Alignment of Multi-Order Diffractive Engineered (MODE) lens segments using the Kinematically-Engaged Yoke System

Marcos A. Esparza, Heejoo Choi, Dae Wook Kim

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations


With the continued development of multi-order diffractive engineered (MODE) lenses that consist of both multi-order diffractive surfaces and a diffractive Fresnel lens surface, it is becoming more realistic that these components may be used as an ultralight large aperture primary for space telescopes. As conceptual designs for these large primaries push the size limits of optics manufactured by compression molding, it becomes necessary to make a segmented MODE lens primary rather than a monolithic one. We use the Kinematically-Engaged Yoke System (KEYS) to align the segments of a 0.24-m, PMMA, monochromatic, MODE-like lens (having no diffractive Fresnel lens features). The KEYS alignment system consists of modified ultra-fine alignment screws with ball bearings on the end that kinematically engage with the step-like features of the MODE lens surface (similar to a Fresnel lens) to constrain the segments in 5 degrees of freedom, leaving rotation about the optical axis unconstrained. The alignment of the segments is verified using multiple methods including a scanning white light interferometer and deflectometry. Such an alignment system has the capability of fixing the segments together in order to bond them with adhesive while aligned. These tests offer a proof of concept for a system that can be used for an eventual 0.24- m, compression molded, glass, segmented MODE lens.

Original languageEnglish (US)
Title of host publicationOptical Manufacturing and Testing XIII
EditorsDae Wook Kim, Rolf Rascher
ISBN (Electronic)9781510637801
StatePublished - 2020
EventOptical Manufacturing and Testing XIII 2020 - Virtual, Online, United States
Duration: Aug 24 2020Sep 4 2020

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceOptical Manufacturing and Testing XIII 2020
Country/TerritoryUnited States
CityVirtual, Online


  • Alignment
  • Flexures
  • Kinematic constraint
  • MODE lens
  • Metrology
  • Multi-segmented optics
  • Optomechanics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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