Simultaneous femtosecond inscription of two wavelength-separated fiber Bragg gratings at the same spot

A. Halstuch, A. A. Ishaaya

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

A simple method for the simultaneous inscription of two spectrally separated fiber Bragg gratings (FBGs) with a femtosecond laser at the same spatial spot is presented. The inscription setup consists of the following elements, i.e., an amplified near-IR femtosecond laser, two identical Phase-Masks (PM), two cylindrical focusing lenses, a negative defocusing spherical lens and a 50%:50% beam splitter. The inscription beam is divided into two equal beams each containing ~50% of the energy by means of a beam splitter. Each beam is then focused on the same spatial spot of the optical fiber through a 2140 nm period PM and a cylindrical lens. One beam is focused from one side, while the other beam is focused on the same spot, but from the opposite side. This ensures the simultaneous inscription of two FBGs at the same spatial spot. The wavelength separation is achieved by defocusing one of the beams with a negative spherical lens. The transmission and reflection spectrum of the two FBGs are measured. The center Bragg wavelength of the shorter FBG is ~1548.6 nm, and the center Bragg wavelength of the longer FBG is ~1553.9 nm or ~1550.4 nm when using a defocusing lens of −400 mm or −1000 mm, respectively, in the second inscription beam path. The measured transmission dip of all FBGs is greater than −4 dB.

Original languageAmerican English
Title of host publicationLaser + Photonics for Advanced Manufacturing
EditorsFrancois Courvoisier, Sylvain Lecler, Wilhelm Pfleging
PublisherSPIE
ISBN (Electronic)9781510673281
DOIs
StatePublished - 1 Jan 2024
EventLaser + Photonics for Advanced Manufacturing 2024 - Strasbourg, France
Duration: 8 Apr 202411 Apr 2024

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume13005

Conference

ConferenceLaser + Photonics for Advanced Manufacturing 2024
Country/TerritoryFrance
CityStrasbourg
Period8/04/2411/04/24

Keywords

  • Femtosecond inscription
  • Fiber Bragg gratings
  • Optical fibers
  • Parallel processing
  • Phase-mask

All Science Journal Classification (ASJC) codes

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

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