New flashlight focusing cavity with multiple lights and multiple sticks

Abstract

A multi-lamp multi-rod flash lamp focusing cavity comprises a flash lamp, a crystal rod, a focusing cavity, a cooling channel, a reflector and a glass tube. The focusing cavity adopts a combined amplification mode of multiple flash lamps pumping multiple laser crystal rods. One crystal rod is pumped by multiple flash lamps at the same time, and one flash lamp can pump multiple crystal rods at the same time, finally realizing the amplified output of laser pulse energy and power. The present invention has the characteristics of compact structure, small space and small thermal effect, high efficiency, strong practicality and strong expansibility, and is suitable for the development of high-energy and high-repetition-rate pulse lasers.

Description

Technical Field

[0001] The invention belongs to the field of laser technology, in particular to a novel flash lamp focusing cavity with multiple lamps and multiple rods, which is mainly applied to large-energy solid-state rod-discharge lasers. Background Art

[0002] High-energy, high-repetition-rate pulsed lasers have important uses in industries such as industry and scientific research, for example, they can be used for impact strengthening of aerospace materials, plasma generation, and pumping sources. Flash lamp-pumped lasers are one of the important ways to achieve high-energy laser output, and their cost is relatively low for practical applications, so flash lamp-pumped lasers have a wide range of applications and demands. The output energy of the laser oscillator is low. In order to obtain high-energy laser output, an oscillator-amplifier structure is usually used. Both parts require a flash lamp-pumped laser cavity. This type of laser cavity mainly includes a focusing cavity, a crystal, a flash lamp, and a housing. Currently, a crystal is usually used in these laser cavities, and the crystal is pumped by multiple flash lamps at the same time, such as Figure 1 As shown. In order to ensure that more pump light is absorbed by the crystal, the flash lamp and the crystal are located at the focal position of the elliptical focusing cavity, but the total light-to-light conversion efficiency of the laser structure with multiple flash lamps pumping a single crystal is low. A large part of the light is converted into heat, which in turn causes the thermal effect of the crystal and causes the output laser beam quality to deteriorate. Especially for high-energy lasers, thermal issues are an important research topic. In order to develop high-energy and high-repetition-rate lasers, beam combining is one of the important means to obtain high-energy laser output. Multiple laser beams will use multiple amplification modules at the same time, but this will undoubtedly greatly increase the overall volume of the laser.

[0003] Although the single-lamp dual-rod and dual-lamp dual-rod structures are proposed in the patents (CN101626137B, CN205985735 and CN201374494Y), for large-sized crystal rods, four or six rods are required to pump to achieve high-energy laser output. The above invention patents cannot meet actual application needs. In addition, when the structures mentioned in the above patents are applied to the development of multi-beam (more than two beams) laser beam combining, the number of crystal rods and flash lamps used in the structures described in the above patents is limited. For multi-beam laser beam combining, the number of laser modules needs to be increased, which will also increase the volume of the entire laser. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a multi-lamp and multi-rod flash lamp focusing cavity. In this structure, one crystal rod is pumped by multiple flash lamps at the same time, and one flash lamp can pump multiple crystals at the same time, which greatly improves the energy utilization efficiency and reduces the thermal effect, while making the volume of the high-energy and high-repetition-rate laser more compact.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A flashlight focusing cavity with multiple lamps and multiple rods, comprising a flashlight, a crystal rod and a focusing cavity, wherein the focusing cavity comprises a cooling channel, an elliptical reflector and a glass tube; the focusing cavity comprises a plurality of symmetrically distributed elliptical reflectors constituting the focusing cavity, the elliptical reflectors are located in the focusing cavity, the crystal rod group comprises more than two crystal rods, the flashlight group comprises more than six flashlights, the flashlights penetrate the elliptical reflectors and are located in the focusing cavity, a plurality of flashlights surround each crystal rod, the surface of the elliptical reflector comprises a plurality of elliptical reflection surfaces, and the corresponding crystal rods and flashlights are respectively located at two foci of the same elliptical reflection surface;

[0007] The ratio of the major axis to the minor axis of the elliptical reflective surface of the elliptical reflector is 1.1 to 1.6, and the inner focus of the elliptical reflective surface is located on the cross line divided by the square of the focusing cavity, the side length of the square is the length of the short side of the focusing cavity, and the elliptical reflective surface satisfies the ellipse formula:

[0008]

[0009] The center of the crystal rod coincides with the inner focus of the elliptical reflector, and the elliptical reflector coincident with it is located on the diagonal of the square division of the focusing cavity, and the focus coincident with it is located on the inner side of the elliptical reflector; the center of the peripheral flash lamp of the focusing cavity coincides with the focus of the outer side of all elliptical reflectors, and the line connecting the center of two adjacent flash lamps and the center of the adjacent crystal rod is an isosceles right triangle, satisfying the triangle formula:

[0010] A 2 +B 2 =C 2

[0011] Among them, A and B are the lengths of the two right angles of the isosceles right triangle, and C is the length of the hypotenuse;

[0012] The focusing cavity uses a glass tube to constrain the direction and speed of water flow. The center of the glass tube coincides with the center of the flash lamp or the center of the crystal rod. The ratio of the diameter of the glass tube to the diameter of the flash lamp or the diameter of the crystal rod is 1.1-1.5.

[0013] The crystal rod is Nd:YAG crystal, Nd:YLF crystal or other laser gain medium crystal, and the crystal rod is a cylinder.

[0014] The flash lamp is a xenon lamp or other high-voltage pulse light source.

[0015] The elliptical reflector is made of metal material, ceramic material or powder material.

[0016] The cooling channels are distributed around the flash lamp and are placed in the light-focusing cavity. Meanwhile, the cooling channels use the glass tube to constrain the water flow path.

[0017] Compared with the existing technology, the present invention has the following advantages:

[0018] 1) The flash lamp or crystal rod is placed in the glass tube, and the glass tube is made of fused quartz and can filter out ultraviolet light.

[0019] 2) The crystal rod, flash lamp and focusing cavity are fixed and supported by the end cap. Multiple flash lamps surround the crystal rod, and the flash lamps can pump multiple crystal rods at the same time. The flash lamps, crystal rod and reflector are cooled by the coolant in the cooling channel.

[0020] 3) In the present invention, a crystal rod is pumped by multiple flash lamps at the same time. One flash lamp can pump multiple crystals at the same time, which greatly improves the energy utilization efficiency and reduces the thermal effect. At the same time, it makes the volume of the high-energy and high-repetition-rate laser more compact. It can improve the photoelectric conversion efficiency and ensure that the flash lamp energy is fully absorbed by the crystal rod.

[0021] 4) The present invention can greatly reduce the volume of the focusing cavity, making the focusing cavity structure more compact.

[0022] 5) The present invention can accommodate more crystal rods, thereby increasing the output energy of the laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the existing multi-lamp single-rod focusing cavity structure.

[0024] Figure 2 This is a schematic diagram of the structure of the 4-lamp focusing cavity of Example 2-9 of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the 2-lamp-rod focusing cavity of Embodiment 1-6 of the present invention.

[0026] Figure 4 Schematic diagram of the design of the focusing cavity of the 2-stick flash lamp of Example 1-6 of the present invention

[0027] Figure 5 Schematic diagram of the design of the focusing cavity of the 4-stick flash lamp of Example 2-9 of the present invention

[0028] Figure 6 It is a volume comparison diagram of the focusing cavity of the present invention, the common elliptical multi-lamp multi-rod cavity, and the multi-lamp single-rod cavity. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but the protection scope of the present invention shall not be limited thereto.

[0030] See also Figure 2 The multi-lamp and multi-rod flashlight focusing cavity of the present invention comprises a flashlight 1, a crystal rod 2 and a focusing cavity 3, and is characterized in that the focusing cavity 3 comprises a cooling channel 4, an elliptical reflector 5 and a glass tube 6; the focusing cavity 3 comprises a plurality of symmetrically distributed elliptical reflectors 5 constituting the focusing cavity, the elliptical reflectors 5 are located in the focusing cavity 3, the crystal rod group comprises more than two crystal rods 2, the flashlight group comprises more than six flashlights 1, the flashlights 1 penetrate the elliptical reflectors 5 and are located in the focusing cavity, a plurality of flashlights 1 surround each crystal rod 2, the surface of the elliptical reflector 5 is composed of a plurality of elliptical reflection surfaces, and the corresponding crystal rods 2 and flashlights 1 are respectively located at two foci of the same elliptical reflection surface;

[0031] The ratio of the major axis to the minor axis of the elliptical reflective surface of the elliptical reflector 5 is 1.1 to 1.6, and the inner focus of the elliptical reflective surface is located on the square cross line of the focusing cavity. The side length of the square is the length of the short side of the focusing cavity. The elliptical reflective surface satisfies the ellipse formula:

[0032]

[0033] The center of the crystal rod 2 coincides with the inner focus of the elliptical reflector 5, and the elliptical reflector 5 coincident with it is located on the diagonal of the square division of the focusing cavity, and the focus coincident with it is located on the inner side of the elliptical reflector 5; the center of the peripheral flash lamp 1 of the focusing cavity coincides with the focus of the outer side of all elliptical reflectors 5, and the line connecting the center of two adjacent flash lamps 1 and the center of the adjacent crystal rod 2 is an isosceles right triangle, satisfying the triangle formula:

[0034] A 2 +B 2 =C 2

[0035] Among them, A and B are the lengths of the two right angles of the isosceles right triangle, and C is the length of the hypotenuse;

[0036] The focusing cavity 3 uses a glass tube 6 to constrain the direction and speed of the water flow. The center of the glass tube 6 coincides with the center of the flash lamp 1 or the center of the crystal rod 2. The ratio of the diameter of the glass tube 6 to the diameter of the flash lamp 1 or the diameter of the crystal rod 2 is 1.1 to 1.5.

[0037] Example 1

[0038] See also Figure 3 , this embodiment includes 6 flash lamps 1 and 2 crystal rods 2, the 2 crystal rods 2 are in the same horizontal direction, the flash lamps 1 are arranged in a 3×2 structure, the crystal rods 2 are located at the center of the diagonal of a square with the short side as the length, the flash lamps 1 are placed at the outer focus of the elliptical cavity and the flash lamps in the middle of each row are located on the diagonal of two squares, the elliptical focus is located on the diagonal of the square, and the distances from all flash lamps 1 to adjacent crystal rods 2 are equal. The laser injection beam is divided into two beams, which enter the two crystal rods 2 respectively to be amplified, and then combined after passing through a polarization beam splitter prism to obtain a high-energy pulsed laser output. Compared with the focusing cavity structure of four lamps and a single rod, the volume of the elliptical focusing cavity using 6 lamps and 2 rods is 1.9 times that of the four lamps and a single rod cavity, and the amplification capacity is twice that of the four lamps and a single rod cavity; while for the focusing cavity of 6 lamps and 2 rods of the present invention, its volume is only 1.2 times that of the four lamps and a single rod cavity, and the amplification capacity is twice that of the four lamps and a single rod cavity.

[0039] Example 2

[0040] See also Figure 2 , Figure 2 Schematic diagram of the structure of the 4-rod focusing cavity of Example 2-9 of the present invention, the focusing cavity includes 9 flash lamps 1 and 4 crystal rods 2, the 4 crystal rods 2 are arranged in a 2×2 structure, the flash lamps 1 are arranged in a 3×3 structure, the crystal rods 2 are located on the diagonal of the square and are the inner focus of the elliptical cavity, the flash lamps 1 are placed at the outer focus of the elliptical cavity and the central flash lamp is located at the center of the entire focusing cavity, the elliptical focus is located on the horizontal and vertical center lines and diagonals of the square, the distances from all flash lamps 1 to adjacent crystal rods 2 are equal, and two adjacent flash lamps 1 and adjacent crystal rods 2 form an isosceles triangle (see Figure 5 ). The laser injection beam is divided into four beams, which enter four crystal rods 2 respectively to be amplified, and then combined after passing through a polarization beam splitter prism to obtain a high-energy pulse laser output.

[0041] See also Figure 6 Experiments show that, compared with the focusing cavity structure of four lamps and one rod, the volume of the elliptical focusing cavity with nine lamps and four rods in this embodiment is 2.7 times that of the cavity with four lamps and one rod, and the amplification capacity is 4 times that of the cavity with four lamps and one rod; while for the focusing cavity with nine lamps and four rods of the present invention, its area is only 1.78 times that of the cavity with four lamps and one rod, and the amplification capacity is 4 times that of the cavity with four lamps and one rod.

[0042] 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A flashlight focusing cavity with multiple lamps and multiple rods, comprising a flashlight (1), a crystal rod (2) and a focusing cavity (3), characterized in that: The light focusing cavity (3) comprises a cooling channel (4), an elliptical reflector (5) and a glass tube (6); the light focusing cavity (3) comprises a plurality of symmetrically distributed elliptical reflectors (5) constituting the light focusing cavity; the elliptical reflectors (5) are located in the light focusing cavity (3); the crystal rod group comprises more than two crystal rods (2); the flash lamp group comprises more than six flash lamps (1); the flash lamps (1) penetrate the elliptical reflector (5) and are located in the light focusing cavity; a plurality of flash lamps (1) surround each crystal rod (2); the surface of the elliptical reflector (5) comprises a plurality of elliptical reflection surfaces; the corresponding crystal rods (2) and the flash lamps (1) are respectively located at two foci of the same elliptical reflection surface; The ratio of the major axis to the minor axis of the elliptical reflective surface of the elliptical reflector (5) is 1.1 to 1.6, and the inner focus of the elliptical reflective surface is located on the square cross line of the focusing cavity, the side length of the square is the length of the short side of the focusing cavity, and the elliptical reflective surface satisfies the ellipse formula: The center of the crystal rod (2) coincides with the inner focus of the elliptical reflector (5), and the elliptical reflector (5) coincident with it is located on the diagonal of the square division of the focusing cavity, and the focus coincident with it is located on the inner side of the elliptical reflector (5); the center of the peripheral flash lamp (1) of the focusing cavity coincides with the focus of the outer side of all elliptical reflectors (5), and the line connecting the center of two adjacent flash lamps (1) and the center of the adjacent crystal rod (2) is an isosceles right triangle, satisfying the triangle formula: A 2 +B 2 =C 2 Among them, A and B are the lengths of the two right angles of the isosceles right triangle, and C is the length of the hypotenuse; The focusing cavity (3) uses a glass tube (6) to constrain the direction and speed of the water flow, the center of the glass tube (6) coincides with the center of the flash lamp (1) or the center of the crystal rod (2), and the ratio of the diameter of the glass tube (6) to the diameter of the flash lamp (1) or the diameter of the crystal rod (2) is 1.1 to 1.

5.

2. The multi-lamp multi-rod flashlight focusing cavity according to claim 1, characterized in that: The crystal rod (2) is a Nd:YAG crystal or a Nd:YLF crystal, and the crystal rod is a cylinder.

3. The multi-lamp multi-rod flashlight focusing cavity according to claim 1, characterized in that: The flash lamp (1) is a xenon lamp.

4. The multi-lamp multi-rod flashlight focusing cavity according to claim 1, characterized in that: The elliptical reflector (5) is made of metal material, ceramic material or powder material and has an elliptical shape.

5. The multi-lamp multi-rod flashlight focusing cavity according to claim 1, characterized in that: The cooling channel (4) is distributed around the flash lamp (1) and is placed in the light focusing cavity (3). At the same time, the cooling channel (4) uses the glass tube (6) to constrain the water flow path.

6. The multi-lamp multi-rod flashlight focusing cavity according to claim 1, characterized in that: The glass tube (6) is used as a sleeve, and the flash lamp (1) and the crystal rod (2) are both placed in the glass tube (6). The glass tube (6) is made of fused quartz and filters out ultraviolet light.

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