Measurement of retardance variations over the apertures of liquid-crystal variable retarders

Claudio N. Ramirez, Neil C. Bruce, Juan M. Lopez-Tellez, Oscar G. Rodriguez-Herrera, Martha Rosete-Aguilar

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review


Variations of the induced retardance in the aperture of liquid-crystal variable retarders LCVR and spatial light modulators LC-SLM are measured. It is found that the induced retardance, in LCVR, shows variations over the aperture which depend on the wavelength of the light used and the voltage applied. Larger retardance variations appear near to the edges of the cell. There are also larger variations in the maximum and minimum unwrapped retardances in the retardance versus voltage curves. These voltage values and the edges positions of the cells should be avoided in applications of these devices. On the other hand, the induced retardance is calculated pixel by pixel in LC-SLM. For the same gray level over the entire LC-SLM screen, there are differences in the induced retardance between pixels located in a central area and pixels located in the edges. For correct calibration of the LC-SLM, the retardance value as a function of gray level was determined, pixel by pixel.

Original languageEnglish
Title of host publicationProceedings of SPIE - Optical Manufacturing and Testing XIII
EditorsDae Wook Kim, Rolf Rascher
Place of PublicationBellingham Washington USA
Number of pages12
ISBN (Electronic)9781510637801
ISBN (Print)9781510637801
Publication statusPublished - 2020
Externally publishedYes
EventConference on Optical Manufacturing and Testing XIII 2020 - Online, United States of America
Duration: 24 Aug 20204 Sept 2020 (Proceedings)

Publication series

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


ConferenceConference on Optical Manufacturing and Testing XIII 2020
Country/TerritoryUnited States of America
Internet address


  • Polarimetry
  • Polarization imaging
  • Polarization optics
  • Retardance variations
  • Spatial light modulator
  • Variable retarder

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