KIND OF ALL-SOLID-STATE HIGH-POWER SLAB LASER BASED ON PHONON BAND-EDGE EMISSION

Abstract

A kind of all-solid-state high-power slab laser based on phonon band-edge emission, which is comprised of a pumping source, a focusing system, a resonant cavity and a self-frequency-doubling crystal; the said self-frequency-doubling crystal is a Yb-doped RECOB crystal cut into slab shape along the direction of the crystal's maximum effective nonlinear coefficient of its non-principal plane; by changing the cutting direction of the crystal, the phase matching of different wavelengths is realized, thus realizing laser output at the band of 560-600 nm; the said pumping source is a diode laser matrix with a wavelength of 880 nm-980 nm; the input cavity mirror and the output cavity mirror are coated with films to obtain laser output at the band of 560-600 nm; the two large faces of the said self-frequency-doubling crystal is cooled by heat sink and located between the input cavity mirror and the output cavity mirror.

Claims

1. An all-solid-state high-power slab laser based on phonon band-edge emission, which is comprised of a pumping source, a focusing system, a resonant cavity and a self-frequency-doubling crystal in the resonant cavity; in which the said pumping source, focusing system and resonant cavity are successively arranged along the optical path, and the said resonant cavity is located at the output end of the said focusing system; in which the said self-frequency-doubling crystal is a Yb-doped RECOB crystal; the resonant cavity is comprised of an input cavity mirror and an output cavity mirror, in which the said input cavity mirror and the output cavity mirror are respectively coated with a dielectric film, to suppress the starting laser oscillation at the band of 1020-1080 nm and realize the starting laser oscillation at the band of 1120-1200 nm; which is characterized in that: the said self-frequency-doubling crystal is cut into slab shape along the direction of the crystal's maximum effective nonlinear coefficient; the said pumping source is a diode laser matrix at 880 nm-980 nm, and the pump light emitted by the said pumping source forms a rectangular spot through the said focusing system and is focused on the light transmission face of the self-frequency-doubling in the said resonant cavity; the said light transmission direction is the lengthwise direction of the slab-shaped crystal.

2. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that the said focusing system is one of the following forms: a. a single piano-convex cylindrical lens or the assembly of multiple piano-convex cylindrical lenses, b. a single plano-convex lens or the assembly of multiple plano-convex lenses, c. a single biconvex lens or the assembly of multiple biconvex lenses, d. the assembly of a plano-convex lens, a plano-convex cylindrical lens and a plano-concave cylindrical mirror, e. the assembly of a biconvex lens, a plano-convex cylindrical lens and a plano-concave cylindrical mirror.

3. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that the focal length of the focusing system is 1 cm-30 cm; the preferred focal length is 1-10 cm; and the said focusing system focuses the pump light emitted by the pumping source into a rectangular spot.

4. the all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that the light transmission face of the said self-frequency-doubling crystal is rectangular; the light transmission direction of the self-frequency-doubling crystal is the lengthwise direction of the crystal, and the length is 0.5 mm-50 mm; the thickness of the crystal is 0.4 mm-2 mm, and the width of the self-frequency-doubling crystal is greater than the thickness of the crystal; according to a further preferred embodiment, the self-frequency-doubling crystal has a length of 6 mm-10 mm, a width of 12 mm, and a thickness of 1 mm; it is preferred to cool the two large faces of the said self-frequency-doubling crystal by heat sink.

5. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that the self-frequency-doubling crystal is cut along the optimum phase matching direction, i.e. the direction of the effective nonlinear coefficient of the non-principal plane; according to a preferred embodiment, the optimum phase matching direction is an angle of (12010) to axis Z in the principal axis direction with the maximum crystal refractive index and an angle of (4010) to axis X in the principal axis direction with the minimum crystal refractive index.

6. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that the said input cavity mirror is formed by coating the input mirror with dielectric film A, or coating the light incidence face of the said self-frequency-doubling crystal with dielectric film A; the said dielectric film A has a dielectric film with high transmittance to the pump light at 880 nm-980 nm and a dielectric film with high transmittance at 1020-1080 nm, or the said dielectric film A at least has a dielectric film with high transmittance at 880 nm-1100 nm.

7. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that the said output cavity mirror is formed by coating the output mirror with dielectric film B, or coating the light emission face of the said self-frequency-doubling crystal with dielectric film B; according to a preferred embodiment, the said dielectric film B has a dielectric film with high reflectivity to the pump light at 880 nm-980 nm and a dielectric film with high transmittance at 1020-1080 nm. Or, the said dielectric film B at least has a dielectric film with high reflectivity at 880 nm-980 nm and with transmittance at 980-1100 nm.

8. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 6, which is characterized in that the said input cavity mirror is also coated with a dielectric film with high reflectivity at bands of 1100 nm-1200 nm and 560 nm-600 nm, and the output cavity mirror is coated with a dielectric film with high reflectivity at 1100 nm-1200 nm and high transmittance at 560 nm-600 nm.

9. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that it is comprised of a pumping source, a focusing system, an input cavity mirror, a self-frequency-doubling crystal and an output cavity mirror successively ranged along the optical path; the said pumping source is a diode laser matrix with a wavelength of 880 nm-980 nm; the said self-frequency-doubling crystal is a Yb-doped COB crystal and is cut into slab shape along the direction of the crystal's maximum effective nonlinear coefficient, and the said self-frequency-doubling crystal is located at the focus of the focusing system; the said input cavity mirror and the output cavity mirror form a laser resonant cavity; the input cavity mirror is the input mirror coated with dielectric film A with high transmittance at 880-1100 nm and high reflectivity at 1100-1200 nm and 560-600 nm; the output cavity mirror is the output mirror coated with dielectric film B with high reflectivity at 880-980 nm and 1100-1200 nm and high transmittance at 980-1100 nm and 560-600 nm.

10. The all-solid-state high-power slab laser based on phonon band-edge emission according to claim 1, which is characterized in that it is comprised of a pumping source, a focusing system, an input cavity mirror, a self-frequency-doubling crystal and an output cavity mirror successively ranged along the optical path; the said pumping source is a diode laser matrix with a wavelength of 880 nm-980 nm; the said self-frequency-doubling crystal is a Yb-doped RECOB crystal and is cut into slab shape along the direction of the crystal's maximum effective nonlinear coefficient, and the said self-frequency-doubling crystal is located at the focus of the focusing system; the input cavity mirror is the incidence face of the self-frequency-doubling crystal coated with dielectric film A with high transmittance at 880-1100 nm and high reflectivity at 1100-1200 nm and 560-600 nm; the output cavity mirror is the emission face of the self-frequency-doubling crystal coated with dielectric film B with high reflectivity at 880-980 nm and 1100-1200 nm and high transmittance at 980-1100 nm and 560-600 nm; the said dielectric film A and dielectric film B form a laser resonant cavity.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0048] FIG. 1 is the schematic diagram of the slab-shaped crystal. The left is the incidence face. Pumping Laser represents the incidence direction of the pump light, W the width of the crystal, and t the thickness of the crystal, and the two faces of Wt are the light transmission faces of the crystal, where the width W is greater than the thickness t. The crystal length L is the light transmission direction of the crystal and the right is the emission face. Output Laser represents the emission direction of the laser.

[0049] FIG. 2 is the schematic diagram of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 1; where 1 is the pumping source, 2 the focusing system, 3 the dielectric film A, 4 the self-frequency-doubling crystal, 5 the dielectric B and 6 the laser output.

[0050] FIG. 3 is the solid figure of FIG. 2.

[0051] FIG. 4 is the laser output spectrum of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 1, where the x-coordinate represents the wavelength (nm) and the y-coordinate represents the intensity.

[0052] FIG. 5 is the schematic diagram of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 9; where 7 is the input cavity mirror and 8 is the output cavity mirror. 3-1 is a dielectric film with high transmittance at 880-1100 nm, and 3-2 is a dielectric film with high reflectivity at 1100-1200 nm and 560-600 nm. 5-1 is a dielectric film with high reflectivity at 880-980 nm and 1100-1200 nm, and 5-2 is a dielectric film with high transmittance at 980-1100 nm and 560-600 nm.

[0053] FIG. 6 is the solid figure of FIG. 5.

[0054] FIG. 7 is the heat dissipation structure of the crystal of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 1, where 9 is the heat sink and 10 is the indium foil.

[0055] FIG. 8 is the laser output spectrum of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 9, where the x-coordinate represents the wavelength (nm) and the y-coordinate represents the intensity.

[0056] FIG. 9 is the laser output spectrum of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 17, where the x-coordinate represents the wavelength (nm) and the y-coordinate represents the intensity.

[0057] FIG. 10 is the laser output spectrum of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 18, where the x-coordinate represents the wavelength (nm) and the y-coordinate represents the intensity.

[0058] FIG. 11 is the laser output spectrum of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 19, where the x-coordinate represents the wavelength (nm) and the y-coordinate represents the intensity.

[0059] FIG. 12 is the laser output spectrum of the all-solid-state high-power slab laser based on phonon band-edge emission in Embodiment 20, where the x-coordinate represents the wavelength (nm) and the y-coordinate represents the intensity.

DETAILED DESCRIPTION

[0060] The present invention is further described in combination with the attached figures and embodiments as follows, but the protection scope of the present invention is not limited to this.

[0061] Unless otherwise specified, all components used in the embodiments reflect the state of the art.

Embodiment 1

[0062] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, with a structure as shown in FIGS. 2 and 3, which is comprised of a pumping source 1, a focusing system 2, and a self-frequency-doubling crystal 4 successively arranged along the optical path. The pumping source 1 is a diode laser matrix with emission center wavelength of 976 nm; the focusing system 2 is comprised of a piano-convex cylindrical lens with a focal length of 6.35 cm; the self-frequency-doubling crystal 4 is a Yb-doped YCOB crystal with a doping concentration of ytterbium ion of 20 at. %, the crystal length in the light transmission direction is 8 mm, the light transmission face is a rectangle of 121 mm.sup.2 polished, the two large faces of the crystal is cooled by the heat sink 9 (as shown in FIG. 7), the cutting direction is along the phase matching direction of the maximum effective nonlinear coefficient, the optimum phase matching direction is: forming an angle of (1201) to axis Z and an angle of (382) to axis X, and the said self-frequency-doubling crystal 4 is located at the focus of the focusing system; the incidence face of the self-frequency-doubling crystal 4 is coated with dielectric film A with high transmittance at 880-1100 nm and high reflectivity at 1100-1200 nm and 560-600 nm, as represented by 3 in FIG. 2; the emission face is coated with dielectric film B with high reflectivity at 880-980 nm and 1100-1200 nm and high transmittance at 980-1100 nm and 560-600 nm, as represented by 5 in FIG. 2; the dielectric film A 3 and dielectric film B 5 form a laser resonant cavity.

[0063] After starting the pumping source 1 and increasing the pumping power, 5 W high-power yellow laser output at band of 568.7 nm can be obtained under the pumping power of 65 W. The output wavelength is as shown in FIG. 4.

Embodiments 2-4

[0064] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 1, which differs in the self-frequency-doubling crystal 4. The length in light transmission direction of the Yb-doped YCOB crystal is respectively 4 mm, 6 mm and 10 mm. Other conditions and components are consistent with those described in Embodiment 1. After starting the pumping source 1 and increasing the pumping power, yellow laser output at the band of about 570 nm can be realized in all cases.

Embodiments 5-8

[0065] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 1, which differs in the self-frequency-doubling crystal 4. The light transmission face of the Yb-doped YCOB crystal is respectively 61 mm.sup.2, 81 mm.sup.2, 101 mm.sup.2 and 120.5 mm.sup.2. Other conditions and components are consistent with those described in Embodiment 1. Yellow laser output at the band of about 570 nm can be realized in all cases. The four kinds of light transmission face have different lengths and can be used to match spot sizes focused by different pumping sources. The spot length is kept equivalent to the crystal width.

Embodiment 9

[0066] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, with a structure as shown in FIGS. 5 and 6, which is comprised of a pumping source 1, a focusing system 2, an input cavity mirror 7, a self-frequency-doubling crystal 4 and an output cavity mirror 8 successively arranged along the optical path.

[0067] The pumping source 1 is a diode laser matrix with emission center wavelength of 976 nm; the focusing system 2 is comprised of a piano-convex cylindrical lens with a focal length of 6.35 cm; the input cavity mirror 7 and an output cavity mirror 8 form a laser resonant cavity. The input cavity mirror 7 is a plano-plano lens, and the light transmission face is coated with a dielectric film with high transmittance at 880-1100 nm (as represented by 3-1 in FIG. 5) and a dielectric film with high reflectivity at 1100-1200 nm and 560-600 nm (as represented by 3-2 in FIG. 5), which form the dielectric film A together (as represented by 3 in FIG. 2); the self-frequency-doubling crystal 4 is a Yb-doped YCOB crystal with a doping concentration of ytterbium ion of 20 at. %, the crystal length in the light transmission direction is 8 mm, the light transmission face is a rectangle of 121 mm.sup.2, the two large faces of the crystal is cooled by the heat sink 9, the light transmission face is polished and coated with a dielectric film with high transmittance at 880 nm-1200 nm and 560 nm-600 nm, the cutting direction is along the phase matching direction of the maximum effective nonlinear coefficient, and the cutting angle is: (1201) to axis Z and (382) to axis X. And the said self-frequency-doubling crystal 4 is located at the focus of the focusing system; the output cavity mirror 8 is coated with a dielectric film with high reflectivity at 880-980 nm and 1100-1200 nm (as represented by 5-1 in FIG. 5) and a dielectric film with high transmittance at 980-1100 nm and 560-600 nm (as represented by 5-1 in FIG. 5), which form dielectric film B together (as represented by 5 in FIG. 2).

[0068] After starting the pumping source 1, increasing the pumping power, and adjusting the laser resonant cavity and the self-frequency-doubling crystal 4, laser output at the band of 569.2 nm is obtained. The output wavelength is as shown in FIG. 8.

Embodiments 10-12

[0069] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 9, which differs in the self-frequency-doubling crystal 4. The length in light transmission direction of the Yb-doped YCOB crystal is respectively 4 mm, 6 mm and 10 mm. Other conditions and components are consistent with those described in Embodiment 9. After starting the pumping source 1 and increasing the pumping power, yellow laser output at the band of about 570 nm can be realized in all cases.

Embodiments 13-16

[0070] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 9, which differs in the self-frequency-doubling crystal 4. The light transmission face of the Yb-doped YCOB crystal is respectively 61 mm.sup.2, 81 mm.sup.2, 101 mm.sup.2 and 120.5 mm.sup.2. Other conditions and components are consistent with those described in Embodiment 9. Yellow laser output at the band of about 570 nm can be realized in all cases after starting the pumping source 1 and increasing the pumping power. Different lengths of the light transmission face can be used to match spot sizes focused by different pumping sources.

Embodiment 17

[0071] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 1, which differs in that the cutting angle of the Yb-doped YCOB crystal of the self-frequency-doubling crystal is: (1201) to axis Z and (342) to axis X. Other conditions and components are consistent with those described in Embodiment 1. After starting the pumping source 1 and increasing the pumping power, yellow laser output at the band of about 590 nm can be realized. The output wavelength is 590.2 nm, as shown in FIG. 9.

Embodiment 18

[0072] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 1, which differs in that the self-frequency-doubling crystal is a Yb-doped GdCOB crystal and the doping concentration of ytterbium ion is lat. %. The cutting angle of the crystal is: (1201) to axis Z and (462) to axis X. Other conditions and components are consistent with those described in Embodiment 1. After starting the pumping source 1 and increasing the pumping power, yellow laser output at the band of 580 nm can be realized. The output wavelength is 582.7 nm, as shown in FIG. 10.

Embodiment 19

[0073] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 1, which differs in the cutting angle of the Yb-doped YCOB crystal of the self-frequency-doubling crystal. The crystal is cut along the phase matching direction of the maximum effective nonlinear coefficient at 1120 nm. Other conditions and components are consistent with those described in Embodiment 1. After starting the pumping source 1 and increasing the pumping power, yellow laser output at the band of 560 nm can be realized. The output wavelength is 560.1 nm, as shown in FIG. 11.

Embodiment 20

[0074] A kind of all-solid-state high-power slab laser based on phonon band-edge emission, as described in Embodiment 1, which differs in the cutting angle of the Yb-doped YCOB crystal of the self-frequency-doubling crystal. The crystal is cut along the phase matching direction of the maximum effective nonlinear coefficient at 1200 nm. Other conditions and components are consistent with those described in Embodiment 1. After starting the pumping source 1 and increasing the pumping power, yellow laser output at the band of 600 nm can be realized. The output wavelength is 599.8 nm, as shown in FIG. 12.