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52HiLASE-I-13
Femtosecond laser inscription of fiber Bragg gratings for laser and sensing applications
A. Dostovalov1,2, A. Wolf1'2, E. Evmenova1, M. Skvortsov1,2, S. Abdullina1, K. Bronnikov1,2, S. Yakushin2, A. Kuznetsov1, S. Kablukov1, S. Babin1,2
institute of Automation andElectrometry SB RAS, Fiber optics lab, Novosibirsk, Russian Federation
2Novosibirsk State University, The Department of Physics, Novosibirsk, Russian Federation
The possibility of a local refractive index change in transparent materials by femtosecond laser pulses has opened up new possibilities for creating fiber Bragg gratings (FBGs) for laser and sensing applications. In particular, it expanded the operating temperature (due to the use of sapphire fibers) and strain range (due to inscription without removing the protective coating) in comparison with FBGs inscribed by UV radiation. In case of FBG inscription for fiber lasers, the flexibility of femtosecond laser writing technology made it possible to create new configurations of fiber laser cavities, in particular, to inscribe FBGs in active optical fibers that are non-photosensitive for UV radiation.
The results of FBG inscription by femtosecond laser radiation to create single-frequency DFB fiber lasers generating radiation in spectral ranges of 1.55 p,m (erbium)[1,2] and 2 p,m (thulium, holmium) with a spectral linewidth of the order of 10 kHz will be presented. In addition, the results of FBG writing in multimode fiber for the selection of transverse modes in Raman fiber laser will be presented [3]. In this case, due to the precise positioning of the FBG in the multimode fiber cross section, it is possible to select certain transverse modes efficiently, which in the case of fundamental mode selection results in an improvement in output beam quality (M2 =1.2). In addition, the technology of refractive index modification by fs laser pulses allows selective inscription of FBGs in multicore optical fibers that is an actual task for various applications. One of them is sensing systems, including structural-health monitoring, robotics and minimally invasive surgery, where the 3D shape estimation of manipulator is required for accurate and reliable control of the manipulator movement inside the patient's body. The results of FBG arrays inscription in various types of 7 cores fibers, with straight and twisted side cores, to be presented [4]. 2D and 3D shape reconstructions based on these fiber sensors and sources of reconstruction errors will be discussed.
This work was supported by Russian Science Foundation (Grant 18-72-00139).
References
[1] M. I. Skvortsov, A. A. Wolf, A. V Dostovalov, A. A. Vlasov, V. A. Akulov, and S. A. Babin, "Distributed feedback fiber laser based on a fiber Bragg grating inscribed using the femtosecond point-by-point technique," Laser Phys. Lett. 15, 035103 (2018).
[2] A. Wolf, A. Dostovalov, M. Skvortsov, K. Raspopin, A. Parygin, and S. Babin, "Femtosecond-pulse inscription of fiber Bragg gratings with single or multiple phase-shifts in the structure," Opt. Laser Technol. 101, 202-207 (2018).
[3] E. A. Evmenova, A. G. Kuznetsov, I. N. Nemov, A. A. Wolf, A. V. Dostovalov, S. I. Kablukov, and S. A. Babin, "2Nd-Order Random Lasing in a Multimode Diode-Pumped Graded-Index Fiber," Sci. Rep. 8, 17495 (2018).
[4] A. Wolf, A. Dostovalov, K. Bronnikov, and S. Babin, "Arrays of fiber Bragg gratings selectively inscribed in different cores of 7-core spun optical fiber by IR femtosecond laser pulses," Opt. Express 27, 13978-13990 (2019).
