Single-step alignment of a two-mirror telescope using sigma vectors in nodal aberration theory


Yeşiltepe M., Romer N., Ceylan E., Rolland J. P., Karcı Ö.

Applied Optics, vol.64, no.28, pp.8196-8203, 2025 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 64 Issue: 28
  • Publication Date: 2025
  • Doi Number: 10.1364/ao.566286
  • Journal Name: Applied Optics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Applied Science & Technology Source, Aquatic Science & Fisheries Abstracts (ASFA), Communication Abstracts, Compendex, Computer & Applied Sciences, EMBASE, DIALNET
  • Page Numbers: pp.8196-8203
  • Gazi University Affiliated: No

Abstract

We present a single-step telescope alignment method based on the sigma vectors in nodal aberration theory (NAT) for high-precision telescope systems. Field dependency investigation of aberrations is crucial for precise alignment campaigns of modern, complex telescope systems. Since NAT is a surface-based theory, the contribution of a specific surface to the net aberration field is distinguishable and identifiable. Sigma vectors provide the foundation for a deterministic and precise telescope alignment. They successfully describe and quantify aberration field centers for aberrations in misaligned optical systems. Here, we demonstrate the use of sigma vectors for a deterministic, accurate, and fast telescope alignment on a 490 mm entrance pupil diameter Cassegrain telescope. From an arbitrary state of misalignment, the telescope is aligned to within 4 microns of decenter and 0.001 deg of tilt error by a single-step secondary mirror misalignment correction with a five-axis stage.