Laser incident angle adjusting device based on linkage angle adjusting mechanism

Abstract

The invention provides a laser incident angle adjusting device based on a linkage angle adjusting mechanism, and belongs to the technical field of laser, in a laser light path, variable-angle mounting devices are arranged for a focusing lens and a last-stage reflector respectively, the rotation angle of the focusing lens is set to be twice of the rotation angle of the reflector, and the rotation angle of the focusing lens is set to be twice of the rotation angle of the reflector; when the angles of the focusing lens and the reflector are linked according to the proportion, the final focusing point of the laser can be kept at the center of the target material and is not changed, and meanwhile, the incident angle of the laser beam can be accurately adjusted.

Description

Technical Field

[0001] The present invention belongs to the field of laser technology, and in particular relates to a laser incident angle adjustment device based on a linkage angle adjustment mechanism. Background Art

[0002] Pulsed laser deposition (PLD) is an important thin-film deposition technology. Due to its advantages, such as controllable composition and high-quality films, it is widely used in fields such as high-temperature superconductors, iron-based superconductors, functional ceramics, and magnetic materials. In PLD, a laser beam is focused onto the target surface through a series of mirrors and focusing lenses, generating a plasma plume to deposit the material.

[0003] The laser incident angle (i.e., the angle between the laser beam and the target normal) is a critical parameter influencing target ablation uniformity, plasma plume directionality, and thin film deposition morphology. In the fabrication of high-quality thin films, fine-tuning the incident angle is often necessary based on the characteristics of the material system. However, most current PLD systems utilize fixed optical components, making adjustment of the laser beam incident angle extremely difficult and often requiring the entire lens or mirror frame to be moved, making continuous adjustment or precise control impossible. The lack of a highly precise, compact, and easy-to-use incident angle adjustment method severely limits the flexibility and reproducibility of PLD parameter optimization experiments.

[0004] Currently, the optical path of most PLD systems is fixed, and the laser incident angle is usually achieved by moving the entire optical bracket or fine-tuning the reflector individually. This results in a complex structure and discontinuous adjustment. In existing adjustment schemes, the laser spot position may shift during the adjustment of the incident angle, causing the focus to deviate from the center of the target material, affecting the consistency of the thin film. It is impossible to achieve precise angle adjustment of the laser beam while maintaining a fixed focus. Most systems lack a unified adjustment logic relationship, resulting in a reliance on experience in the adjustment process and poor repeatability. Summary of the Invention

[0005] The present invention provides a laser incident angle adjustment device based on a linkage angle adjustment mechanism to solve the problems of difficult laser incident angle adjustment, large adjustment errors, and unstable control of the light spot position in existing PLD systems. The specific technical solution is as follows:

[0006] A laser incident angle adjustment device based on a linkage angle adjustment mechanism is provided. In the laser light path, a variable angle mounting device is provided between the focusing lens and the reflector. The variable angle mounting device realizes the following angle linkage through the linkage structure, setting the rotation angle of the focusing lens to twice the rotation angle of the reflector, namely:

[0007] ;

[0008] in, is the rotation angle of the focusing lens; is the mirror rotation angle.

[0009] The present invention has the following beneficial effects:

[0010] The laser incident angle is precisely adjustable: through the linkage of the lens and the reflector angle, a clear angle adjustment logic (1:2 angle relationship) is provided, which can achieve continuous and controllable adjustment of the laser incident angle;

[0011] Stable spot position: The laser focus remains at the center of the target during adjustment, effectively avoiding energy density changes caused by spot offset;

[0012] Simplified operation process: No need to frequently move equipment or perform complex calibration, significantly lowering the operating threshold;

[0013] Strong structural compatibility: Suitable for upgrading and renovating most existing PLD systems, with minimal changes required and easy implementation; Improved film consistency and process precision: Optimizes the controllability of the laser-target interaction area, improving film formation quality and repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the position of the lens and reflector;

[0015] Figure 2 Schematic diagram of the linkage structure. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned objectives, the present invention adopts the following technical solutions.

[0017] The present invention provides a laser incident angle adjustment device based on a linkage angle adjustment mechanism, such as Figure 1 As shown, in the laser light path, variable angle mounting devices are provided for the focusing lens and the reflector, such as electric or manual rotating frames; the variable angle mounting devices realize the following angle linkage through the linkage structure;

[0018] Angle setting relationship: Set the rotation angle of the focusing lens to twice the rotation angle of the reflector, that is:

[0019] ;

[0020] in, is the rotation angle of the focusing lens; is the mirror rotation angle;

[0021] When the focusing lens and the reflector angle are linked according to the above ratio, the final focus point of the laser can be kept fixed at the center of the target material, while achieving precise adjustment of the incident angle of the laser beam.

[0022] The laser can be aligned with the incident mark on the target material to assist in observing the angle change, and a laser power meter or thermal paper can also be used to assist in focusing.

[0023] Variable angle mounting can be accomplished using mechanical linkage, electric encoder control, or software feedback algorithms, suitable for manual or automatic control modes.

[0024] like Figure 2 , which is an example of the linkage structure of the present invention, wherein the focusing lens is mounted on the first gear, the reflector is mounted on the second gear, the first gear and the second gear are engaged with each other, the radius of the first gear is twice the radius of the second gear, and the angle between the focusing lens and the center line of the two gears is twice the angle between the reflector and the center line of the two gears.

[0025] The present invention can accurately adjust the laser incident angle, reduce manual operation errors, and ensure that the laser is perpendicular to the lens. Based on the laser incident angle, the plume shape can be precisely controlled. It can match lasers of different wavelengths, such as excimer lasers. The variable-angle mounting device includes a rotating bracket and a fine-tuning mechanism. The fine-tuning mechanism can finely adjust the tilt angle of the reflector and lens with an adjustment accuracy better than 0.5°. This variable-angle mounting device is suitable for PLD cavities of different sizes and configurations. It can achieve standardized control of the laser incident angle through angle linkage, improving the uniformity and repeatability of thin film deposition. After the laser passes through the above-mentioned lens, its spot shape remains constant, with a maximum deviation of no more than ±5%, thereby ensuring the consistency of deposition conditions. Specific embodiments

[0027] Taking a PLD device for preparing YBCO superconducting thin films as an example, the specific implementation method is as follows:

[0028] The laser uses a 248 nm KrF excimer laser, which enters the optical path after shaping;

[0029] A focusing lens with a focal length of 800 mm is set up and the lens is mounted on an adjustable angle turntable;

[0030] A reflector is set in front of the focusing lens and is also mounted on an adjustable angle platform. The two are connected by a linkage mechanism that can achieve 2:1 angle adjustment.

[0031] When the reflector angle α is adjusted during operation, the lens angle automatically changes to 2α, thereby achieving a change in the laser incident angle while the laser focus remains stable;

[0032] Without moving the target, the laser incident angle can be precisely adjusted within the range of ±15°, the target spot position offset is less than 0.5 mm, the film thickness uniformity is improved by about 10%, and the deposition reproducibility is significantly improved.

Claims

1. A laser incident angle adjustment device based on a linkage angle adjustment mechanism, characterized in that: In the laser optical path, a variable angle mounting device is provided between the focusing lens and the reflector. The variable angle mounting device realizes the following angle linkage through the linkage structure, setting the rotation angle of the focusing lens to twice the rotation angle of the reflector, namely: ； in, is the rotation angle of the focusing lens; is the mirror rotation angle.

2. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: When the focusing lens and the reflector angle are linked according to the above ratio, the final focus point of the laser remains fixed at the center of the target material, and the incident angle of the laser beam is adjusted at the same time.

3. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: The laser is aligned with the incident mark on the target to assist in observing the angle change, and a laser power meter or thermal paper is used to assist in focusing.

4. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: Variable angle mounts utilize either a motorized or manual swivel mount.

5. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 4, characterized in that: The variable angle mounting device is completed using a mechanical linkage system, electric encoder control or software feedback algorithm, and is suitable for manual or automatic control mode.

6. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: The linkage structure includes a first gear and a second gear, the focusing lens is mounted on the first gear, the reflector is mounted on the second gear, the first gear and the second gear are engaged with each other, the radius of the first gear is twice the radius of the second gear, and the angle between the center line of the focusing lens and the two gears is twice the angle between the center line of the reflector and the two gears.

7. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: The reflector is installed on an adjustable angle turntable. A focusing lens is set behind the reflector and also installed on the adjustable angle platform. The two are connected to a linkage mechanism that can achieve 1:2 angle adjustment.

8. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: The focal length of the focusing lens is 800 mm.

9. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: Without moving the target, the laser incident angle can be adjusted within the range of ±15°.

10. The laser incident angle adjustment device based on the linkage angle adjustment mechanism according to claim 1, characterized in that: The light spot position deviation is less than 0.5 mm.

Images