阅读说明：本技术 镱离子掺杂abgs晶体及自倍频超短脉冲激光器 (Ytterbium ion doped ABGS crystal and self-frequency-doubling ultrashort pulse laser ) 是由 张栩朝 郭世义 王正平 许心光 于 2020-05-15 设计创作，主要内容包括：本发明涉及镱离子掺杂ABGS晶体及自倍频超短脉冲激光器,该激光器包括沿光路设置的半导体激光泵浦源、聚焦系统、第一谐振腔镜M<Sub>1</Sub>、自倍频激光晶体、第二谐振腔镜M<Sub>2</Sub>、GTI镜、第三谐振腔镜M<Sub>3</Sub>、第四谐振腔镜M<Sub>4</Sub>、可饱和吸收体；自倍频激光晶体为镱离子掺杂A<Sub>3</Sub>BGa<Sub>3</Sub>Si<Sub>2</Sub>O<Sub>14</Sub>晶体,A＝Ca或Sr,B＝Nb或Ta。该晶体同时具有激光发射和非线性光学效应,使用一块自倍频晶体通过锁模技术,实现超短脉冲自倍频绿光输出。本发明成本低,采用一块自倍频激光晶体替代激光晶体和非线性晶体两块晶体,生产成本大大降低,同时也简化了加工和装配环节,提高了生产效率。(The invention relates to an ytterbium ion doped ABGS crystal and a self-frequency doubling ultrashort pulse laser, wherein the laser comprises a semiconductor laser pumping source, a focusing system and a first resonant cavity mirror M which are arranged along a light path 1 Self-frequency-doubling laser crystal and second resonant cavity mirror M 2 GTI mirror, third resonant cavity mirror M 3 And the fourth resonant cavity mirror M 4 A saturable absorber; the self-frequency-doubling laser crystal is ytterbium ion doped A 3 BGa 3 Si 2 O 14 Crystal, A ═ Ca or Sr, B ═ Nb or Ta. The crystal has both laser emission and nonlinear optical effects, and realizes ultrashort pulse self-frequency-doubling green light output by using a self-frequency-doubling crystal through a mode locking technology. The invention has low cost, adopts a piece of self-frequency doubling laser crystal to replace two crystals, namely the laser crystal and the nonlinear crystal, greatly reduces the production cost, simplifies the processing and assembling links and improves the production efficiency.)

1. The self-frequency-doubling ultrashort pulse laser based on the ytterbium ion doped ABGS crystal is characterized by comprising a semiconductor laser pumping source, a focusing system and a first resonant cavity mirror M which are arranged along a light path₁Self-frequency-doubling laser crystal and second resonant cavity mirror M₂GTI mirror, third resonant cavity mirror M₃And the fourth resonant cavity mirror M₄A saturable absorber; the self-frequency-doubling laser crystal is ytterbium ion doped A₃BGa₃Si₂O₁₄Crystal, A ═ Ca or Sr, B ═ Nb or Ta.

2. The self-frequency-doubled ultrashort pulse laser based on ytterbium ion doped ABGS crystal as claimed in claim 1, wherein the ytterbium ion doping A is doped₃BGa₃Si₂O₁₄The length of the crystal in the light passing direction is 0.1-100 mm.

3. The self-frequency-doubled ultrashort pulse laser based on ytterbium ion doped ABGS crystal as claimed in claim 1, wherein the ytterbium ion doping A is doped₃BGa₃Si₂O₁₄The cutting directions of the crystal are both along 1064nm frequency doubling phase matching directions, 532nm green laser output is realized after frequency doubling, and the specific output wavelength is influenced by experimental conditions and can be changed due to different parameters of a pumping source and a resonant cavity mirror.

4. The self-frequency-doubled ultrashort pulse laser based on ytterbium ion doped ABGS crystal as claimed in claim 1, wherein the ytterbium ion doping A is doped₃BGa₃Si₂O₁₄The ytterbium ion doping concentration of the crystal is (0.1-50) at.%.

5. The self-frequency-doubled ultrashort pulse laser based on ytterbium ion doped ABGS crystal as claimed in claim 1, wherein the laser is characterized in thatIn the step A, the ytterbium ion is doped₃BGa₃Si₂O₁₄The crystal is a cuboid or a cylinder;

preferably, the ytterbium ion is doped with A₃BGa₃Si₂O₁₄The cutting angle of the I-type phase matching of the crystal is (theta, phi), wherein the value range of theta is 31.6-41.6 degrees, and the value range of phi is-180.0 degrees;

preferably, the ytterbium ion is doped with A₃BGa₃Si₂O₁₄The cutting angle of the class II phase matching of the crystal is (theta 1, phi 1), the value range of the theta 1 is 51.5 degrees to 61.5 degrees, and the value range of the phi 1 is-180 degrees to 180 degrees.

6. The self-frequency-doubling ultrashort pulse laser based on the ytterbium ion doped ABGS crystal as claimed in claim 1, wherein the left and right light-passing end faces of the self-frequency-doubling laser crystal are respectively coated with (960-990) nm, (1000-1100) nm and (500-550) nm antireflection films.

7. The self-frequency-doubling ultrashort pulse laser based on the ytterbium ion doped ABGS crystal as claimed in claim 1, wherein the semiconductor laser pump source is a direct output semiconductor laser or a fiber-coupled output semiconductor laser with the central wavelength of (960-;

preferably, the first resonator mirror M₁At least is plated with a dielectric film which has high transmittance to (960-990) nm light and high reflectance to (1000-1100) nm light; the second resonant cavity mirror M₂At least is plated with a dielectric film with high reflection to (960-990) nm light and (1000-1100) nm light; the fourth resonant cavity mirror M₄At least a dielectric film with high reflection to (1000-1100) nm light is plated;

preferably, the third resonant cavity mirror M₃At least is coated with a dielectric film with the light transmission rate of (1000-1100) nm of (0.1-20)%.

8. The self-frequency-doubled ultrashort pulse laser based on ytterbium ion doped ABGS crystal of claim 1, wherein the saturable absorber is Cr: YAG crystal, SESAM,Graphene, MoS₂、WS₂Any one of the above.

9. Ytterbium ion doped A as claimed in claim 1₃BGa₃Si₂O₁₄Crystal, A ═ Ca or Sr, B ═ Nb or Ta.

10. Ytterbium ion doped A as claimed in claim 1₃BGa₃Si₂O₁₄The crystal is applied, wherein A is Ca or Sr, and B is Nb or Ta, and is characterized in that the crystal is applied to self-frequency-doubling film-locked lasers.

Technical Field

The invention relates to a passive mode-locking self-frequency-doubling ultrashort pulse laser, in particular to a laser based on ytterbium ion doping A₃BGa₃Si₂O₁₄A self-frequency-doubling laser of (A ═ Ca, Sr; B ═ Nb, Ta) crystal belongs to the laser technology field, relates to laser and non-linearityA crystal device.

Background

Visible wave band (380nm-760nm) pulse laser, especially ultrashort pulse laser (picosecond and femtosecond magnitude) is used as an important technical means for researching objective world ultrafast phenomenon, and is widely applied to the fields of micro-nano processing, optical detection, military defense and the like. For example, for unknown personnel entering military exclusion zones during war time, interlopers can be temporarily blinded and stopped using a green (532 nm) pulsed laser, which can achieve effective but harmless area defense. At present, the common way to obtain all-solid-state visible pulse laser is to use Nd and Yb doped laser crystal to obtain near-infrared ultrashort pulse laser through mode locking technology and then use nonlinear crystal to carry out frequency doubling, or use Pr doped laser of blue LD pump³⁺,Sm³⁺,Tb³⁺,Dy³⁺,Ho³⁺,Er³⁺A laser.

However, the conventional Nd and Yb doped laser needs a plurality of optical elements to obtain visible band pulse laser, and has a complex structure; especially, when the mode-locked laser is operated, the loss in the cavity is increased after the nonlinear crystal is introduced, which is not beneficial to obtaining ultrashort pulse; while the extra-cavity frequency conversion will make the laser device more complex. Pr-doped of blue-light LD pump³⁺,Sm³⁺,Tb³⁺,Dy³⁺,Ho³⁺,Er³⁺The laser can realize laser output with multiple wavelengths, and can obtain higher conversion efficiency in the aspect of continuous laser operation, but the blue LD is relatively lagged in development and expensive, and factors such as low output power, poor temperature stability and the like are not favorable for obtaining high-energy, high-peak power and ultrashort pulse laser, while the lack of a mature and stable visible waveband light modulation device is another important factor for limiting the performance of the pulse laser.

The visible waveband mode-locked pulse laser utilizing the self-frequency doubling crystal can simultaneously realize laser generation and nonlinear frequency doubling only by one self-frequency doubling crystal, and can directly obtain visible waveband ultrashort pulse laser by utilizing a mode-locking technology.

Patent document CN 104659648A discloses a neodymium-doped lanthanum gallium silicate (Nd: LGS) self-frequency-doubled ultrashort pulse laser, which is a non-phase-matching self-frequency-doubled pulse laser based on Nd: LGS crystal. However, the LGS crystal does not satisfy the phase matching condition, and therefore cannot achieve continuous self-frequency doubling output, and such non-phase matching self-frequency doubling can only be achieved under the condition of higher pulse energy density of the mode-locked laser, and such a self-frequency-doubling pulse laser has low frequency doubling conversion efficiency, low laser power, and requires more accurate temperature control (14 ℃), and cannot satisfy the requirements of practical applications. Further, the inventors of the present invention have disclosed in earlier patent documents self-frequency-doubling laser crystals such as: CN104018225A discloses Nd-doped A3BGa3Si2O14 series crystals and a preparation method and application thereof, CN105048274A discloses a pulse type self-frequency-doubling green laser for passively adjusting Q, CN106801257A discloses an ytterbium-doped crystal and a growth method and application thereof, CN105603529A discloses an ytterbium-doped crystal and a growth method and application thereof, and CN109698461A discloses a pulse type self-frequency-doubling green laser for passively adjusting Q. However, none of these patents relate to the pulse laser performance of ytterbium ion doped self-frequency-doubling laser crystals, especially to the ultra-short pulse laser realized by the mode-locking technique.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides an all-solid-state self-frequency doubling ultrashort pulse laser based on an ytterbium ion doped ABGS crystal.

Drawings

FIG. 1 shows Yb: Ca according to example 3 of the present invention₃NbGa₃Si₂O₁₄Pictures of crystal samples cut and polished along class I phase matched cut angles (36.0 °,30.0 °);

fig. 2 is a schematic structural diagram of a green light self-frequency-doubling ultrashort pulse laser according to embodiment 3 of the present invention;

FIG. 3 is a graph of the intensity autocorrelation of the self-doubling ultrashort pulse of the present invention;

wherein, 1, a semiconductor laser pumping source, 2, a focusing system, 3, a first resonant cavity mirror M₁4, self-frequency-doubling laser crystal, 5, second resonant cavity mirror M₂6, GTI mirror, 7, third resonant cavity mirror M₃8, fourth resonant cavity mirror M₄9, saturable absorber, 10, fundamental mode-locked pulse laser, 11, self-frequency-doubling mode-locked pulse laser.

Detailed Description

The invention is further defined in the following, but not limited to, the figures and examples in the description.

In view of the well-known public knowledge of the researchers in this field, the present invention describes a Yb: A based alloy₃BGa₃Si₂O₁₄Many embodiments of (a ═ Ca, Sr; B ═ Nb, Ta) crystal mode-locked pulse lasers, however, given the variability and tunability of laser experiments, many other variations or modifications consistent with the principles of the present invention can be directly deduced from the present disclosure, such as cavity shape variations, use of slab or flake crystals, variations in the number of GTI mirrors, variations in the manner of dispersion compensation (prism versus dispersion compensation), etc. It is therefore to be understood and appreciated that the invention includes all such variations or modifications.