A high-energy linearly polarized 1319nm laser

Abstract

The present invention provides a high-energy linearly polarized 1319nm laser, comprising n Pelling-Broca prisms, n+1 Nd:YAG laser modules, a high-reflection mirror, an output mirror, and a Q-switch, where n is an integer greater than or equal to 1. The output mirror and the high-reflection mirror serve as cavity mirrors to form a resonant cavity. The Nd:YAG laser modules and the Pelling-Broca prisms are alternately arranged within the resonant cavity, with each Pelling-Broca prism located between two Nd:YAG laser modules. The Q-switch is located between the high-reflection mirror and the Nd:YAG laser module or between the output mirror and the Nd:YAG laser module. The technical solution of the present invention can produce high-energy 1319nm laser output.

Description

Technical Field

[0001] The present invention relates to the field of laser technology, and in particular to a high-energy linearly polarized 1319nm laser. Background Art

[0002] 1319nm all-solid-state lasers have significant application value and prospects in sodium beacons, laser displays, laser medicine, fiber-optic communications, and environmental monitoring. Sodium beacon lasers are one of the most important applications of 1319nm lasers. Sodium beacons are produced by resonant fluorescence scattering of 589nm laser light by sodium atoms in the atmospheric ionosphere. Currently, the most common approach to generating 589nm laser light is sum-frequency generation of a 1319nm laser with a 1064nm laser in an Nd:YAG gain medium. Furthermore, frequency doubling of a 1319nm laser can produce a 660nm red laser, and tripling of the 1319nm laser can produce a 440nm blue laser, both of which hold great promise for applications in laser displays. 1319nm lasers can also be directly applied in laser medicine. Because water strongly absorbs 1319nm laser light, while blood attenuates it less, 1319nm laser light has a greater penetration depth into biological tissues, making it well-suited for applications in neurosurgery, repair of microscopic tissues such as blood vessels and skin. 1319nm lasers also have extensive applications in fiber-optic communications.

[0003] Typically, Nd:YAG lasers produce 1064nm laser light with the strongest transition, while the relative performance of the 1319nm laser transition is only 1 / 3 of that of the 1064nm radiation. Therefore, in order to obtain the 1319nm wavelength transition, measures need to be taken to suppress the oscillation of the 1064nm laser. The most commonly used method is to use an output mirror coated with a highly selective dielectric film. By coating the cavity mirror of the resonant cavity with a 1319nm film system and a 1064nm high-transmittance film at the same time, the loss of the 1064nm laser is reduced. However, for a 1319nm high-energy Q-switched laser, multiple modules need to be connected in series. Before the Q switch is turned on, the number of inverted particles gradually increases. When the gain of the 1064nm laser exceeds the self-oscillation threshold, 1064nm laser light will be output. The coating method cannot suppress the high-gain 1064nm laser. At the same time, the coating needs to take into account both 1319nm and 1064nm lasers, resulting in high coating costs. Summary of the Invention

[0004] In response to the above-mentioned technical problems existing in the prior art, a high-energy linearly polarized 1319nm laser is provided. The present invention adopts the method of connecting multiple modules in series with a Pelling-Broca prism, so that the 1319nm laser gain is amplified in multiple series modules, while the 1064nm laser gain exists only in a single module, so that the gain of the 1319nm laser exceeds that of the 1064nm laser, thereby suppressing the 1064nm laser and obtaining a high-energy 1319nm laser output.

[0005] The technical means adopted in the present invention are as follows:

[0006] A high-energy linearly polarized 1319nm laser comprises n Pelling-Broca prisms, n+1 Nd:YAG laser modules, a high-reflection mirror, an output mirror, and a Q-switch, wherein n is an integer greater than or equal to 1; the output mirror and the high-reflection mirror serve as cavity mirrors to form a resonant cavity; the Nd:YAG laser modules and the Pelling-Broca prisms are alternately arranged in the resonant cavity, and each Pelling-Broca prism is located between two Nd:YAG laser modules; the Q-switch is located between the high-reflection mirror and the Nd:YAG laser module or between the output mirror and the Nd:YAG laser module.

[0007] Furthermore, the gain medium of the Nd:YAG laser module is made of Nd:YAG crystal or Nd:YAG ceramic.

[0008] Furthermore, the gain medium of the Nd:YAG laser module is in the shape of a rod, a slab or a disk.

[0009] Furthermore, the Nd:YAG laser module pumps the gain medium using a side pump or end pump method.

[0010] Furthermore, the material of the Pelling-Broca prism is JGS1 or BK7.

[0011] Furthermore, the high-reflection mirror is coated with a high-reflection film system with a reflectivity of more than 95% for 1319nm laser.

[0012] Furthermore, the output mirror is coated with a film system that is partially transparent to the 1319 nm laser, and the transmittance of the film system is between 5% and 95%.

[0013] Furthermore, the Q switch is an active or passive Q-switching element, including but not limited to: a mechanical Q-switching switch, an electro-optical Q-switching switch, an acousto-optic Q-switching switch, and a saturated absorber.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] For an Nd:YAG Q-switched laser, before the Q switch is turned on, the intracavity loss is greater than the 1319nm laser gain, and the stimulated emission cross-section of the 1064nm laser is greater than that of the 1319nm laser. Therefore, its gain may be greater than the intracavity loss, causing self-oscillation and outputting 1064nm laser. The present invention adopts a Pelling-Broca prism to connect multiple modules in series, so that the 1319nm laser gain is amplified in multiple modules, while the 1064nm laser gain exists only in a single module. This makes the gain of the 1319nm laser in the Nd:YAG Q-switched laser exceed that of the 1064nm laser, thereby suppressing the generation of self-oscillation of the 1064nm laser, and obtaining a high-energy linearly polarized 1319nm laser output. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] Figure 1 This is a schematic diagram of the structure of the high-energy linearly polarized 1319nm laser described in Example 1.

[0018] Figure 2 Schematic diagram of the structure of the high-energy linearly polarized 1319nm laser described in Example 2.

[0019] In the figure: 1. Nd:YAG laser module I; 2. Pelling-Broca prism I; 3. Nd:YAG laser module II; 4. High-reflection mirror; 5. Output mirror; 6. Q-switch; 7. Pelling-Broca prism II; 8. Nd:YAG laser module III; 9. Pelling-Broca prism III; 10. Nd:YAG laser module IV. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0024] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0025] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0026] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0027] Example 1

[0028] The present invention provides a high-energy linearly polarized 1319nm laser, comprising n Pelling-Broca prisms, n+1 Nd:YAG laser modules, a high-reflection mirror 4, an output mirror 5, and a Q-switch 6, wherein n is an integer greater than or equal to 1; the output mirror 5 and the high-reflection mirror 4 serve as cavity mirrors to form a resonant cavity, and the laser propagates bidirectionally in the resonant cavity and is output through the output mirror 5; the Nd:YAG laser modules and the Pelling-Broca prisms are alternately arranged in the resonant cavity, and each Pelling-Broca prism is located between two Nd:YAG laser modules; the Q-switch 6 is located between the high-reflection mirror 4 and the Nd:YAG laser module or between the output mirror 5 and the Nd:YAG laser module, and is used to pulse-modulate the laser after gain amplification to obtain high-energy laser output.

[0029] Furthermore, the gain medium of the Nd:YAG laser module is made of Nd:YAG crystal or Nd:YAG ceramic.

[0030] Furthermore, the gain medium of the Nd:YAG laser module is in the shape of a rod, a slab or a disk.

[0031] Furthermore, the Nd:YAG laser module pumps the gain medium using a side pump or end pump method.

[0032] Furthermore, the material of the Pelling-Broca prism is JGS1 or BK7, or other materials that do not absorb 1319nm laser.

[0033] Furthermore, the high-reflection mirror is coated with a high-reflection film system with a reflectivity of more than 95% for 1319nm laser.

[0034] Furthermore, the output mirror is coated with a film system that is partially transparent to the 1319 nm laser, and the transmittance of the film system is between 5% and 95%.

[0035] Furthermore, the Q switch is an active or passive Q-switching element, including but not limited to: a mechanical Q-switching switch, an electro-optical Q-switching switch, an acousto-optic Q-switching switch, and a saturated absorber.

[0036] The Nd:YAG laser module can generate lasers with wavelengths of 946nm, 1064nm, 1319nm, 1338nm, etc. The laser generated by the Nd:YAG laser module enters the Pelling-Broca prism at the Brewster angle and is separated after being emitted. Among them, the 1319nm P-polarized laser enters the next Nd:YAG laser module for gain amplification, so that its gain exceeds that of the 1064nm laser before the Q switch is turned on, suppressing the self-oscillation of the 1064nm laser and oscillating in the resonant cavity formed by the high-reflection mirror and the output mirror. The gain of the lasers of other wavelengths is deflected after passing through the Pelling-Broca prism and cannot be amplified by the next laser module.

[0037] For a Q-switched Nd:YAG laser, before the Q-switch is turned on, the intracavity loss is greater than the gain of the 1319nm laser, while the stimulated emission cross section of the 1064nm laser is greater than that of the 1319nm laser. This means that the gain of the laser may be greater than the intracavity loss, causing self-oscillation and outputting 1064nm laser light. The present invention utilizes a Pelling-Broca prism connected in series with multiple modules to amplify the gain of the 1319nm laser within multiple modules, while the gain of the 1064nm laser exists only within a single module. This allows the gain of the 1319nm laser in the Q-switched Nd:YAG laser to exceed that of the 1064nm laser, thereby suppressing the self-oscillation of the 1064nm laser and achieving high-energy, linearly polarized 1319nm laser output.

[0038] Preferably, if Figure 1 As shown, the high-energy linearly polarized 1319nm laser is provided with two laser modules: the Nd:YAG laser module I1 and the Nd:YAG laser module II3, and the Pelling-Broca prism I2 arranged between the Nd:YAG laser module I1 and the Nd:YAG laser module II3, and also includes the high-reflection mirror 4, the output mirror 5 and the Q switch 6.

[0039] Preferably, the Nd:YAG laser module I1 and the Nd:YAG laser module II3 are side-pumped Nd:YAG crystal rods, the laser rod doping concentration is 0.6%, the end face diameter is 3mm, the length is 100mm, and the pump light power is 240W.

[0040] Preferably, the material of the Pelling-Broca prism I 2 is BK7, the Brewster angle is 56.5°, and the clear aperture is 10 mm.

[0041] Preferably, the cross-sectional diameter of the high-reflection mirror is 25 mm, the thickness is 4 mm, and it is coated with a film system with high reflection at 1319 nm, with a reflectivity greater than 99.9%.

[0042] Preferably, the output mirror has a cross-sectional diameter of 25 mm and a thickness of 4 mm, and is coated with a film system that is partially transmissive to 1319 nm and has a reflectivity of 80%.

[0043] Preferably, the Q switch is a potassium dideuterium phosphate (KD*P) electro-optical Q-switched crystal with a clear aperture of 6 mm.

[0044] The 1319 nm laser energy generated by the high energy linearly polarized 1319 nm laser described in the above scheme is: 100 mJ, the repetition frequency is 500 Hz, and the pulse width is 50 ns.

[0045] Example 2

[0046] The difference between this embodiment and embodiment 1 is that: Figure 2 As shown, the high-energy linear polarization 1319nm laser is equipped with four Nd:YAG laser modules and three Pelling-Broca prisms, including Nd:YAG laser module I1, Pelling-Broca prism I2;3, Nd:YAG laser module II3, high-reflection mirror 4, output mirror 5, Q switch 6, Pelling-Broca prism II7, Nd:YAG laser module III8, Pelling-Broca prism III9 and Nd:YAG laser module IV10.

[0047] Compared with Example 1, this embodiment increases the number of laser modules to 4, so that the 1319nm laser gain is doubled, and a laser output with greater energy can be obtained.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high energy linear polarization 1319nm laser, characterized in that: The invention comprises n Pelling-Broca prisms, n+1 Nd:YAG laser modules, a high-reflection mirror, an output mirror, and a Q-switch, wherein n is an integer greater than or equal to 1; the output mirror and the high-reflection mirror serve as cavity mirrors to form a resonant cavity; the Nd:YAG laser modules and the Pelling-Broca prisms are alternately arranged in the resonant cavity, and each Pelling-Broca prism is located between two Nd:YAG laser modules; the Q-switch is located between the high-reflection mirror and the Nd:YAG laser module or between the output mirror and the Nd:YAG laser module; The laser generated by the Nd:YAG laser module enters the Pelling-Broca prism at the Brewster angle, and the 1319nm P-polarized laser enters the next Nd:YAG laser module for gain amplification, so that its gain exceeds that of the 1064nm laser before the Q switch is turned on. The gain of the 1064nm laser is deflected after passing through the Pelling-Broca prism and cannot be amplified by the next laser module.

2. The high energy linear polarization 1319 nm laser according to claim 1, characterized in that: The gain medium of the Nd:YAG laser module is made of Nd:YAG crystal or Nd:YAG ceramic.

3. The high energy linear polarization 1319 nm laser according to claim 1, characterized in that: The gain medium of the Nd:YAG laser module is in the shape of a rod, a slab or a disk.

4. The high-energy linearly polarized 1319 nm laser according to claim 1, characterized in that: The Nd:YAG laser module pumps the gain medium using a side pump or end pump method.

5. The high energy linear polarization 1319 nm laser according to claim 1, characterized in that: The material of the Pelling-Broca prism is JGS1 or BK7.

6. The high-energy linearly polarized 1319 nm laser according to claim 1, characterized in that: The high-reflection mirror is coated with a high-reflection film system with a reflectivity of more than 95% for 1319nm laser.

7. The high-energy linearly polarized 1319 nm laser according to claim 1, characterized in that: The output mirror is coated with a film system that partially transmits 1319nm laser light, and the transmittance of the film system is between 5% and 95%.

8. The high-energy linearly polarized 1319 nm laser according to claim 1, characterized in that: The Q switch is an active or passive Q-switching element, including but not limited to: a mechanical Q-switching switch, an electro-optical Q-switching switch, an acousto-optical Q-switching switch, and a saturated absorber.

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