[1] [1] TOVAR P,WANG Y,CHEN L,et al.Distributed birefringence sensing at 10-9 accuracy over ultra-long PMF by optical frequency comb and distributed Brillouin amplifier[J].Optics Express,2022,30(18):33156-33169.

[3] [3] ZHOU P,HUANG L,XU J M,et al.High power linearly polarized fiber laser:Generation,manipulation and application[J].Science China Technological Sciences,2017,60(12):1784-1800.

[4] [4] SZCZEPANEK J,KARDA＾ST M,RADZEWICZ C,et al.Nonlinear polarization evolution of ultrashort pulses in polarization maintaining fibers[J].Optics Express,2018,26(10):13590-13604.

[7] [7] AMMA Y,TAKENAGA K,MATSUO S,et al.Fusion splice techniques for multicore fibers[J].Optical Fiber Technology,2017,35:72-79.

[8] [8] KATO Y.Fusion splicing of polarization preserving fibers[J].Applied Optics.1985,24(15):2346-2350.

[11] [11] ABEBE M,VILLARRUEL C A.Reproducible fabrication method for polarization preserving single-mode fiber couplers[J].Journal of Lightwave Technology,1988,6(7):1191-1198.

[13] [13] SHEN L,GAN L,DONG Z R,et al.End-view image processing based angle alignment techniques for specialty optical fibers[J].IEEE Photonics Journal,2017,9(2):1-8.

[14] [14] YAN J,MIAO L,HUANG T,et al.Development of method for polarization alignment of PANDA polarization maintaining fiber[J].Optical Fiber Technology,2019,53:101999.

[15] [15] HORVTH M,NAGYILLS B G,GRSZ T,et al.Wavelength-dependent orientation of the principal axes of photonic crystal fibers measured by windowed Fourier-transform spectral interferometry[J].Optics Express,2020,28(2):2156-2165.