Design of a silicon polarization grating with a sub-wavelength anisotropic structure

Koji Anju, Hiroyuki Tsuda, Hisato Uetsuka

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

1 Citation (Scopus)

Abstract

Polarization gratings, which have the important properties of being highly efficient for first order diffraction and having high polarization sensitivity, can be applied to beam splitters, displays, spectro-polarimeters, and so on. Usually, polarization gratings are fabricated utilizing the periodic anisotropy of liquid crystal molecules. However, high tolerance to light, heat, and humidity is required, in particular, for optical communication applications. Therefore, a polarization grating based on an inorganic material is more suitable than one based on an organic one. We propose a silicon polarization grating with form birefringence induced by an anisotropic surface microstructure with features shorter than the wavelength of light (sub-wavelength anisotropic structure), allowing the birefringence to be controlled through selection of the dimensions of the periodic structure. In this paper, we describe the design of sub-wavelength structures of half wave plates using a thin film of silicon. By optimizing the line width, the line spacing, and the thickness of the film, a transmittance of more than 99% at an incident wavelength of 1550 nm was obtained. A polarization grating based on this half wave plate was designed. The orientation of the half wave plate structure was rotated in a particular direction. Furthermore, we evaluated the wavelength dependence and incident angle dependence of the diffraction efficiency using a finite-difference time-domain method.

Original languageEnglish
Title of host publicationIntegrated Optics: Devices, Materials, and Technologies XX
PublisherSPIE
Volume9750
ISBN (Electronic)9781628419856
DOIs
Publication statusPublished - 2016
EventIntegrated Optics: Devices, Materials, and Technologies XX - San Francisco, United States
Duration: 2016 Feb 152016 Feb 17

Other

OtherIntegrated Optics: Devices, Materials, and Technologies XX
CountryUnited States
CitySan Francisco
Period16/2/1516/2/17

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Keywords

  • beam steering
  • polarization grating
  • sub-wavelength anisotropic structure

ASJC Scopus subject areas

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

Cite this

Anju, K., Tsuda, H., & Uetsuka, H. (2016). Design of a silicon polarization grating with a sub-wavelength anisotropic structure. In Integrated Optics: Devices, Materials, and Technologies XX (Vol. 9750). [97501P] SPIE. https://doi.org/10.1117/12.2211990