Peak wavelength and bandwidth tunable fiber Bragg grating notch filter induced by femtosecond laser point by point inscription

• Published in: Optics communications 2022-10, Vol.521, p.128583, Article 128583
• Main Authors: Sun, Yang, Yao, Yicun, Niu, Huijuan, Zha, Hao, Zhang, Liqiang, Tian, Zhen, Chen, Nan-Kuang, Ren, Yingying
• Format: Article
• Language: English
• Subjects: Fiber Bragg grating; Multi-parameter sensor; Tunable filter; Wavelength filter
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2022.128583

In this work we present a novel fiber wavelength notch filter induced by femtosecond laser point-by-point technique. The filter consists of a pair of slightly shifted grating inscribed around a fiber taper. Such a structure offers similar properties as that of phase shifted Bragg grating, but with more facile fabrication process. More interestingly, simultaneous modulation of peak position and bandwidth can be easily realized. The proposed fiber notch filter may find applications in the areas of multi-parameter sensing and tunable fiber lasing. •Fiber notch filter with transmission curves similar of phase shifted FBG is achieved with easy fabrication of cascaded FBGs combined of fs laser inscription and fiber tapering technique.•Both the peak wavelength and bandwidth can be tuned separately, which may find applications in the fields tunable fiber wavelength filter and fiber lasers.•Simultaneous measurement of tension and temperature is realized with low cross sensitivity, which is difficult for traditional FBG and phase shifted FBG structures.