Monocular passive ranging through a PQ:PMMA holographic wavelength division demultiplexer

Julian Gamboa*, Tabassom Hamidfar, Xi Shen, Jason Bonacum, Selim M. Shahriar

*Corresponding author for this work

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


Distance estimation is an important yet challenging part of any tracking system, as being able to quickly locate an object in 3D space allows for the automated targeting of communication, delivery, and interception systems, as well as providing important telemetry about fast moving objects. A monocular passive ranging system is defined as that which only requires one observation point through which it measures some outside signal to estimate range. The approach presented here simultaneously observes the intensity of light emitted by the target at three wavelength bands with ~10nm FWHM, centered at 750, 762, and 780 nm. The light is separated using a PQ:PMMA holographic optical element (HOE) configured as a wavelength division demultiplexer. Light at the two outer bands experiences negligible absorption in the atmosphere, while light at ~762 nm is strongly absorbed by O2. By comparing the intensity of the two unabsorbed bands, we may interpolate the expected intensity of the 762 nm band if there is no O2 in the path. This is then used in conjunction with the 762 nm band measurement to approximate the total O2 transmissivity. Finally, Beer's law and the HITRAN database provide us with the tools to convert a transmissivity into a distance estimation. The use of an HOE is pivotal in the practicality of such a system, as it allows us to measure all three signals simultaneously, thus eliminating the effects of turbulence and reducing overall noise.

Original languageEnglish (US)
Title of host publicationPractical Holography XXXVII
Subtitle of host publicationDisplays, Materials, and Applications
EditorsPierre-Alexandre J. Blanche, Seung-Hyun Lee
ISBN (Electronic)9781510659957
StatePublished - 2023
EventPractical Holography XXXVII: Displays, Materials, and Applications 2023 - San Francisco, United States
Duration: Jan 31 2023Feb 1 2023

Publication series

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


ConferencePractical Holography XXXVII: Displays, Materials, and Applications 2023
Country/TerritoryUnited States
CitySan Francisco


  • Distance Estimation
  • Holography
  • Monocular Passive Ranging
  • Wavelength Division Multiplexing

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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