CN102751649A - 469nm full-fiber-structure high-power blue light fiber laser device - Google Patents

Abstract

The invention discloses a 469nm full-fiber-structure high-power blue light fiber laser device which comprises a semiconductor laser device pumping source, a first total reflection fiber grating, a second total reflection fiber grating and a third total reflection fiber grating, wherein a double-coated ytterbium-doped fiber is connected between the first total reflection fiber grating and the second total reflection fiber grating; an in-cavity frequency doubler is connected between the second total reflection fiber grating and the third total reflection fiber grating; the third total reflection fiber grating is connected with an output tail fiber; the double-coated ytterbium-doped fiber is arranged in an ultralow-temperature semiconductor refrigerator; and the head and tail ends of the double-coated ytterbium-doped fiber are arranged outside the ultralow-temperature semiconductor refrigerator. The invention adopts the full fiber structure, and the neodymium-doped double-coated fiber is arranged in the ultralow-temperature semiconductor refrigerator, thereby enhancing the relative probability of transition from 4F3/2-4I9/2 to Nd<3+>; and the invention adopts a frequency doubling cavity structure composed of the convergence fiber frequency doubler and the tri-fiber grating, thereby implementing the output of the high-power high-quality blue light laser.

Description

The high-power Blue-light optical fiber laser of 469nm all optical fibre structure

Technical field

The invention belongs to laser technology field, be specifically related to a kind of fiber laser, the high-power Blue-light optical fiber laser of particularly a kind of 469nm all optical fibre structure.

Background technology

Fiber laser is little with its volume, advantages such as efficient is high, good stability, good beam quality, and development very rapidly.Near the 469nm Blue-light optical fiber laser, can be used as laser projection, laser television, laser form images under water etc. desirable blue laser light source.At present, obtaining near the common method of the blue laser of 469nm, is Nd ³⁺: YAG produces 938nm laser and obtains through after the frequency multiplication.

In all solid state laser, utilize the nonlinear frequency transformation technology obtaining to have obtained fine effect aspect the visible light wave range laser technology; All solid state laser inner cavity frequency-doubling technology particularly almost becomes the main force of visible waveband solid state laser, but runs into a contradiction when inner cavity frequency-doubling technology is applied to fiber laser: the advantage of fiber laser is its full fiberize welding; No discrete component; So its good stability, non-maintaining and be easy to use, if but insert the such discrete component of frequency-doubling crystal, the fiber laser good stability must have been destroyed; Non-maintaining and wieldy advantage loses the market competitiveness.Realize that the interior frequency multiplication of fiber laser cavity must adopt the intracavity frequency doubling device of optical fiber structure, in fiber laser, realizes the frequency doubled light fibre laser of all optical fibre structure with its welding.Existing fiber laser frequency doubling technology adopts cavity external frequency multiplication or inner chamber discrete component frequency multiplication more; Like double-side pumping intracavity frequency doubling double clad green-light fiber laser (application number: 200620079299); Doubly clad optical fiber intracavity frequency doubling laser (the patent No.: 03116633.4); Inner cavity frequency doubling Blue-light optical fiber laser (application number: 200820155748), high-power blue-light fiber laser (application number: 200620079296), obtain near the fiber laser commonly used of the blue laser of 469nm; Be called the high-power blue-light laser like name, the patent No. is the disclosed a kind of laser of the Chinese patent of ZL200610043062.6.Above-mentioned these lasers all are that discrete component constitutes; In essence, these technology all are the reprints of all solid state intracavity frequency doubling technology, though it is moved into fiber laser; But the high stability that fiber laser self is had has been destroyed, and can not show the advantage of fiber laser.

Inventor of the present invention is in the patent of invention (application number: 201110158949.0 of application on June 14th, 2011; Title: all optical fibre structure intracavity frequency doubling green (light) laser); It is a kind of fiber laser of employing three optical grating constructions; It adopts GRIN Lens length is the interior frequency doubled light fibre laser of all optical fiber cavity of 0.23P (P is the GRIN Lens pitch), is mainly used in high power fiber laser, and the GRIN Lens length that is adopted because of its chamber inner fiber frequency multiplier adopts 0.23P; Fundamental frequency light is converted into directional light by GRIN Lens, in frequency-doubling crystal, produces second harmonic (frequency multiplication) effect.The inventor finds in the follow-up study to the intracavity frequency doubling device; The length of GRIN Lens and the length of frequency-doubling crystal, refractive index all can influence the inner laser of intracavity frequency doubling device and distribute; Thereby influence the intensity of shoot laser, because the GRIN Lens length in this laser is fixed as 0.23P, fundamental frequency light is converting directional light into through GRIN Lens expansion bundle; And the mode with directional light is advanced in frequency-doubling crystal; So it is high-power or shg efficiency is than higher when the frequency-doubling crystal non linear coefficient is higher, but it is at middle low power or frequency-doubling crystal non linear coefficient when not being very high, and shg efficiency is relatively low.Through further discovering,, make when fundamental frequency light can converge that just can obtain very high shg efficiency, especially at middle low power or frequency-doubling crystal non linear coefficient when not being very high, effect is more obvious when changing GRIN Lens length in frequency-doubling crystal.

Summary of the invention

To defective that exists in the above-mentioned prior art or deficiency; The objective of the invention is to; Provide a kind of 469nm all optical fibre structure high-power Blue-light optical fiber laser, this laser has avoided adopting in the existing blue laser scheme of discrete parts, has adopted all optical fibre structure; And the neodymium-doped doubly clad optical fiber placed in the ultralow temperature semiconductor cooler; Improve the relative probability of Nd3+, adopt the optical fiber frequency multiplier of convergent type and the frequency doubling cavity body structure that three fiber gratings are formed simultaneously, realized output high-power, high-quality blue laser by the 4F3/2-4I9/2 transition.Can be widely used in fields such as the imaging under water of laser projection, laser television, laser, laser medicine, laser radar.

In order to achieve the above object, the present invention adopts following technical solution:

The high-power Blue-light optical fiber laser of a kind of 469nm all optical fibre structure; Comprise diode-end-pumped source, the first total reflection optical fiber grating, the second total reflection optical fiber grating, the 3rd total reflection optical fiber grating and ultralow temperature semiconductor cooler; Be connected with the double clad Yb dosed optical fiber between the said first total reflection optical fiber grating and the second total reflection optical fiber grating; Be connected with the intracavity frequency doubling device between the second total reflection optical fiber grating and the 3rd total reflection optical fiber grating; The output of the 3rd total reflection optical fiber grating connects the output tail optical fiber, and above-mentioned each element connects through fusing mode, and the output tail optical fiber is a laser output; It is the 938nm laserresonator that the said first total reflection optical fiber grating, double clad neodymium-doped fiber and three parts of the 3rd total reflection optical fiber grating constitute wavelength; The second total reflection optical fiber grating and intracavity frequency doubling device constitute the frequency multiplication part of laser; The double clad Yb dosed optical fiber and with it the weld of the preceding tail optical fiber of back tail optical fiber and the second total reflection optical fiber grating of the first total reflection optical fiber grating of phase welding all place the ultralow temperature semiconductor cooler, the preceding tail optical fiber of the back tail optical fiber of the first total reflection optical fiber grating and the second total reflection optical fiber grating is drawn from the ultralow temperature semiconductor cooler.

The present invention also comprises following other technologies characteristic:

Adopt with 100 μ m tail optical fiber output center wavelengths in said diode-end-pumped source is the semiconductor laser of 35W for 808nm power; It is 938nm total reflection Bragg fiber grating that the first total reflection optical fiber grating, the 3rd total reflection optical fiber grating all adopt the reflection kernel wavelength, and reflectivity is greater than 99%; It is the double clad neodymium-doped fiber of 6/125 μ m that the double clad neodymium-doped fiber adopts core diameter, and length is 12m; It is 469nm total reflection Bragg fiber grating that the second total reflection optical fiber grating and negate are hit cardiac wave long, and reflectivity is greater than 99%; It is the non-doped fiber of double clad of 6/125 μ m that the output tail optical fiber is selected core diameter.

Said intracavity frequency doubling device comprises full-automatic temperature controlling stove, first tail optical fiber, sleeve pipe, first GRIN Lens, frequency-doubling crystal, second GRIN Lens, heat conduction copper billet and second tail optical fiber; Wherein, first GRIN Lens and second GRIN Lens are bonded in the left and right two ends of frequency-doubling crystal respectively; The left end of first GRIN Lens and first tail optical fiber have the end bonding of tail optical fiber contact pin, and the right-hand member of second GRIN Lens and second tail optical fiber have the end bonding of tail optical fiber contact pin; First tail optical fiber, sleeve pipe, first GRIN Lens, frequency-doubling crystal, second GRIN Lens and the second tail optical fiber center conllinear, constituting jointly with the frequency-doubling crystal is the symmetry structure at center; The outside of first GRIN Lens, frequency-doubling crystal, the second GRIN Lens three's integral body is enclosed with indium foil and heat conduction copper billet successively; The bottom surface of said heat conduction copper billet contacts with full-automatic temperature controlling stove; The remaining surface of heat conduction copper billet is encapsulated in inside pipe casing; First tail optical fiber from the left end of sleeve pipe pass and with the second total reflection optical fiber grating welding, second tail optical fiber passes and the 3rd total reflection optical fiber grating welding from the right two ends of sleeve pipe, adopts fibre core to aim at during each element welding.

Said first GRIN Lens is selected identical GRIN Lens for use with second GRIN Lens, and its length is 0.3P ~ 0.45P, and said frequency-doubling crystal, first GRIN Lens and second GRIN Lens satisfy formula 1:

$L=-\frac{2{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\mathrm{Tan}\left(\mathrm{\&alpha;\; d}\right)}{\mathrm{\&alpha;}{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0}$ Formula 1

In the formula, L is the length of frequency-doubling crystal; n ₁Refractive index for frequency-doubling crystal; n ₀It is the refractive index of the centre of first GRIN Lens; D is the length of first GRIN Lens, gets 0.3P ~ 0.45P; α is the first GRIN Lens refractive index profile coefficient; The refractive index n of first GRIN Lens (r) radially r distribution satisfies formula 2:

N (r)=n ₀(1-α ²r ²/ 2) formula 2

In the formula, r is a radial coordinate.

It is that 3mm, length are the circular GRIN Lens of 6mm that said first GRIN Lens, second GRIN Lens all adopt d=0.30P, diameter; Frequency-doubling crystal is chosen lbo crystal, and cross sectional dimensions is chosen 3mm*3mm, and frequency-doubling crystal length is 18.8mm; First tail optical fiber, second tail optical fiber are all selected 6/125 μ m double clad non-impurity-doped optical fiber for use, and length is got 2 meters; Heat conduction copper billet length is got 28.8mm, wall thickness 5mm; The length of encapsulation sleeve pipe is got 40.8mm, side thickness 3mm, the thick 6mm of end wall.

Said ultralow temperature semiconductor cooler comprises that semiconductor refrigerating heap, fiber reel are around post, vacuum (-tight) housing and water-filled radiator; Wherein, Fiber reel places semiconductor refrigerating heap upper surface around post; Semiconductor refrigerating is stacked in the upper surface of water-filled radiator, and the upper surface of semiconductor refrigerating heap is a heat absorbing end, and lower surface is a release end of heat; Vacuum (-tight) housing is the hollow cylinder of lower ending opening, and vacuum (-tight) housing is buckled in the water-filled radiator top and fiber reel is stacked in inside around post and semiconductor refrigerating, and the inner cavity that forms of vacuum (-tight) housing is a vacuum chamber.

The heat preserving and insulating material that said semiconductor refrigerating heap comprises the refrigeration inner core and is coated on refrigeration inner core side; The refrigeration inner core is made up of one or more identical refrigeration bodies; Described refrigeration body is formed by a plurality of semiconductor chilling plates and a plurality of enthusiasm alternated; And the upper and lower surfaces of refrigeration body is semiconductor chilling plate, between semiconductor chilling plate and enthusiasm, is coated with heat conduction auxiliary agent or Heat Conduction Material; Each semiconductor chilling plate all is connected with DC power supply; The upper surface heat absorption lower surface heat release of semiconductor chilling plate.

Said fiber reel is carved with groove around the circumferencial direction of post.

Said vacuum (-tight) housing adopts double-deck outer wall, and should be vacuum between the bilayer outer wall.

Said water-filled radiator comprises shell and the water inlet pipe and the outlet pipe that are connected with this enclosure; This enclosure is provided with the dividing plate of many vertical directions; Dividing plate makes shell inner cavity form a circuitous cooling water channel that advances; Water inlet pipe connects the inlet of cooling water channel, and outlet pipe connects the outlet of this cooling water channel.

Technical characterictic of the present invention and advantage are following:

1) laser of the present invention is formed by connecting through the fused fiber splice mode LD pumping source, fiber grating, double clad neodymium-doped fiber, convergent type intracavity frequency doubling device, output tail optical fiber; And the double clad neodymium-doped fiber placed in the ultralow temperature semiconductor cooler, obtain the 938nm base frequency oscillation and realize that through convergent type intracavity frequency doubling device frequency multiplication obtains the output of 469nm high power laser light in the fiber laser cavity.

2) laser of the present invention adopts all optical fibre structure; No discrete component needs adjustment; Good beam quality, reliability height, compact conformation, operating cost are low, non-maintaining, overcome complex structure in traditional separate structure fiber laser, be difficult to the defective of integrated and poor stability.

3) the present invention adopts three fiber grating cavity structures, makes fundamental frequency light not have to leak, frequency doubled light is all collected and through tail optical fiber output.

4) the present invention adopts frequency multiplier realization all optical fibre structure intracavity frequency doubling in the convergent type fiber laser cavity; When frequency-doubling crystal and GRIN Lens parameter are selected to satisfy certain condition; Just can be so that fundamental frequency light and frequency doubled light converge at the frequency-doubling crystal center; Converge and inject among the tail optical fiber through GRIN Lens at two ends, solved in the fiber laser cavity leakage problem of fundamental frequency light and frequency doubled light in the frequency multiplication implementation procedure, have very high power density and make it have very high frequency-doubling conversion efficiency.

5) frequency-doubling crystal adopts the indium foil parcel to be encapsulated in the heat conduction copper billet; Heat conduction copper billet bottom surface links to each other with full-automatic temperature controlling stove; Full-automatic temperature controlling stove can-10 ℃ ~ 200 ℃ be regulated temperature; The usefulness that both can be used for frequency-doubling crystal cooling under the angular phase matching way, control of frequency-doubling crystal temperature and adjusting when also can be used for temperature phase matched mode.

6) fundamental frequency light converges at a bit in the frequency-doubling crystal midpoint behind GRIN Lens; Make that its facula area in frequency-doubling crystal is less, power density is bigger, and shg efficiency is improved; Even so under the low-power situation; Also can obtain very high shg efficiency, particularly when middle low power, very high frequency-doubling conversion efficiency arranged equally.

Description of drawings

Fig. 1 is the structure principle chart of laser of the present invention.

Fig. 2 is an intracavity frequency doubling device structural representation.Wherein, (a) being front view, (b) is vertical view, (c) is left view.

Fig. 3 is the ray trajectory figure of laser in GRIN Lens and frequency-doubling crystal.

Fig. 4 is the index path of advancing of fundamental frequency light in the laser of the present invention and frequency doubled light.

Fig. 5 is the structural representation of ultralow temperature semiconductor cooler.

Fig. 6 is cylindrical semiconductor refrigerating pile structure sketch map.Wherein, (a) being vertical view, (b) is front view.

Fig. 7 is a truncated cone-shaped semiconductor refrigerating pile structure sketch map.Wherein, (a) being vertical view, (b) is front view.

Fig. 8 is the plane structure chart of difform semiconductor refrigerating heap.Wherein, (a) be cylindroid, adopt two refrigeration bodies to form the refrigeration inner core; (b) be two semicircle rectangular column, adopt three refrigeration bodies to form the refrigeration inner core; (c) be cylinder, adopt four refrigeration bodies to form the refrigeration inner core; (d) be cuboid, adopt six refrigeration bodies to form the refrigeration inner core.

Fig. 9 is that difform fiber reel is around the rod structure sketch map.Wherein, (a) be cylinder; (b) be two semicircle rectangular column.

Figure 10 is the structural representation of vacuum (-tight) housing.

Figure 11 is the internal structure sketch map of water-filled radiator, and the direction of arrow is water (flow) direction among the figure.

Figure 12 is the scheme of installation of double clad Yb dosed optical fiber on the ultralow temperature semiconductor cooler.

Figure 13 is laser output spectrum figure of the present invention.

Figure 14 is pump power and power output graph of a relation.

Below in conjunction with accompanying drawing and embodiment the present invention is further explained.

Embodiment

As shown in Figure 1; The high-power Blue-light optical fiber laser of 469nm all optical fibre structure of the present invention; Comprise diode-end-pumped source 1, the first total reflection optical fiber grating 2, the second total reflection optical fiber grating 4, the 3rd total reflection optical fiber grating 6 and ultralow temperature semiconductor cooler 16; Be connected with the output that is connected with intracavity frequency doubling device 5, the three total reflection optical fiber gratings 6 between double clad Yb dosed optical fiber 3, the second total reflection optical fiber gratings 4 and the 3rd total reflection optical fiber grating 6 between the said first total reflection optical fiber grating 2 and the second total reflection optical fiber grating 4 and connect output tail optical fiber 7; Above-mentioned each element connects through fusing mode, welding spot printing low-refraction glue.Output tail optical fiber 7 is a laser output; It is the 938nm laserresonator that the said first total reflection optical fiber grating 2, double clad neodymium-doped fiber 3 and 6 three parts of the 3rd total reflection optical fiber grating constitute wavelength; The frequency multiplication part of the second total reflection optical fiber grating 4 and intracavity frequency doubling device 5 formation lasers.Double clad Yb dosed optical fiber 3 and with it the weld of the preceding tail optical fiber of back tail optical fiber and the second total reflection optical fiber grating 4 of the first total reflection optical fiber grating 2 of phase welding all place the back tail optical fiber of ultralow temperature semiconductor cooler 16, the first total reflection optical fiber gratings 2 and the preceding tail optical fiber of the second total reflection optical fiber grating 4 to draw along the eck of ultralow temperature semiconductor cooler 16.

In the present embodiment, adopt with 100 μ m tail optical fiber output center wavelengths in diode-end-pumped source 1 is the semiconductor laser of 35W for 808nm power; It is 938nm total reflection Bragg fiber grating that the first total reflection optical fiber grating 2, the 3rd total reflection optical fiber grating 6 all adopt the reflection kernel wavelength, and reflectivity is greater than 99%; It is the double clad neodymium-doped fiber of 6/125 μ m that double clad neodymium-doped fiber 3 is selected core diameter, and length is 12m; It is 469nm total reflection Bragg fiber grating that the second total reflection optical fiber grating 4 is hit cardiac wave long with negate, and reflectivity is greater than 99%; It is the non-doped fiber of double clad of 6/125 μ m that output tail optical fiber 7 is selected core diameter, also can adopt the tail optical fiber of the second total reflection optical fiber grating 4 to substitute output tail optical fiber 7.

As shown in Figure 2; Intracavity frequency doubling device 5 comprises full-automatic temperature controlling stove 15, first tail optical fiber 8, sleeve pipe 9, first GRIN Lens 10, frequency-doubling crystal 11, second GRIN Lens 12, heat conduction copper billet 13 and second tail optical fiber 14; Wherein, first GRIN Lens 10 and second GRIN Lens 12 are bonded in frequency-doubling crystal 11 left and right two ends respectively; The left end of first GRIN Lens 10 and first tail optical fiber 8 have the end bonding of tail optical fiber contact pin, and the right-hand member of second GRIN Lens 12 and second tail optical fiber 14 have the end bonding of tail optical fiber contact pin; First tail optical fiber 8, sleeve pipe 9, first GRIN Lens 10, frequency-doubling crystal 11, second GRIN Lens 12 and second tail optical fiber, 14 center conllinear, constituting with frequency-doubling crystal 11 jointly is the symmetry structure at center; The outside of first GRIN Lens 10, frequency-doubling crystal 11, second GRIN Lens, 12 threes' integral body is enclosed with indium foil and heat conduction copper billet 13 successively; The bottom surface of said heat conduction copper billet 13 contacts with full-automatic temperature controlling stove 15; The remaining surface of heat conduction copper billet 13 is encapsulated in sleeve pipe 9 inside; First tail optical fiber 8 from the left end of sleeve pipe 9 pass and with 4 weldings of the second total reflection optical fiber grating; Second tail optical fiber 14 passes and 6 weldings of the 3rd total reflection optical fiber grating from the right two ends of sleeve pipe 9, adopts fibre core to aim at during each element welding.

Require to select the frequency-doubling crystal type according to the fundamental light wave length of the fiber laser of wanting frequency multiplication, power output, matching way etc., in this wavelength, frequency-doubling crystal should satisfy: 1. bigger nonlinear polarization coefficient is arranged; 2. have the good transparency, absorption loss is little; 3. higher damage threshold satisfies power requirement; 4. chemical stability is good, is difficult for deliquescence; 5. phase matched satisfies design requirement, promptly satisfies angle coupling, the requirement of temperature coupling.

Intracavity frequency doubling device 5 is as the core component of laser of the present invention, and the travel track of its inner fundamental frequency light is as shown in Figure 3, thereby will guarantee that light advances at frequency-doubling crystal 11 inner focusings in a bit with drawn track in scheming.First GRIN Lens 10 is selected identical GRIN Lens for use with second GRIN Lens 12, and GRIN Lens length is chosen for 0.3P ~ 0.45P.Frequency-doubling crystal 11 is employed in the 938nm place has bigger non linear coefficient, and simultaneously, said frequency-doubling crystal 11, first GRIN Lens 10 and second GRIN Lens 12 satisfy formula 1:

$L=-\frac{2{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\mathrm{Tan}\left(\mathrm{\&alpha;\; d}\right)}{\mathrm{\&alpha;}{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0}$ Formula 1

In the formula, L is the length of frequency-doubling crystal 11; n ₁Refractive index for frequency-doubling crystal 11; n ₀It is the refractive index of the centre of first GRIN Lens 10; D is the length of first GRIN Lens 10, gets 0.3P ~ 0.45P; α is first GRIN Lens, 10 refractive index profile coefficients; The refractive index n of first GRIN Lens 10 (r) radially r distribution satisfies formula 2:

N (r)=n ₀(1-α ²r ²/ 2) formula 2

In the formula, r is a radial coordinate.

GRIN Lens, frequency-doubling crystal are cylinder and both cross sections are identical, has both helped assembling, also is convenient to heat conduction.Can adopt the cylinder or the cross section length of side of cross-sectional diameter 2 ~ 5mm is the cuboid of 2 ~ 5mm.In the present embodiment, it is that 3mm, length are the circular GRIN Lens of 6mm that first GRIN Lens 10, second GRIN Lens 12 all adopt d=0.30P, diameter.Frequency-doubling crystal 11 is chosen lbo crystal, and cross sectional dimensions is chosen 3mm*3mm, obtains frequency-doubling crystal length L=18.8mm according to frequency-doubling crystal length computation formula 1; First tail optical fiber 8, second tail optical fiber 14 are all selected 6/125 μ m double clad non-impurity-doped optical fiber for use, and length is got 2 meters; Heat conduction copper billet 13 length are got 28.8mm, wall thickness 5mm; The length of encapsulation sleeve pipe 9 is got 40.8mm, side thickness 3mm, the thick 6mm of end wall.

Theoretical according to optical matrix, the derivation principle of formula 1 is following:

The refraction index profile of first GRIN Lens is:

${\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">n</figure-callout>}}^2={{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0}^2[1-\frac{1}{2}{\left(\mathrm{\&alpha;r}\right)}^2]$

In the formula, n ₀Be the first GRIN Lens refractive index of the centre, n is that radius is the refractive index at r place.

Laser gets into the first GRIN Lens matrix

$\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">m</figure-callout>}1=\left[\begin{array}{cc}1& 0\\ 0& {\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\end{array}\right]$

Propogator matrix in first GRIN Lens

$\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}2=\left[\begin{array}{cc}\cos \left(\mathrm{\&alpha;d}\right)& (1/\mathrm{\&alpha;})\sin \left(\mathrm{\&alpha;d}\right)\\ -\mathrm{\&alpha;}\sin \left(\mathrm{\&alpha;d}\right)& \cos \left(\mathrm{\&alpha;d}\right)\end{array}\right]$

In the formula, d is a GRIN Lens length

First GRIN Lens gets into the frequency-doubling crystal matrix

$\mathrm{<figure-callout\; id="3"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}3=\left[\begin{array}{cc}1& 0\\ 0& {\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1/{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\end{array}\right]$

N in the formula ₁Be the frequency-doubling crystal refractive index

Propogator matrix in the frequency-doubling crystal

$\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}4=\left[\begin{array}{cc}1& \mathrm{<figure-callout\; id="0"\; label="s"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">s</figure-callout>}\\ 0& 1\end{array}\right]$

In the formula, s is a frequency-doubling crystal length

Frequency-doubling crystal gets into the second GRIN Lens matrix

$\mathrm{<figure-callout\; id="5"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}5=\left[\begin{array}{cc}1& 0\\ 0& {\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0/{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\end{array}\right]$

Propogator matrix in second GRIN Lens

$\mathrm{<figure-callout\; id="6"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}6=\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}2=\left[\begin{array}{cc}\cos \left(\mathrm{\&alpha;d}\right)& (1/\mathrm{\&alpha;})\sin \left(\mathrm{\&alpha;d}\right)\\ -\mathrm{\&alpha;}\sin \left(\mathrm{\&alpha;d}\right)& \cos \left(\mathrm{\&alpha;d}\right)\end{array}\right]$

Leave the second GRIN Lens matrix

$\mathrm{<figure-callout\; id="7"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}7=\left[\begin{array}{cc}1& 0\\ 0& 1/{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\end{array}\right]$

Light beam through the propogator matrix of first GRIN Lens, frequency-doubling crystal, second GRIN Lens does

$M=\left[\begin{array}{cc}A& B\\ C& D\end{array}\right]=\mathrm{<figure-callout\; id="1"\; label="m"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">m</figure-callout>}1\&CenterDot;\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}2\&CenterDot;\mathrm{<figure-callout\; id="3"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}3\&CenterDot;\mathrm{<figure-callout\; id="4"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}4\&CenterDot;\mathrm{<figure-callout\; id="5"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}5\&CenterDot;\mathrm{<figure-callout\; id="6"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}6\&CenterDot;\mathrm{<figure-callout\; id="7"\; label="m"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">m</figure-callout>}7$

Matrix multiple just can obtain transmission matrix M, and its matrix element ABCD is respectively

$A={\left[\cos \left(\mathrm{\&alpha;d}\right)\right]}^2-\frac{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\mathrm{\&alpha;}\sin \left(\mathrm{\&alpha;d}\right)[s\cos \left(\mathrm{\&alpha;d}\right)+\frac{{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\sin \left(\mathrm{\&alpha;d}\right)}{\mathrm{\&alpha;}{n}_0}]}{{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1}$

$B=\frac{\frac{\cos \left(\mathrm{\&alpha;d}\right)\sin \left(\mathrm{\&alpha;d}\right)}{\mathrm{\&alpha;}}+\frac{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\cos \left(\mathrm{\&alpha;d}\right)[s\cos \left(\mathrm{\&alpha;d}\right)+\frac{{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\sin \left(\mathrm{\&alpha;d}\right)}{\mathrm{\&alpha;}{n}_0}]}{n_1}}{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0}$

$C=-{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\mathrm{\&alpha;}\sin \left(\mathrm{\&alpha;d}\right)\cos \left(\mathrm{\&alpha;d}\right)-\frac{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\mathrm{\&alpha;}\sin \left(\mathrm{\&alpha;d}\right)[-{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\mathrm{s\&alpha;}\sin \left(\mathrm{\&alpha;d}\right)+{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\cos \left(\mathrm{\&alpha;d}\right)]}{{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1}$

$D=\frac{\frac{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\cos \left(\mathrm{\&alpha;d}\right)[-{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\mathrm{s\&alpha;}\sin \left(\mathrm{\&alpha;d}\right)+{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\cos \left(\mathrm{\&alpha;d}\right)]}{n_1}-n_0{\left[\sin \left(\mathrm{\&alpha;d}\right)\right]}^2}{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0}$

If light 1

${\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">r</figure-callout>}}_1=\left[\begin{array}{cc}{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">y</figure-callout>}}_1& \\ {\mathrm{\&theta;}}_1& \end{array}\right]$

After the transmission of first GRIN Lens, frequency-doubling crystal, second GRIN Lens, obtain light 2

${\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">r</figure-callout>}}_2=\left[\begin{array}{cc}{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HDA00001830840300011.png,HDA00001830840300062.png"\; state="\{\{state\}\}">y</figure-callout>}}_2& \\ {\mathrm{\&theta;}}_2& \end{array}\right]=\left[\begin{array}{cc}{\mathrm{<figure-callout\; id="1"\; label="Ay"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">Ay</figure-callout>}}_1+B{\mathrm{\&theta;}}_1& \\ \mathrm{<figure-callout\; id="1"\; label="C\; y"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">C</figure-callout>}{y}_{}{}_1+D{\mathrm{\&theta;}}_1& \end{array}\right]$

When light 1 is the central point incident of the first GRIN Lens incident end face; And require it to converge at the central point of the outgoing end face of second GRIN Lens; In order to simplify derivation, the central point (being the center of circle of GRIN Lens end face) that we establish GRIN Lens is the height coordinate initial point, and the y of working as is then arranged ₁, y must be arranged at=0 o'clock ₂=0, our solving equation B θ for this reason ₁=0, and cos (α d)<>0, also promptly find the solution

$\left\{\begin{array}{c}\frac{\frac{\cos \left(\mathrm{\&alpha;d}\right)\sin \left(\mathrm{\&alpha;d}\right)}{\mathrm{\&alpha;}}+\frac{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0\cos \left(\mathrm{\&alpha;d}\right)[s\cos \left(\mathrm{\&alpha;d}\right)+\frac{{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\sin \left(\mathrm{\&alpha;d}\right)}{\mathrm{\&alpha;}{n}_0}]}{n_1}}{{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0}{\mathrm{\&theta;}}_1=0\\ \cos \left(\mathrm{\&alpha;d}\right)<>0\end{array}\right.$

Can obtain:

$s=-\frac{2{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="HDA00001830840300011.png"\; state="\{\{state\}\}">n</figure-callout>}}_1\tan \left(\mathrm{\&alpha;d}\right)}{\mathrm{\&alpha;}{\mathrm{<figure-callout\; id="0"\; label="n"\; filenames="HDA00001830840300072.png"\; state="\{\{state\}\}">n</figure-callout>}}_0}.$

As shown in Figure 5; Ultralow temperature semiconductor cooler 16 comprises that semiconductor refrigerating heap 17, fiber reel are around post 18, vacuum (-tight) housing 19 and water-filled radiator 20; Wherein, fiber reel places semiconductor refrigerating to pile 17 upper surfaces around post 18, and semiconductor refrigerating heap 17 places the upper surface of water-filled radiator 20; The upper surface of semiconductor refrigerating heap 17 is a heat absorbing end, and lower surface is a release end of heat; Vacuum (-tight) housing 19 is the hollow cylinder of lower ending opening, and vacuum (-tight) housing 19 is buckled in water-filled radiator 20 tops and fiber reel is placed inside around post 18 and semiconductor refrigerating heap 17, and the vacuum (-tight) housing 19 inner cavitys that form are vacuum chamber; Semiconductor refrigerating heap 17 is used for the heat in the vacuum chamber is passed continually with water-filled radiator 20, to keep continuing ultralow temperature in the vacuum chamber.

Like Fig. 6-shown in Figure 8; The heat preserving and insulating material 23 that semiconductor refrigerating heap 17 comprises the refrigeration inner core and is coated on refrigeration inner core side; Heat preserving and insulating material 23 adopts polyurethane foam or heat insulation foam; The refrigeration inner core is made up of one or more identical refrigeration bodies; Described refrigeration body is formed by a plurality of semiconductor chilling plates 21 and a plurality of enthusiasm 22 alternated, and the upper and lower surface of refrigeration body is semiconductor chilling plate 21, between semiconductor chilling plate 21 and enthusiasm 22, is coated with heat conduction auxiliary agent or Heat Conduction Material.Each semiconductor chilling plate 21 all is connected with DC power supply; The upper surface heat absorption lower surface heat release of semiconductor chilling plate 21.Heat conduction auxiliary agent or Heat Conduction Material can adopt ductile glue, paste or the softer metals with good thermal conductivity characteristic, like heat-conducting silicone grease, thermal paste, thermal grease or indium foil; Enthusiasm 22 adopts the sheet metal with good thermal conductivity characteristic, like copper, aluminium; The number of plies of semiconductor chilling plate 21 and enthusiasm 22 alternated depends on the temperature requirement in the vacuum chamber, and the temperature required low more then number of plies is many more.Select the semiconductor chilling plate of different size for use according to the needs routine of refrigerating capacity.

The quantity of the refrigeration body that the refrigeration inner core comprises is confirmed around the situation of post 18 required coolings according to fiber reel.When the refrigeration inner core only comprises a refrigeration body; The regular prism (as shown in Figure 6) or down big of being shaped as of this refrigeration body is gone up little terrace with edge (as shown in Figure 7), and the shape of corresponding semiconductor refrigerating heap 17 can be cylinder (as shown in Figure 6) or big down and little round platform (as shown in Figure 7); When the refrigeration inner core comprises a plurality of refrigeration body; Each refrigeration body is regular prism; All refrigeration bodies are close to each other arranges new regular prism or the cuboid of back formation, and the shape of corresponding semiconductor refrigerating heap 17 can be cylinder (shown in Fig. 8 (c)), cuboid (shown in Fig. 8 (d)), terrace with edge, cylindroid (shown in Fig. 8 (a)), elliptical table, two semicircle rectangular column (shown in Fig. 8 (b)) or two semicircle rectangle platform.

As shown in Figure 9; Fiber reel is cylinder (seeing Fig. 8 (a)) or two semicircle rectangular column (seeing Fig. 8 (b)) around post 18; Be carved with groove along fiber reel around the circumferencial direction of post 18; Groove be shaped as rectangle half slot, square groove, rectangular channel and V-shaped groove, but be not limited thereto, the size of groove is submerging optical fiber wherein.

Shown in figure 10, vacuum (-tight) housing 19 adopts double-deck outer wall, and should be vacuum between the bilayer outer wall; The profile of vacuum (-tight) housing 19 is confirmed according to the shape of semiconductor refrigerating heap 17; Can be column (shown in figure 10), column neck or platform shape neck; No matter select which kind of shape, all need guarantee vacuum (-tight) housing 19 can with semiconductor refrigerating pile 17 with fiber reel in post 18 is enclosed in.The material of vacuum (-tight) housing 19 adopts metal, alloy or glass.

Shown in figure 11; Water inlet pipe 24 and outlet pipe 25 that water-filled radiator 20 comprises shell and is connected with this enclosure; This enclosure is provided with the dividing plate 36 of many vertical directions, and dividing plate 36 makes shell inner cavity form a circuitous cooling water channel 26 that advances, and water inlet pipe 24 connects the inlet of cooling water channel 26; Outlet pipe 25 connects the outlet of this cooling water channel 26, and water inlet pipe 24 is also discharged in order to the cooling water channel of water being introduced in the shell 26 with outlet pipe 25; Water-filled radiator 20 should have certain counterweight simultaneously also as the chassis.The upper and lower end face of said shell is the plane; Heat conductivility good metal material is adopted in the upper surface, like copper, aluminium.Water-filled radiator 20 also can be selected common water cooling equipment.

With reference to Fig. 2, Figure 12, manufacturing process of the present invention is following:

Frequency-doubling crystal, GRIN Lens, heat conduction copper billet, encapsulation sleeve pipe, tail optical fiber etc. are assembled together; And be fixed on the temperature controller 15, whole assembling process must guarantee the center conllinear of first tail optical fiber 8, first GRIN Lens 10, frequency-doubling crystal 11, second GRIN Lens 12 and second tail optical fiber 14.

Semiconductor chilling plate 21 is selected TEC1-12712 for use, and enthusiasm 22 adopts the red copper piece of 62mm*62mm*6mm, and polishing is done on the surface; Adopting 10 layers piles up; Also be totally 11 of semiconductor chilling plates 21, totally 10 of enthusiasm 22 are smeared one deck heat-conducting silicone grease between semiconductor chilling plate 21 and the enthusiasm 22 when piling up; Need punching, tapping in advance in semiconductor chilling plate 21 sides of top layer and bottom, will pile up good semiconductor chilling plate and enthusiasm tension with tie rod; At its outside parcel heat preserving and insulating material 23, select polyurethane heat insulation material in this instance for use then, make columniform semiconductor refrigerating heap 17, its external diameter is consistent with vacuum (-tight) housing 19 internal diameters, accomplishes to closely cooperate.

Fiber reel adopts aluminum profile extrusion to become high 15cm around post 18, and diameter is the cylinder of 10cm, and is carved into the thread groove that the degree of depth is 0.3mm*0.3mm, separation 1mm above that.Double clad neodymium-doped fiber (3) is coiled in fiber reel on post 18; And double clad neodymium-doped fiber 3 placed groove; The tail optical fiber of the first total reflection optical fiber grating 2, the second total reflection optical fiber grating 4, semiconductor refrigerating is laid out outside piling the heat preserving and insulating material 23 in 17 outsides; Semiconductor laser 1, the first total reflection optical fiber grating 2, the second total reflection optical fiber grating 4 all place outside the ultralow temperature semiconductor cooler 16, add a cover vacuum (-tight) housing 19.Vacuum (-tight) housing 19 adopts stainless steel materials to process, and it is adiabatic to reach insulation that interlayer is evacuated, and internal diameter is got 13cm, in high 26cm, the thick 1.5cm of interlayer, inwall polishes smooth.

It is that the thick 1.2cm of 20cm is cylindric that water-filled radiator 20 adopts copper materials to be processed into diameter, and inner shown in figure 11 have many vertical dividing plates 36, and dividing plate forms cooling water channel 26.Between the heat-absorbent surface of the radiating surface of semiconductor refrigerating heap 17 and water-filled radiator 20, smear one deck heat-conducting silicone grease, and be fixed; Heat-absorbent surface and fiber reel at semiconductor refrigerating heap 17 are smeared one deck heat-conducting silicone grease between the bottom surface of post 18, also be fixed.

In the present embodiment, the travel track of fundamental frequency light in first GRIN Lens 18, frequency-doubling crystal 19 and second GRIN Lens 20 is as shown in Figure 3, and it converges at the central point of frequency-doubling crystal 19.

In the present embodiment; Diode-end-pumped source 1 provides laser pumping; Pump light sees through the inner cladding that the first total reflection optical fiber grating 2 injects double clad neodymium-doped fibers 3, along with pump light transmits in inner cladding and gets into the fibre core of double clad neodymium-doped fiber 3 continuously; The fibre core of double clad neodymium-doped fiber 3 constitutes working-laser material (Nd ³⁺), it is the 938nm laserresonator that the fibre core of the first total reflection optical fiber grating 2, double clad neodymium-doped fiber 3 and the 3rd total reflection optical fiber grating 6 constitute wavelength, i.e. the fundamental frequency part of the fiber laser of this instance, working-laser material (Nd ³⁺) produce the fluorescent radiation of 938nm after the absorptive pumping light energy; This fluorescent radiation is constantly reflection between the first total reflection optical fiber grating 2 and the 3rd total reflection optical fiber grating 6; Repeatedly being strengthened forming wavelength by continuous amplification through the fibre core of double clad neodymium-doped fiber 3 is the laser generation of 938nm; At this moment; Because fundamental frequency light is constantly reflection and not output between first fiber grating 2 and the 3rd fiber grating 6, there not be the fiber laser exported thereby form one, the dotted line of the latter half is the fundamental frequency light light path of advancing among Fig. 4.

The frequency multiplication part of the second total reflection optical fiber grating 4 and interior frequency multiplier 5 formations of convergent type fiber laser cavity laser of the present invention; Along with the base frequency oscillation of laserresonator is constantly strengthened; Fundamental frequency light is through producing second harmonic (frequency multiplication) during frequency multiplier 5 in the convergent type fiber laser cavity; Thereby from wavelength is that the fundamental frequency light of 938nm converts the frequency doubled light that wavelength is 469nm into, and the dotted line of Fig. 4 the first half is the frequency doubled light light path of advancing, and the frequency doubled light of left-hand is become dextrad by the second total reflection optical fiber grating, 4 reflection back direct of travels; The frequency doubled light that dextrad is advanced is exported by its tail optical fiber through the 3rd total reflection optical fiber grating 6 backs, thereby can obtain very high shg efficiency.In whole process; The pumping assembly continues to provide energy to inject, and double clad neodymium-doped fiber 3 consumes pump light and produces fundamental frequency light, and the frequency-doubling crystal 11 in the convergent type intracavity frequency doubling device 5 consumes fundamental frequency light and produces frequency doubled light; This process finally reaches stable state, keeps continuous stable state double-frequency laser output.

Open the power supply of semiconductor refrigerating heap 17, make semiconductor refrigerating heap 17 begin refrigeration, after 20 minutes; Open semiconductor laser 1 and progressively increase electric current; Shown in figure 13 etc. stable back acquisition laser spectroscopy, when pump power 30W, obtained the laser output of 5.1W, shown in figure 14.

Claims (10)

1. high-power Blue-light optical fiber laser of 469nm all optical fibre structure; It is characterized in that; Comprise diode-end-pumped source (1), the first total reflection optical fiber grating (2), the second total reflection optical fiber grating (4), the 3rd total reflection optical fiber grating (6) and ultralow temperature semiconductor cooler (16); Be connected with double clad Yb dosed optical fiber (3) between the said first total reflection optical fiber grating (2) and the second total reflection optical fiber grating (4); Be connected with intracavity frequency doubling device (5) between the second total reflection optical fiber grating (4) and the 3rd total reflection optical fiber grating (6); The output of the 3rd total reflection optical fiber grating (6) connects output tail optical fiber (7), and above-mentioned each element connects through fusing mode, and output tail optical fiber (7) is a laser output; It is the 938nm laserresonator that the said first total reflection optical fiber grating (2), double clad neodymium-doped fiber (3) and (6) three parts of the 3rd total reflection optical fiber grating constitute wavelength; The second total reflection optical fiber grating (4) and intracavity frequency doubling device (5) constitute the frequency multiplication part of laser; Double clad Yb dosed optical fiber (3) and with it the weld of the preceding tail optical fiber of back tail optical fiber and the second total reflection optical fiber grating (4) of the first total reflection optical fiber grating (2) of phase welding all place ultralow temperature semiconductor cooler (16), the preceding tail optical fiber of the back tail optical fiber of the first total reflection optical fiber grating (2) and the second total reflection optical fiber grating (4) is drawn from ultralow temperature semiconductor cooler (16).

2. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 1 is characterized in that, adopt with 100 μ m tail optical fiber output center wavelengths in said diode-end-pumped source (1) is the semiconductor laser of 35W for 808nm power; It is 938nm total reflection Bragg fiber grating that the first total reflection optical fiber grating (2), the 3rd total reflection optical fiber grating (6) all adopt the reflection kernel wavelength, and reflectivity is greater than 99%; It is the double clad neodymium-doped fiber of 6/125 μ m that double clad neodymium-doped fiber (3) adopts core diameter, and length is 12m; It is 469nm total reflection Bragg fiber grating that the second total reflection optical fiber grating (4) is hit cardiac wave long with negate, and reflectivity is greater than 99%; It is the non-doped fiber of double clad of 6/125 μ m that output tail optical fiber (7) is selected core diameter.

3. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 1; It is characterized in that; Said intracavity frequency doubling device (5) comprises full-automatic temperature controlling stove (15), first tail optical fiber (8), sleeve pipe (9), first GRIN Lens (10), frequency-doubling crystal (11), second GRIN Lens (12), heat conduction copper billet (13) and second tail optical fiber (14); Wherein, first GRIN Lens (10) and second GRIN Lens (12) are bonded in the left and right two ends of frequency-doubling crystal (11) respectively; The left end of first GRIN Lens (10) and first tail optical fiber (8) have the end bonding of tail optical fiber contact pin, and the right-hand member of second GRIN Lens (12) and second tail optical fiber (14) have the end bonding of tail optical fiber contact pin; First tail optical fiber (8), sleeve pipe (9), first GRIN Lens (10), frequency-doubling crystal (11), second GRIN Lens (12) and second tail optical fiber (14) center conllinear, constituting with frequency-doubling crystal (11) jointly is the symmetry structure at center; The outside of first GRIN Lens (10), frequency-doubling crystal (11), second GRIN Lens (12) three's integral body is enclosed with indium foil and heat conduction copper billet (13) successively; The bottom surface of said heat conduction copper billet (13) contacts with full-automatic temperature controlling stove (15); The remaining surface of heat conduction copper billet (13) is encapsulated in sleeve pipe (9) inside; First tail optical fiber (8) from the left end of sleeve pipe (9) pass and with second total reflection optical fiber grating (4) welding; Second tail optical fiber (14) passes and the 3rd total reflection optical fiber grating (6) welding from the right two ends of sleeve pipe (9), adopts fibre core to aim at during each element welding.

4. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 3; It is characterized in that; Said first GRIN Lens (10) is selected identical GRIN Lens for use with second GRIN Lens (12); Its length is 0.3P ~ 0.45P, and said frequency-doubling crystal (11), first GRIN Lens (10) and second GRIN Lens (12) satisfy formula 1:

$L=-\frac{2n_1\mathrm{Tan}\left(\mathrm{\&alpha;\; d}\right)}{\mathrm{\&alpha;}{n}_0}$ Formula 1

In the formula, L is the length of frequency-doubling crystal (11); n ₁Refractive index for frequency-doubling crystal (11); n ₀It is the refractive index of the centre of first GRIN Lens (10); D is the length of first GRIN Lens (10), gets 0.3P ~ 0.45P; α is first GRIN Lens (a 10) refractive index profile coefficient; The refractive index n (r) of first GRIN Lens (10) radially r distribution satisfies formula 2:

N (r)=n ₀(1-α ²r ²/ 2) formula 2

In the formula, r is a radial coordinate.

5. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 3; It is characterized in that it is that 3mm, length are the circular GRIN Lens of 6mm that said first GRIN Lens (10), second GRIN Lens (12) all adopt d=0.30P, diameter; Frequency-doubling crystal (11) is chosen lbo crystal, and cross sectional dimensions is chosen 3mm*3mm, and frequency-doubling crystal length is 18.8mm; First tail optical fiber (8), second tail optical fiber (14) are all selected 6/125 μ m double clad non-impurity-doped optical fiber for use, and length is got 2 meters; Heat conduction copper billet (13) length is got 28.8mm, wall thickness 5mm; The length of encapsulation sleeve pipe (9) is got 40.8mm, side thickness 3mm, the thick 6mm of end wall.

6. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 1; It is characterized in that; Said ultralow temperature semiconductor cooler (16) comprises that semiconductor refrigerating heap (17), fiber reel are around post (18), vacuum (-tight) housing (19) and water-filled radiator (20); Wherein, fiber reel places semiconductor refrigerating heap (17) upper surface around post (18), and semiconductor refrigerating heap (17) places the upper surface of water-filled radiator (20); The upper surface of semiconductor refrigerating heap (17) is a heat absorbing end, and lower surface is a release end of heat; Vacuum (-tight) housing (19) is the hollow cylinder of lower ending opening, and vacuum (-tight) housing (19) is buckled in water-filled radiator (20) top and fiber reel is placed inside around post (18) and semiconductor refrigerating heap (17), and the inner cavity that forms of vacuum (-tight) housing (19) is a vacuum chamber.

7. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 6; It is characterized in that; The heat preserving and insulating material (23) that said semiconductor refrigerating heap (17) comprises the refrigeration inner core and is coated on refrigeration inner core side; The refrigeration inner core is made up of one or more identical refrigeration bodies; Described refrigeration body is formed by a plurality of semiconductor chilling plates (21) and a plurality of enthusiasm (22) alternated, and the refrigeration body upper and lower surface be semiconductor chilling plate (21), between semiconductor chilling plate (21) and enthusiasm (22), be coated with heat conduction auxiliary agent or Heat Conduction Material; Each semiconductor chilling plate (21) all is connected with DC power supply; The upper surface heat absorption lower surface heat release of semiconductor chilling plate (21).

8. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 6 is characterized in that said fiber reel is carved with groove around the circumferencial direction of post (18).

9. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 6 is characterized in that said vacuum (-tight) housing (19) adopts double-deck outer wall, and should be vacuum between the bilayer outer wall.

10. the high-power Blue-light optical fiber laser of 469nm all optical fibre structure as claimed in claim 6; It is characterized in that; Water inlet pipe (24) and outlet pipe (25) that said water-filled radiator (20) comprises shell and is connected with this enclosure; This enclosure is provided with the dividing plate (36) of many vertical directions; Dividing plate (36) makes shell inner cavity form a circuitous cooling water channel (26) that advances, and water inlet pipe (24) connects the inlet of cooling water channel (26), and outlet pipe (25) connects the outlet of this cooling water channel (26).

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