A focusing lens for laser myopia surgery scanning

Abstract

The application discloses a focusing lens for laser myopia operation scanning, which is composed of seven lenses. The seven lenses are arranged in sequence along the light transmission direction, and are a plano-concave lens for diffusing an incident light beam, a first plano-convex lens for converging the diffused light beam into a parallel light beam, a second plano-convex lens for focusing a target in the light beam deflection process, a lenticular lens for converging the light beam into a parallel light beam, a double-concave lens for adjusting the focal length, a third plano-convex lens for re-converging the light beam into a parallel light beam, and a window piece for transmitting light. The focusing lens can focus laser light energy into a very small space area, and thus the operation precision is high and the vision correction range is large in the laser myopia operation scanning process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to a focusing lens for laser myopia surgery scanning. BACKGROUND

[0002] At present, nearly half of the population in China suffers from different degrees of myopia, and the proportion of young people is relatively high. There are also a considerable number of presbyopia patients, and corneal-related diseases such as refractive errors seriously endanger human visual health. With the continuous improvement of China's economic conditions, people's demand for the quality of life is getting higher and higher. In the future, the amount of corneal refractive surgery in China will increase significantly. Laser myopia surgery can effectively treat myopia. It treats myopia through six development stages of laser optical corneal cutting, excimer laser in situ corneal lathing, excimer laser subepithelial corneal lathing, wavefront aberration guided excimer laser surgery, femtosecond, and half femtosecond laser.

[0003] In the clinical treatment of corneal flap ophthalmic surgery for myopia, the cornea of the patient needs to be scanned for cutting to correct the vision of the eye. The existing technology is to place an optical scanner at a certain distance in front of the patient's eye for scanning. The light source of the optical scanner is generally a frequency scanning laser, which is a femtosecond infrared laser. When the laser hits the patient's cornea, there will be a converging green dot. The converging green dot is scanned by a galvanometer to achieve the scanning effect. Due to the lack of a focusing scanning lens, the scanning beam will spread over a large area, making it difficult to concentrate on a single point. Therefore, during the laser myopia surgery scanning process, the accuracy of the surgery will be reduced. SUMMARY

[0004] The present application provides a focusing lens for laser myopia surgery scanning to solve the above technical problems.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A focusing lens for laser myopia surgery scanning is composed of seven lenses. The seven lenses are arranged in the order of a plano-concave lens for diffusing incident light beams, a first plano-convex lens for converging the diffused light beams into parallel light beams, a second plano-convex lens for focusing the target in the light beam deflection process, a double-convex lens for converging the light beams into parallel light beams, a double-concave lens for adjusting the focal length, a third plano-convex lens for re-converging the light beams into parallel light beams, and a window piece for transmitting light.

[0007] Preferably, the entrance pupil diameter of the focusing lens is 20mm, the working wavelength is 1030nm, and the effective focal length is 59.4mm.

[0008] Preferably, the concave surface of the plano-concave lens, the plane of the first plano-convex lens, and the convex surfaces of the second and third plano-convex lenses are all facing the direction of the incident light beam.

[0009] Preferably, the radii of curvature of the two sides of the plano-concave lens along the optical path transmission direction are -64.6 mm and 0, respectively; the radii of curvature of the two sides of the first plano-convex lens are 0 and -155 mm, respectively; the radii of curvature of the two sides of the second plano-convex lens are 77.52 mm and 0, respectively; the radii of curvature of the two sides of the biconvex lens are 153.49 mm and -153.49 mm, respectively; the radii of curvature of the two sides of the biconcave lens are -46.23 mm and 46.23 mm, respectively; the radii of curvature of the two sides of the third plano-convex lens are 25.84 mm and 0, respectively; and the radii of curvature of the two sides of the window are both 0.

[0010] Preferably, the center thickness of the plano-concave lens is 5mm, the center thickness of the first plano-convex lens is 12.5mm, the center thickness of the second plano-convex lens is 48.3mm, the center thickness of the biconvex lens is 9mm, the center thickness of the biconcave lens is 2.5mm, the center thickness of the third plano-convex lens is 5mm, and the center thickness of the window is 2mm.

[0011] Preferably, the distance between the plano-concave lens and the aperture stop is 30 mm, the distance between the plano-concave lens and the first plano-convex lens is 143.4 mm, the distance between the first plano-convex lens and the second plano-convex lens is 20 mm, the distance between the second plano-convex lens and the biconvex lens is 37.2 mm, the distance between the biconvex lens and the biconcave lens is 19.4 mm, the distance between the biconcave lens and the third plano-convex lens is 26.2 mm, and the distance between the third plano-convex lens and the window plate is 27.1 mm.

[0012] Preferably, the refractive index of the plano-concave lens, the first plano-convex lens, the second plano-convex lens, the biconvex lens, the biconcave lens, and the third plano-convex lens is 1.5168, and the Abbe number is 64.167. The refractive index of the window is 1.4585, and the Abbe number is 67.795.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The focusing lens disclosed in this invention can focus laser light energy into a spatial area with a very small diameter, thereby achieving high precision and a large range of vision correction during laser myopia surgery scanning. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the optical path design layout of the present invention;

[0016] Figure 2 The optical dispersion pattern is shown in the optical path design of this invention.

[0017] Figure 3 The modulation transfer function (MTF) diagram for the optical path design of this invention;

[0018] Figure 4 Field curvature / distortion in the optical path design of this invention.

[0019] Figure labels: 1. Plano-concave lens, 2. First plano-convex lens, 3. Second plano-convex lens, 4. Biconvex lens, 5. Biconcave lens, 6. Third plano-convex lens, 7. Window plate. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention.

[0021] like Figure 1 The laser vision correction surgery focusing lens shown consists of seven lenses. Along the optical path, the seven lenses sequentially include a plano-concave lens 1, which diffuses the laser beam after passing through the aperture, thereby increasing the beam width; a first plano-convex lens 2, which re-convexes the diffused beam into a parallel beam, specifically expanding the original beam to a specified size so that the wavefront difference of the parallel beam is less than one wavelength; and a second plano-convex lens 3, an aspherical lens with excellent beam deflection capability, which plays a major converging role in the focusing lens and bears the main optical power. In the design, due to… Aspherical surfaces have more parameter variables, making it easier to achieve the focusing target and reducing design difficulty; the biconvex lens 4 can converge the beam into a parallel beam to optimize the size of the light spot; the biconcave lens 5 serves to diverge the laser light and control the focal length of the entire converging lens; the third plano-convex lens 6 re-convexes the beam into a parallel beam to optimize the size of the light spot for better focusing effect; the window 7 is used to transparently transmit and protect the light, wherein the concave surface of the plano-concave lens 1, the plane of the first plano-convex lens 2, and the convex surfaces of the second plano-convex lens 3 and the third plano-convex lens 6 are all facing the direction of beam incidence.

[0022] In the corneal flap creation ophthalmic surgery for myopia treatment using laser, the laser beam, after passing through the aperture, is successively diffused by a plano-concave lens 1 to increase the beam's width; then, by a first plano-convex lens 2, the diffused beam is re-convexed into a parallel beam, specifically, the original beam is expanded to a specified size so that the wavefront difference of the parallel beam is less than one wavelength; then, by a second plano-convex lens 3, the beam is focused on the target; then, by a second biconvex lens 4, the beam is converged into a parallel beam to optimize the spot size; then, by a biconcave lens 5, the laser beam is diverged and the focal length of the focusing lens is adjusted; then, by a third plano-convex lens 6, the beam is re-convexed into a parallel beam again to further optimize the spot size for a better focusing effect; finally, by a transparent window 7, the light is transmitted to achieve focused scanning within a certain range of the human eye.

[0023] Specifically, the entrance pupil diameter of the aforementioned focusing lens is 20mm, the working wavelength is 1030nm, and the effective focal length is 59.4mm. Along the optical path transmission direction, the center thickness of the plano-concave lens 1 is 5mm, and the radii of curvature on its two sides are -64.6mm and 0, respectively. The center thickness of the first plano-convex lens 2 is 12.5mm, and the radii of curvature on its two sides are 0 and -155mm, respectively. The center thickness of the second plano-convex lens 3 is 48.3mm, and the radii of curvature on its two sides are 77.52mm and -155mm, respectively. The biconvex lens 4 has a center thickness of 9mm and radii of curvature of 153.49mm and -153.49mm on its two sides, respectively. The biconcave lens 5 has a center thickness of 2.5mm and radii of curvature of -46.23mm and 46.23mm on its two sides, respectively. The third plano-convex lens 6 has a center thickness of 5mm and radii of curvature of 25.84mm and 0 on its two sides, respectively. The window 7 has a center thickness of 5mm and radii of curvature of 0 on both sides. Furthermore, the plano-concave lens 1 and the aperture stop... The spacing between the two lenses is 30mm; the spacing between the plano-concave lens 1 and the first plano-convex lens 2 is 143.4mm; the spacing between the first plano-convex lens 2 and the second plano-convex lens 3 is 20mm; the spacing between the second plano-convex lens 3 and the biconvex lens 4 is 37.2mm; the spacing between the biconvex lens 4 and the biconcave lens 5 is 19.4mm; the spacing between the biconcave lens 5 and the third plano-convex lens 6 is 26.2mm; and the spacing between the third plano-convex lens 6 and the window plate 7 is 27.1mm. Lens 1, first plano-convex lens 2, second plano-convex lens 3, biconvex lens 4, biconcave lens 5, and third plano-convex lens 6 all have a refractive index of 1.5168 and an Abbe number of 64.167. Window 7 has a refractive index of 1.4585 and an Abbe number of 67.795. This achieves an Airy disk radius of approximately 3.7 μm and a root mean square radius of approximately 3.5 μm, enabling the light spot to scan within a circular area with a diameter of 9 mm. There are no significant aberrations within the wavelength range, and the wavefront aberration is less than one wavelength.

[0024] The table below shows the data parameters of each lens in the focusing lens.

[0025]

[0026] In the table above, the object plane is the plane facing the direction of the incident beam, and the phase plane is the plane facing away from the direction of the incident beam. In this embodiment, the optical blur pattern, modulation transfer function (MTF) diagram, and field curvature / distortion diagram of the focusing lens are respectively as follows: Figures 2-4 As shown.

[0027] like Figure 2 The optical diffusion pattern shown in the embodiment has an Airy disk radius of about 3.7 μm and a root mean square radius of about 3.5 μm, which enables the light spot to scan within a circular area with a diameter of 9 mm and achieves good image quality.

[0028] like Figure 3 The modulation transfer function (MTF) plot for this embodiment allows you to view the MTF value and spatial frequency resolution. When the spatial frequency reaches 80 / mm, the MTF value is greater than 0.4.

[0029] like Figure 4 The field curvature / distortion in the example is less than 2.2% across the entire field of view, and the distortion is small.

[0030] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A focusing lens for laser myopia surgery scanning, characterized in that, It consists of seven lenses arranged at intervals. The seven lenses are arranged in sequence along the optical path transmission direction as follows: a plano-concave lens (1) for diffusing the incident beam, a first plano-convex lens (2) for converging the diffused beam into a parallel beam, a second plano-convex lens (3) for focusing the target during beam deflection, a biconvex lens (4) for converging the beam into a parallel beam, a biconcave lens (5) for adjusting the focal length, a third plano-convex lens (6) for re-convexizing the beam into a parallel beam, and a window (7) for transmitting light. The concave surface of the plano-concave lens (1), the plane of the first plano-convex lens (2), and the convex surfaces of the second plano-convex lens (3) and the third plano-convex lens (6) are all facing the direction of beam incidence. The entrance pupil diameter of the focusing lens is 20 mm, the working wavelength is 1030 nm, and the effective focal length is 59.4 mm.

2. The focusing lens for laser myopia surgery scanning according to claim 1, characterized in that, Along the optical path transmission direction, the curvature radii of the two sides of the plano-concave lens (1) are -64.6 mm and 0, respectively; the curvature radii of the two sides of the first plano-convex lens (2) are 0 and -155 mm, respectively; the curvature radii of the two sides of the second plano-convex lens (3) are 77.52 mm and 0, respectively; the curvature radii of the two sides of the biconvex lens (4) are 153.49 mm and -153.49 mm, respectively; the curvature radii of the two sides of the biconcave lens (5) are -46.23 mm and 46.23 mm, respectively; the curvature radii of the two sides of the third plano-convex lens (6) are 25.84 mm and 0, respectively; and the curvature radii of the two sides of the window (7) are all 0.

3. The focusing lens for laser myopia surgery scanning according to claim 1, characterized in that, The center thickness of the plano-concave lens (1) is 5 mm, the center thickness of the first plano-convex lens (2) is 12.5 mm, the center thickness of the second plano-convex lens (3) is 48.3 mm, the center thickness of the biconvex lens (4) is 9 mm, the center thickness of the biconcave lens (5) is 2.5 mm, the center thickness of the third plano-convex lens (6) is 5 mm, and the center thickness of the window plate (7) is 2 mm.

4. The focusing lens for laser myopia surgery scanning according to claim 2, characterized in that, The distance between the plano-concave lens (1) and the aperture stop is 30 mm, the distance between the plano-concave lens (1) and the first plano-convex lens (2) is 143.4 mm, the distance between the first plano-convex lens (2) and the second plano-convex lens (3) is 20 mm, the distance between the second plano-convex lens (3) and the biconvex lens (4) is 37.2 mm, the distance between the biconvex lens (4) and the biconcave lens (5) is 19.4 mm, the distance between the biconcave lens (5) and the third plano-convex lens (6) is 26.2 mm, and the distance between the third plano-convex lens (6) and the window plate (7) is 27.1 mm.

5. The focusing lens for laser myopia surgery scanning according to claim 1, characterized in that, The refractive index of the plano-concave lens (1), the first plano-convex lens (2), the second plano-convex lens (3), the biconvex lens (4), the biconcave lens (5), and the third plano-convex lens (6) is 1.5168, and the Abbe number is 64.

167. The refractive index of the window (7) is 1.4585, and the Abbe number is 67.795.

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