[1] Wang W, Huang L, Leng J, et al. 2 kW CW near single mode all-fiber Ytterbium-doped fiber laser [J]. Optik, 2015, 126: 1712-1715.
[2] Zhang X, Liu Y, He Y, et al. Characteristics of eye-safe high repetition frequency narrow pulse width single mode all fiber laser[J]. Infrared and Laser Engineering, 2015, 44(4): 1105-1109. (in Chinese)
[3] Zhang H, Cao Y, Shi W, et al. Experimental investigation on spectral linewidth and relative intensity noise of high-power single-frequency polarization-maintained Thulium-doped fiber amplifier[J]. IEEE Photonics Journal, 2016, 8(3): 1-9.
[4] Shi W, Fang Q, Zhu X, et al. Fiber lasers and their applications [J]. Applied Optics, 2014, 53(28): 6554-6568.
[5] Tao M, Huang Q, Yu T, et al. LD clad-pumped high efficient Tm-doped fiber lasers with different laser cavities [J]. Infrared and Laser Engineering, 2013, 42(8): 2008-2011.(in Chinese)
[6] Liu A, Ueda K. The absorption characteristics of circular, offset, and rectangular double-clad fibers[J]. Optics Communication, 1996, 132(5): 511-518.
[7] Barmenkov Yu O, Kir′yanov A V, Andrés M V. Resonant and thermal changes of refractive index in a heavily doped erbium fiber pumped at wavelength 980 nm[J]. Applied Physics Letters, 2004, 85(13): 2466-2468.
[8] Lu D, Ge T, Wu J, et al. Thermal stress induced birefringence in double cladding fiber with non-circular inner cladding [J]. Journal of Modern Optics, 2009, 56(5): 638-645.
[9] Zenteno L. High-power double-clad fiber lasers [J]. Journal of Lightwave Technology, 1993, 11(9): 1435-1446.
[10] Fan Y, He B, Zhou J, et al. Thermal effects in kilowatt all-fiber MOPA [J]. Optics Express, 2011, 19(16): 15162-15172.
[11] Xue D. Three-dimensional simulation of the temperature field in high-power double-clad fiber laser [J]. Optik, 2011, 122(10): 932-935.
[12] Rosa L, Coscelli E, Poli F, et al. Thermal modeling of gain completion in Yb-doped large-mode-area photonic-crystal fiber amplifier[J]. Optics Express, 2015, 23(14): 18638-18644.
[13] Mohamme Z, Saghafifar H, Soltanolkotabi M. An approximate analytical model for temperature and power distribution in high-power Yb-doped double-clad fiber lasers [J]. Laser Physics, 2014, 24(11): 115107.
[14] Fang Q, Shi W, Kieu K, et al. High power and high energy monolithic single frequency 2 μm nanosecond pulsed fiber laser by using large core Tm-doped germanate fibers: experiment and modeling [J]. Optics Express, 2012, 20(15): 16410-16420.
[15] Marcuse D. Gaussian approximation of the fundamental modes of graded-index fibers [J]. Journal of the Optical Society of America, 1978, 68(1): 103-109.