CN1275462A - wavelength matching optical path - Google Patents

本发明是一种波长匹配光路,属于一种使两种不同波长的光,对同一物面上的物体,经同一成象物镜,成象在同一象面上的技术领域。其特征是通过在物面和物镜之间增设由四个镀有不同膜层的反射镜组成的增程光路,增加较长波长光的物距,来达到使两种不同波长光的象面一致。本发明提供的方法结构简单,安装容易,制作成本低,消除了误操作,加工位置准确,精度高。在激光加工等领域具有广泛的应用价值。

The invention relates to a wavelength matching optical path, which belongs to the technical field of making two kinds of light of different wavelengths image an object on the same object surface on the same image surface through the same imaging objective lens. It is characterized in that by adding an extended-range optical path composed of four reflectors coated with different coating layers between the object plane and the objective lens, the object distance of the longer wavelength light is increased to achieve the same image plane of the two different wavelength lights. . The method provided by the invention has the advantages of simple structure, easy installation, low manufacturing cost, elimination of misoperation, accurate processing position and high precision. It has wide application value in laser processing and other fields.

波长匹配光路wavelength matching optical path

本发明是一种波长匹配光路，涉及一种使两种不同波长的光，对同一物面上的物体，经同一成象物镜，成象在同一象面上的技术领域。The invention relates to a wavelength matching optical path, which relates to the technical field of making two kinds of light of different wavelengths image an object on the same object surface on the same image surface through the same imaging objective lens.

在激光加工中，通常会碰到需要观察和对准加工位置的问题。在红外激光缩小投影成象加工中，因为红外激光处于不可见光波段，加工前须使用可见光预先观察对准加工位置。但是，由于红外激光和可见光波长不同，红外光波长比可见光波长长，在使用同一成象物镜时，物镜的焦距在用红外光时比用可见光时长，从而使同一物面上的物体经物镜成象后，象面的位置不同，红外光的象面比可见光的象面距物镜较远。这样就会出现用可见光观察对准的象面位置与红外激光加工时的象面位置不一致的问题。为了解决这个问题，通常采用的方法有：①根据波长不同，采用与所用波长相对应的两个物镜，在使用中通过更换物镜来使两种光的象面一致；②使用变焦距物镜，通过调焦来统一象面位置；③只用一个物镜，先用可见光观察对准加工位置后，再将加工面平移到红外激光象面位置，进行激光加工。这些方法都存在操作复杂，以及在更换、调整和移动部件过程中可能产生位置偏差等缺点。中国专利CN1163177A介绍了一种激光加工装置，它包括置于激光器与待加工物之间光路中的遮光板以及使该遮光板缩小成象在加工面上的透镜和象转印光学系统等。该装置通过可变曲率反射镜的象转印光学系统实现激光加工过程中的可见光和激光的象面一致。但该方法存在可变曲率反射镜制造成本高、系统复杂等缺点。In laser processing, it is often encountered the need to observe and align the processing position. In the infrared laser reduction projection imaging processing, because the infrared laser is in the invisible light band, the visible light must be used to observe and align the processing position before processing. However, due to the different wavelengths of infrared laser and visible light, and the wavelength of infrared light is longer than that of visible light, when using the same imaging objective lens, the focal length of the objective lens is longer when using infrared light than when using visible light, so that objects on the same object surface can be formed by the objective lens. After imaging, the position of the image surface is different, and the image surface of infrared light is farther away from the objective lens than the image surface of visible light. In this way, there will be a problem that the position of the image plane aligned by visible light observation is inconsistent with the position of the image plane during infrared laser processing. In order to solve this problem, the commonly used methods are: ①According to the different wavelengths, use two objective lenses corresponding to the wavelengths used, and make the image planes of the two kinds of light consistent by changing the objective lenses during use; ②Use a zoom objective lens, through Adjust the focus to unify the position of the image plane; ③Use only one objective lens, first use visible light to observe and align the processing position, and then translate the processing plane to the position of the infrared laser image plane for laser processing. These methods all have disadvantages such as complicated operation and possible positional deviation during the process of replacing, adjusting and moving parts. Chinese patent CN1163177A introduces a laser processing device, which includes a shading plate placed in the optical path between the laser and the object to be processed, and a lens and an image transfer optical system for reducing the image of the shading plate on the processing surface. The device realizes that the visible light in the laser processing process is consistent with the image plane of the laser through the image transfer optical system of the variable curvature reflector. However, this method has the disadvantages of high manufacturing cost and complex system of the variable curvature mirror.

本发明的目的是提供一种结构简单，制作成本低，易于操作，能使两种不同波长光对同一物面上的物体，经同一成象物镜，成象在同一象面上的波长匹配光路。The purpose of the present invention is to provide a wavelength matching optical path with simple structure, low manufacturing cost, easy operation, and enabling two different wavelengths of light to object on the same object surface to be imaged on the same image surface through the same imaging objective lens. .

本发明的目的可以通过以下措施来达到：The object of the present invention can be achieved through the following measures:

在缩小投影成象物镜的物方光路上，即物面和成象物镜之间，设置一组由光学元件组成的增程光路。增程光路由四个镀有不同膜层的反射镜组成，其中反射镜1和4是半透半反镜，镀有可见光增透膜和红外激光增反膜，反射镜镜2和3是全反镜，镀有红外激光全反膜。通过增程光路增加长波长红外激光的物距，从而使红外激光的象面与可见光的象面一致。观察对准时，照到物面物体上的可见光直接透过半透半反镜1和4，经物镜成象在可见光象面上；激光加工时，照到物面物体上的红外激光依次经过反射镜1、2、3和4反射，由于增加了物距，经物镜成象在与可见光相同的象面上。On the object-side optical path of the reduced projection imaging objective lens, that is, between the object plane and the imaging objective lens, a group of extended-range optical paths composed of optical elements is arranged. The range-extending optical route is composed of four mirrors coated with different coatings, among which mirrors 1 and 4 are half mirrors, coated with visible light anti-reflection coating and infrared laser anti-reflection coating, mirrors 2 and 3 are full Reflective mirror, coated with infrared laser full reflection film. The object distance of the long-wavelength infrared laser is increased through the extended-range optical path, so that the image plane of the infrared laser is consistent with the image plane of visible light. When observing and aligning, the visible light irradiated on the object on the object plane directly passes through the half mirrors 1 and 4, and is imaged on the visible light image surface through the objective lens; during laser processing, the infrared laser irradiated on the object on the object plane passes through the mirrors in turn 1, 2, 3 and 4 reflections, due to the increase of the object distance, are imaged on the same image plane as visible light through the objective lens.

本发明与已有技术相比具有以下特点：Compared with the prior art, the present invention has the following characteristics:

由于采用了四个反射镜组成的增程光路增加了长波长红外激光成象的物距，达到了对同一物面上的物体，经同一物镜成象，使红外激光的象面与可见光的象面一致。这样，只需用一个成象物镜就能把两种不同波长光的象面匹配在一起。并且，照到物体上的可见光只能透过半透半反镜1和4，再经物镜成象在观察对准象面上；照到物体上的红外激光必然依次经过反射镜1、2、3和4反射后，增加了物距，再经物镜成象在与可见光的观察对准象面一致的象面上。按本发明方法设计安装的光路，不管是观察对准还是激光加工，使用中不必再更换、调整或移动任何部件，消除了误操作，加工位置准确，精度高，并且装置结构简单，成本低。在激光加工等领域具有广泛的应用价值。Due to the use of the extended-range optical path composed of four reflectors, the object distance of long-wavelength infrared laser imaging is increased, and the object on the same object surface is imaged through the same objective lens, so that the image surface of the infrared laser and the image of visible light Consistent. In this way, only one imaging objective lens can be used to match the image planes of light of two different wavelengths together. And, the visible light that shines on the object can only pass through half-transparent mirrors 1 and 4, and then image the image on the observation and alignment image plane through the objective lens; the infrared laser light that shines on the object must pass through mirrors 1, 2, and 3 After the reflection of and 4, the object distance is increased, and then the image is formed on the image plane consistent with the observation alignment image plane of visible light through the objective lens. The optical path designed and installed according to the method of the present invention, whether it is observation alignment or laser processing, does not need to replace, adjust or move any parts during use, eliminating misoperation, accurate processing position, high precision, simple structure and low cost. It has wide application value in laser processing and other fields.

附图是本发明波长匹配光路示意图。下面结合附图和具体实施例对本发明作进一步详细的说明。The accompanying drawing is a schematic diagram of the wavelength matching optical path of the present invention. The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

如附图所示，可见光和红外激光两种不同波长的光照到物面P上，使物面P上的物体经成象物镜L缩小投影成象在象面P′上。由于采用了镀有不同膜层的四个反射镜1、2、3和4所组成的增程光路来增加长波长红外激光的成象物距，使可见光和红外激光两种不同波长的光经物镜L后，均成象在同一象面P′上。半透半反镜1和4镀有可见光增透膜和红外激光增反膜，全反镜2和3镀有红外激光全反膜。为调整方便，四个反射镜的放置均使其法线与入射主光线成45°角。观察对准时，照到物体上的可见光直接透过半透半反镜1和4，经物镜L成象在象面P′上，可见光的物距是S，象距是S′；激光加工时，照到物体上的长波长红外激光依次经过反射镜1、2、3和4反射后，增加了物距(a+b)，经物镜L成象在与可见光象面相同的象面P′上。红外激光的物距是(S+a+b)，象距同样是S′。增程光路所增加的物距(a+b)可根据实际使用的波长和物镜倍率等参数计算得到。As shown in the figure, light of two different wavelengths, visible light and infrared laser light, shines on the object plane P, so that the object on the object plane P is projected and imaged on the image plane P′ through the imaging objective lens L. Since the extended-range optical path composed of four mirrors 1, 2, 3 and 4 coated with different coating layers is used to increase the imaging object distance of the long-wavelength infrared laser, the light of two different wavelengths, the visible light and the infrared laser, can pass through After the objective lens L, they are all imaged on the same image plane P'. Half mirrors 1 and 4 are coated with visible light anti-reflection film and infrared laser anti-reflection film, and total reflection mirrors 2 and 3 are coated with infrared laser total reflection film. For the convenience of adjustment, the four reflectors are placed so that their normal and the incident chief ray form an angle of 45°. When observing and aligning, the visible light irradiated on the object directly passes through the half mirrors 1 and 4, and forms an image on the image plane P' through the objective lens L. The object distance of visible light is S, and the image distance is S'; during laser processing, The long-wavelength infrared laser light irradiated on the object is reflected by mirrors 1, 2, 3 and 4 in sequence, increasing the object distance (a+b), and forming an image on the same image plane P' as the visible light image plane through the objective lens L . The object distance of the infrared laser is (S+a+b), and the image distance is also S'. The increased object distance (a+b) of the extended range optical path can be calculated according to the parameters such as the wavelength actually used and the magnification of the objective lens.

在本发明的一个典型实施例中，波长匹配光路被用于一个掩模缺陷激光修正装置中。这个装置的加工目的是将物面P上的可调矩形光阑，经物镜L缩小成象在位于象面P′的掩模面上，对准掩模面上的缺陷，用红外脉冲激光气化掉缺陷。在这个装置中，观察对准用的可见光中心波长为0.55微米，激光加工用的YAG红外脉冲激光波长为1.06微米，成象物镜为40×显微物镜。经计算得出，四个反射镜对1.06微米红外激光，相对于可见光增加的物距(a+b)为48.34毫米。这样，通过波长匹配光路，把0.55微米和1.06微米两个不同波长光的象面匹配到同一象面上，实际使用效果很好。In an exemplary embodiment of the present invention, the wavelength matching optical path is used in a mask defect laser correction device. The processing purpose of this device is to reduce the adjustable rectangular diaphragm on the object plane P to the image on the mask surface located on the image plane P′ through the objective lens L, aim at the defects on the mask surface, and use infrared pulsed laser gas Eliminate defects. In this device, the central wavelength of visible light used for observation and alignment is 0.55 microns, the wavelength of YAG infrared pulsed laser used for laser processing is 1.06 microns, and the imaging objective lens is a 40×microscopic objective lens. It is calculated that the object distance (a+b) increased by the four mirrors to the 1.06 micron infrared laser relative to the visible light is 48.34 mm. In this way, through the wavelength matching optical path, the image planes of two different wavelength lights of 0.55 micron and 1.06 micron are matched to the same image plane, and the practical effect is very good.

本发明的波长匹配光路也能应用于紫外激光缩小投影成象加工中。仍然用可见光作观察对准，那么，由于紫外激光的波长比可见光的波长短，同一成象物镜的焦距在用紫外激光时比用可见光时短，对同一物面上的物体来说，紫外激光的象面比可见光的象面距物镜较近。在实际使用中，应以紫外激光的成象面为基准象面，使照到物体上的紫外激光沿光轴直接透过半透半反镜1和4，经物镜L成象在象面P′上；而用四个反射镜组成的增程光路增加可见光的成象物距，使照到物体上的可见光依次经过反射镜1、2、3和4反射后，经物镜L将可见光的象面匹配到紫外光的象面P′上。四个反射镜所镀膜层也应作相应改变，即半透半反镜1和4应镀紫外激光增透膜和可见光增反膜，全反镜2和3应镀可见光全反膜。The wavelength matching optical path of the invention can also be applied to ultraviolet laser reduction projection imaging processing. Still use visible light for observation alignment, then, because the wavelength of ultraviolet laser is shorter than that of visible light, the focal length of the same imaging objective lens is shorter than that of visible light when using ultraviolet laser. The image plane of visible light is closer to the objective lens than the image plane of visible light. In actual use, the imaging plane of the ultraviolet laser should be taken as the reference image plane, so that the ultraviolet laser light irradiated on the object directly passes through the half mirrors 1 and 4 along the optical axis, and forms an image on the image plane P' through the objective lens L and the extended-range optical path composed of four reflectors increases the imaging object distance of visible light, so that the visible light irradiated on the object is reflected by reflectors 1, 2, 3 and 4 in turn, and the image surface of visible light is transformed by the objective lens L Match to the image plane P' of ultraviolet light. The coating layers of the four reflectors should also be changed accordingly, that is, half-mirrors 1 and 4 should be coated with ultraviolet laser antireflection coating and visible light antireflection coating, and total reflection mirrors 2 and 3 should be coated with visible light total reflection coating.

此发明不仅适用于激光加工，也适用于其它的需将两种不同波长光的成象面匹配在同一象面的情况。This invention is not only applicable to laser processing, but also applicable to other situations where two imaging planes of light with different wavelengths need to be matched on the same imaging plane.