Optical lens for near-infrared laser focusing

Abstract

The invention discloses an optical lens for near-infrared laser focusing, which comprises a lens body, and a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens which are sequentially and coaxially arranged in the lens along the incident direction of a light beam, the second lens and the seventh lens are plano-concave lenses, the object side surface of the second lens is a concave surface, the image side surface of the seventh lens is a concave surface, the third lens, the fourth lens, the fifth lens and the sixth lens are plano-convex lenses, the image side surfaces of the third lens and the fourth lens are convex surfaces, and the image side surfaces of the fifth lens and the sixth lens are concave surfaces. The object side surfaces of the fifth lens and the sixth lens are convex surfaces, and the eighth lens is a window lens. The structure is simple, the aberration problem is effectively solved, the scanning and cutting precision is guaranteed, the operation effect is guaranteed, and safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and in particular to a standardized optical lens for near-infrared laser focusing. Background Art

[0002] In recent years, optical technology has developed rapidly, and laser lenses have been increasingly widely used in the fields of clinical medicine and scientific research. In the industrial and technological fields, laser lenses are the core components in links such as laser printing, laser cutting, and optical communication. With their precise beam guiding ability, they have greatly improved production and transmission efficiency. In clinical medicine, laser lenses play an irreplaceable role. Taking the laser corneal refractive keratectomy for myopia in the human eye as an example, this surgery has extremely high requirements for the performance of the laser lens. To improve the surgical accuracy, doctors usually choose a laser focusing lens with a small focal spot and a reasonable scanning range. Such a lens can achieve precise scanning and cutting within a very small range, reducing damage to surrounding tissues. However, limited by the current technical level, the focusing effect of some laser lenses is not good. Aberration problems will lead to a decline in the spot quality, which not only affects the cutting range of the cornea during surgery but also reduces the accuracy of scanning and cutting, thereby affecting the surgical effect and safety. Therefore, the research and development of higher-performance, low-aberration laser lenses has become a key link in promoting the progress of laser medical technology. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides an optical lens for near-infrared laser focusing, which has a simple structure, effectively solves the aberration problem, and ensures the scanning and cutting accuracy, the surgical effect, and the safety.

[0004] To achieve the above object, the present invention provides an optical lens for near-infrared laser focusing, including a lens body, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, and an eighth lens arranged coaxially in sequence along the light beam incident direction in the lens. The first lens is set as a biconcave lens, the second lens and the seventh lens are set as plano-concave lenses, the object side surface of the second lens is concave, the image side surface of the seventh lens is concave, the third lens, the fourth lens, the fifth lens, and the sixth lens are set as plano-convex lenses, the image side surfaces of the third lens and the fourth lens are convex, the object side surfaces of the fifth lens and the sixth lens are convex, and the eighth lens is a window lens.

[0005] The beneficial effects of such a setting are as follows: With this setting, this lens consists of a lens barrel and eight lenses arranged coaxially along the incident light beam direction. The first lens is a biconcave lens to expand the parallel incident light beam; the second lens is a plano-concave lens to expand the light into a larger light beam; the third lens is a plano-convex lens to expand the light beam during the deflection process of the light beam; the fourth lens is a plano-convex lens to converge the light beam into a parallel light beam; the fifth lens is a plano-convex lens to diverge the light and adjust the focal length; the sixth lens is a plano-convex lens to focus the light and adjust the focal length; the seventh lens is a plano-concave lens to converge the light; the eighth lens is a window lens to transmit the light. Such a setting is highly effective in reducing costs and improving performance. From the perspective of processing and assembly, this lens greatly reduces the processing difficulty and cost. The types of each lens are simple and clear, with a combination of biconcave, plano-concave, and plano-convex lenses, reducing the processing requirements for complex curved surfaces. This design also facilitates assembly and debugging, reducing the technical threshold and time cost during the production process. In terms of optical performance, the distances between the lenses are carefully designed, and there is sufficient expansion space for the light between the lenses. The third to sixth lenses are plano-convex lenses, which, in cooperation with the biconcave and plano-concave lenses, can effectively guide and focus the light, reducing aberrations such as high-order spherical aberration and coma, and significantly improving the imaging quality and stability. As a preference, the wavelength range of the lens structure is 1030 nm, and it can achieve laser scanning with a focused spot within a diameter of 9 mm. By reasonably adjusting the optical path of the lens group, this lens achieves excellent spot performance, and the laser energy at the center of the spot can reach 80% of the overall incident energy, greatly improving the utilization rate of laser energy. Taking the application of laser cutting and scanning as an example, a high-energy-density spot can achieve more precise processing. Compared with traditional lenses, it effectively solves the problem of small energy density, enables a higher precision in the cutting and scanning range, and can meet the stringent requirements of high-precision processing. In a near-infrared imaging system, this lens, with its characteristics of low aberration and high energy utilization rate, ensures the clarity and stability of the image. This not only helps to improve the overall performance of the system but also provides the possibility for the miniaturization and lightweight design of related equipment, further expanding the application space of near-infrared laser technology in industrial manufacturing, medical treatment, scientific research, and other fields.

[0006] As a further setting of the present invention, the entrance pupil diameter of the lens barrel is 20 mm, the effective focal length of the lens barrel is 50.8 mm, and the F-number of the lens barrel is 2.5.

[0007] The beneficial effects of such a setting are as follows: The structural arrangement is reasonable, ensuring the use effect of the lens, ensuring the converging effect of the laser energy, improving the use reliability of the structure, and having a good use effect.

[0008] As a further setting of the present invention, the field of view angle of the lens barrel is 5°.

[0009] The beneficial effects of such a setting are as follows: By setting it in this way, the light in a specific area can be more concentratedly focused, the incidence of marginal light can be reduced, thereby reducing the influence of aberration and distortion. At the same time, more laser energy can be concentrated in a smaller field of view, which is beneficial to increasing the proportion of laser energy at the center of the light spot.

[0010] As a further setting of the present invention, the total system length of the lens body is 456.5 mm.

[0011] The beneficial effects of such a setting are as follows: The overall structure is compact, ensuring the use effect and the stability of the function, and having a good use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic layout structure diagram of the optical lens according to the embodiment of the present invention; Figure 2 It is a field point diagram of the field of view when the object surface is at 0° according to the embodiment of the present invention; Figure 3 It is a field point diagram of the field of view when the object surface is at 1.5° according to the embodiment of the present invention; Figure 4 It is a field point diagram of the field of view when the object surface is at 2.5° according to the embodiment of the present invention; Figure 5 It is a field point diagram of the field of view when the object surface is at 3° according to the embodiment of the present invention; Figure 6 It is a field point diagram of the field of view when the object surface is at 5° according to the embodiment of the present invention; Figure 7 It is a geometric encircled energy diagram of the optical path design in the embodiment of the present invention; Figure 8 It is a field curvature diagram of the optical path design in the embodiment of the present invention; Figure 9 It is a distortion diagram of the optical path design in the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] The present invention provides an embodiment of an optical lens for near-infrared laser focusing as Figure 1 and Figure 9As shown in the figure, it includes a lens body, and the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, and the eighth lens L8 are arranged coaxially in sequence along the light beam incident direction in the lens. The first lens L1 is set as a biconcave lens, the second lens L2 and the seventh lens L7 are set as plano-concave lenses. The object side of the second lens L2 is concave, and the image side of the seventh lens L7 is concave. The third lens L3, the fourth lens L4, the fifth lens L5, and the sixth lens L6 are set as plano-convex lenses. The image sides of the third lens L3 and the fourth lens L4 are convex, and the object sides of the fifth lens L5 and the sixth lens L6 are convex. The eighth lens L8 is a window lens. With such a setting, this lens is composed of a lens body and eight lenses arranged coaxially along the light beam incident direction. The first lens L1 is a biconcave lens to expand the parallel incident light beam; the second lens L2 is a plano-concave lens to expand the light beam into a larger one; the third lens L3 is a plano-convex lens to expand the light beam during the deflection process of the light beam; the fourth lens L4 is a plano-convex lens to converge the light beam into a parallel light beam; the fifth lens L5 is a plano-convex lens to diverge the light and adjust the focal length; the sixth lens L6 is a plano-convex lens to focus the light and adjust the focal length; the seventh lens L7 is a plano-concave lens to converge the light; the eighth lens L8 is a window lens to transmit the light. Such a setting has achieved remarkable results in reducing costs and improving performance. From the perspective of processing and assembly, this lens greatly reduces the processing difficulty and cost. The types of each lens are simple and clear, and the combination of biconcave, plano-concave, and plano-convex reduces the processing requirements for complex curved surfaces. This design also facilitates assembly and debugging, reducing the technical threshold and time cost in the production process. In terms of optical performance, the distances between the lenses are carefully designed, and there is sufficient expansion space for the light beam between the lenses. The third to sixth lenses L6 are plano-convex lenses, which can effectively guide and focus the light beam in cooperation with the biconcave and plano-concave lenses, reducing aberration such as high-order spherical aberration and coma, and significantly improving the imaging quality and stability. As an option, the wavelength range of the lens structure is 1030nm, and it can achieve laser scanning with a focused spot within a diameter of 9mm. By reasonably adjusting the optical path of the lens group, this lens achieves excellent spot performance, and the laser energy at the center of the spot can reach 80% of the overall incident energy, greatly improving the laser energy utilization rate. Taking the application of laser cutting and scanning as an example, a high-energy-density spot can achieve more precise processing. Compared with traditional lenses, it effectively solves the problem of small energy density, making the cutting and scanning range more accurate and capable of meeting the strict requirements of high-precision processing. In a near-infrared imaging system, this lens, with its characteristics of low aberration and high energy utilization rate, ensures the clarity and stability of the image. This not only helps to improve the overall performance of the system but also provides the possibility for the miniaturization and lightweight design of related equipment, further expanding the application space of near-infrared laser technology in fields such as industrial manufacturing, medical treatment, and scientific research.

[0014] As a further setting of this embodiment, the entrance pupil diameter of the lens body is 20 mm, the effective focal length of the lens body is 50.8 mm, and the F-number of the lens body is 2.5. The beneficial effects of such a setting are as follows: the structural layout is reasonable, ensuring the use effect of the lens, ensuring the focusing effect of the laser energy, improving the use reliability of the structure, and having a good use effect.

[0015] As a further setting of this embodiment, the field of view angle of the lens body is 5°. The beneficial effects of such a setting are as follows: with such a setting, the light in a specific area can be focused more intensively, the incidence of marginal light can be reduced, thereby reducing the influence of aberration and distortion. At the same time, more laser energy can be concentrated in a smaller field of view, which is beneficial to increasing the proportion of laser energy at the center of the light spot.

[0016] As a further setting of this embodiment, the total length of the lens body system is 456.5 mm. The beneficial effects of such a setting are as follows: the overall structural design is reasonable, ensuring the use effect and the stability of the function, and having a good use effect.

[0017] The relevant parameters of each lens in the optical lens provided by this embodiment are shown in Table 1: As Figures 2 to 6 shown, the focused spot of the spot diagram is about 3.2 um, and the root mean square radius is 3.6 um, and laser scanning within a diameter range of 9 mm of the focused spot can be realized.

[0018] As Figure 7 shown, it can be realized that at a certain oblique incidence, the spot radius can be ensured within the required range for each field of view angle, the energy entering the geometric circle reaches 80%, and it is less than the diffraction limit.

[0019] As Figure 8 and Figure 9 shown, it is the field curvature / distortion diagram of the embodiment. Among them, with respect to the wavelength of the legend, the sagittal field curvature is 0.0434 mm, and the meridional field curvature is 0.0876 mm; the maximum field of view distortion is less than 0.3939%, having the design feature of small distortion.

[0020] The above examples are only one of the preferred specific examples of the present invention, and the common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. An optical lens for near-infrared laser focusing, characterized in that: The invention comprises a lens body, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens and the eighth lens are coaxially arranged in sequence along the incident direction of the light beam, the first lens is configured as a double concave lens, the second lens and the seventh lens are configured as plano-concave lenses, the object side surface of the second lens is a concave surface, the image side surface of the seventh lens is a concave surface, the third lens, the fourth lens, the fifth lens and the sixth lens are configured as plano-convex lenses, the image side surfaces of the third lens and the fourth lens are convex surfaces, the object side surfaces of the fifth lens and the sixth lens are convex surfaces, and the eighth lens is a window mirror.

2. The optical lens for near-infrared laser focusing according to claim 1, characterized in that: The entrance pupil diameter of the lens body is 20 mm, the effective focal length of the lens body is 50.8 mm, and the F number of the lens body is 2.

5.

3. The optical lens for near-infrared laser focusing according to claim 1, characterized in that: The field of view angle of the mirror body is 5°.

4. The optical lens for near-infrared laser focusing according to claim 1, characterized in that: The total system length of the mirror body is 456.5 mm.

Images