Light recycling beam steering on a DMD lidar

Guanghao Chen, Brandon Hellman, Joshua Rodriguez, Braden Smith, Adley Gin, Yuzuru Takashima

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

3 Scopus citations


Spatial light modulators (SLMs) that operate in a phase modulation mode enable beam steering with higher diffraction efficiency compared to amplitude modulation mode, thus potentially be used for an efficient beam steering with no moving part. Currently, Twisted Nematic phase SLMs are widely adopted for phase modulation. However, their refresh rate is typically in the range below kilohertz. Recently, a new method for binary and spatial phase modulation using Digital Micromirror Device (DMD) was proposed by a research group in Germany. In the method, complemental self-images of DMD, corresponding to on- A nd off-pixels, are formed by two auxiliary optics while adding a pi phase shift between two images. The optics function as recycling of light in a coherent manner. The method enables over kilohertz refresh rate and higher diffraction efficiency in binary phase modulation mode to conventional amplitude binary modulation. As alternatives to the binary phase modulation, we propose and experimentally evaluated high-speed beam steering by DMD based on light recycling. In our experiment, with binary phase modulation mode, system output efficiency reaches 8%. It can be doubled to 16% with light recycling method. Efficiency is still low compared to the reported value of 27% without light recycling. To further increase beam efficiency, system loss was analysed.

Original languageEnglish (US)
Title of host publicationOptical Data Storage 2018
Subtitle of host publicationIndustrial Optical Devices and Systems
EditorsRyuichi Katayama, Yuzuru Takashima
ISBN (Electronic)9781510620858
StatePublished - 2018
Event5th Optical Data Storage 2018: Industrial Optical Devices and Systems, ODS 2018 - San Diego, United States
Duration: Aug 19 2018 → …

Publication series

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


Conference5th Optical Data Storage 2018: Industrial Optical Devices and Systems, ODS 2018
Country/TerritoryUnited States
CitySan Diego
Period8/19/18 → …

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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