Abstract

In this paper, dual-wavelength laser emission of an erbium-doped fiber laser (EDFL) with a tunable distinct wavelength selection of the simultaneously produced laser lines was achieved by applying a parallel comb filter configuration based on the optical Vernier effect. The intracavity inserted proposed comb filter consists of two parallel branches to generate the Vernier effect. Each branch is an in-line Mach–Zehnder interferometer (MZI) filter, which is composed of a polarization-maintaining fiber fusion spliced between single-mode fibers with sphere shapes at both ends. The tunability of the selected laser wavelength was realized by submerging the proposed filter in different sodium chloride/water mixtures. The proposed comb filter-based Vernier effect was used to independently achieve the selection of the dual-wavelength EDFL lines and for refractive index (RI) sensing applications. The in-line ${{\rm MZI}_1}$ and ${{\rm MZI}_2}$ structures show a wavelength shift sensitivity to RI variations of $-88$ and 79 nm/RIU, respectively. Our proposed MZI structure presents a reliable, straightforward, and low-cost spectral comb filter for separate tunable dual-wavelength laser generation in the c-band region. Furthermore, the proposed filter structure-based Vernier effect presents a new perspective and method in the RI sensing application.

© 2023 Optica Publishing Group

Vernier effect based on hybrid fiber interferometers: a new tool for wavelength switchability and adjustable free spectral range fiber lasing

Hussein Alaa Al-Rubaiyee, Sarah Kadhim Al-Hayali, and Abdul Hadi Al-Janabi
Opt. Continuum 2(5) 1203-1215 (2023)

Combined-Vernier effect based on hybrid fiber interferometers for ultrasensitive temperature and refractive index sensing

Zejun Jiang, Fugen Wu, Jun Yang, Kunhua Wen, Pengbai Xu, Zhangjun Yu, Jiangquan Sun, Yuncai Wang, and Yuwen Qin
Opt. Express 30(6) 9578-9589 (2022)

Mach–Zehnder interferometer comb filter for multi-wavelength mode-locked generation from erbium-doped fiber laser

Fay F. Ridha, Abdulhadi Al-Janabi, and Sarah Kadhim Al-Hayali
Appl. Opt. 61(15) 4387-4396 (2022)

Optical Vernier sensor based on a cascaded tapered thin-core microfiber for highly sensitive refractive index sensing

Huiji Chen, Binbin Luo, Decao Wu, Xiangwen Yang, Shenghui Shi, Xue Zou, Yujie Li, Shanghai Jiang, and Mingfu Zhao
Appl. Opt. 61(36) 10727-10734 (2022)

High sensitivity of taper-based Mach–Zehnder interferometer embedded in a thinned optical fiber for refractive index sensing

J. Yang, L. Jiang, S. Wang, B. Li, M. Wang, H. Xiao, Y. Lu, and H. Tsai
Appl. Opt. 50(28) 5503-5507 (2011)