Beam combining device and optical system

Abstract

The utility model provides a beam combining device and an optical system. In the beam combining device, a first light source outputs a first light beam, and a second light source outputs a second light beam; the first focusing module focuses the first light beam and emits the first light beam to the beam combiner module; the second focusing module focuses the second light beam and emits the second light beam to the beam combiner module; the beam combiner module converges the first light beam and the second light beam to the light receiving surface of the light path transmission module. The beam combining device processes a first light beam output by a first light source based on a first focusing module, processes a second light beam output by a second light source based on a second focusing module, and then converges the processed first light beam and second light beam on a light receiving surface of a light path transmission module based on the same beam combiner module. Compared with the prior art, the uniformity of the light source can be guaranteed, the diameter of the light source is kept unchanged, and the beam combining light quality can be improved to a great extent.

Description

Technical Field

[0001] The utility model relates to the technical field of optics, and more specifically to a beam combining device and an optical system. Background Art

[0002] In the field of wafer CD (Critical Dimension) measurement, multiple light sources are required, especially in double-sided overlay accuracy detection.

[0003] The light source is generally a component that generates relatively high heat. The temperature is relatively high and it is equipped with a cooling fan, which makes it relatively large in size. Obviously, it cannot be arranged near the imaging unit and can only be extended to the imaging unit through components such as optical fiber light guides.

[0004] At present, the existing technology is to realize the beam combining of multiple light sources through multiple optical fiber light guides, such as Figure 1 As shown, Figure 1 Schematic diagram of beam combining based on optical fiber light guide in the prior art, as exemplified by Figure 1 As shown, two first optical fiber light guides 11 and second optical fiber light guides 12 of smaller sizes are combined into a target optical fiber light guide 13 of larger size. Since the diameter of the optical fiber light guide is about 50um, it is easy to break and thus cannot transmit the light beam. Therefore, there is no good way to ensure the uniform distribution of the optical fiber light guide. In addition, since at least two smaller optical fiber light guides are combined into a larger optical fiber light guide at the same time, the diameter of the light source will increase, the numerical aperture (NA) will increase, and the brightness will decrease.

[0005] Therefore, how to design a beam combining device that can output high-quality combined light is a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0006] In view of this, in order to solve the above problems, the utility model provides a beam combining device and an optical system, and the technical solution is as follows:

[0007] A beam combining device, comprising: a first light source, a first focusing module, a second light source, a second focusing module, a beam combining mirror module and an optical path transmission module;

[0008] Wherein, the first light source is used to output a first light beam, and the second light source is used to output a second light beam;

[0009] The first focusing module is used to focus the first light beam and make it incident on the beam combining mirror module;

[0010] The second focusing module is used to focus the second light beam and make it incident on the beam combining mirror module;

[0011] The beam combining mirror module is used to converge the first light beam and the second light beam to the light receiving surface of the light path transmission module respectively.

[0012] Preferably, in the above-mentioned beam combining device, the optical path of the first light beam from the first light source to the first focusing module is the first optical path;

[0013] The optical path of the second light beam from the second light source to the second focusing module is the second optical path;

[0014] Wherein, the first light path is perpendicular to the second light path.

[0015] Preferably, in the above-mentioned beam combining device, the beam combining mirror module is a beam combining mirror semi-reflective and semi-transparent module, and the beam combining mirror semi-reflective and semi-transparent module includes a first surface and a second surface;

[0016] The first light beam is incident on the first surface, and the second light beam is incident on the second surface;

[0017] The first light beam passes through the first surface and converges to the light receiving surface of the light path transmission module;

[0018] The second light beam is reflected by the second surface and converges to the light receiving surface of the light path transmission module.

[0019] Preferably, in the above-mentioned beam combining device, the transmittance of the first surface is greater than the reflectivity;

[0020] The reflectivity of the second surface is greater than the transmittance.

[0021] Preferably, in the above-mentioned beam combining device, the beam combining device further comprises:

[0022] An antireflection film is located on the first surface.

[0023] Preferably, in the above-mentioned beam combining device, the first light beam is an infrared light beam;

[0024] The second light beam is a visible light beam.

[0025] Preferably, in the above-mentioned beam combining device, the distance between the first light source and the first focusing module is a first distance;

[0026] The distance between the second light source and the second focusing module is a second distance;

[0027] Wherein, the first distance is smaller than the second distance.

[0028] Preferably, in the above-mentioned beam combining device, the optical path transmission module is an optical fiber light guide;

[0029] The light receiving surface is the end surface of the optical fiber light guide.

[0030] Preferably, in the above-mentioned beam combining device, the first focusing module is a convex lens;

[0031] The second focusing module is a convex lens.

[0032] The utility model also provides an optical system, which includes any one of the beam combining devices described above.

[0033] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0034] The utility model provides a beam combining device including: a first light source, a first focusing module, a second light source, a second focusing module, a beam combining mirror module and an optical path transmission module; wherein the first light source is used to output a first light beam, and the second light source is used to output a second light beam; the first focusing module is used to focus the first light beam and incident it to the beam combining mirror module; the second focusing module is used to focus the second light beam and incident it to the beam combining mirror module; the beam combining mirror module is used to converge the first light beam and the second light beam to the light receiving surface of the optical path transmission module respectively. The beam combining device processes the first light beam output by the first light source based on the first focusing module, processes the second light beam output by the second light source based on the second focusing module, and then converges the processed first light beam and the second light beam to the light receiving surface of the optical path transmission module based on the same beam combining mirror module. Compared with the prior art, the uniformity of the light source can be guaranteed, and the diameter of the light source remains unchanged, which can greatly improve the quality of the combined light. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0036] Figure 1 It is a schematic diagram of beam combining based on optical fiber light guide in the prior art;

[0037] Figure 2 It is an equivalent analysis schematic diagram of combining two first optical fiber light guides and second optical fiber light guides with smaller sizes into one target optical fiber light guide with larger size in the prior art;

[0038] Figure 3A schematic diagram of the optical path structure of a beam combining device provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] Based on the content of the background technology, refer to Figure 2 , Figure 2 FIG. 1 is an equivalent analysis diagram of combining two first optical fiber light guides and a second optical fiber light guide of smaller size into one target optical fiber light guide of larger size in the prior art. If the first optical fiber light guide 1 is as follows Figure 2 (a) Nine-grid distribution, if the second optical fiber light guide 2 is as follows Figure 2 (b) The distributed nine-square grid cannot be formed by combining the beams. Figure 2 (c) The nine-grid distribution leads to changes in uniformity. Even if the Figure 2 (c) The distribution of the nine-grid. As the spacing and other parameters change, the distribution of light intensity will also change. You can imagine a similar effect of interpolation when a photo is enlarged.

[0041] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0042] refer to Figure 3 , Figure 3 A schematic diagram of the optical path structure of a beam combining device provided in an embodiment of the utility model, the beam combining device provided in an embodiment of the utility model includes: a first light source 1-1, a first focusing module 1-2, a second light source 2-1, a second focusing module 2-2, a beam combining mirror module 3 and an optical path transmission module 4.

[0043] The first light source 1 - 1 is used to output a first light beam, and the second light source 2 - 1 is used to output a second light beam.

[0044] The first focusing module 1 - 2 is used to focus the first light beam and make it incident on the beam combining mirror module 3 .

[0045] The second focusing module 2 - 2 is used to focus the second light beam and make it incident on the beam combining mirror module 3 .

[0046] The beam combining mirror module 3 is used to converge the first light beam and the second light beam to the light receiving surface of the light path transmission module 4 respectively.

[0047] Specifically, in the embodiment of the utility model, the first focusing module 1-2 includes but is not limited to a convex lens, and the second focusing module 2-2 includes but is not limited to a convex lens. In an optional embodiment of the utility model, based on parameters such as the size of the light source, the divergence angle, and the distance between the light source and the focusing module, the specific optical path form of the first focusing module 1-2 and the specific optical path form of the second focusing module 2-2 can also be reasonably set. In the embodiment of the utility model, only the first focusing module 1-2 and the second focusing module 2-2 are taken as focusing lenses for illustration.

[0048] The beam combining device processes the first light beam output by the first light source 1-1 based on the first focusing module 1-2, and processes the second light beam output by the second light source 2-1 based on the second focusing module 2-2, and then converges the processed first light beam and second light beam on the light receiving surface of the optical path transmission module 4 based on the same beam combining mirror module 3. Compared with the prior art, the uniformity of the light source can be guaranteed, and the diameter of the light source remains unchanged, which can greatly improve the quality of the combined light. In other words, the beam combining device is realized by combining light beams through a prism, which is equivalent to area multiplexing, so the uniformity and diameter do not change. Since the optical path is not reorganized, the quality of the combined light can be further improved while keeping the original unchanged.

[0049] Optionally, in another embodiment of the present invention, a light path of the first light beam from the first light source 1 - 1 to the first focusing module 1 - 2 is the first light path.

[0050] The optical path of the second light beam from the second light source 2 - 1 to the second focusing module 2 - 2 is the second optical path.

[0051] Wherein, the first light path is perpendicular to the second light path.

[0052] Specifically, in the embodiment of the utility model, when the first light path and the second light path are perpendicular, a perfect circular light spot can be output; if they are not perpendicular, the light spot will become an ellipse; if the first light path and the second light path are one perpendicular and one inclined, it is equivalent to a perfect circle and an ellipse superimposed.

[0053] Optionally, in another embodiment of the present invention, the beam combining mirror module 3 is a beam combining mirror semi-reflective and semi-transparent module, and the beam combining mirror semi-reflective and semi-transparent module includes a first surface and a second surface.

[0054] The first light beam is incident on the first surface, and the second light beam is incident on the second surface.

[0055] The first light beam passes through the first surface and converges to the light receiving surface of the light path transmission module 4 .

[0056] The second light beam is reflected by the second surface and converges to the light receiving surface of the light path transmission module 4 .

[0057] Specifically, in the embodiment of the utility model, the transmittance of the first surface is greater than the reflectivity, thereby ensuring that the first light beam can pass through the beam combiner semi-reflective and semi-transparent module 3 to the greatest extent, greatly reducing the reflection effect of the beam combiner semi-reflective and semi-transparent module 3 on the first light beam, that is, greatly reducing the light loss of the beam combiner semi-reflective and semi-transparent module 3 on the first light beam, further improving the brightness of the light converged on the light receiving surface, and realizing the improvement of light quality.

[0058] The reflectivity of the second surface is greater than the transmittance, thereby ensuring that the second light beam can be reflected by the second surface to the light receiving surface to the greatest extent, greatly reducing the transmission effect of the beam combiner semi-reflective and semi-transparent module 3 on the second light beam, that is, greatly reducing the light loss of the beam combiner semi-reflective and semi-transparent module 3 on the second light beam, further improving the brightness of the light converged on the light receiving surface, and realizing the improvement of light quality.

[0059] Optionally, in another embodiment of the present invention, the beam combining device further comprises: an anti-reflection film located on the first surface.

[0060] Specifically, in the embodiment of the utility model, an anti-reflection film can be provided on the first surface to further improve the transmittance of the first light beam, especially when the brightness of the first light beam itself is relatively low, the effect is more significant, and the transmittance of the first light beam can be at least 80%.

[0061] Optionally, in another embodiment of the utility model, the first light source 1-1 includes but is not limited to an infrared light source, and the second light source 2-1 includes but is not limited to a visible light source. In the embodiment of the utility model, the first light source 1-1 is an infrared light source for example, and the second light source 2-1 is a visible light source for example.

[0062] Specifically, in the embodiment of the utility model, when the first light source 1-1 is an infrared light source, the first light beam is an infrared light beam; when the second light source 2-1 is a visible light source, the second light beam is a visible light beam; compared with the brightness of the visible light beam, the brightness of the infrared light beam is relatively low, and the brightness of the visible light beam is higher, so the distance between the first light source 1-1 and the first focusing module 1-2 can be designed to be smaller than the distance between the second light source 2-1 and the second focusing module 2-2; that is, the distance between the first light source 1-1 and the first focusing module 1-2 is the first distance; the distance between the second light source 2-1 and the second focusing module 2-2 is the second distance; wherein, the first distance is smaller than the second distance.

[0063] That is to say, the infrared light beam chooses the relatively shorter of the two optical paths, and the visible light beam chooses the other relatively longer optical path, which further reduces the light loss of the infrared light beam during transmission, further increases the brightness of the infrared light converged on the light receiving surface, and achieves an improvement in light quality.

[0064] Furthermore, even if a portion of the visible light beam incident on the second surface is transmitted and not utilized, since the brightness of the visible light beam is relatively high, the brightness of the visible light converged on the light receiving surface is not greatly affected.

[0065] It should be noted that the first optical path and the second optical path can also be swapped. When the first light source 1-1 is an infrared light source and the second light source 2-1 is a visible light source, the infrared light beam emitted by the infrared light source can be reflected and the visible light beam emitted by the visible light source can be transmitted.

[0066] In summary, the beam combining device provided in the embodiment of the utility model can ensure the uniformity of the light source, and the diameter of the light source remains unchanged, which can greatly improve the quality of the combined light.

[0067] It should be noted that, in an optional embodiment of the present invention, the optical transmission module 4 includes but is not limited to an optical fiber light guide; when the optical transmission module is an optical fiber light guide, the light receiving surface is the end face of the optical fiber light guide.

[0068] It should be noted that in the embodiment of the present utility model, Figure 3When using the beam combining device shown in the figure, the optical path transmission module 4 can be fixed first, for example, the optical fiber light guide can be fixed first; then the first light source 1-1 and the first focusing module 1-2, as well as the angle of the beam combining mirror module 3 and the distance from the optical fiber light guide are adjusted so that the first light beam emitted by the first light source 1-1 can be converged onto the end face of the optical fiber light guide; on this basis, the second light source 2-1 and the second focusing module 2-2 are adjusted so that the second light beam emitted by the second light source 2-1 can also be converged onto the end face of the optical fiber light guide.

[0069] Based on the above embodiments of the present invention, an optical system is further provided in another embodiment of the present invention. The optical system includes the beam combining device described in the above embodiments.

[0070] Specifically, in this embodiment, the optical system has the same technical effect as the beam combining device.

[0071] The above is a detailed introduction to a beam combining device and an optical system provided by the utility model. Specific examples are used in this article to illustrate the principle and implementation mode of the utility model. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model. At the same time, for general technical personnel in this field, according to the idea of ​​the utility model, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the utility model.

[0072] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0073] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device that includes a series of elements is inherent to the elements, or also includes elements inherent to these processes, methods, articles or devices. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0074] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A beam combining device, characterized in that: The beam combining device comprises: a first light source, a first focusing module, a second light source, a second focusing module, a beam combining mirror module and an optical path transmission module; Wherein, the first light source is used to output a first light beam, and the second light source is used to output a second light beam; The first focusing module is used to focus the first light beam and make it incident on the beam combining mirror module; The second focusing module is used to focus the second light beam and make it incident on the beam combining mirror module; The beam combining mirror module is used to converge the first light beam and the second light beam to the light receiving surface of the light path transmission module respectively.

2. The beam combining device according to claim 1, characterized in that: The optical path of the first light beam from the first light source to the first focusing module is the first optical path; The optical path of the second light beam from the second light source to the second focusing module is the second optical path; Wherein, the first light path is perpendicular to the second light path.

3. The beam combining device according to claim 1 or 2, characterized in that: The beam combining mirror module is a beam combining mirror semi-reflective and semi-transparent module, and the beam combining mirror semi-reflective and semi-transparent module includes a first surface and a second surface; The first light beam is incident on the first surface, and the second light beam is incident on the second surface; The first light beam passes through the first surface and converges to the light receiving surface of the light path transmission module; The second light beam is reflected by the second surface and converges to the light receiving surface of the light path transmission module.

4. The beam combining device according to claim 3, characterized in that: The transmittance of the first surface is greater than the reflectivity; The reflectivity of the second surface is greater than the transmittance.

5. The beam combining device according to claim 3, characterized in that: The beam combining device further comprises: An antireflection film is located on the first surface.

6. The beam combining device according to claim 1, characterized in that: The first light beam is an infrared light beam; The second light beam is a visible light beam.

7. The beam combining device according to claim 6, characterized in that: The distance between the first light source and the first focusing module is a first distance; The distance between the second light source and the second focusing module is a second distance; Wherein, the first distance is smaller than the second distance.

8. The beam combining device according to claim 1, characterized in that: The optical path transmission module is an optical fiber light guide; The light receiving surface is the end surface of the optical fiber light guide.

9. The beam combining device according to claim 1, characterized in that: The first focusing module is a convex lens; The second focusing module is a convex lens.

10. An optical system, characterized in that: The optical system comprises the beam combining device according to any one of claims 1-9.

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