Gain fibre photon darkening test macro
Technical field
The invention belongs to the optic fibre manufacturing technology field, relate to a kind of gain fibre photon darkening test macro that is used to test the photon darkening effect of gain fibre, instruct the gain fibre of development high-level efficiency, low photon darkening effect.
Background technology
Gain fibre is the gain media of fiber laser, and mixing the rare earth fibre core is its gain region.Because fiber laser has little, in light weight, the advantages such as efficient is high, good beam quality of volume, has been widely used in fields such as industrial processes, scientific research, military affairs.For obtaining high power optical fibre laser output, need to suppress various nonlinear effects, as stimulated Brillouin scattering (SBS), stimulated Raman scattering (SRS) etc., just need to adopt short as far as possible optical fiber, improve the doping content of gain fibre simultaneously.
Photon darkening (photo darkening) is meant when gain fibre excites with certain wavelength, occurs the phenomenon of energy loss in the optical fiber during Laser Transmission, and this phenomenon as is mixed ytterbium, mixes thulium, mixed praseodymium optical fiber etc. in many doped gain fiber.It will directly cause the permanent degeneration of gain fibre, and its forming process is irreversible.The doping content of gain fibre is big more, and its photon darkening is also obvious more, and the generation of photon darkening will significantly to shorten with the gain fibre be the serviceable life of the fiber laser of gain media.
Therefore, realize high-capacity optical fiber laser, will make the doping content of gain fibre obtain certain balance, can suppress the various nonlinear effects of gain fibre, guarantee that again it has less photon darkening effect.But for the photon darkening effect of gain fibre, still there is not reliable method of testing at present.
Summary of the invention
Purpose of the present invention provides a kind of gain fibre photon darkening test macro, gain fibre photon darkening test macro of the present invention is easy to be reliable, the photon darkening effect that can effectively detect gain fibre and guides gain fibre to select suitable doping content, has very important significance for the gain fibre of developing high-level efficiency, low photon darkening effect.
Technical scheme of the present invention is:
Gain fibre photon darkening test macro comprises the fine red-light source of magnetic tape trailer, the fine optoisolator of magnetic tape trailer, the fine semiconductor laser of magnetic tape trailer, fiber coupler, tested gain fibre, collimation lens, semiconductor laser output wavelength optical filter, gain fibre excitation wavelength optical filter, narrow-band optical filter, power detector; The fine red-light source of magnetic tape trailer links to each other by the fine optoisolator of optical fiber and magnetic tape trailer, the input end signal optical fiber welding mutually of the fine optoisolator of magnetic tape trailer and fiber coupler, the input end pumping optical fiber welding mutually of the fine semiconductor laser of magnetic tape trailer and fiber coupler, the output end signal optical fiber of fiber coupler and the welding mutually of tested gain fibre one end, the other end of tested gain fibre cuts into the plane, and output beam passes through semiconductor laser output wavelength optical filter successively behind the collimation lens collimation, gain fibre excitation wavelength optical filter, enter power detector behind the narrow-band optical filter.
The fine red-light source of described magnetic tape trailer is a visible red, and wavelength is the ruddiness of 630nm-650nm.
The fine optoisolator of described magnetic tape trailer inserts loss less than 1.5dB to the forward of 630nm-650nm ruddiness, and the reverse isolation degree guarantees the safe operation of the fine 630nm-650nm nm of magnetic tape trailer red-light source greater than 30dB.
The output wavelength of the fine semiconductor laser of described magnetic tape trailer is done corresponding selection according to the doped dielectric of gain fibre.As to Yb dosed optical fiber, can select wavelength for use is the semiconductor laser of 915nm or 976nm; To thulium doped fiber, selecting wavelength for use is the semiconductor laser of 790nm.
Described fiber coupler input end has signal optical fibre and pumping optical fiber, its signal optical fibre and the welding mutually of the fine optoisolator of magnetic tape trailer, and the fine semiconductor laser of its pumping optical fiber and magnetic tape trailer is welded together.
Described tested gain fibre is a rare earth doped fiber, as mixes ytterbium, mixes thulium, mixes praseodymium optical fiber etc.
Described collimation lens is plano-convex lens or convex lens, and the gain fibre outgoing beam is collimated.
Described semiconductor laser output wavelength optical filter noise spectra of semiconductor lasers output wavelength reflection of light rate greater than 99.9%, is used for the light of the semiconductor laser output wavelength of filtering remnants to other wavelength light transmitance greater than 99.9%.
Described gain fibre excitation wavelength optical filter, to gain fibre excitation wavelength reflection of light rate greater than 99.9%, to other wavelength light transmitance greater than 99.9%.Its wavelength is selected according to the excitation wavelength of doped gain fiber, and as to Yb dosed optical fiber, the reflectivity of 8 pairs of 1000nm-1200nm wavelength light of wave filter is greater than 99.9%, to other wavelength light transmitance greater than 99.9%.
The bandwidth of described narrow-band optical filter is less than 1nm, to the transmitance of 630nm-650nm wave band greater than 99.9%, to other wavelength light reflectivity greater than 99.9%.
Described power detector is the existing power detector that comprises photoelectric probe and data acquisition system (DAS), is used to detect the also power data of real time record incident beam, and the line data of going forward side by side is handled.
Gain fibre photon darkening test macro of the present invention is easy to be reliable, the photon darkening effect that can effectively detect gain fibre and guides gain fibre to select suitable doping content, has very important significance for the gain fibre of developing high-level efficiency, low photon darkening effect.
Description of drawings
Fig. 1 is a structural representation of the present invention.
Fig. 2 is for adopting the various dissimilar photon darkening effects of mixing the ytterbium gain fibre that test out of the present invention figure as a result.
Embodiment
The invention will be further described in conjunction with the accompanying drawings.
As shown in Figure 1, the present invention includes the fine 633nm red-light source 1 of magnetic tape trailer, the fine optoisolator 2 of magnetic tape trailer, the fine semiconductor laser 3 of magnetic tape trailer, fiber coupler 4, tested gain fibre 5, collimation lens 6, semiconductor laser output wavelength optical filter 7, gain fibre excitation wavelength optical filter 8,633nm narrow-band optical filter 9, power detector 10; The fine 633nm red-light source 1 of magnetic tape trailer links to each other by the fine optoisolator 2 of optical fiber and magnetic tape trailer, the input end signal optical fiber welding mutually of the fine optoisolator 2 of magnetic tape trailer and fiber coupler 4, the input end pumping optical fiber welding mutually of the fine semiconductor laser 3 of magnetic tape trailer and fiber coupler 4, the output end signal optical fiber of fiber coupler 4 and the welding mutually of tested gain fibre 5 one ends, the other end of tested gain fibre 5 cuts into the plane, and output beam is a parallel beam behind collimation lens 6 collimations, and this moment, collimated light beam comprised 633nm ruddiness, the light that light that has not been absorbed by tested gain fibre 5 that the fine semiconductor laser of magnetic tape trailer is sent and tested gain fibre 5 are excited; Collimated light beam is earlier through semiconductor laser output wavelength optical filter 7, the light of the semiconductor laser output wavelength of filtering remnants; Pass through the light that the tested gain fibre 5 of gain fibre excitation wavelength optical filter 8 filterings is excited again; At last by to the transmitance of 633nm wave band greater than 99.9% 633nm narrow-band optical filter 9, adopt the power and the real-time recorded data of power detector 10 measuring beams, carry out data processing at last.
The forward of 2 pairs of 633nm ruddiness of the fine optoisolator of described magnetic tape trailer inserts loss less than 1.5dB, and the reverse isolation degree guarantees the safe operation of the fine 633nm red-light source 1 of magnetic tape trailer greater than 30dB.The fine semiconductor laser 3 of described magnetic tape trailer, its output wavelength is done corresponding selection according to the doped dielectric of gain fibre.As to Yb dosed optical fiber, can select wavelength for use is the semiconductor laser of 915nm or 976nm; To thulium doped fiber, selecting wavelength for use is the semiconductor laser of 790nm.Described tested gain fibre 5 is a rare earth doped fiber, as mixes ytterbium, mixes thulium, mixes praseodymium optical fiber etc.Described collimation lens 6 is plano-convex lens or convex lens, and the gain fibre outgoing beam is collimated.Described semiconductor laser output wavelength optical filter 7 noise spectra of semiconductor lasers output wavelength reflection of light rates greater than 99.9%, are used for the light of the semiconductor laser output wavelength of filtering remnants to other wavelength light transmitance greater than 99.9%.Described gain fibre excitation wavelength optical filter 8, to gain fibre excitation wavelength reflection of light rate greater than 99.9%, to other wavelength light transmitance greater than 99.9%.Its wavelength is selected according to the excitation wavelength of doped gain fiber, and as to Yb dosed optical fiber, the reflectivity of 8 pairs of 1000nm-1200nm wavelength light of wave filter is greater than 99.9%, to other wavelength light transmitance greater than 99.9%.
Described power detector 10 is the existing power detector that comprises photoelectric probe and data acquisition system (DAS), is used to detect the also power data of real time record incident beam, and the line data of going forward side by side is handled.
To mix the ytterbium gain fibre is example, according to above-mentioned put up test platform after, open the fine 633nm red-light source 1 of magnetic tape trailer earlier, power detector 10 can detect the 633nm red signal light subsequently; Open the fine semiconductor laser 3 of magnetic tape trailer then, the 633nm red signal light power that power detector 10 is detected can change, and gathers time dependent power data in real time, and it is carried out data analysis.Fig. 2 is the photon darkening effect figure as a result that tested out various dissimilar are mixed the ytterbium gain fibre, and the 633nm ruddiness power that detects descends soon more in time, and then its photon darkening effect is big more.