TY - GEN
T1 - Simultaneous femtosecond inscription of two wavelength-separated fiber Bragg gratings at the same spot
AU - Halstuch, A.
AU - Ishaaya, A. A.
N1 - Publisher Copyright: © 2024 SPIE.
PY - 2024/1/1
Y1 - 2024/1/1
N2 - 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.
AB - 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.
KW - Femtosecond inscription
KW - Fiber Bragg gratings
KW - Optical fibers
KW - Parallel processing
KW - Phase-mask
UR - http://www.scopus.com/inward/record.url?scp=85198991062&partnerID=8YFLogxK
U2 - https://doi.org/10.1117/12.3017270
DO - https://doi.org/10.1117/12.3017270
M3 - Conference contribution
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Laser + Photonics for Advanced Manufacturing
A2 - Courvoisier, Francois
A2 - Lecler, Sylvain
A2 - Pfleging, Wilhelm
PB - SPIE
T2 - Laser + Photonics for Advanced Manufacturing 2024
Y2 - 8 April 2024 through 11 April 2024
ER -