Low-heat-effect self-optical parametric oscillation laser based on ytterbium ion doped crystal

Abstract

The invention discloses a low-heat-effect self-optical parametric oscillation laser based on an ytterbium ion doped crystal, which relates to the technical field of laser, and comprises a pumping source, a focusing system, an input mirror, the ytterbium ion doped crystal and an output mirror which are sequentially arranged along the direction of an optical path, wherein the ytterbium ion doped crystal is a functional composite crystal capable of simultaneously realizing fundamental frequency optical gain and optical parametric oscillation, and the input mirror and the output mirror form a self-optical parametric oscillation laser resonant cavity. Compared with a traditional self-optical parametric oscillation laser, the self-optical parametric oscillation laser has the advantages that the heat production proportion of the laser is reduced from 25.5% to 11.3%, the heat effect is remarkably reduced, and the power stability of the laser is improved. The self-optical parametric oscillator has the advantages of being simple in structure, small in size, low in heat effect, high in stability and the like, and solves the problems that a traditional optical parametric oscillator is complex in structure and a self-optical parametric oscillator generates heat seriously.

Description

Technical Field

[0001] This invention relates to the field of laser technology, specifically including a low-thermal-effect self-parametric oscillator laser based on a ytterbium ion-doped crystal. Background Technology

[0002] Optical parametric oscillators (OPOs) based on nonlinear frequency conversion offer a wide tuning range for their output laser wavelengths, and the pump laser wavelength is also unrestricted, making them one of the mainstream technologies for obtaining wide-tunable lasers. However, on the one hand, existing OPOs typically consist of a pump laser, a fundamental laser, an OPO resonant cavity, and coupling and isolation systems between each stage, resulting in a complex optical path that is difficult to integrate. On the other hand, while existing OPOs, such as ordinary low-thermal-effect self-oscillation optical parametric oscillators (LDSOs), can improve the heat deposition problem in OPOs, the reduction in thermal effects is not significant, and in certain special scenarios, they cannot meet the conditions for long-term safe and stable operation of LDSOs.

[0003] Therefore, how to simplify the structure of optical parametric oscillators and effectively reduce their thermal effects has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a low-thermal-effect self-optical parametric oscillator laser based on ytterbium ion-doped crystal, which at least solves some of the technical problems in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal includes: a pump source, a focusing system, an input mirror, a ytterbium-doped crystal, and an output mirror arranged sequentially along the optical path; wherein the ytterbium-doped crystal is a functional composite crystal capable of simultaneously realizing fundamental frequency optical gain and optical parametric oscillation, and the input mirror and the output mirror constitute a self-parametric oscillator laser resonator.

[0007] Preferably, the pump source includes a semiconductor diode laser, and the pump light reflected by the semiconductor diode laser has a wavelength of 940 nm-985 nm.

[0008] Preferably, the focusing system comprises a group of convex lenses with different focal lengths.

[0009] Preferably, the focusing system is used to collimate and focus the pump light emitted from the pump source to 100 μm-500 μm.

[0010] Preferably, the ytterbium ion-doped crystal includes ytterbium ion-doped yttrium calcium borate crystal Yb:YCa4O(BO3)3, ytterbium ion-doped yttrium aluminum borate crystal Yb:YAl3(BO3)4, and ytterbium ion-doped lanthanum calcium borate crystal Yb:La2CaB 10 O 19 Ytterbium ion-doped sodium lanthanum borate crystal Yb:Na3La9O3(BO3)8, ytterbium ion-doped gadolinium oxycalcium borate crystal Yb:GdCa4O(BO3)3, or ytterbium ion-doped lithium magnesium oxide niobate crystal Yb:MgO:LiNbO3.

[0011] Preferably, the ytterbium ion doping concentration of the ytterbium ion-doped crystal is 0.1%-30%.

[0012] Preferably, the input mirror in the self-parametric oscillating laser resonator is coated with a dielectric film A that has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm and 1400 nm-1800 nm; the output mirror is coated with a dielectric film B that has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, partial reflectance for 1400 nm-1800 nm, and a transmittance between 1% and 30%.

[0013] To achieve effective output of lasers in three wavelengths: near-infrared (1.0~1.2 μm), eye-safe (1.5~1.8 μm), and mid-infrared (2.9~3.1 μm).

[0014] Preferably, the emission wavelength of the pump source is 976 nm. In this case, the input mirror in the self-optical parametric oscillating laser resonator is coated with a dielectric film that has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm; the output mirror is coated with a dielectric film that has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, high transmittance for 1400 nm-1800 nm, and partial reflectance for 2900 nm-3100 nm.

[0015] To construct a self-optical parametric oscillator with idler frequency optical single resonance, and to achieve effective output of lasers at three wavelengths: near-infrared, eye-safe, and mid-infrared.

[0016] Preferably, the emission wavelength of the pump source is 976 nm. In this case, the input mirror in the self-parametric oscillating laser resonator is coated with a dielectric film that has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm, and the output mirror is coated with a dielectric film that has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, partial reflection for 1400 nm-1800 nm, and partial reflection for 2900 nm-3100 nm.

[0017] To construct a self-optical parametric oscillator with dual resonance of idler and signal light, and to achieve effective output of lasers at three wavelengths: near-infrared, eye-safe, and mid-infrared.

[0018] Preferably, both dielectric film A and dielectric film B are photonic crystal dielectric films with SiO2 / Ta2O5 dielectric layers arranged periodically.

[0019] As can be seen from the above technical solution, the present invention discloses a low-thermal-effect self-optical parametric laser based on ytterbium ion-doped crystal, which has the following beneficial effects:

[0020] Compared to existing neodymium-doped self-parametric oscillating laser crystals and lasers, this invention uses a ytterbium-doped crystal as the crystal within the self-parametric oscillating laser resonator. This reduces the quantum defect from pump light to fundamental light in existing self-parametric oscillating lasers from 25.5% to 11.3%, significantly reducing thermal effects during laser operation and improving laser power stability. Simultaneously, utilizing the self-parametric oscillation effect, and employing a single pump source and a single crystal, effective laser output at three wavelengths can be simultaneously achieved: near-infrared (1.0–1.2 μm), eye-safe (1.5–1.8 μm), and mid-infrared (2.9–3.1 μm).

[0021] The low-thermal-effect self-optical parametric oscillator laser designed in this invention has a simple structure, low cost, high efficiency and suitability for mass production, thus meeting the application needs of special scenarios such as medical treatment. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 A schematic diagram of the structure of a low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal provided by the present invention;

[0024] Figure 2 A comparison of heat generation and crystal temperature between Yb:YCOB crystals doped with ytterbium ions and Nd:GdCOB crystals doped with neodymium ions, provided for this invention.

[0025] Figure 3 The laser wavelength spectrum of three lasers operating simultaneously at 1104 nm, 1745 nm and 3007 nm is provided by the self-optical parametric oscillator laser of the ytterbium ion-doped crystal provided by the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figure 1 As shown in the figure, this invention discloses a low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal, comprising a semiconductor excitation source 1, a focusing system 2, an input mirror 3, a ytterbium-doped composite crystal 4, and an output mirror 5. The ytterbium-doped crystal is a functional composite crystal capable of simultaneously achieving fundamental frequency gain and optical parametric oscillation. The ytterbium-doped crystal is located between the input mirror and the output mirror, which together form a self-parametric oscillator laser resonant cavity. The pump light emitted from the semiconductor excitation source is collimated by the focusing system and then incident on the ytterbium-doped composite crystal through the input mirror. Under the action of the self-parametric oscillator resonant cavity, effective laser output of three wavelengths is simultaneously achieved: near-infrared (1.0~1.2 μm), eye-safe (1.5~1.8 μm), and mid-infrared (2.9~3.1 μm).

[0028] The present invention will be further described below with reference to different embodiments.

[0029] Example 1

[0030] The phonon coupling adaptive phase-matching technique and wide-tunable frequency-doubled laser of this invention consist of a semiconductor excitation source 1, a focusing system 2, an input mirror 3, a ytterbium-doped composite crystal 4, and an output mirror 5. The pump source 1 is a diode laser emitting a wavelength of 976 nm; the focusing system 2 is a lens group composed of convex lenses with focal lengths of 5 and 10 cm; the laser crystal 4 is a ytterbium-doped yttrium oxide-calcium borate crystal (Yb:YCa4O(BO3)3) with a ytterbium doping concentration of 10%, a crystal length of 10 mm, and a light-transmitting surface area of ​​3*3 mm. 2The laser resonator consists of a double-sided polished crystal with the crystal angle aligned to the phase-matching direction required for optical parametric oscillation. The input mirror 3 and output mirror 5 form the laser resonant cavity. The input mirror 3 is a photonic crystal dielectric film A with periodically arranged SiO2 / Ta2O5 dielectric layers. This dielectric film A has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm and 1400 nm-1800 nm. The output mirror 5 is a photonic crystal dielectric film B with periodically arranged SiO2 / Ta2O5 dielectric layers. This dielectric film B has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, and partial reflectance for 1400 nm-1800 nm, with a transmittance of 1%, forming a self-optical parametric oscillator with single-resonance signal light.

[0031] like Figure 2 As shown, under the same pumping power of 10 W, the Yb:YCOB crystal, as a self-optical parametric oscillator crystal, has a temperature difference between the front and rear faces that is 120 K lower than that of the Nd:YCOB crystal, which significantly alleviates the thermal effect during the self-optical parametric oscillation process.

[0032] like Figure 3 As shown, when the pump source excites the laser crystal, the Yb:YCa4O(BO3)3 crystal, as a functionally composite self-optical parametric oscillator crystal, simultaneously achieves three laser outputs at 1104 nm, 1745 nm, and 3007 nm.

[0033] Example 2

[0034] As described in Example 1, the difference is that the ytterbium ion-doped laser crystal 4 is selected as either ytterbium ion-doped yttrium aluminum borate crystal Yb:YAl3(BO3)4 or ytterbium ion-doped calcium lanthanum borate crystal Yb:La2CaB. 10 O 19 Ytterbium ion-doped sodium lanthanum borate crystal Yb:Na3La9O3(BO3)8, ytterbium ion-doped gadolinium oxide calcium borate crystal Yb:GdCa4O(BO3)3, and ytterbium ion-doped magnesium oxide lithium niobate crystal Yb:MgO:LiNbO3 were prepared under the same conditions as described in Example 1.

[0035] Example 3

[0036] Similar to Example 1, except that the ytterbium ion-doped composite crystal 4 is selected from ytterbium ion-doped yttrium oxy-calcium borate crystal Yb:YCa4O(BO3)3, with a doping concentration of 15%, 20% or 30%, and other conditions are the same as those described in Example 1.

[0037] Example 4

[0038] Similar to Example 1, except that the ytterbium ion-doped composite crystal 4 is selected as ytterbium ion-doped yttrium oxy calcium borate crystal Yb:YCa4O(BO3)3, with a length of 20 mm, 30 mm or 40 mm, and other conditions are the same as described in Example 1.

[0039] Example 5

[0040] Similar to Example 1, except that the input mirror 3 and the output mirror 5 are directly plated on the ytterbium ion-doped composite crystal 4, while the other conditions are the same as described in Example 1.

[0041] Example 6

[0042] Similar to Example 1, the difference is that the input mirror 3 is coated with a dielectric film that has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm, and the output mirror 5 is coated with a dielectric film that has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, high transmittance for 1400 nm-1800 nm, and partial reflectance for 2900 nm-3100 nm, forming a self-optical parametric oscillator with idler frequency optical single resonance, and simultaneously outputting lasers of three different wavelengths: near-infrared, eye-safe, and mid-infrared.

[0043] Example 7

[0044] Similar to Example 1, the difference is that the input mirror 3 is coated with a dielectric film that has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm, and the output mirror 5 is coated with a dielectric film that has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, partial reflectance for 1400 nm-1800 nm, and partial reflectance for 2900 nm-3100 nm, forming a self-optical parametric oscillator with dual resonance of idler light and signal light, and simultaneously outputting lasers of three different wavelengths: near-infrared, eye-safe, and mid-infrared.

[0045] The embodiments of the present invention are not limited to the above embodiments. Each embodiment focuses on describing the differences from other embodiments, and the same or similar parts between the embodiments can be referred to mutually. As for the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method section description.

[0046] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A low-thermal-effect self-parametric oscillator laser based on ytterbium-doped crystal, characterized in that, include: A pump source, a focusing system, an input mirror, a ytterbium-doped crystal, and an output mirror are arranged sequentially along the optical path; wherein, the ytterbium-doped crystal is a functional composite crystal capable of simultaneously realizing fundamental frequency optical gain and optical parametric oscillation, and the input mirror and the output mirror constitute an optical parametric oscillation laser resonator.

2. The low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The pump source includes a semiconductor diode laser, and the pump light reflected by the semiconductor diode laser has a wavelength of 940 nm-985 nm.

3. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The focusing system comprises a group of convex lenses with different focal lengths.

4. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The focusing system is used to collimate and focus the pump light emitted from the pump source to 100 μm-500 μm.

5. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The ytterbium ion-doped crystals include ytterbium ion-doped yttrium calcium borate crystal Yb:YCa4O(BO3)3, ytterbium ion-doped yttrium aluminum borate crystal Yb:YAl3(BO3)4, and ytterbium ion-doped lanthanum calcium borate crystal Yb:La2CaB 10 O 19 Ytterbium ion-doped sodium lanthanum borate crystal Yb:Na3La9O3(BO3)8, ytterbium ion-doped gadolinium oxycalcium borate crystal Yb:GdCa4O(BO3)3, or ytterbium ion-doped lithium magnesium oxide niobate crystal Yb:MgO:LiNbO3.

6. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The ytterbium ion doping concentration of the ytterbium ion-doped crystal is 0.1%-30%.

7. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The input mirror in the self-parametric oscillating laser resonator is coated with a dielectric film A, which has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm and 1400 nm-1800 nm; the output mirror is coated with a dielectric film B, which has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, partial reflectance for 1400 nm-1800 nm, and a transmittance between 1% and 30%. To achieve effective output of lasers in three wavelengths: near-infrared (1.0~1.2 μm), eye-safe (1.5~1.8 μm), and mid-infrared (2.9~3.1 μm).

8. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The emission wavelength of the pump source is 976 nm. At this time, the input mirror in the self-optical parametric oscillating laser resonator is coated with a dielectric film that has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm; the output mirror is coated with a dielectric film that has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, high transmittance for 1400 nm-1800 nm, and partial reflectance for 2900 nm-3100 nm. To construct a self-optical parametric oscillator with idler frequency optical single resonance, and to achieve effective output of lasers at three wavelengths: near-infrared, eye-safe, and mid-infrared.

9. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 1, characterized in that, The emission wavelength of the pump source is 976 nm. At this time, the input mirror in the self-parametric oscillating laser resonator is coated with a dielectric film that has high transmittance for 940 nm-885 nm and high reflectance for 1020 nm-1140 nm, and the output mirror is coated with a dielectric film that has high reflectance for 940 nm-1110 nm, high transmittance for 1140 nm-1200 nm, partial reflection for 1400 nm-1800 nm, and partial reflection for 2900 nm-3100 nm. To construct a self-optical parametric oscillator with dual resonance of idler and signal light, and to achieve effective output of lasers at three wavelengths: near-infrared, eye-safe, and mid-infrared.

10. A low-thermal-effect self-parametric oscillator laser based on a ytterbium-doped crystal according to claim 7, characterized in that, Both dielectric film A and dielectric film B are photonic crystal thin films with periodically arranged SiO2 / Ta2O5 dielectric layers.

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