Device for monitoring influence of optical fiber residual stress on pulse laser output

Abstract

The invention relates to a device for monitoring the influence of optical fiber residual stress on pulse laser output, which comprises a pulse laser light source 1, an isolator 2, an optical fiber three-dimensional measuring device 3, a residual stress display 4 and an autocorrelator 6, and t symmetric large-mode-field gain optical fiber 5 to be measured is placed in the optical fiber three-dimensional measuring device 3. The high-precision and high-sensitivity optical fiber residual stress measuring device 3 can measure low-magnitude optical fiber residual stress change; the residual stress display 4 and the autocorrelator 6 respectively display residual stress distribution and pulse waveform change of the cross section of the optical fiber; according to the device, the influence of the residual stress of the optical fiber on laser pulse transmission can be researched visually, more meticulously and deeply in real time; the research means and the research method in the aspect are optimized and improved, and a certain guiding effect is provided for design, manufacturing and optimization of the large-mode-field gain optical fiber and application of the large-mode-field gain opticalfiber in a high-power optical fiber laser and an amplifier.

Description

technical field [0001] The invention relates to a device for monitoring the influence of optical fiber residual stress on pulsed laser output, which belongs to the field of high-quality optical fiber laser. Background technique [0002] The fiber laser was invented in 1963, and the first batch of commercial fiber lasers appeared on the market in the late 1980s. It has experienced more than 20 years of development. Fiber lasers are regarded as amplifiers for ultra-high-speed optical communications. Fiber laser technology presents broad application prospects and huge technological advantages in high-speed and large-capacity wavelength division multiplexing optical fiber communication systems, high-precision optical fiber sensing technology and high-power lasers. Fiber lasers have many unique advantages, such as: low laser threshold, high gain, good heat dissipation, multiple tunable parameters, wide absorption and radiation, compatibility with other fiber optic devices, and s...

AI Technical Summary

Problems solved by technology

However, the large mode field gain fiber is very sensitive to some unintentional residual stress and refractive index disturbance during its production and use, and the inherent residual stress of the fiber during its production process will change as the temperature of the fiber increases. The arc welding process will also lead to changes in residual stress. The change in refractive index caused by these residual stress changes will affect the optical characteristics of the large mode field gain fiber, thereby affecting the output power and beam quality of the laser and amplification system, and even lead to system not working properly

[0004] In recent years, some papers have studied the influence of fusion splice loss on the power distribution of high-power ytterbium-doped fiber laser systems [S.Yin, P.Yart, M.Gong, "Influence of fusion splice on high power ytterbium-doped fiber laser with master oscillator multi-stage power amplifiers structure”, Opt.Lasers Eng.49(8):1054-1059(2011)], there is also a paper that studies the impact of butt offset and tilt on the output beam quality of Ytterbium-doped fiber laser [P. Yan, J.P.Hao, Q.R.Xiao, Y.P.Wang, M.L.Gong, "The influence of fusion splicing on the beam quality of aytterbium-doped fiber laser", Laser Phys.23(4):045109(2013)], however, these papers However, there is no research on the influence of the fiber itself on the performance of the laser due to thermal stress changes and fusion splicing operations.

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