusual profile results. This paper looks at various alignment issues with measurements and by raytrace simulations to determine the best strategy to minimize radius of curvature errors in the measurement of cylindrical aspheres.

Citation Download Citation

Peter Z. Takacs "Cylinder lens alignment in the LTP", Proc. SPIE 5921, Advances in Metrology for X-Ray and EUV Optics, 592105 (15 September 2005); https://doi.org/10.1117/12.621202

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available