Nanostructured Multilayer Coatings for Spatial Filtering

Grineviciute L., Babayigit C., Gailevicius D., Peckus M., Turduev M., Tolenis T., ...More

Advanced Optical Materials, vol.9, no.9, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 9 Issue: 9
  • Publication Date: 2021
  • Doi Number: 10.1002/adom.202001730
  • Journal Name: Advanced Optical Materials
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Compendex, INSPEC
  • Keywords: metamaterials, microlasers, photonic crystals, physical vapor deposition, spatial filtering
  • TED University Affiliated: Yes


© 2021 The Authors. Advanced Optical Materials published by Wiley-VCH GmbHSpatial filtering is an important mechanism to improve the spatial quality of laser beams. Typically, a confocal arrangement of lenses with a diaphragm in the focal plane is used for intracavity spatial filtering. Such conventional filtering requires access to the far-field domain. In microlasers, however, conventional filtering is impossible due to the lack of space in microresonators to access the far-field. Therefore, a novel concept for more compact and efficient spatial filtering is necessary. In this study, a conceptually novel mechanism of spatial filtering in the near-field domain is proposed and demonstrated, by a nanostructured multilayer coating—a 2D photonic crystal structure with a periodic index modulation along the longitudinal and transverse directions to the beam propagation. The structure is built on a nanomodulated substrate, to provide the transverse periodicity. The physical vapor deposition is used to provide self-repeating modulation in the longitudinal direction. A 5 µm thick photonic multilayer structure composed of nanostructured multiple layers of alternating high- and low-index materials providing spatial filtering in the near-infrared frequencies with 2° low angle passband is experimentally demonstrated. The proposed photonic structure can be considered as an ideal component for intracavity spatial filtering in microlasers.