An improved illumination system for spatial coherence control

Zhiqiang Liu, Takeshi Gemma, Joseph Rosen, Mitsuo Takeda

Research output: Contribution to journalConference articlepeer-review

5 Scopus citations


A longitude coherence control system needs a source that is temporally coherent and yet spatially incoherent. For this reason, a zone plate-like pattern is imaged onto a rotating ground glass. Generally the ground glass exhibits a strong directivity. It is far from an ideal uniform diffuser that is implicitly assumed in the theory. To solve this problem, we propose a new illumination system. In our system, the beam illuminating the zone plate-like pattern is focused on the test surface. We measured the longitudinal coherence functions in our optical system. The result shows that the longitude coherent function is better controlled in our interferometer.

Original languageEnglish
Article number25
Pages (from-to)220-227
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 1 Dec 2004
EventInterferometry XII: Techniques and Analysis - Denver, CO, United States
Duration: 2 Aug 20043 Aug 2004

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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