A laser processing optical isolator device

Abstract

This utility model relates to a laser processing optical isolator device, comprising an input fiber collimator, an isolator core, a Kepler telescope beam expander system, an F-theta lens, and a target material arranged sequentially along the optical path. The Kepler telescope beam expander system is used to expand and collimate the forward-propagating laser beam, and includes a first positive lens and a second positive lens, wherein the rear focal point of the first positive lens coincides with the front focal point of the second positive lens. A pinhole aperture is provided between the first positive lens and the second positive lens, located at the point where the rear focal point of the first positive lens and the front focal point of the second positive lens coincide, for transmitting the forward-propagating laser beam and blocking the reverse-propagating backlight. This utility model can block more backlight, reduce the impact of backlight on the laser, and thus improve the quality of laser processing.

Description

Technical Field

[0001] This utility model relates to the field of laser technology, specifically to a laser processing optical isolator device. Background Technology

[0002] Optical isolators are key components in laser processing equipment, used to prevent back-propagating light from interfering with or damaging the light source. In actual processing equipment, an optical isolator consists of an isolator core and a beam expander system, typically a Galilean telescope system with a negative lens and a positive lens. During high-power laser processing, the high-power laser used for processing, after passing through an F-theta lens, illuminates the target material and is scattered by the target. Some of the reflected laser returns to the optical isolator along the direction of the emitted laser and is then isolated by the isolator core using the Faraday rotation effect. However, there are specific angles at which reflected laser light does not return to the optical isolator along the direction of the emitted laser and instead passes directly through the optical isolator back to the laser, thus affecting the quality of laser processing. Existing solutions include... Figure 4 As shown, the system sequentially includes an input fiber collimator 7, an isolator core 8, a first pinhole stop 9, a second pinhole stop 10, a Kepler telescope beam expander system 11, an F-theta lens 12, and a target material 13. Pinhole stops are placed before and after the isolator core to block reflected laser light at this specific angle. However, because it is a Galilean telescope system, the diameter of the laser beam passing through the optical isolator is relatively large, meaning the pinhole diameter of the pinhole stops cannot be too small, and therefore cannot completely block the reflected laser light. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a laser processing optical isolator device.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A laser processing optical isolator device includes an input fiber collimator, an isolator core, a Kepler telescope beam expander system, an F-theta lens, and a target material arranged sequentially along the optical path. The input fiber collimator is used to input laser light; The isolator core is used to allow forward-propagating laser light to pass through while isolating reverse-propagating laser light. The Kepler telescope beam expanding system is used to expand and collimate forward-propagating laser beams. It includes a first positive lens and a second positive lens, wherein the rear focal point of the first positive lens coincides with the front focal point of the second positive lens. A pinhole aperture is provided between the first positive lens and the second positive lens. The pinhole aperture is located at the point where the rear focal point of the first positive lens and the front focal point of the second positive lens coincide. It is used to transmit the forward-transmitting laser light and block the reverse-transmitting reflected light. The F-theta lens is used to uniformly focus the collimated laser onto the target material.

[0005] Furthermore, the isolator core includes a first optical beam splitter, a half-wave plate, a Faraday rotator, and a second optical beam splitter arranged sequentially.

[0006] Furthermore, the first positive lens is a biconvex lens, a plano-convex lens, or a meniscus lens.

[0007] Furthermore, the second positive lens is a single lens or a cemented lens.

[0008] The beneficial effects of this utility model by adopting the above technical solution are as follows: by using a Kepler telescope beam expander system instead of a Galilean telescope beam expander system in the optical path, the spot diameter at the point where the back focal point of the first positive lens and the front focal point of the second positive lens of the Kepler telescope beam expander system coincide is much smaller than the spot diameter of the Galilean telescope beam expander system; at the same time, placing a pinhole aperture at this position can block more reflected light, reduce the impact of reflected light on the laser, and thus improve the quality of laser processing. Attached Figure Description

[0009] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the forward light transmission structure of this utility model; Figure 2 This is a schematic diagram of the reverse light transmission structure of this utility model; Figure 3 This is a schematic diagram of the isolator core of this utility model; Figure 4 Schematic diagram of the forward and reverse light transmission structures of an existing laser processing optical isolator; In the diagram, solid lines represent forward light, and dashed lines represent reverse light. Detailed Implementation

[0010] like Figure 1-3 As shown, the laser processing optical isolator device of this utility model includes: an input fiber collimator 1, an isolator core 2, a Kepler telescope beam expander system 3, an F-theta lens (a flat field focusing lens for laser scanning systems) 5, and a target material 6 arranged in sequence.

[0011] The isolator core 2 consists of a first optical beam splitter 201, a half-wave plate 202, a Faraday rotator 203, and a second optical beam splitter 204. The Kepler telescope beam expander system 3 consists of a first positive lens 301 and a second positive lens 302. Here, the first positive lens 301 is a plano-convex lens (or a biconvex lens or a meniscus lens), and the second positive lens 302 is a cemented lens (or a single lens). The back focal point of the first positive lens 301 and the front focal point of the second positive lens 302 coincide. A pinhole aperture 4 is provided between the first positive lens 301 and the second positive lens 302. The pinhole aperture 4 is placed at the point where the rear focal point of the first positive lens 301 and the front focal point of the second positive lens 302 coincide. The diameter of the light-transmitting aperture of the pinhole aperture 4 is slightly larger than the beam diameter of the forward-transmitting laser at this point of coincidence.

[0012] like Figure 1 The optical path shown in the forward-passing light path is as follows: the collimated laser emitted by the fiber collimator 1 passes through the isolator core 2 and then enters the first positive lens 301. It is first focused by the first positive lens 301, then passes through the pinhole aperture 4 and is then transmitted to the second positive lens 302, where it is collimated. Finally, it is transmitted to the F-theta lens 5, and the laser is uniformly focused onto the target material 6 for processing.

[0013] like Figure 2 The reflected light from the target 6 is collimated by the F-theta lens 5 and then incident on the second positive lens 302. The reflected light is focused by the second positive lens 302. Because the reflected light is different from the light path of the forward-transmitting laser, it is blocked by the pinhole aperture 4 set at the focal position and cannot pass through the pinhole aperture 4. The reflected light cannot enter the first positive lens 301 and the isolator core 2, thereby reducing the impact of the reflected light on the laser and improving the quality of laser processing.

[0014] The specific embodiments of this utility model have been described above. However, those skilled in the art should understand that this is only an example. Those skilled in the art can make various changes or modifications to this embodiment without departing from the principle and essence of this utility model, but all such changes and modifications fall within the protection scope of this utility model.

Claims

1. A laser processing optical isolator device, characterized in that: It includes an input fiber collimator, an isolator core, a Kepler telescope beam expander system, an F-theta lens, and a target material arranged sequentially along the optical path; The input fiber collimator is used to input laser light; The isolator core is used to allow forward-propagating laser light to pass through while isolating reverse-propagating laser light. The Kepler telescope beam expanding system is used to expand and collimate forward-propagating laser beams. It includes a first positive lens and a second positive lens, wherein the rear focal point of the first positive lens coincides with the front focal point of the second positive lens. A pinhole aperture is provided between the first positive lens and the second positive lens. The pinhole aperture is located at the point where the rear focal point of the first positive lens and the front focal point of the second positive lens coincide. It is used to transmit the forward-transmitting laser light and block the reverse-transmitting reflected light. The F-theta lens is used to uniformly focus the collimated laser onto the target material.

2. The laser processing optical isolator device according to claim 1, characterized in that: The isolator core includes a first optical beam splitter, a half-wave plate, a Faraday rotator, and a second optical beam splitter arranged sequentially.

3. The laser processing optical isolator device according to claim 1, characterized in that: The first positive lens is a biconvex lens, a plano-convex lens, or a meniscus lens.

4. The laser processing optical isolator device according to claim 1, characterized in that: The second positive lens is a single lens or a cemented lens.

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