Resonant diffractive structures integrating waveguide-gratings on optical fiber endfaces

Practical implementation of fiber-endface waveguide gratings entails thin-film deposition and diffraction grating fabrication. Homogeneous dielectric thin-film coatings deposited on fiber endfaces are commercially available for applications such as antireflection coatings or spectral filtering. However, fabrication of fiber-endface diffraction gratings has, to the best of our knowledge, not been reported to date. In the work, diffraction gratings with submicron periods have been recorded by interference with an Ar⁺ laser (λ = 365 nm) in photoresist deposited on coated and uncoated endfaces of single-mode and multimode fibers