Optical path system and optical measurement apparatus

Abstract

The present application relates to the protection of optical path system, provide a kind of optical path system and optical measuring equipment.Light path system, including: light source module and / or light detection module;Light beam processing device, the light beam processing device is used to process the light beam passing;Mounting matrix, the mounting matrix has installation cavity, at least one the light beam processing device is arranged in the installation cavity, the light source module and / or light detection module are arranged outside the mounting matrix;The mounting matrix has light entrance and light exit, the light entrance is for the light beam to be processed to enter the installation cavity, the light exit is for the light beam processed by the light beam processing device to be emitted from the installation cavity;And gas supply device, gas supply device includes gas supply connector;Gas supply connector is connected on the mounting matrix, for supplying protective gas in the installation cavity.The present application mainly solves the technical problem that the light path of wide spectrum light source is easy to produce ozone and cause oxidative damage.

Description

Technical Field

[0001] This invention relates to the protection of optical path systems. Background Technology

[0002] In optical measurement equipment, the performance of the light source is crucial to the measurement device. Currently, broadband light sources are gradually becoming the preferred light source for semiconductor optical measurement equipment due to their advantages such as wide spectral range, ultra-high brightness / luminance, ultra-long lifespan, and ultra-high stability. For example, ellipsometers used in semiconductor film thickness measurement equipment are increasingly adopting broadband light sources as their light source devices.

[0003] While broadband light sources offer the advantages mentioned above, they also have drawbacks. When using a broadband light source as the light source for a measurement device, the ultraviolet light in the ultraviolet band of the broadband light source can cause photolysis of oxygen in the measurement optical path, producing ozone. Ozone has strong oxidizing properties and may cause oxidative damage to the coatings and structural components of some beam processing devices (such as lenses) in the measurement optical path. This oxidative damage will affect the performance of the measurement optical path; for example, damaged lens coatings will lead to a decrease in transmitted or reflected light intensity, and volatiles generated by the oxidation of the original black anodized surface layer of structural components by ozone will contaminate the optical path. Summary of the Invention

[0004] This invention primarily addresses the technical problem that light paths containing ultraviolet light are prone to ozone generation, leading to oxidative damage.

[0005] In a first aspect, the present invention provides an optical path system.

[0006] An optical path system, comprising:

[0007] Light source module and / or light detection module;

[0008] The beam processing device inside the incident arm is used for beam shaping and polarization application; the beam processing device inside the reflecting arm is used for polarization analysis.

[0009] The mounting base has a mounting cavity, at least one of the beam processing devices is disposed in the mounting cavity, and the light source module and / or light detection module is disposed outside the mounting base; the mounting base has a light inlet and a light outlet, the light inlet allows the beam to be processed to enter the mounting cavity, and the light outlet allows the beam processed by the beam processing device to exit from the mounting cavity.

[0010] The light source module and the light detection module are respectively connected to the light inlet and light outlet of the mounting cavity through the sealing tube, and a beam channel is provided inside the sealing tube;

[0011] And a gas supply device, the gas supply device including a gas supply connector; the gas supply connector is connected to the mounting base for supplying protective gas to the mounting cavity, the beam processing device being isolated in the mounting cavity and under a protective gas atmosphere.

[0012] In one technical solution, the mounting base includes a base and a protective cover, the beam processing device is disposed on the base, the protective cover has an inner cavity, the protective cover is fastened to the base and together with the base forms the mounting cavity.

[0013] In one technical solution, the base is provided with a first fastening surface, the protective cover is provided with a second fastening surface, at least one of the first fastening surface and the second fastening surface is provided with a sealing groove, and a sealing element is provided in the sealing groove; the sealing groove on the first fastening surface and / or the second fastening surface has a slot for the sealing ring to be inserted, and the slot is a constricted structure.

[0014] In one technical solution, the cross-section of the sealing groove is dovetail-shaped, and the sealing element is an O-ring.

[0015] In one technical solution, a groove is provided on the side wall of the protective cover. The end of the groove away from the base passes through the protective cover. The end of the groove near the base is a blind end. The blind end forms a step on the protective cover. A through hole is provided on the step. The through hole allows the shank of the screw to pass through to press and fix the protective cover to the base. The groove is used to avoid the head of the screw.

[0016] In one technical solution, the screw includes an inner screw located on the side of the seal near the mounting cavity, and an outer screw located on the side of the seal away from the mounting cavity.

[0017] In one technical solution, the sealing tube is flexible, allowing the light source module and / or light detection module to adjust their position relative to the protective cover.

[0018] In one technical solution, the protective cover is provided with an optical path reflector, the optical axis of the light source module and / or the light detection module has an angle with the optical axis of the beam processing device, and the optical path reflector is used to reflect light between the beam processing device and the light source module and / or the light detection module.

[0019] In one technical solution, the end of the sealing tube is detachably connected to the light source module or the light detection module via a magnetic attraction structure.

[0020] In one technical solution, the protective cover includes at least two covers, which are connected in sequence, and a sealing structure is provided at the joint of adjacent covers.

[0021] In one technical solution, the beam processing device includes a focusing module, the light exit port and / or the light entrance port are provided with the focusing module, and the focusing module is sealed to the mounting base.

[0022] In one technical solution, the mounting base is provided with a cable hole, and a cable seal is provided at the cable hole for the cable to pass through and for sealing cooperation with the cable.

[0023] In one technical solution, a flow equalization element is further included. The flow equalization element is disposed on the mounting base and corresponds to the air outlet of the air supply connector. The flow equalization element is used to disperse the gas discharged from the air supply connector.

[0024] In one technical solution, the flow equalization element is a flow equalization plate, which is fastened to the inner wall of the mounting cavity and forms an air chamber with the inner wall of the mounting cavity, and the air outlet of the air supply connector is connected to the air chamber.

[0025] Secondly, the present invention provides an optical measurement device.

[0026] An optical measurement device, comprising:

[0027] An optical path system, wherein the optical path system is the optical path system described in any of the above technical solutions;

[0028] And a detection device, which is used to detect the object being tested.

[0029] The beneficial effects of this invention are:

[0030] According to the aforementioned optical path system, by setting a mounting cavity on the mounting substrate and supplying protective gas into the mounting cavity through a gas supply device, the beam processing device can be isolated in the mounting cavity and placed in a protective gas atmosphere. This reduces or avoids contact between the beam processing device and oxygen, thereby improving or preventing ozone generated by broadband light sources from damaging the coatings or structural components of the optical elements on the beam processing device, which is beneficial to ensuring the stability of the optical path system. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of an embodiment of the optical path system in this invention;

[0032] Figure 2 for Figure 1 An exploded view of the beam processing device corresponding to the light source module;

[0033] Figure 3 for Figure 1 A cross-sectional view of the beam processing device corresponding to the light source module;

[0034] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0035] List of feature names corresponding to the labels in the figure:

[0036] 100. Incident arm;

[0037] 110. Light source module;

[0038] 120. First mounting base; 121. Base; 122. Protective cover; 123. Mounting cavity; 124. Sealing groove; 125. Seal; 126. First cover; 127. Second cover; 128. Stop; 129. Groove;

[0039] 130. First beam processing device;

[0040] 140. First sealing pipe; 141. Adsorption flange; 142. Adapter flange; 143. Magnet;

[0041] 150. First gas supply device; 151. Gas supply connector; 152. Flow equalization element; 153. Branch gas pipe; 154. Main connector; 155. Gas chamber;

[0042] 160. First optical path reflector;

[0043] 170. First focusing lens module; 171. O-ring seal;

[0044] 180. Cable seals;

[0045] 200. Reflector arm;

[0046] 210. Optical detection module;

[0047] 220. Second mounting base;

[0048] 240. Second sealing tube;

[0049] 250. Second gas supply device;

[0050] 260. Second optical path reflector;

[0051] 270. Second focusing lens module;

[0052] 300. The object being tested. Detailed Implementation

[0053] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid obscuring the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0054] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0055] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0056] An embodiment of an optical path system in this invention:

[0057] In an embodiment of the present invention, the optical path system includes a light source module 110 and / or a light detection module 210, a beam processing device, and a gas supply device. The light source module 110 provides the illumination required by the optical path system; the light detection module 210 detects the light reflected from the object 300 to achieve the detection purpose; the beam processing device processes the passing beam and includes a mounting base having a mounting cavity 123 (see reference). Figure 3 The mounting cavity 123 is used to form a local gas environment. At least one beam processing device is disposed in the mounting cavity 123, and the light source module 110 and / or the light detection module 210 are disposed outside the mounting base. The mounting base has a light inlet and a light outlet. The light inlet allows the beam to be processed to enter the mounting cavity 123, and the light outlet allows the beam processed by the beam processing device to exit from the mounting cavity 123. In order to form a protective gas atmosphere in the local gas environment around the beam processing device and protect the beam processing device, the gas supply device includes a gas supply connector 151, which is connected to the mounting base and is used to supply protective gas into the mounting cavity 123.

[0058] In one specific embodiment, please refer to Figure 1 and Figure 2 The optical path system includes both a light source module 110 and a light detection module 210, each with its own mounting base and beam processing device. Specifically, the light source module 110 forms an incident arm 100 corresponding to the first mounting base 120, the first beam processing device 130, the first sealing tube 140, and the first gas supply device 150; the light detection module 210 forms a reflecting arm 200 corresponding to the second mounting base 220, the second beam processing device (obscured in the figure), the second sealing tube 240, and the second gas supply device 250. The incident arm 100 and the reflecting arm 200 are arranged in a basically symmetrical manner on two opposite sides of the object under test 300. The light source module 110 and the light detection module 210 are fixed on the first mounting base 120 and the second mounting base 220, respectively.

[0059] The present invention will be further described below using a portion of the optical path system corresponding to the light source module 110 (i.e., the incident arm 100) as an example.

[0060] In one embodiment, the light source module 110 is a broadband light source containing the deep ultraviolet band. However, it should be understood that in some other embodiments, other types of light sources containing ultraviolet light can also be configured as the optical path system of this invention. Furthermore, the object under test 300 can be any compatible item such as a wafer, chip, photomask, or glass screen.

[0061] The mounting base adopts a split structure, specifically including a base 121 and a protective cover 122. The beam processing device is mounted on the base 121, and the protective cover 122 has an inner cavity. The protective cover 122 is fastened to the base 121 and together with the base 121 forms a mounting cavity 123. The split structure facilitates the processing of the mounting base and the installation of the beam processing device. In one embodiment, the beam processing device protrudes from the top surface of the base 121, and the inner cavity shape of the protective cover 122 is adapted to the base 121, resulting in a compact structure and convenient installation. Please refer to [reference needed]. Figure 3 In one embodiment, the top surface of the base 121 for fixing the beam processing device is inclined, which can adapt to the beam path between the light source module 110 and the object under test 300, and meet the spatial layout requirements of the optical measurement equipment. Of course, in other embodiments, the beam processing device can also be arranged horizontally or vertically. In addition, in other embodiments, the mounting base can also be a single component, for example, a cavity is provided on a block-shaped base as a mounting cavity, and the beam processing device is placed in the cavity.

[0062] The aforementioned beam processing device can utilize existing equipment, and its specific structure can be configured according to the requirements of the optical path. For example, in Figure 2 In one embodiment shown, the beam processing device is used to perform beam shaping and polarization application.

[0063] To ensure a certain degree of airtightness in the mounting cavity 123 formed by the base 121 and the protective cover 122, and to create a stable local gas environment, in one embodiment, the base 121 has a first fastening surface, and the protective cover 122 has a second fastening surface. At least one of the first and second fastening surfaces has a sealing groove 124, and a sealing element 125 is provided within the sealing groove 124. The sealing groove 124 on the first and / or second fastening surfaces has an opening for the insertion of a sealing ring, and the opening is a constricted structure. Through the sealing groove 124 and the sealing element 125 on the fastening surfaces, the base 121 and the protective cover 122 can easily form a seal.

[0064] The groove of the sealing groove 124 adopts a narrowing structure, which facilitates the positioning of the seal 125 and makes disassembly and maintenance easier, especially for... Figure 2 The sealing groove 124 shown is irregular in shape. In one specific embodiment, the sealing groove 124 has a dovetail-shaped cross-section, which is easy to process, while the seal 125 is an O-ring, which has good versatility and helps to reduce costs. In some other embodiments, the sealing groove 124 may also take other forms, such as a rectangular, arc-shaped, or right-angled trapezoidal cross-section.

[0065] It should be noted that this invention does not limit the degree of sealing between objects with a sealing relationship. It can be a complete seal, or it can have a predetermined sealing performance, forming a protective gas atmosphere that matches the gas supply speed of the gas supply device. However, if the sealing performance of the mounting cavity 123 is too poor, resulting in significant leakage of protective gas, although it can still limit the oxygen concentration within the mounting cavity 123 and provide protection, it may cause significant airflow disturbance, which is detrimental to the accurate detection of optical measuring equipment. It also requires a larger consumption of protective gas and precise calculation of gas flow rate and leakage flow rate. Therefore, in many cases, appropriate sealing is acceptable, but an excessively high degree of sealing is not necessary.

[0066] For ease of manufacturing and assembly / disassembly, in one embodiment, the protective cover 122 includes at least two covers, which are sequentially joined together, and a sealing structure is provided at the joint of adjacent covers. Specifically, please refer to... Figure 1 and Figure 2The protective cover 122 adopts a split structure, comprising a first cover 126 and a second cover 127, which are arranged sequentially along the optical path. Adjacent ends of the first cover 126 and the second cover 127 are provided with stop 128, allowing them to overlap and thus achieve mutual positioning and a certain degree of sealing. Alternatively, in some other embodiments, the protective cover 122 may be a single, integrated structure composed of individual parts.

[0067] To make full use of the space inside the protective cover 122, in one embodiment, please refer to... Figure 1 and Figure 2 The protective cover 122 has a groove 129 on its side wall. The end of the groove 129 away from the base 121 passes through the protective cover 122. The end of the groove 129 near the base 121 is a blind end. The blind end forms a step on the protective cover 122. The step has a through hole for the shank of the screw to pass through in order to press and fix the protective cover 122 to the base 121. The groove 129 is used to avoid the head of the screw. Figure 2 In this design, the groove 129 has an arc-shaped cross-section, forming a local arc-shaped protrusion on the inner wall of the protective cover 122. The portion of the protective cover 122 other than the groove 129 can form a larger space. In other embodiments, the groove 129 can also be other shapes, such as elliptical or rectangular. Figure 1 In the embodiment shown, the side of the protective cover 122 with the groove 129 is flush with the corresponding side of the base 121, resulting in a compact and aesthetically pleasing overall structure that effectively improves space utilization.

[0068] In one embodiment, the screws for securing the protective cover 122 include an inner screw located on the side of the seal 125 near the mounting cavity 123, and an outer screw located on the side of the seal 125 away from the mounting cavity 123. Correspondingly, please refer to... Figure 2 The base 121 has an inner screw mounting hole on the side of the seal 125 near the mounting cavity 123, and an outer screw mounting hole on the side of the seal 125 away from the mounting cavity 123. This layout allows for more flexible setting of fixing points and facilitates structural design. While the inner screws may reduce the airtightness of the protective cover 122, they do not significantly affect the protective gas atmosphere of the protective cover 122, and gas leakage at the inner screw can be prevented by adding a sealing ring between the screw head and the protective cover. Of course, in other embodiments, the protective cover 122 can also be fixed to the base in other ways, such as by providing an outward-folded flange as a connecting flange at the opening on the side of the protective cover 122 facing the base, achieving fixation through flange connection.

[0069] In one embodiment, to meet detection requirements, the beam processing device includes a focusing module, with the light exit port and / or light entrance port equipped with the focusing module, and the focusing module being sealed to the mounting substrate.

[0070] Specifically, such as Figure 1 The optical path components corresponding to both the light source module 110 and the light detection module 210 include focusing modules. The focusing module corresponding to the light source module 110 is a first focusing lens module 170, and the focusing module corresponding to the light detection module 210 is a second focusing lens module 270. The first focusing lens module 170 and the second focusing lens module 270 are respectively fixed on the mounting base on their respective sides. To achieve a seal between the focusing module and the mounting base, in one embodiment, please refer to... Figure 2 and Figure 3 The base 121 and protective cover 122, which are joined together, have matching end faces. The first focusing lens module 170 has a sealing ring groove on its end face near the mounting base, and an O-ring 171 is installed in the sealing ring groove, allowing a seal to be formed between the O-ring 171 and the matching end face. Of course, in some other embodiments, the focusing module and the mounting base can also be sealed together in other ways, such as by providing a sealing gasket between adjacent end faces of the focusing module and the mounting base, applying sealant to the connection between the focusing module and the mounting base, or achieving a seal through a threaded structure.

[0071] It should be noted that in other embodiments, lenses may also be provided at the light exit port and / or light entrance port. The lenses are used to close the light exit port and / or light entrance port while allowing light to pass through.

[0072] Please refer to Figure 1 and Figure 2 In one embodiment, the gas supply device includes a gas supply connector 151, branch gas pipes 153, and a main connector 154. Multiple gas supply connectors 151 are provided, distributed at different locations on the protective cover 122 to ensure more uniform airflow. In one embodiment, three gas supply connectors 151 are provided, located at both ends of the first cover 126 and on the second cover 127, respectively. Each gas supply connector 151 is connected to its respective branch gas pipe 153, and all branch gas pipes 153 converge and connect to the main connector 154, which in turn connects to a protective gas supply device (e.g., a nitrogen supply device). In other embodiments, the number of gas supply connectors 151 in the gas supply device can be increased or decreased, and the gas supply connectors 151 can also be directly connected to the protective gas supply device via pipelines.

[0073] For optical systems, airflow can affect light transmission, thus impacting the stability of the piping system. To avoid this problem, in one embodiment, the optical system further includes a flow equalization element 152. The flow equalization element 152 is disposed on the inner wall of the mounting cavity 123 and corresponds to the outlet of the gas supply connector 151. The flow equalization element 152 is used to disperse the gas discharged from the gas supply connector 151. In a specific embodiment, the flow equalization element 152 is a flow equalization plate, which is fastened to the inner wall of the mounting cavity 123 and forms an air chamber 155 with the inner wall of the mounting cavity 123. The outlet of the gas supply connector 151 communicates with the air chamber 155. The flow equalization plate filters and equalizes the passing gas, preventing airflow disturbances from affecting the measurement of optical path parameters. Optionally, the flow equalization plate adopts a porous sintered stainless steel structure. Please refer to [reference needed]. Figure 4 The inner wall of the protective cover 122 is provided with an annular protrusion. The flow equalization plate is fastened to the annular protrusion and fixed to the annular protrusion by screws. There is a gap between the flow equalization plate and the inner wall of the protective cover 122, which forms an air chamber 155. The air pipe connector corresponds to the air chamber 155 one by one.

[0074] Since the beam processing device requires cable connections, please refer to [reference needed]. Figure 2 In one embodiment, the mounting base has a cable hole, and a cable seal 180 is provided at the cable hole for the cable to pass through and for sealingly engaging with the cable. The cable hole and cable seal 180 ensure that the cable can be threaded through the mounting cavity 123 while maintaining the airtightness of the mounting cavity 123. For details, please refer to... Figure 2 The cable seal 180 is made of an elastic material, such as silicone or rubber, and has an annular groove on its outer circumference to fit into the cable hole and improve sealing. The cable seal 180 also has an opening that allows the cable to pass through. Naturally, the better the match between the opening size and the cable diameter, the better the sealing of the mounting cavity 123.

[0075] Based on the positional relationship between the light source module 110 and the mounting base, in order to guide the light emitted by the light source module 110 into the beam processing device, in one embodiment, the optical path system further includes an optical path reflector. The optical path reflector is fixed on the protective cover 122, and the optical axis of the light source module 110 and the optical axis of the beam processing device form an angle. The optical path reflector is used to reflect light between the beam processing device and the light source module 110. Please refer to... Figure 2The optical path reflector includes a first optical path reflector 160 corresponding to the incident arm 100 and a second optical path reflector 260 corresponding to the reflecting arm 200. The optical path reflector is fixed to a mirror mount, the bottom of which has a flange for fixing it to a base 121. A lateral opening is provided on the protective cover 122 at a position corresponding to the optical path reflector. The optical path reflector is fastened to the lateral opening and sealed with the edge of the lateral opening by a sealing ring. In other embodiments, the optical path reflector can also be directly fixed to the protective cover, forming a single unit with it.

[0076] The optical path system of optical measurement equipment often requires adjustment of the orientation of optical elements along the optical path to ensure that light rays are smoothly directed to the target position. To ensure that the ultraviolet light emitted by the light source module 110 remains within the protective gas environment when its position is adjusted relative to the mounting substrate, such as... Figure 1 and Figure 2 In the illustrated embodiment, the optical path system further includes a sealing tube, one end of which is connected to the light source module 110, and the other end is connected to the light entrance of the protective cover 122 (for the light detection module 210, one end of the sealing tube is connected to the light detection module 210, and the other end is connected to the light entrance of the protective cover 122); the sealing tube communicates with the mounting cavity 123, and a beam channel is provided inside the sealing tube; the sealing tube is flexible, allowing the light source module 110 to adjust its position relative to the protective cover 122. The sealing tube includes a first sealing tube 140 corresponding to the light source module 110 and a second sealing tube 240 connected to the light detection module 210. In one embodiment, the sealing tube is a metal corrugated pipe, capable of expansion, end misalignment, and / or swaying. Of course, in other embodiments, the sealing tube can also be made of plastic, rubber, or silicone, relying on its own material flexibility to achieve expansion, end misalignment, and / or swaying.

[0077] In some cases, the protective cover 122 needs to be disassembled for maintenance and adjustment of the internal beam processing device. Since the protective cover 122 is connected to the sealing tube, to facilitate disassembly, in one embodiment, both ends of the first sealing tube 140 are detachably fixed to the light source module 110 and the protective cover respectively via magnetic structures. In a specific embodiment, both ends of the first sealing tube 140 are provided with adsorption flanges 141, which are made of a material that can be attracted by magnets 143. Correspondingly, the light source module 110 and the protective cover are respectively provided with transition flanges 142, which are fixed to the light source module 110 and the protective cover. Magnets 143 are distributed circumferentially on the transition flanges 142, and the magnets 143 are embedded in the transition flanges 142. During assembly, the adsorption flanges 141 at both ends of the sealing tube are brought close to the corresponding transition flanges 142, and the connection between the sealing tube and the light source module 110 and the protective cover is achieved by the attraction of the magnets 143. When it is necessary to disassemble the protective cover 122, the protective cover 122 can be separated from the sealing tube by slightly overcoming the magnetic attraction, or the sealing tube can be separated from the light source module 110 but kept connected to the protective cover 122, or the sealing tube can be separated from both the protective cover 122 and the light source module 110 at the same time, and then the protective cover 122 can be easily removed. In other embodiments, a magnet can also be provided on the end face of the sealing tube, and an attraction part for the magnet to attract can be provided on the light source module 110; of course, magnets can also be provided on both the sealing tube and the light source module 110.

[0078] In some other embodiments, the sealing tube can also be connected to the light source module 110 and the protective cover in other ways, such as by flange connection with bolts, or by providing threaded joints at both ends of the sealing tube for direct connection via threaded structure.

[0079] For the reflector arm 200 corresponding to the optical detection module 210, the optical detection module 210 is a spectral acquisition device, and its beam processing device is used for polarization analysis. The optical detection module 210 is housed inside the protective cover 122. The side of the protective cover 122 closest to the incident arm 100 is connected to the second focusing module 270, and the side of the protective cover 122 furthest from the incident arm 100 is connected to the second sealing tube 240 and the second optical path reflector 260. The second sealing tube 240 is connected to the optical detection module 210. The layout of the components on the reflector arm 200 is the same as that of the incident arm 100, and will not be repeated here.

[0080] During operation, the broadband light emitted by the broadband light source in the measurement system is reflected by the first optical path reflector 160, and the optical path is parallel to the incident arm 100 of the measurement optical path. The light is then incident on the beam processing device inside the protective cover 122 through the measurement optical path for spot shaping and polarization. The beam is then focused onto the object under test 300 by the first focusing lens module. The object under test 300 then reflects the beam into the second focusing module 270, where it is analyzed by the beam processing device inside the reflecting arm 200, and finally reflected by the second optical path reflector 260 into the light detection module 210. In this way, the incident arm 100 of the measurement optical path forms a relatively sealed local environment under the protection of the protective cover 122, and high-purity protective nitrogen is introduced to reduce the oxygen content in the local environment, prevent the gas in the local environment from undergoing photolysis reaction to produce ozone, and thus prevent the coatings of various lenses and structural components in the measurement optical path from being oxidized and damaged by ozone. This ensures the performance of the measurement optical path and prevents problems such as reduced transmitted or reflected light intensity due to damage to the lens coating, and volatile substances that pollute the optical path due to the oxidation of the original black anodized surface treatment layer of the structural components by ozone.

[0081] Embodiments of the optical measurement device in this invention:

[0082] An optical measurement device includes: an optical path system, which is the optical path system of any of the above embodiments and will not be repeated here; and a detection device for detecting the object under test. The detection device can adopt a structure in the prior art and is not directly connected to the protection point of this invention, and will not be described in detail here.

[0083] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. An optical path system, characterized in that, include: Light source module and / or light detection module; The beam processing device inside the incident arm is used for beam shaping and polarization application; the beam processing device inside the reflecting arm is used for polarization analysis. The mounting base has a mounting cavity, at least one of the beam processing devices is disposed in the mounting cavity, and the light source module and / or light detection module is disposed outside the mounting base; the mounting base has a light inlet and a light outlet, the light inlet allows the beam to be processed to enter the mounting cavity, and the light outlet allows the beam processed by the beam processing device to exit from the mounting cavity. The light source module and the light detection module are respectively connected to the light inlet and light outlet of the mounting cavity through the sealing tube, and a beam channel is provided inside the sealing tube; And a gas supply device, the gas supply device including a gas supply connector; the gas supply connector is connected to the mounting base for supplying protective gas to the mounting cavity, the beam processing device being isolated in the mounting cavity and under a protective gas atmosphere.

2. The optical path system as described in claim 1, characterized in that, The mounting base includes a base and a protective cover. The beam processing device is disposed on the base. The protective cover has an inner cavity and is fastened to the base, forming the mounting cavity with the base.

3. The optical path system as described in claim 2, characterized in that, The base has a first fastening surface, and the protective cover has a second fastening surface. At least one of the first and second fastening surfaces has a sealing groove, and a sealing element is provided in the sealing groove. The sealing groove on the first and / or the second fastening surface has a slot for embedding a sealing ring, and the slot is a constricted structure.

4. The optical path system as described in claim 3, characterized in that, The cross-section of the sealing groove is dovetail-shaped, and the sealing element is an O-ring.

5. The optical path system as described in claim 3, characterized in that, The protective cover has a groove on its side wall. The end of the groove away from the base passes through the protective cover. The end of the groove near the base is a blind end. The blind end forms a step on the protective cover. The step has a through hole for the shank of the screw to pass through in order to press and fix the protective cover to the base. The groove is used to avoid the head of the screw.

6. The optical path system as described in claim 5, characterized in that, The screws include an inner screw located on the side of the seal near the mounting cavity, and an outer screw located on the side of the seal away from the mounting cavity.

7. The optical path system as described in claim 2, characterized in that, The sealing tube is flexible, allowing the light source module and / or light detection module to adjust their position relative to the protective cover.

8. The optical path system as described in claim 7, characterized in that, The protective cover is equipped with an optical path reflector. The optical axis of the light source module and / or the light detection module has an angle with the optical axis of the beam processing device. The optical path reflector is used to reflect light between the beam processing device and the light source module and / or the light detection module.

9. The optical path system as described in claim 7, characterized in that, The end of the sealing tube is detachably connected to the light source module or the light detection module via a magnetic attraction structure.

10. The optical path system as described in claim 2, characterized in that, The protective cover includes at least two covers, which are connected in sequence, and a sealing structure is provided at the joint of adjacent covers.

11. The optical path system as described in any one of claims 1 to 10, characterized in that, The beam processing device includes a focusing module, and the focusing module is provided at the light exit port and / or the light entrance port. The focusing module is sealed to the mounting base.

12. The optical path system as described in any one of claims 1 to 10, characterized in that, The mounting base is provided with a cable hole, and a cable seal is provided at the cable hole for the cable to pass through and to seal with the cable.

13. The optical path system as described in any one of claims 1 to 10, characterized in that, It also includes a flow equalization element, which is disposed on the mounting base and corresponds to the gas outlet of the gas supply connector. The flow equalization element is used to disperse the gas discharged from the gas supply connector.

14. The optical path system as described in claim 13, characterized in that, The flow equalization element is a flow equalization plate, which is fastened to the inner wall of the mounting cavity and forms an air chamber with the inner wall of the mounting cavity. The air outlet of the air supply connector is connected to the air chamber.

15. An optical measuring device, characterized in that, include: An optical path system, wherein the optical path system is the optical path system according to any one of claims 1 to 14; And a detection device, which is used to detect the object being tested.

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