Low-power soft-edge aperture beam shaping device and its application in dye laser amplification systems

Abstract

This invention discloses a low-power soft-edge aperture beam shaping device and its application method in a dye laser amplification system. The low-power soft-edge aperture beam shaping device includes a soft-edge aperture, an aperture clamp for fixing the soft-edge aperture, a 90° bending head for controlling the vertical or horizontal orientation of the aperture clamp, an adjustable support rod assembly for adjusting the height of the soft-edge aperture, and a two-dimensional adjustment platform fixed below the adjustable support rod assembly for two-dimensional adjustment. This low-power soft-edge aperture beam shaping device uses a soft-edge aperture to straighten the beam profile and remove stray light, avoiding the modulation of the beam energy distribution that occurs when using a hard-edge aperture, resulting in higher efficiency for subsequent amplification and applications.

Description

Technical Field

[0001] This invention relates to the field of laser beam shaping technology, and in particular to a low-power soft-edge aperture beam shaping device and its method of use in a dye laser amplification system. Background Technology

[0002] In laser applications, apertures are typically used to shape the laser spot, remove edge beams and stray light, and give it a regular shape and uniform intensity distribution to improve image quality and match the aperture of subsequent optical components. Currently, hard-edge aperture shaping devices are widely used.

[0003] The hard-edge aperture shaping device consists of a hard-edge aperture (i.e., a metal plate with a hole in the center matching the desired light spot shape and size), a hard-edge aperture support rod, a support rod sleeve, and a fixed base. The hard-edge aperture is connected to the hard-edge aperture support rod by screws. The hard-edge aperture support rod is placed in the support rod sleeve, and the height of the support rod in the support rod sleeve is fixed by tightening screws. The sleeve is fixed to the fixed base by threads, and the fixed base is connected and fixed to the optical platform by screws.

[0004] By placing a hard-edged aperture whose shape and size match the beam in the optical path, only the required beam is allowed to pass through the central hole of the hard-edged aperture. The original part of the target beam shape and stray light will be blocked by the solid part outside the hole of the hard-edged aperture and cannot be further transmitted to subsequent beam applications.

[0005] After passing through the hard-edge aperture, the beam will generate diffraction modulation rings and on-axis periodic diffraction modulation, resulting in uneven energy distribution of the beam spot. This can easily cause nonlinear small-scale self-focusing and nonlinear full focusing of the working medium, as well as modulation strong center, etc. The existence of these effects will reduce the transmission efficiency and amplification extraction efficiency in the amplification and transmission system, and reduce the quality of the output laser beam. Summary of the Invention

[0006] The purpose of this invention is to address the technical shortcomings of existing technologies where hard-edge apertures reduce the quality of the output laser beam, and to provide a low-power soft-edge aperture beam shaping device.

[0007] Another aspect of the present invention is to provide a dye laser amplification system.

[0008] Another aspect of the present invention is to provide a method of using the above-described dye laser amplification system.

[0009] The technical solution adopted to achieve the purpose of this invention is:

[0010] A low-power soft-edge aperture beam shaping device includes a soft-edge aperture, an aperture clamp for fixing the soft-edge aperture, a 90° bending head for controlling the vertical or horizontal position of the aperture clamp, an adjustable support rod assembly for adjusting the height position of the soft-edge aperture, and a two-dimensional adjustment platform fixed to the lower part of the adjustable support rod assembly.

[0011] The aperture clamp is fixed to the top of the adjustable support rod assembly via a 90° bend. The 90° bend includes a fixed part and a bending part that are hinged to each other. The fixed part is fixedly installed on the top of the adjustable support rod assembly, and the aperture clamp is fixedly installed on the bending part and is in a vertical or horizontal state as the bending part bends.

[0012] In the above technical solution, the aperture fixture has an aperture mounting hole in the middle for installing the soft-edge aperture, and an annular baffle is provided on the back of the aperture mounting hole. When the pressure ring is assembled in the aperture mounting hole, the soft-edge aperture is fixed between the annular baffle and the pressure ring.

[0013] In the above technical solution, the pressure ring is fitted into the aperture mounting hole.

[0014] In the above technical solution, the pressure ring is threadedly assembled into the aperture mounting hole, and the aperture mounting hole has an internal thread. The pressure ring is threadedly connected to the aperture mounting hole to fix the soft-edge aperture between the annular baffle and the pressure ring.

[0015] In the above technical solution, the bent part and the aperture clamp are connected by bolts.

[0016] In the above technical solution, the adjustable support rod assembly includes a support rod, a support rod cylinder, and a support rod fixing button; the upper end of the support rod is fixedly connected to the fixing part, the lower end is inserted into the support rod cylinder and can move up and down inside the support rod cylinder to adjust its vertical height, the support rod fixing button passes vertically through the side wall of the support rod cylinder to press the support rod, the support rod fixing button is threadedly connected to a threaded hole formed on the side wall of the support rod cylinder, and the lower end of the support rod cylinder is fixed to the two-dimensional adjustment platform.

[0017] In the above technical solution, the support rod and the fixing part are connected by bolts.

[0018] In the above technical solution, a base that can be matched and installed on the optical platform is provided below the two-dimensional adjustment platform.

[0019] In the above technical solution, the base is provided with a fixing hole, and the screw passes through the fixing hole to fix the low-power soft-edge aperture beam shaping device on the optical platform.

[0020] In another aspect of the present invention, a dye laser amplification system includes a dye laser oscillator, a collimator and expander, a dye laser amplification chain, and the aforementioned low-power soft-edge aperture beam shaping device disposed between the collimator and expander and the dye laser amplification chain.

[0021] Another aspect of the present invention relates to a method of using the seed oscillation optical path in the above-described dye laser amplification system.

[0022] The method of using the low-power soft-edge aperture beam shaping device for the first time includes the following steps:

[0023] Step 1: Place the low-power soft-edge aperture beam shaping device in the optical path after the seed oscillation light is collimated and expanded, turn the 90° bending head to make the aperture clamp vertical, adjust the height of the adjustable support rod assembly to make the seed oscillation light beam pass through the soft-edge aperture, and perform coarse positioning in the y direction.

[0024] Step 2: Adjust the position of the low-power soft-edge aperture beam shaping device in the x-direction to perform coarse positioning in the x-direction;

[0025] Step 3: Adjust the angle of the low-power soft-edge aperture beam shaping device so that the seed oscillation light beam is perpendicularly incident into the soft-edge aperture, and at the same time, the seed oscillation light beam is perpendicular to the x-adjustment direction of the two-dimensional adjustment platform.

[0026] Step 4: Fix the coarsely positioned low-power soft-edge aperture beam shaping device onto the optical platform;

[0027] Step 5: Finely adjust the x and z adjustment directions of the two-dimensional adjustment platform to ensure a precise match between the seed oscillation light beam and the soft-edge aperture;

[0028] The method of using the seed oscillation light in the dye laser amplification system each time the optical path is adjusted includes the following steps:

[0029] Step a: Move the 90° bending head to make the aperture clamp horizontal, and adjust the seed oscillation light beam so that the seed oscillation light beam directly enters the dye laser amplification chain;

[0030] Step b: Turn the 90° bending head to make the aperture clamp vertical, and finely adjust the x and z adjustment directions of the two-dimensional adjustment platform to ensure a precise match between the seed oscillation light beam and the soft-edge aperture, so that the seed oscillation light beam is shaped by the soft-edge aperture before entering the dye laser amplification chain.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. The low-power soft-edge aperture beam shaping device provided by the present invention uses a soft-edge aperture to straighten the beam profile and remove stray light. It does not exhibit the modulation phenomenon of beam energy distribution that occurs when using a hard-edge aperture, thus ensuring the consistency of energy distribution before and after the beam and making subsequent amplification and application more efficient.

[0033] 2. The low-power soft-edge aperture beam shaping device provided by the present invention controls the aperture clamp to be vertical or horizontal through a 90° bending head, so that it can be set vertically or horizontally as needed in the dye laser amplification system without moving the entire shaping device, which is convenient to use.

[0034] 3. The method of using the low-power soft-edge aperture beam shaping device provided by this invention allows the adjustable support rod assembly to be used only for coarse height adjustment when the device is first placed in the optical path. After adjustment, no further adjustment is required. During normal use, it is only necessary to focus on the matching relationship between the beam and the aperture. If there is any deviation, the two adjustment directions of the two-dimensional adjustment frame can be finely adjusted to ensure a precise match between the beam and the aperture. The method of use is simple and easy to implement. Attached Figure Description

[0035] Figure 1 The diagram shows the structure of a low-power soft-edge aperture beam shaping device when the aperture clamp is vertical;

[0036] Figure 2 The diagram shows the structure of a low-power soft-edge aperture beam shaping device when the aperture clamp is horizontal.

[0037] Figure 3 The diagram shown is a schematic of the soft-edge aperture.

[0038] Figure 4 The diagram shown is a schematic of the aperture clamp structure.

[0039] Figure 5 The diagram shown is a schematic of a dye laser amplification system.

[0040] Figure 6 The diagram shows the shape of the light spot after the beam passes through the soft-edge aperture.

[0041] In the diagram: 1-Soft-edged aperture, 2-Aperture clamp, 2-1-Aperture mounting hole, 2-2-Annular baffle, 2-3-Pressure ring, 3-90° bend head, 3-1-Fixing part, 3-2-Bending part, 4-Two-dimensional adjustment platform, 5-Support rod, 6-Support rod cylinder, 7-Support rod fixing button, 8-Base, 9-Fixing hole. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0043] Example 1

[0044] A low-power soft-edge aperture beam shaping device, such as Figure 1 , Figure 2 As shown, it includes a soft-edge aperture 1, an aperture clamp 2 for fixing the soft-edge aperture 1, a 90° bending head 3 for controlling the vertical or horizontal position of the aperture clamp 2, an adjustable support rod assembly for adjusting the height position of the soft-edge aperture 1, and a two-dimensional adjustment platform 4 fixed below the adjustable support rod assembly for two-dimensional adjustment.

[0045] The 90° bend head 3 includes a fixed part 3-1 and a bending part 3-2 that are hinged to each other. The fixed part 3-1 is fixedly installed above the adjustable support rod assembly. The aperture clamp 2 is fixedly installed on the bending part 3-2 by bolts and becomes vertical or horizontal as the bending part 3-2 bends.

[0046] Specifically, the soft-edge aperture 1 is as follows: Figure 3 As shown, the outer contour is a circle with a diameter of d1 = 50 mm, and the number of upper teeth is greater than or equal to 20. The tip diameter of each tooth is d2 = 7 mm, and the root diameter is d3 = 9 mm. The thickness of the soft-edge aperture 1 is h = 2 mm, and the material is stainless steel.

[0047] Specifically, the aperture clamp 2 is as follows: Figure 4 As shown, an aperture mounting hole 2-1 for installing the soft-edged aperture 1 is provided in the middle. An annular baffle 2-2 is provided on the back of the aperture mounting hole 2-1. An internal thread is provided on the hole wall of the aperture mounting hole 2-1. A pressure ring 2-3 is threadedly connected to the aperture mounting hole 2-1 to fix the soft-edged aperture 1 between the annular baffle 2-2 and the pressure ring 2-3.

[0048] Alternatively, the pressure ring 2-3 can be engaged and assembled within the aperture mounting hole 2-1.

[0049] Specifically, the adjustable support rod assembly includes a support rod 5, a support rod cylinder 6, and a support rod fixing button 7. The upper end of the support rod 5 is fixedly connected to the fixing part 3-1 by bolts, and the lower end is inserted into the support rod cylinder 6 and can move up and down within the support rod cylinder 6 to adjust its vertical height. The support rod fixing button 7 is located on the support rod cylinder 6, and when tightened, it locks and fixes the support rod 5 and the support rod cylinder 6. The lower part of the support rod cylinder 6 is fixed to the two-dimensional adjustment platform 4. The height adjustment range of the support rod 5 and the support rod cylinder 6 is 45mm.

[0050] Preferably, a base 8 is provided below the two-dimensional adjustment platform 4, and a fixing hole 9 (not shown in the figure) is provided on the base 8. The screw passes through the fixing hole 9 to fix the low-power soft-edge aperture beam shaping device on the optical platform.

[0051] Example 2

[0052] A dye laser amplification system, such as Figure 2 As shown, it includes a dye laser oscillator, a collimator and expander, a dye laser amplification chain, and a low-power soft-edge aperture beam shaping device as described in Example 1, disposed between the collimator and expander and the dye laser amplification chain.

[0053] A first 45° reflector is provided between the dye laser oscillator and the collimator beam expander, and the oscillating light emitted by the dye laser oscillator is reflected by the first 45° reflector to the collimator beam expander.

[0054] A second 45° reflector is provided between the collimator and the low-power soft-edge aperture beam shaping device. The oscillating light processed by the collimator is reflected by the second 45° reflector to the low-power soft-edge aperture beam shaping device for shaping, and then enters the dye laser amplification chain.

[0055] Example 3

[0056] This embodiment describes the method of using the seed oscillation optical path in the dye laser amplification system described in Embodiment 2.

[0057] The method of using the low-power soft-edge aperture beam shaping device for the first time includes the following steps:

[0058] Step 1: Place the low-power soft-edge aperture beam shaping device in the optical path after the seed oscillation light is collimated and expanded, turn the 90° bending head 3 to make the aperture clamp 2 vertical, adjust the height of the adjustable support rod assembly to make the seed oscillation light beam pass through the soft-edge aperture 1, and perform coarse positioning in the y direction.

[0059] Step 2: Adjust the position of the low-power soft-edge aperture beam shaping device in the x-direction to perform coarse positioning in the x-direction;

[0060] Step 3: Adjust the angle of the low-power soft-edge aperture beam shaping device so that the seed oscillation light beam is perpendicularly incident into the soft-edge aperture 1, and at the same time the seed oscillation light beam is perpendicular to the x-adjustment direction of the two-dimensional adjustment platform 4.

[0061] The angle of the low-power soft-edge aperture beam shaping device is determined by the shape of the beam after passing through the soft-edge aperture 1, such as... Figure 6 As shown, 6a represents the shape of the seed oscillating light beam after it is perpendicularly incident on the soft-edge aperture 1. Figure 6b represents the shape of the seed oscillating light beam after it is obliquely incident on the soft-edge aperture 1. When the adjustment direction of the two-dimensional adjustment platform 4 is not perpendicular to the seed oscillating light beam, adjusting one direction will cause the light spot to move in both directions. It is necessary to repeatedly and carefully rotate the relationship between the two-dimensional adjustment frame and the beam until the light spot moves only in one direction when adjusting one direction.

[0062] Step 4: Fix the coarsely positioned low-power soft-edge aperture beam shaping device onto the optical platform;

[0063] Step 5: Finely adjust the x and z adjustment directions of the two-dimensional adjustment platform 4 to ensure a fine match between the seed oscillation light beam and the soft-edge aperture 1;

[0064] The method of using the seed oscillation light in the dye laser amplification system each time the optical path is adjusted includes the following steps:

[0065] Step a: Move the 90° bending head 3 to make the aperture clamp 2 horizontal, and adjust the seed oscillation light beam so that the seed oscillation light beam directly enters the dye laser amplification chain;

[0066] Step b: Turn the 90° bending head 3 to make the aperture clamp 2 vertical, and finely adjust the x and z adjustment directions of the two-dimensional adjustment platform 4 to ensure a fine match between the seed oscillation light beam and the soft-edge aperture 1, so that the seed oscillation light beam is shaped by the soft-edge aperture 1 before entering the dye laser amplification chain.

[0067] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A dye laser amplification system, characterized in that, It includes a dye laser oscillator, a collimator and expander, a dye laser amplification chain, and a low-power soft-edge aperture beam shaping device disposed between the collimator and expander and the dye laser amplification chain. The low-power soft-edge aperture beam shaping device includes a soft-edge aperture (1), an aperture clamp (2) for fixing the soft-edge aperture (1), a 90° bending head (3) for controlling the vertical or horizontal position of the aperture clamp (2), an adjustable support rod assembly for adjusting the height position of the soft-edge aperture (1), and a two-dimensional adjustment platform (4) fixed at the lower part of the adjustable support rod assembly. The aperture clamp (2) is fixed to the top of the adjustable support rod assembly by a 90° bend head (3). The 90° bend head (3) includes a fixed part (3-1) and a bending part (3-2) that are hinged to each other. The fixed part (3-1) is fixedly installed on the top of the adjustable support rod assembly. The aperture clamp (2) is fixedly installed on the bending part (3-2) and is in a vertical or horizontal state as the bending part (3-2) bends. A first 45° reflector is provided between the dye laser oscillator and the collimator beam expander, and the seed oscillation light emitted by the dye laser oscillator is reflected by the first 45° reflector to the collimator beam expander. A second 45° reflector is provided between the collimator and the low-power soft-edge aperture beam shaping device. The seed oscillation light processed by the collimator is reflected by the second 45° reflector to the low-power soft-edge aperture beam shaping device for shaping, and then enters the dye laser amplification chain.

2. The dye laser amplification system as described in claim 1, characterized in that: The aperture fixture (2) has an aperture mounting hole (2-1) in the middle for mounting the soft-edged aperture (1). An annular baffle (2-2) is provided on the back of the aperture mounting hole (2-1). When the pressure ring (2-3) is assembled in the aperture mounting hole (2-1), the soft-edged aperture (1) is fixed between the annular baffle (2-2) and the pressure ring (2-3).

3. The dye laser amplification system as described in claim 2, characterized in that: The pressure ring (2-3) is engaged and assembled in the aperture mounting hole (2-1).

4. The dye laser amplification system as described in claim 2, characterized in that: The pressure ring (2-3) is threaded into the aperture mounting hole (2-1). The aperture mounting hole (2-1) has an internal thread on its wall. The pressure ring (2-3) is threaded into the aperture mounting hole (2-1) to fix the soft-edge aperture (1) between the annular baffle (2-2) and the pressure ring (2-3).

5. The dye laser amplification system as described in claim 1, characterized in that: The bent portion (3-2) is connected to the aperture clamp (2) by bolts.

6. The dye laser amplification system as described in claim 1, characterized in that: The adjustable support rod assembly includes a support rod (5), a support rod cylinder (6), and a support rod fixing button (7); the upper end of the support rod (5) is fixedly connected to the fixing part (3-1), the lower end is inserted into the support rod cylinder (6) and can move up and down inside the support rod cylinder (6) to adjust its vertical height, the support rod fixing button (7) passes vertically through the side wall of the support rod cylinder (6) to press the support rod (5), the support rod fixing button (7) is threadedly connected to the threaded hole formed on the side wall of the support rod cylinder (6), and the lower end of the support rod cylinder (6) is fixed on the two-dimensional adjustment platform (4).

7. The dye laser amplification system as described in claim 6, characterized in that: The support rod (5) is connected to the fixing part (3-1) by bolts.

8. The dye laser amplification system as described in claim 1, characterized in that: Below the two-dimensional adjustment platform (4) is a base (8) that can be matched and installed on the optical platform.

9. The dye laser amplification system as described in claim 8, characterized in that: The base (8) is provided with a fixing hole (9), and the screw passes through the fixing hole (9) to fix the low-power soft-edge aperture beam shaping device on the optical platform.

10. A method of using the seed oscillation optical path of the dye laser amplification system according to any one of claims 1-9, characterized in that: The method of using the low-power soft-edge aperture beam shaping device for the first time includes the following steps: Step 1: Place the low-power soft-edge aperture beam shaping device in the optical path after the seed oscillation light is collimated and expanded, turn the 90° bending head (3) to make the aperture clamp (2) vertical, adjust the height of the adjustable support rod assembly to make the seed oscillation light beam pass through the soft-edge aperture (1) and perform coarse positioning in the y direction. Step 2: Adjust the position of the low-power soft-edge aperture beam shaping device in the x-direction to perform coarse positioning in the x-direction; Step 3: Adjust the angle of the low-power soft-edge aperture beam shaping device so that the seed oscillation beam is perpendicularly incident into the soft-edge aperture (1), and at the same time the seed oscillation beam is perpendicular to the x-adjustment direction of the two-dimensional adjustment platform (4); Step 4: Fix the coarsely positioned low-power soft-edge aperture beam shaping device onto the optical platform; Step 5: Finely adjust the x and z adjustment directions of the two-dimensional adjustment platform (4) to ensure a fine match between the seed oscillation light beam and the soft-edge aperture (1); The method of using the seed oscillation light in the dye laser amplification system each time the optical path is adjusted includes the following steps: Step a: Move the 90° bend head (3) to make the aperture clamp (2) horizontal, and adjust the seed oscillation light beam so that the seed oscillation light beam directly enters the dye laser amplification chain; Step b: Turn the 90° bending head (3) to make the aperture clamp (2) vertical, and finely adjust the x and z adjustment directions of the two-dimensional adjustment platform (4) to ensure that the seed oscillation light beam is finely matched with the soft-edge aperture (1), so that the seed oscillation light beam is shaped by the soft-edge aperture (1) before entering the dye laser amplification chain.

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