[1] Fan Y Y, Zhou J, He B et al. Preparation and high-power fiber laser experimentation of double-clad fiber grating[J]. Chinese Journal of Lasers, 37, 2395-2399(2010).

[2] Pan Y Z, Zhang J, Hu G J et al. High-power ytterbium-doped fiber laser based on fiber grating[J]. Acta Optica Sinica, 24, 1237-1239(2004).

[3] Voigtländer C, Krämer R G, Liem A et al. 1 kW fiber laser oscillator with fs-written fiber Bragg gratings. [C]∥The European Conference on Lasers and Electro-Optics, June 21-25, 2015, Munich, Germany. Washington: Optical Society of America, CJ_11(2015).

[4] Xiao Q R, Zhang D Y, Wang Z H et al. Review of high power fiber laser pump coupling technology[J]. Chinese Journal of Lasers, 44, 0201008(2017).

[5] Bernard P, Bessard J, Brochu G et al. Active thermography for reliability assessment of high power fiber laser FBG reflectors. [C]∥Fiber Laser Applications, February 16-17, 2011, Istanbul, Turkey. Washington: Optical Society of America, FThE12(2011).

[6] Littler I C M, Grujic T, Eggleton B J. Photothermal effects in fiber Bragg gratings[J]. Applied Optics, 45, 4679-4685(2006). http://europepmc.org/abstract/MED/16799682

[7] Ding M, Chen D J, Fang Z J et al. Photothermal effects in phase shifted FBG with varied light wavelength and intensity[J]. Optics Express, 24, 25370-25379(2016). http://europepmc.org/abstract/med/27828475

[8] Wang D, Pi H Y, Li X et al. Measurement and analysis of loss in fiber Bragg gratings[J]. Chinese Journal of Lasers, 45, 0606005(2018).

[9] Tarnowski K, Urbanczyk W. Origin of Bragg reflection peaks splitting in gratings fabricated using a multiple order phase mask[J]. Optics Express, 21, 21800-21810(2013).

[10] Rollinson C M, Wade S A, Dragomir N M et al. Reflections near 1030 nm from 1540 nm fibre Bragg gratings: evidence of a complex refractive index structure[J]. Optics Communications, 256, 310-318(2005).

[11] Kouskousis B P, Rollinson C M, Kitcher D J et al. Quantitative investigation of the refractive-index modulation within the core of a fiber Bragg grating[J]. Optics Express, 14, 10332-10338(2006).

[12] Rollinson C M, Wade S A, Kouskousis B P et al. Variations of the growth of harmonic reflections in fiber Bragg gratings fabricated using phase masks[J]. Journal of the Optical Society of America A, 29, 1259-1268(2012).

[13] Mahakud R, Prakash O, Nakhe S V et al. Analysis on the saturation of refractive index modulation in fiber Bragg gratings (FBGs) written by partially coherent UV beams[J]. Applied Optics, 51, 1828-1835(2012).

[14] Zhang Y J, Wang M, Wang Z F et al. Fabrication of chirped and tilted fiber Bragg gratings and investigation of Raman filtering effect[J]. Acta Optica Sinica, 37, 0106002(2017).