High-power ASE (Amplified Spontaneous Emission) light source with multi-section cascade 1064nm wave bands

Abstract

The invention provides a high-power ASE light source with multi-section cascade 1064nm wave bands. The ASE light source comprises a source beam combiner, an optical isolator, an active doubly coated optical fibre, a cladding mode filter, a functional multi-mode optical fibre, a semiconductor pumping laser and the like. The ASE light source is characterized by comprising an n-section cascade structure, wherein the output power of the semiconductor pumping laser is divided into n parts according to certain proportion for respectively pumping N YDF (Ytterbium-doped Fibre) sections, so that pumping power at each level is rationally distributed and sufficiently utilized; the active beam combiner is adopted to simply the process, so that a complicated welding and re-coating process is avoided in the use of the traditional beam combiner; the functional multi-mode optical fibre is adopted to restrain the light reflection on the end surface of the optical fibre and to reduce the light damage effects on the end surface of the optical fibre. Besides, the adopted cladding mode fibre can effectively filter the pump light of a residual cladding, and prevent the residual cladding from breaking the effects. In a word, the high-power ASE light source can effectively restrain the generation of the laser, and can ensure the high-power ASE light output.

Description

technical field [0001] The invention relates to a light source used in the fields of optical fiber communication, optical fiber sensing, and optical fiber detection, in particular to a 1064nm band high-power output ASE optical fiber light source with a multi-segment cascade structure. Background technique [0002] The 1064nm band ASE light source uses rare earth doped ytterbium ions (Yb 3+ ) The broadband light source produced by the principle of fiber amplified spontaneous emission (Amplified Spontaneous Emission, ASE), due to its wide emission spectrum, high output power (the output power of ordinary ASE light source is about tens of mW), high stability and easy integration with optical fiber system Effective coupling and other advantages make it the best choice for an ideal ASE light source. [0003] This type of ASE light source adopts multi-mode cladding pumping technology, and pumps rare earth-doped ytterbium ions (Yb 3+ ) active double-clad fiber (YDF), which can ge...

AI Technical Summary

Problems solved by technology

Since light-emitting diodes (LEDs), superluminescent light-emitting diodes (SLDs) or traditional ASE light sources all have the disadvantage of low output power, which severely limits their wide application in communication systems, especially for high-power output ASE light sources, very Urgent needs

[0004] For a single-stage structure ASE light source, regardless of the forward, backward or bidirectional pumping method, or single-pass or double-pass output, in order to obtain high-power ASE light output, it is necessary to use a strong pump power to pump the YDF accordingly. luck, this creates some insurmountable problems

One is that the YDF gain is very high, relying on simply increasing the pump light power, it is very easy to self-oscillate to form a laser output, and cannot produce ASE light

The second is that after the pumping process is completed, the residual pumping energy will be relatively considerable, and the residual cladding pumping light will cause damage to the optical fiber and optical devices, and cause output power instability

Third, the output end of the high-power ASE light source is generally connected to a 1064nm high-power optical isolator to ensure unidirectional transmission of light and suppress light reflection, but its isolation index and working bandwidth are limited, and the isolation of its center wavelength is only about 30dB. Can it effectively guarantee the ability to suppress light reflection or light feedback at the end face of the fiber? The fourth is the recoating process of the double-clad fiber fusion joint. Generally, the passive double-clad fiber output by the beam combiner and the active double-clad fiber need to be welded, and the joint after stripping requires a special high-cost coating machine. Re-coating protection, the quality of the coating process will directly affect the pump coupling efficiency (poor uniformity, mismatched contact coating effect leads to pump light leakage), at least about 30% of the pump light cannot enter the active dual pack The inner cladding of the fiber also affects the mechanical properties of the fiber

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