Dual-light source system for measuring the infrared radiation characteristics of targets

Abstract

This invention provides a dual-source system for measuring the infrared radiation characteristics of a target, comprising a second source, a first source, and an imaging chamber. The first source is located between the second source and the imaging chamber. One of the second and first sources is an infrared laser, and the other is a blackbody radiation source. A working reference surface for the light spot is formed within the imaging chamber, which can hold an infrared testing device or a target material. The system also includes a first moving device for moving the first source out of the optical path when the second source is in operation. By sequentially arranging the blackbody radiation source and the infrared laser in the direction of radiation source illumination, and using the first moving device to allow the first source to enter / exit the optical path, this invention enables smooth switching between broadband blackbody mode and narrowband laser mode without disassembling any optical components. This completely eliminates the problems of optical axis drift, repeated alignment, and recalibration caused by traditional discrete optical paths, significantly improving system stability and repeatability.

Description

Technical Field

[0001] This invention relates to the field of optical equipment technology, and in particular to a dual-light source system for measuring the infrared radiation characteristics of a target. Background Technology

[0002] With the development of infrared technology, the measurement of target infrared radiation characteristics is increasingly widely used in remote sensing, military, engineering, and many other fields. In practical applications, studying the infrared reflection and transmission characteristics of materials requires a relatively stable and uniform infrared radiation source to illuminate the target. Similarly, measuring the radiation characteristics of targets using infrared systems such as infrared thermal imagers also requires a uniform infrared radiation source as a standard radiation source to calibrate the equipment. These applications typically place high demands on the spot size and uniformity of the infrared radiation source.

[0003] Accurate measurement of the infrared radiation characteristics of a target typically relies on different types of infrared radiation sources, such as thermal infrared radiation sources for broadband measurements and infrared laser sources for narrowband or spectral measurements. Testing systems often need to switch between these two operating modes.

[0004] Existing technologies generally employ a discrete light source architecture. When the measurement requirement focuses on wide-band measurements, a thermal infrared radiation source (such as a blackbody radiation source) is selected; when the requirement focuses on spectral or narrow-band measurements, an infrared laser source is used instead. Because thermal infrared radiation sources and infrared laser sources differ significantly in mechanical interfaces, optical apertures, temperature control methods, and radiation characteristics, existing systems often require a complete process of "disassembly—reinstallation—optical path alignment—radio calibration" in the field. A single switchover typically takes no less than thirty minutes, severely restricting the testing cycle time. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a dual-source system for measuring the infrared radiation characteristics of a target, in order to eliminate or improve one or more defects existing in the prior art.

[0006] This invention provides a dual-light source system for measuring the infrared radiation characteristics of a target. The system includes a second light source, a first light source, and an imaging chamber. In the direction of the optical path, the first light source is located between the second light source and the imaging chamber. One of the second and first light sources is configured as an infrared laser, and the other as a blackbody radiation source. A light spot working reference surface is formed within the imaging chamber for placing the infrared testing device or target material to be irradiated. The system also includes a first moving device for either moving the first light source away from the optical path when the second light source is operating, or ensuring that the first light source remains within the optical path when operating.

[0007] In some embodiments, a circular imaging lens is provided at the beam inlet position of the imaging chamber. The imaging lens includes a plano-convex lens, with its flat surface facing the first light source and its convex surface facing the interior of the imaging chamber.

[0008] In some embodiments, the pre-imaging position of the second light source is located at the cavity opening position of the first light source, and the pre-imaging size of the second light source is the same as the cavity opening size of the first light source.

[0009] In some embodiments, the imaging chamber is configured as an infrared low-temperature chamber, and its internal operating temperature is adjustable within 0℃±5℃; the plano-convex lens is fixedly and sealed at the beam inlet position.

[0010] In some embodiments, the first moving device includes a first three-dimensional displacement stage for realizing the first light source moving along the X-axis and Y-axis in the horizontal direction and along the Z-axis in the vertical direction, wherein the Y-axis direction is parallel to the optical axis direction; or, the first moving device includes a first support platform that can move in the horizontal direction; or, when the first moving device includes a first three-dimensional displacement stage and a first support platform, the first three-dimensional displacement stage is mounted on the first support platform, and the displacement accuracy of the first three-dimensional displacement stage is higher than that of the first support platform.

[0011] In some embodiments, the first light source is configured as a blackbody radiation source, including one of a replaceable chamber blackbody or a surface blackbody; or, the first light source is configured as a blackbody radiation source, including a chamber blackbody and a surface blackbody, wherein the chamber blackbody and the surface blackbody are respectively mounted on a first mounting bracket that can move in the X-axis or Z-axis direction, so as to alternately use the chamber blackbody or the surface blackbody.

[0012] In some embodiments, the second light source includes an infrared laser and a laser homogenization and amplification optical device; the infrared laser includes a tunable laser or at least one single-wavelength laser; the laser homogenization and amplification optical device is disposed on the exit side of the infrared laser and is used to amplify and homogenize the beam diameter of the infrared laser by a set factor.

[0013] In some embodiments, the system further includes a second moving device for moving the second light source in a horizontal or vertical direction; the second moving device includes a second three-dimensional displacement stage for moving the second light source along the X-axis and Y-axis in the horizontal direction, and along the Z-axis in the vertical direction, wherein the Y-axis direction is parallel to the optical axis direction; when the second light source includes two or more single-wavelength infrared lasers, each of the infrared lasers is mounted on a second mounting bracket that can move in the X-axis or Z-axis direction to move the selected wavelength infrared laser to the working position; or, the second moving device includes a second support platform that can move in the horizontal direction; or, when the second moving device includes a second three-dimensional displacement stage and a second support platform, the second three-dimensional displacement stage is mounted on the second support platform, and the displacement accuracy of the second three-dimensional displacement stage is higher than that of the second support platform.

[0014] In some embodiments, the laser homogenization and amplification optical device includes a first lens, a second lens, an infrared diffuser, an infrared integrating rod, and a third lens arranged along the optical axis; wherein the first lens and the second lens are plano-convex lenses, the first lens having a convex surface as an incident surface and the second lens having a convex surface as an exit surface, and the planes of the first lens and the second lens are arranged opposite to each other; the optical center distance between the first lens and the second lens is configured to be equal to the sum of the focal lengths of the two lenses, and M1 is equal to the ratio of the focal length of the second lens to that of the first lens; the infrared diffuser is a circular thin sheet with frosted surfaces on both sides, its straight... The diameter is not less than the diameter of the laser beam magnified by M1 times; the infrared integrating rod is a cylindrical structure, and its end face shape is set to be circular, square or rectangular according to the shape of the laser source or target spot; the infrared integrating rod is set on one side of the emission surface of the infrared diffuser, and the two are set adjacent to each other; the third lens is a positive meniscus lens, with a concave surface as the incident surface and a convex surface as the emission surface, and the position of the third lens on the optical axis is adjustable, and its adjustment range is between one focal length and two focal lengths away from the infrared integrating rod, so as to magnify the beam again by M2 times.

[0015] In some embodiments, the infrared materials of each optical element in the system are the same, such as silicon, germanium, zinc sulfide, or zinc selenide; and / or, the end face of each optical element in the system is coated with an infrared anti-reflection film.

[0016] The dual-source system for measuring the infrared radiation characteristics of a target in this embodiment of the invention arranges a blackbody radiation source and an infrared laser sequentially in the direction of the radiation source's illumination, and uses a first moving device to cut the first source into / out of the optical path. This allows for smooth switching between broadband blackbody mode and narrowband laser mode without disassembling any optical components. This structure completely eliminates the problems of optical axis drift, repeated alignment, and recalibration caused by traditional discrete optical paths, significantly improving system stability and repeatability.

[0017] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0018] Those skilled in the art will understand that the objectives and advantages achievable with the present invention are not limited to those specifically described above, and that the above and other objectives achievable with the present invention will become clearer from the following detailed description. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. The components in the drawings are not drawn to scale but are merely illustrative of the principles of the invention. For ease of illustration and description of certain parts of the invention, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary device actually manufactured according to the invention.

[0020] Figure 1 This is a schematic diagram of the overall structure of a dual-light source system for measuring the infrared radiation characteristics of a target according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the optical path of a laser homogenization and amplification optical device according to an embodiment of the present invention.

[0022] Figure 3 This is a uniform large-spot optical system for a blackbody radiation source in one embodiment of the present invention.

[0023] Figure 4 This is an example of an infrared laser uniform large spot optical system in one embodiment of the present invention.

[0024] Figure 5 This is a comparison diagram of the irradiance intensity of a 1300K blackbody and an infrared laser on the working reference plane of the light spot in one embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the arrangement of three single-wavelength lasers in one embodiment of the present invention.

[0026] Figure label:

[0027] 1. Blackbody radiation source; 2. Infrared laser; 3. Laser homogenization and magnification optical device; 31. First lens; 32. Second lens; 33. Infrared diffuser; 34. Infrared integrating bar; 35. Third lens; 4. Imaging lens; 51. First three-dimensional displacement stage; 52. Second three-dimensional displacement stage; 61. First support platform; 62. Second support platform; 7. Infrared low temperature chamber; 8. Working reference plane of the light spot; 9. Central magnified light spot. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0029] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0030] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0031] It should also be noted that, unless otherwise specified, the term "connection" in this article can refer not only to a direct connection, but also to an indirect connection involving an intermediary.

[0032] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0033] This invention provides a dual-light source system for measuring the infrared radiation characteristics of a target, such as... Figure 1 As shown, the system includes a second light source, a first light source, and an imaging chamber. In the direction of the optical path, the first light source is located between the second light source and the imaging chamber. One of the second and first light sources is configured as an infrared laser 2, and the other is configured as a blackbody radiation source 1, using both blackbody and infrared laser—two commonly used infrared radiation sources—as the system's light sources.

[0034] Furthermore, a light spot working reference surface 8 is formed within the imaging chamber for placing the infrared testing device or target material to be irradiated. The system also includes a first moving device for moving the first light source out of the optical path when the second light source is working, or for ensuring that the first light source is within the optical path when working. The first moving device enables the first light source to be moved in or out. Moving it out achieves optical path separation, preventing the second light source from affecting the use of the first light source; while moving the first light source in enables it to work. The second and first light sources share the same optical axis. Combined with a beam expander lens, it is possible to generate a large-area uniform infrared light spot with broadband composite light using the blackbody radiation source 1 in the system, and also to generate a large-area uniform infrared light spot containing only monochromatic light at the same position using an infrared laser. The two light sources can be time-division multiplexed according to testing needs, meeting the requirements for infrared light sources in broadband measurement and spectral or narrowband measurement. At the same time, the infrared laser can be replaced to obtain large-area uniform infrared light spots of multiple wavelengths.

[0035] In the above embodiments, by arranging the blackbody radiation source 1 and the infrared laser 2 sequentially in the irradiation direction of the radiation source, and by using a first moving device to cut into / out of the optical path of the first light source, a smooth switching between broadband blackbody mode and narrowband laser mode can be achieved without disassembling any optical components. This structure completely eliminates the problems of optical axis drift, repeated alignment, and recalibration caused by traditional discrete optical paths, and significantly improves system stability and repeatability.

[0036] The working reference plane 8 of the light spot set in the imaging chamber shares the same exit pupil with the two light sources, keeping the infrared device or target material under test fixed throughout the test. When switching light sources, since it is mainly achieved through translation, the center position of the light spot, the incident angle, and the irradiance solid angle remain unchanged, avoiding pixel mapping failure or loss of bidirectional reflectance distribution function angle reference due to mechanical displacement.

[0037] In some embodiments, such as Figure 1 As shown, a circular imaging lens 4 is installed at the beam inlet of the imaging chamber to converge and shape the incident broadband or monochromatic infrared radiation into a light spot with a specified aperture and uniformity. The main function of the imaging lens 4 is to magnify the beam. It can be a single convex lens or a combination of lenses, depending on the actual situation. As at least one possible implementation, the imaging lens 4 includes a plano-convex lens, with its flat surface facing the first light source and its convex surface facing the interior of the imaging chamber. The flat surface facing the light source ensures that the light emitted by the light source is uniformly transmitted to the convex surface of the lens when passing through it, avoiding uneven refraction or focusing effects. The convex surface facing the interior of the imaging chamber utilizes the refraction effect provided by the convex surface to focus the beam onto the working area inside the imaging chamber, thereby achieving spot formation and precise control of radiation energy.

[0038] To achieve the function of the imaging lens 4, the distance between the emitting end of the first light source and the imaging lens 4 should be set between one and two times the focal length of the imaging lens 4.

[0039] In some embodiments, the pre-imaging position of the second light source is located at the cavity opening of the first light source, and the pre-imaging size of the second light source is the same as the cavity opening size of the first light source. For example, the first light source is a blackbody radiation source 1, and the second light source is an infrared laser 2. The infrared laser 2 pre-magnifies and images the infrared laser through a laser homogenization and magnification optical device 3. The imaging position is located near the cavity opening of the blackbody radiation source 1, and the size is approximately the same as the cavity opening size of the blackbody radiation source 1. This imaging spot is used as the input light source of the imaging lens 4, so that after the imaging lens 4, both the infrared laser and the blackbody can produce a uniform large spot of the same size at the same position without refocusing, thereby achieving uniformity of the spot size of the two light sources. This facilitates the placement of samples or testing equipment at this fixed position in practical applications.

[0040] In some embodiments, the imaging chamber is configured as an infrared low-temperature chamber 7, for example, its internal operating temperature is adjustable within 0℃±5℃, ensuring the system can operate in low-temperature environments to reduce ambient background radiation and help ensure the stability and accuracy of imaging results. Further, the plano-convex lens is fixedly and sealed at the beam inlet position. The fixed plano-convex lens ensures that the relative position of the lens and the incident angle of the beam remain consistent, preventing lens position shifts caused by vibration, temperature changes, or other external factors, thus ensuring the focusing effect of the beam and the stability of the transmission path. The sealed installation of the lens prevents external air, dust, moisture, and other factors from entering the imaging chamber, maintaining a clean and constant environment. Especially in low-temperature environments, the sealing helps reduce the impact of airflow on temperature stability, while ensuring that the internal samples or testing equipment are not interfered with by external contamination, thereby improving the reliability of the measurement.

[0041] In some embodiments, such as Figure 1 As shown, the first moving device includes a first three-dimensional displacement stage 51, used to realize the first light source's X-axis and Y-axis movement in the horizontal direction, and Z-axis movement in the vertical direction, wherein the Y-axis direction is parallel to the optical axis direction. Specifically, X-axis movement can realize the movement of the first light source in or out, requiring a relatively long stroke; Y-axis movement can realize the fine adjustment of the front-to-back position of the first light source in the optical path, adjusting it to the distance of the imaging lens 4, which can change the size of the final light spot. Z-axis movement can move the first light source up and down, adjusting its cavity or beam center to the same height as the optical axis, and aligning it with the optical axis in the vertical direction.

[0042] In some embodiments, the first moving device includes a first support platform 61 that can move in the horizontal direction. The first support platform 61 can also move along the X-axis and the Y-axis. If only the first support platform 61 is used, it is necessary to ensure that the cavity or beam center of the first light source is at the same height as the optical axis.

[0043] Furthermore, when the first moving device includes a first three-dimensional displacement stage 51 and a first support platform 61, the first three-dimensional displacement stage 51 is mounted on the first support platform 61, and the displacement accuracy of the first three-dimensional displacement stage 51 is higher than that of the first support platform 61.

[0044] As at least one possible implementation, the first light source can be configured as a blackbody radiation source 1. The blackbody radiation source 1 can be configured with one or more, including at least one replaceable cavity blackbody or surface blackbody. The radiating area of ​​a surface blackbody can be larger than that of a cavity blackbody, but its temperature is lower, making it suitable for scenarios requiring a larger radiating area and less stringent temperature requirements. Cavity blackbodies have higher emissivity and better temperature uniformity, and low, medium, and high-temperature blackbodies can cover a very wide temperature range (approximately -80 to 3000°C). When the primary test band is near-infrared or mid-infrared, a cavity blackbody is preferred. When the primary test band is far-infrared, a surface blackbody can also be used.

[0045] As another possible implementation, the first light source is configured as a blackbody radiation source 1, comprising a chamber blackbody and a surface blackbody. The chamber blackbody and the surface blackbody are respectively mounted on a first mounting bracket that can move along the X-axis or Z-axis, allowing for the alternating use of either the chamber blackbody or the surface blackbody. This design allows for the switching of the chamber blackbody or the surface blackbody according to actual needs. This configuration provides greater flexibility, adapting to different experimental or measurement requirements, and enables the switching of the blackbody radiation source 1 through a simple motion system.

[0046] In some embodiments, the system further includes a second moving device for driving the second light source to move in a horizontal or vertical direction; the second moving device includes a second three-dimensional displacement stage 52 for realizing the second light source to move along the X-axis and Y-axis in the horizontal direction, and along the Z-axis in the vertical direction, wherein the Y-axis direction is parallel to the optical axis direction.

[0047] like Figure 6As shown, when the second light source includes two or more single-wavelength infrared lasers 2, each of the infrared lasers 2 is mounted on a second mounting bracket that can move in the X-axis or Z-axis direction to move the selected wavelength infrared laser 2 to the working position. Specifically, movement in the X-axis direction allows for the insertion or removal of infrared lasers 2 with different wavelengths to switch between different wavelengths, requiring a relatively long travel distance; movement in the Y-axis direction allows for fine-tuning of the forward and backward position in the optical path of the first light source. Movement in the Z-axis direction allows for the vertical movement of the second light source, adjusting its beam center to be at the same height as the optical axis and aligned with the optical axis in the vertical direction.

[0048] Furthermore, the second moving device includes a second support platform 62 capable of moving horizontally. The second support platform 62 can also achieve X-axis and Y-axis movement. If only the second support platform 62 is used, it is necessary to ensure that the beam center of the second light source is at the same height as the optical axis. When the second moving device includes a second three-dimensional displacement stage 52 and a second support platform 62, the second three-dimensional displacement stage 52 is mounted on the second support platform 62, and the displacement accuracy of the second three-dimensional displacement stage 52 is higher than that of the second support platform 62.

[0049] Optionally, the first support platform 61 and the second support platform 62 can be configured as a table, with horizontally adjustable casters with feet, combining movement and fixation functions. After being fixed in position, the feet provide support, allowing for horizontal adjustment of the optical support platforms. The two optical support platforms are placed parallel to each other in front of the imaging lens 4. The first support platform 61, closer to the imaging lens 4, is used to place the blackbody radiation source 1, and the second support platform 62 is used to place the infrared laser 2. When controlling the distance between the blackbody radiation source 1 or the infrared laser 2 and the imaging lens 4, the optical support platforms can be moved back and forth as a whole using the casters, serving as a coarse adjustment for the distance.

[0050] In this embodiment of the invention, the two three-dimensional displacement stages can be selected according to the requirements of accuracy, load capacity, range of motion and cost, and the appropriate structural design can be selected from mechanical guide rail structure, motor drive structure, pneumatic and hydraulic drive structure, magnetic levitation structure, fine adjustment spiral structure, etc., depending on the actual situation.

[0051] In some embodiments, the second light source includes an infrared laser 2 and a laser homogenization and amplification optical device 3; the infrared laser 2 includes a tunable laser or at least one single-wavelength laser; the tunable laser can adjust its output wavelength within a certain wavelength range to adapt to different application requirements and provide flexible wavelength selection. The single-wavelength laser outputs a single wavelength of laser light, resulting in a more stable output.

[0052] In some embodiments, the laser homogenization and amplification optical device 3 is disposed on the exit side of the infrared laser 2 and is used to amplify and homogenize the beam diameter of the infrared laser 2 by a set factor.

[0053] As at least one possible way, such as Figure 2 As shown, the laser homogenization and magnification optical device 3 includes a first lens 31, a second lens 32, an infrared diffuser 33, an infrared integrating rod 34, and a third lens 35 arranged along the optical axis.

[0054] In this system, the first lens 31 and the second lens 32 are plano-convex lenses. The first lens 31 has a convex surface as its incident surface, and the second lens 32 has a convex surface as its exit surface. The planes of the first lens 31 and the second lens 32 are arranged opposite each other. The distance between the optical centers of the first lens 31 and the second lens 32 is configured to be equal to the sum of the focal lengths of the two lenses, and M1 is equal to the ratio of the focal lengths of the second lens 32 to the first lens 31. Optionally, the first lens 31 faces the light with its convex surface, undertaking the initial convergence of the beam; the second lens 32 sends the light with its convex surface, completing the diameter magnification. The planes of the two lenses face each other, and the distance between their optical centers is strictly equal to the sum of their focal lengths, forming a focusless system. After the incident parallel beam is converged by the first lens 31, it is immediately re-collimated by the second lens 32. This not only ensures that the exit beam remains parallel, but also makes the beam expansion ratio determined by only the single parameter of the focal length ratio, simplifying the design and assembly.

[0055] Optionally, the infrared diffuser 33 is a circular thin sheet with frosted surfaces on both sides, and its diameter is not less than the diameter of the laser beam magnified by M1 times, ensuring that the entire beam can cover its effective area. The double-sided frosted structure causes the incident beam to undergo two random scatterings during transmission, thereby rapidly homogenizing the energy distribution and introducing a controllable divergence angle; at the same time, the infrared diffuser 33 itself is thin (e.g., controlled between 0.5mm and 2mm), with a short additional optical path, and its aberration effect on the subsequent second-stage beam expander is negligible, maintaining a simple and stable overall structure.

[0056] Optionally, the infrared integrating rod 34 is a cylindrical structure, and the shape of its end face is set to be circular, square or rectangular according to the shape of the laser source or target spot; the infrared integrating rod 34 is disposed on one side of the emission surface of the infrared diffuser 33, and the two are disposed adjacent to each other; since the refractive index of the material used in the infrared integrating rod 34 is much larger than that of air, a large amount of light entering the integrating rod will undergo total internal reflection when it is transmitted to the interface (incident end) on the side of the integrating rod. The total internal reflection paths of light with different incident angles are different in the integrating rod, and finally they are randomly superimposed at the emission end of the infrared integrating rod 34 to achieve homogenization.

[0057] Furthermore, the incident surface of the infrared integrating rod 34 is set as a concave spherical surface, and the exit surface is set as a plane. The concave spherical incident end allows the laser to diverge again when entering the infrared integrating rod 34. Compared with a plane end face, the divergence of the concave spherical surface causes more light rays to enter the integrating rod at a large angle. The larger the angle, the more times total internal reflection occurs in the propagation path, and finally, they are randomly superimposed at the exit end to achieve homogenization. If the incident surface of the infrared integrating rod 34 is set as a plane, there will be no increase in light divergence at that point. Light rays with small angles in the laser beam will pass straight through the infrared integrating rod 34, and the number of times total internal reflection occurs at slightly larger angles will not be many. In this case, the effect of random superposition is not obvious, the homogenization is not good enough, and it is difficult to meet the test requirements. Optionally, the length of the infrared integrating rod 34 is configured to be greater than 10 times its maximum radial dimension of the end face. This design ensures that the infrared integrating rod 34 has sufficient length to complete the full integration and homogenization of the beam during beam propagation.

[0058] Optionally, the third lens 35 is a positive meniscus lens, having a concave surface as the incident surface and a convex surface as the exit surface. The third lens 35 can be adjusted in position on the optical axis, with the adjustment range between one and two focal lengths from the infrared integrating bar 34, to further magnify the beam by M². This lens features a concave surface for receiving light and a convex surface for sending light, possessing both converging and diverging curvatures. Due to the combination of its concave and convex surfaces, the incident beam undergoes a certain degree of divergence and redirection when passing through the lens, thereby increasing the beam diameter to meet the requirements of subsequent optical systems. This arrangement can provide low-distortion magnification over a large field of view, while utilizing the aberration self-compensation characteristics of the meniscus lens to reduce spherical aberration and coma, ensuring that the output beam maintains sharp edges and no reduction in uniformity while covering a large-aperture target surface.

[0059] Furthermore, the third lens 35 is adjustable along the optical axis, with its adjustment range between one and two focal lengths from the infrared integrating bar 34. This design can effectively change the size of the light spot to meet the measurement needs of targets of different sizes. For example, when measuring a larger target, adjusting the lens position enlarges the light spot to adapt to the target's size; when measuring a smaller target, reducing the light spot size improves the beam's focusing ability.

[0060] In the above embodiments, if the imaging lens 4 is combined with the three-stage beam expander, a large-area uniform infrared spot can be obtained.

[0061] In some embodiments, the infrared materials of all optical elements within the system are identical. Specifically, the imaging lens 4 is made of the same material as the optical elements in the laser homogenization and magnification optical device 3, uniformly using zinc sulfide (ZnS), zinc selenide (ZnSe), silicon (Si), or germanium (Ge), which have good transmittance in the infrared band. This material consistency ensures that the optical characteristics of the optical elements throughout the system remain consistent, optimizing optical performance and reducing optical errors or wavelength mismatches caused by material differences.

[0062] In some embodiments, the end faces of each optical element within the system are coated with an infrared antireflection film. The function of the antireflection film is to reduce reflection from the surface of the optical elements and improve the transmittance of the light beam. Particularly in the infrared band, the antireflection film can effectively reduce reflection loss, ensuring that more laser light or light passes through the optical elements. The infrared antireflection film can be designed with one or more layers to optimize transmittance for specific wavelength ranges of light, while minimizing reflection and interference to enhance transmission. For example, materials for infrared antireflection films include, but are not limited to, alumina, magnesium fluoride, and calcium fluoride.

[0063] It is understood that the optical elements in the aforementioned embodiments are related to the wavelength of the infrared laser passing through the lens. When the wavelength of the infrared laser changes, the corresponding focal length of the lens will change, and the above distance constraint relationship needs to be recalculated according to the new focal length.

[0064] The dual-light source system for measuring the infrared radiation characteristics of a target in this embodiment of the invention can be divided into two modes: a broadband blackbody mode and a narrow-spectrum laser mode.

[0065] Firstly, the broadband blackbody mode uses a blackbody radiation source 1 to generate a large-area uniform infrared light spot with a wide-band composite light, such as... Figure 3 As shown, the specific operation steps are as follows:

[0066] (1) Turn off infrared laser 2, turn on blackbody radiation source 1, and set the blackbody working temperature;

[0067] (2) Adjust the X-axis translation stage and Z-axis lifting stage of the first moving device where the blackbody radiation source 1 is located so that the cavity center of the blackbody radiation source 1 coincides with the optical axis of the light source system.

[0068] (3) Adjust the Y-axis translation stage where the blackbody radiation source 1 is located, and fine-tune the distance from the output surface of the blackbody radiation source 1 to the imaging lens 4. If necessary, the distance can also be adjusted in a larger range in conjunction with the first support platform 61 so that the cavity of the blackbody radiation source 1 is focused and imaged at the working reference surface 8 of the light spot, forming an enlarged uniform infrared light spot.

[0069] When blackbody radiation source 1 is used as the system light source, a broadband uniform infrared spot is obtained on the working reference plane 8 of the light spot, and its spectral irradiance can be calculated by the following formula:

[0070]

[0071] Where τ is the transmittance of imaging lens 4, D is the diameter of imaging lens 4, r is the image distance of the uniform infrared spot behind imaging lens 4, and L... λ It is the spectral radiance of the blackbody, which can be calculated according to Planck's blackbody radiation law.

[0072] Secondly, the narrow-spectrum laser mode uses an infrared laser 2 to generate a large-area uniform infrared spot containing only monochromatic light, such as... Figure 4 As shown, the specific operation steps are as follows:

[0073] (1) Turn off the power supply of blackbody radiation source 1, adjust the X-axis translation stage where blackbody radiation source 1 is located, and move blackbody radiation source 1 out of the optical path;

[0074] (2) Turn on the power of infrared laser 2, and adjust the X-axis translation stage and Z-axis lifting stage of the second moving device where infrared laser 2 is located, so that the center of the infrared laser beam coincides with the optical axis of the light source system.

[0075] (3) Adjust the Y-axis translation stage where the infrared laser 2 is located, and fine-tune the distance between the infrared laser 2 and the imaging lens 4. If necessary, the distance can also be adjusted in a larger range by combining with the second support platform 62, so that the infrared laser beam is focused and imaged at the working reference plane 8 of the spot, forming an enlarged uniform infrared spot.

[0076] Example 1

[0077] The blackbody radiation source 1 uses a cavity-type intermediate-temperature blackbody with a temperature range of 300℃~1200℃, a cavity diameter of 60mm, an actual emissivity of >0.997, a temperature resolution of 0.1℃, a temperature stability of ≤±0.3℃ / 10min, a temperature uniformity of ≤0.15℃, dimensions of 708mm×400mm×564mm, and a weight of approximately 30kg.

[0078] Infrared laser 2 uses a 60W carbon dioxide laser with a laser wavelength of 10.6μm±0.05μm, a beam diameter of 2mm, dimensions of 750mm×130mm×190mm, and a weight of approximately 10kg.

[0079] Laser homogenization and amplification optical device 3 as attached Figure 2 As shown, the constituent components are as follows:

[0080] First lens 31: Zinc selenide plano-convex lens, 5mm in diameter, focal length f1=8mm (10.6μm).

[0081] Second lens 32: Zinc selenide plano-convex lens, 10mm in diameter, focal length f2 = 24mm (10.6μm).

[0082] The distance d between the optical centers of the first lens 31 and the second lens 32 12 = 32mm.

[0083] Infrared diffuser 33: Zinc selenide disc, frosted on both sides, 8mm in diameter and 2mm in thickness.

[0084] Infrared integrating rod 34: a zinc selenide long cylinder with an end face diameter of 6mm, a length of 70mm, and a concave spherical radius of 6mm.

[0085] Third lens 35: Zinc selenide positive meniscus lens, diameter 50mm, edge thickness 3.50mm, center thickness 6.60mm, concave radius 69.40mm, convex radius 193.20mm, focal length f3 = 75mm (10.6μm).

[0086] The third lens 35 is placed after the infrared integrating rod 34, and the distance d3 from its optical center to the end face of the infrared integrating rod 34 is 82.2 mm.

[0087] Imaging lens 4 also uses zinc selenide material, is a plano-convex lens, has a diameter of 320mm, and a focal length of f. 41 =660mm (6.4μm), f 42 =670mm (10.6μm).

[0088] In the first three-dimensional translation stage 51 and the second three-dimensional translation stage 52, the X-axis translation stage can be a long-stroke, heavy-duty electrically controlled translation stage with a stroke of 1000mm. Besides aligning the optical axis, it can also be used to move the non-working blackbody radiation source 1 out of the optical path. The Y-axis translation stage can be a short-stroke, heavy-duty electrically controlled translation stage with a stroke of 150mm. The Z-axis lifting stage can be a worm gear driven linear bearing guide rail lifting stage with a stroke of 100mm.

[0089] The tabletop dimensions of the first support platform 61 and the second support platform 62 are 1500mm × 1000mm and 1000mm in height. The table legs are horizontally adjustable with casters with feet, which can be used for both movement and fixation. After the position is fixed, the support feet can be used for support to achieve horizontal adjustment of the support platform.

[0090] The infrared low-temperature chamber 7 is about 8 meters long and 7.6 meters wide. The operating temperature is set to 0℃±5℃. A circular window is opened on the wall facing the blackbody and infrared laser 2, and an imaging lens 4 is installed there. The convex surface of the imaging lens 4 faces the interior of the low-temperature chamber.

[0091] When using blackbody radiation source 1 as the system light source, as shown in the attached... Figure 3As shown, the blackbody radiates a wide-band composite light. Based on the transmittance of the selected zinc selenide material, the wavelength range is designed to be 0.8 μm to 12 μm. Since the refractive index of zinc selenide varies at different wavelengths, to account for the entire designed wavelength range, the intermediate wavelength of 6.4 μm is used to calculate the spot imaging result. By adjusting the first support platform 61 where the blackbody radiation source 1 is located and the Y-axis translation stage, the distance between the blackbody cavity opening and the imaging lens 4 is made to satisfy the object distance u1 = 781.9 mm. Then, at the image distance r1 = 4233.4 mm behind the imaging lens 4, a uniform infrared spot with a diameter of 325 mm can be obtained.

[0092] When a 10.6µm infrared laser 2 is used as the system light source, as shown in the attached... Figure 4 As shown, after the 2mm infrared laser passes through the laser homogenization and magnification optical device 3, the beam will be magnified and imaged between the laser homogenization and magnification optical device 3 and the imaging lens 4. The image of the magnified spot 9 is located behind the third lens 35, with an image distance of 856.25mm. The imaging position is located near the cavity opening of the blackbody radiation source 1, and the spot diameter is 62.5mm, which is comparable to the cavity opening size (60mm) of the blackbody radiation source 1.

[0093] By adjusting the second support platform 62 where the infrared laser 2 is located and the Y-axis translation stage, the distance between the laser homogenization and magnification optical device 3 and the imaging lens 4 is made to satisfy the following: the distance d4 between the optical center of the imaging lens 4 and the optical center of the third lens 35 is 1652.25mm. At this time, the central magnified light spot 9 is used as the light source of the imaging lens 4, that is, the object distance u2 = 796mm. After the imaging lens 4, at the image distance r2 = 4232.7mm, a uniform infrared light spot with a diameter of 332mm containing only the laser wavelength can be obtained.

[0094] Whether using a blackbody radiation source 1 or an infrared laser 2 as the light source, a uniform infrared spot with a similar diameter (approximately 330 mm) can be formed at the same distance (approximately 4233 mm) behind the imaging lens 4. The location of this spot is called the working reference surface 8 of the spot. In practical applications, the infrared testing device or target material to be irradiated is placed at this fixed position.

[0095] In this embodiment, the operating temperature of the blackbody radiation source 1 is set to 1026.9℃, or 1300K, and the transmittance τ of the imaging lens 4 is set to 90%. A wide-band uniform infrared spot is obtained on the working reference plane 8, with a total irradiance of approximately 200W / m in the (0.8~12)μm band. 2 The spectral irradiance distribution is shown in the attached figure. Figure 5 As shown, although the total irradiance of the blackbody spot is large, the spectral irradiance at a specific wavelength after 6 μm is very small.

[0096] When infrared laser 2 is used, the laser operating frequency is set to 1kHz and the duty cycle to 40%. The average power measured by a laser power meter on the working reference plane 8 of the laser spot is 0.356mW. Based on the absorption aperture and effective bandwidth of the laser power meter, its equivalent irradiance within a bandwidth of 0.1μm is calculated to be 7.55W / m². 2 From the appendix Figure 5 As can be seen, at 10.6 μm, the irradiance of infrared laser is about two orders of magnitude stronger than that of uniform infrared spot spectral irradiance obtained by blackbody, and can provide irradiance much higher than that of blackbody in spectral or narrowband measurements.

[0097] Similarly, by replacing the infrared laser 2 with one of different wavelengths, a more intense and uniform infrared spot can be obtained at other wavelengths. (See attached image) Figure 6 In another embodiment of the present invention, three single-wavelength infrared lasers 2 are placed side by side on three second mounting frames of the second three-dimensional translation stage. The infrared lasers 2 (2-1, 2-2, 2-3) of different wavelengths are equipped with different laser homogenization and amplification optical devices 3 (3-1, 3-2, 3-3). When a uniform infrared spot of other wavelengths is required, the X-axis translation stage can be adjusted to rotate the infrared lasers 2 of the required wavelengths into the optical path.

[0098] The dual-light source system for measuring the infrared radiation characteristics of a target according to embodiments of the present invention achieves the following technical effects:

[0099] (1) Using two commonly used infrared radiation sources, blackbody radiation source 1 and infrared laser 2, as the system light source, and through the optical path staggered design and shared optical axis, optical lenses are used to magnify and image the two small infrared radiation output surfaces to form a time-division multiplexed blackbody / infrared laser uniform large spot light source system.

[0100] (2) Based on the output light characteristics of infrared laser 2 and blackbody radiation source 1, the system adopts a staggered arrangement of one in front of the other. The infrared laser is pre-magnified and imaged by laser homogenization and magnification optical device 3. The imaging position is located near the cavity opening of blackbody radiation source 1, and the size is approximately the same as the cavity opening size of blackbody radiation source 1. This imaging spot is used as the input light source of imaging lens 4, so that infrared laser 2 and blackbody radiation source 1 can produce uniform large light spots of the same size at the same position after imaging lens 4, thereby realizing the uniformity of the light spots of the two light sources, which is convenient for placing samples or test equipment at this fixed position in practical applications.

[0101] (3) When the system uses blackbody radiation source 1 as the light source, it can generate a large area of ​​uniform infrared light spot with wide-band composite light. The wavelength can cover 1 μm to tens of μm, depending on the selected optical infrared material. The overall light flux of the light spot is large, which is suitable for broadband measurement. When the system uses infrared laser 2 as the light source, it can form a large area of ​​uniform infrared light spot containing only laser wavelength at the same position. Infrared laser 2 has high power and is suitable for spectral or narrowband measurement.

[0102] (4) The optical components in the system are all made of the same special infrared material and can transmit a wide range of infrared wavelengths. Therefore, in actual use, different wavelength infrared lasers 2 can be replaced as needed to obtain a large area of ​​uniform infrared light spot with multiple wavelengths and realize spectral or narrowband measurement at different wavelengths.

[0103] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0104] In this invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or in place of features of other embodiments.

[0105] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A dual light source system for target infrared radiation characteristic measurement, characterized in that, The system comprises a second light source, a first light source and an imaging chamber, the first light source is located between the second light source and the imaging chamber in the extension direction of the light path; One of the second light source and the first light source is arranged as an infrared laser, and the other is arranged as a blackbody radiation source; the infrared laser is used to output narrow-spectrum infrared radiation, and the blackbody radiation source is used to output wide-spectrum infrared radiation, so as to adapt to the narrowband measurement or broadband measurement requirement of the target infrared radiation characteristic; a light spot working reference surface is formed in the imaging chamber, and is used to place an infrared test device or a target material that needs to be irradiated; The second light source comprises an infrared laser and a laser homogenization amplification optical device; the infrared laser comprises a tunable laser or at least one single-wavelength laser; the laser homogenization amplification optical device is arranged on the exit side of the infrared laser, and is used to amplify the beam diameter of the infrared laser by a set multiple and homogenize the beam diameter; The optical axes of the second light source and the first light source are shared, the pre-imaging position of the second light source is located at the cavity opening position of the first light source, and the pre-imaging size of the second light source is the same as the cavity opening size of the first light source; The system further comprises a first moving device, which is used to drive the first light source to be out of the light path when the second light source is working, or is used to ensure that the first light source is located in the light path when the first light source is working.

2. The dual light source system for the measurement of infrared radiation characteristics of a target according to claim 1, characterized in that, A circular imaging lens is arranged at the beam inlet position of the imaging chamber, and the imaging lens comprises a plano-convex lens, the plane of which faces the first light source, and the convex surface of which faces the inside of the imaging chamber.

3. The dual light source system for the measurement of infrared radiation characteristics of a target according to claim 2, characterized in that, The imaging chamber is arranged as an infrared cryogenic chamber, and the working temperature inside the imaging chamber is configured to be adjustable within 0℃±5℃; The plano-convex lens is fixedly and sealingly mounted at the beam inlet position.

4. The dual light source system for measurement of infrared radiation characteristics of a target according to claim 1, wherein, The first moving device comprises a first three-dimensional displacement table, which is used to realize the X-axis movement and Y-axis movement in the horizontal direction and the Z-axis movement in the vertical direction of the first light source, wherein the Y-axis direction is parallel to the optical axis direction; or The first moving device comprises a first support platform that can move in the horizontal direction; or In the case that the first moving device comprises the first three-dimensional displacement table and the first support platform, the first three-dimensional displacement table is mounted on the first support platform, and the displacement precision of the first three-dimensional displacement table is higher than that of the first support platform.

5. The dual light source system for the measurement of infrared radiation characteristics of a target according to claim 4, characterized in that, The first light source is arranged as a blackbody radiation source, and comprises one of a replaceable cavity blackbody or a surface source blackbody; or The first light source is arranged as a blackbody radiation source, and comprises a cavity blackbody and a surface source blackbody, wherein the cavity blackbody and the surface source blackbody are respectively mounted on a first mounting rack that can move in the X-axis or Z-axis direction, so as to alternately use the cavity blackbody or the surface source blackbody.

6. The dual light source system for measurement of infrared radiation characteristics of a target according to claim 1, wherein, The system further comprises a second moving device, which is used to drive the second light source to move in the horizontal direction or the vertical direction; The second moving device comprises a second three-dimensional displacement table for realizing X-axis movement and Y-axis movement in a horizontal direction and Z-axis movement in a vertical direction of the second light source, wherein the Y-axis direction is parallel to the optical axis direction; in the case that the second light source comprises two or more single-wavelength lasers, each of the infrared lasers is mounted on a second mounting frame movable in the X-axis or Z-axis direction to move the infrared laser of a selected wavelength specification to a working position; or, The second moving device comprises a second support platform movable in a horizontal direction; or, In the case that the second moving device comprises a second three-dimensional displacement table and a second support platform, the second three-dimensional displacement table is mounted on the second support platform, and the displacement precision of the second three-dimensional displacement table is higher than that of the second support platform.

7. The dual light source system for measurement of infrared radiation characteristics of a target according to claim 1, wherein, The laser homogenization amplification optical device comprises a first lens, a second lens, an infrared diffuser, an infrared integrating rod and a third lens arranged along an optical axis; The first lens and the second lens are plano-convex lenses, the first lens has a convex surface as an incident surface, and the second lens has a convex surface as an exit surface, and the planes of the first lens and the second lens are oppositely arranged; the distance between the optical centers of the first lens and the second lens is configured to be equal to the sum of the focal lengths of the two lenses, and M1 is equal to the focal length ratio of the second lens to the first lens; The infrared diffuser is a round sheet with frosted surfaces, and the diameter thereof is not less than the laser beam diameter amplified by M1 times; The infrared integrating rod is of a cylindrical structure, and the end surface shape thereof is set to be circular, square or rectangular according to the shape of the laser light source or the target light spot; the infrared integrating rod is arranged on the exit surface side of the infrared diffuser, and the two are arranged in close proximity to each other; The third lens is a positive meniscus lens having a concave surface as an incident surface and a convex surface as an exit surface, and the third lens can be adjustably arranged on the optical axis, and the adjustment range thereof is between one focal length and two focal lengths from the infrared integrating rod, so as to amplify the light beam by M2 times again.

8. The dual light source system for measurement of infrared radiation characteristics of a target according to claim 1, wherein, The infrared materials of the optical elements in the system are the same, and silicon, germanium, zinc sulfide or zinc selenide is used; and / or, The end surfaces of the optical elements in the system are coated with infrared anti-reflection films.

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