Abstract

We study the modal behavior of plane-by-plane femtosecond laser fabricated tilted fiber Bragg gratings (FBGs). The focus is on the differential strain and temperature sensitivities between the cladding mode resonances of an $n$th grating order and those of the ($n-i$)th orders (with $i=1-n$), which are collocated in the same wavelength range. Whereas the Bragg mode exhibits an axial strain sensitivity of 1.2 pm/μϵ, we experimentally show that the strain sensitivity of ultrahigh-order cladding modes is negative and at $-1.99\mathrm{pm}/\mathrm{\mu ϵ}$ in the same spectral window. Using a finite element mode solver, the modal refractive index value is computed to be well below 1, thus confirming that these modes, in reality, are leaky modes.

© 2018 Optical Society of America

Direct writing of plane-by-plane tilted fiber Bragg gratings using a femtosecond laser

Andreas Ioannou, Antreas Theodosiou, Christophe Caucheteur, and Kyriacos Kalli
Opt. Lett. 42(24) 5198-5201 (2017)

Localized tilted fiber Bragg gratings induced by femtosecond laser line-by-line inscription

Bonan Liu, Kaiming Yang, Changrui Liao, Zhihao Cai, Yifan Liu, Bing Sun, and Yiping Wang
Opt. Lett. 46(9) 2204-2207 (2021)

Measurements of milli-Newton surface tension forces with tilted fiber Bragg gratings

Changyu Shen, Chuan Zhong, Dejun Liu, Xiaokang Lian, Jianyao Zheng, Jingjing Wang, Yuliya Semenova, Gerald Farrell, Jacques Albert, and John F. Donegan
Opt. Lett. 43(2) 255-258 (2018)

Strain-assisted femtosecond inscription of phase-shifted gratings

Aviran Halstuch and Amiel. A. Ishaaya
Opt. Lett. 43(16) 3893-3896 (2018)

Tilted fiber Bragg gratings in multicore optical fibers for optical sensing

David Barrera, Javier Madrigal, and Salvador Sales
Opt. Lett. 42(7) 1460-1463 (2017)