Nested air chamber and method of forming a concentric circular light spot in a nested air chamber

Abstract

The application discloses a nested air chamber and a method for forming concentric circular light spots in the nested air chamber. The nested air chamber comprises coaxially arranged first and second mirror surfaces. The first and second mirror surfaces respectively comprise coaxially nested outer and inner concave mirrors, and the outer and inner concave mirrors are circular. An incident hole is arranged on the first or second mirror surface. Light rays incident through the incident hole are adapted to be emitted after multiple reflections between the first and second mirror surfaces, and are adapted to form concentric circular light spots on the first and second mirror surfaces. According to the technical scheme of the application, the light spots can be uniformly distributed on the two mirror surfaces, the utilization rate of the mirror surface is high, the optical path volume ratio is improved, the beam quality is high, and the stability is good.

Description

Technical Field

[0001] This invention relates to the field of trace gas detection technology, and more particularly to a nested gas chamber and a method for determining the formation of concentric circular light spots in the nested gas chamber. Background Technology

[0002] Based on Beer-Lambert's absorption law, the detection limit of gas concentration is inversely proportional to the optical path length; therefore, increasing the optical path length is the main method to improve accuracy. Multiple reflector (MPC) systems utilize the principle of multiple reflections of light between mirrors to increase the optical path length within a limited volume, making them a key component in tunable absorption spectroscopy. Classical MPCs are mainly of three types: Herriott type, White type, and annular type. Classical MPCs are widely used due to their regular light spot arrangement, simple design, and ease of adjustment; however, they also suffer from low mirror utilization, small optical path length, and limited detection accuracy. In recent years, researchers have proposed double spherical mirrors (MPCs) with dense light spot patterns. These can form concentric circles, independent circles, petals, and other dense light spot patterns under off-axis conditions, overcoming the drawback of low mirror utilization and are widely used in the field of trace gas concentration detection.

[0003] The Herriott cell consists of two coaxially placed spherical mirrors with the same radius of curvature. When light propagates paraxially and the inter-mirror distance meets specific values, it can form elliptical or circular light spots on the mirror surface. Herriott provides analytical solutions for the cell parameters, simplifying the cell design. Studies have shown that the cell exhibits excellent stability and beam quality, making it suitable for a wide variety of scenarios. However, the light spots formed by this cell are often distributed around the periphery of the mirror surface, leading to issues such as low mirror utilization, small optical path volume, and limited detection accuracy.

[0004] Multiple reflector chambers with dense light spot patterns can also be constructed from two spherical mirrors with the same radius of curvature, placed coaxially opposite each other. Light propagates off-axis between the mirrors, forming dense light spot patterns such as concentric circles, independent circles, and petals at specific intervals. Although multiple reflector chambers with dense light spot patterns are superior to classic Herriott-type chambers in terms of mirror utilization, they still have the following disadvantages: (1) Due to the off-axis propagation of light, the distance between the mirrors and the size of the mirrors are mutually limited, and the optical path is usually on the order of several meters to tens of meters, which is not suitable for chambers with long optical paths (>100m), thus limiting their application in trace gas detection scenarios; (2) The aberration caused by the off-axis propagation of light causes the light spot shape to become elliptical, resulting in poor beam quality of the emitted light; (3) The formation of dense light spot patterns has not been thoroughly studied, and analytical solutions for chamber parameters have not been obtained, making the design process more complex and cumbersome.

[0005] It is evident that designing a gas cell with high mirror utilization, large optical path volume, high detection accuracy, good stability, and high beam quality for wide application in various scenarios is an urgent problem to be solved.

[0006] Therefore, a nested air chamber and a method for determining the formation of concentric circular light spots in the nested air chamber are needed to solve the problems existing in the above technical solutions. Summary of the Invention

[0007] To address this, the present invention provides a nested air chamber and a method for determining the formation of concentric circular light spots within the nested air chamber, in order to solve or at least alleviate the problems mentioned above.

[0008] According to one aspect of the present invention, a nested air chamber is provided, comprising a first mirror and a second mirror arranged coaxially opposite to each other, wherein: the first mirror and the second mirror respectively include an outer concave mirror and an inner concave mirror arranged coaxially nested, and both the outer concave mirror and the inner concave mirror are circular; an entrance hole is provided on the first mirror or the second mirror, and light rays incident through the entrance hole are adapted to be reflected multiple times between the first mirror and the second mirror before being emitted, and are adapted to form concentric circular light spots on the first mirror and the second mirror.

[0009] Optionally, in the nested air chamber according to the present invention, the mirror parameters of the first mirror and the second mirror are the same; the first mirror includes a first concave outer mirror and a first concave inner mirror coaxially nested, wherein the first concave outer mirror is provided with a first central hole, and the first concave inner mirror is nested in the first central hole; the second mirror includes a second concave outer mirror and a second concave inner mirror coaxially nested, wherein the second concave outer mirror is provided with a second central hole, and the second concave inner mirror is nested in the second central hole.

[0010] Optionally, in the nested air chamber according to the invention, after the light is reflected by the concave mirror, it is adapted to form a unit semi-elliptical light spot on the first mirror and the second mirror, and after being reflected by the concave mirror, it is adapted to form a plurality of semi-elliptical light spots that are rotationally symmetrical with the unit semi-elliptical light spot on the first mirror and the second mirror, so as to form the concentric circular light spot based on the combination of all the semi-elliptical light spots.

[0011] Optionally, in the nested air chamber according to the present invention, in the unit semi-elliptical light spot, every four light spots that are symmetrical about the major and minor axes of the ellipse are located on the same circle; the unit semi-elliptical light spot contains 2n light spots, where n represents the number of concentric circular light spots; the number of reflections corresponding to the concentric circular light spots is 2nk, where k represents the number of semi-elliptical light spots contained in the concentric circular light spots.

[0012] Optionally, in the nested air chamber according to the invention, the radius of the concave mirror is larger than the major axis of the ellipse containing the unit semi-elliptical light spot.

[0013] Optionally, in the nested air chamber according to the invention, all the light spots in the concentric circular light spots are distributed on concentric circles, and the center of the circle is located on the axis of the first mirror and the second mirror.

[0014] Optionally, in the nested air chamber according to the invention, the circumference of the concave mirror is located between the two innermost circles of the concentric circular light spots.

[0015] Optionally, in the nested air chamber according to the invention, light rays incident through the entrance hole are adapted to be reflected multiple times between the first mirror and the second mirror before exiting from the entrance hole.

[0016] Optionally, in the nested air chamber according to the present invention, the range of the inter-mirror distance d between the first mirror and the second mirror is: d < 2R1, where R1 represents the radius of curvature of the concave mirror.

[0017] According to one aspect of the present invention, a method for determining the formation of concentric circular light spots in a nested air chamber is provided, executed in a computing device, wherein the nested air chamber is as described above, the method comprising: establishing an optical model of the nested air chamber based on mirror parameters of a first mirror and a second mirror of the nested air chamber; constructing an array of mirror distances for the mirror distances between the first mirror and the second mirror based on a predetermined mirror distance interval; constructing an array of incident angles for the incident angles of light based on a predetermined angular interval; and for each mirror distance in the array of mirror distances and each incident angle in the array of incident angles... Angle is set, the light rays are incident from a predetermined incident point, and the concentric circular light spots formed by the light rays on the first and second mirror surfaces are determined according to the optical model; concentric circular light spots with a number of concentric circles within a predetermined number of circles and a circle spacing within a predetermined circle spacing are selected as candidate concentric circular light spots, and a set of candidate concentric circular light spots is generated based on all candidate concentric circular light spots; the optical path length corresponding to each candidate concentric circular light spot is determined according to the optical model, so as to select the candidate concentric circular light spot that meets the fixed optical path length condition as the optimal concentric circular light spot.

[0018] Optionally, in the method for determining the formation of concentric circular light spots in nested air chambers according to the present invention, selecting concentric circular light spots whose number of concentric circular light spots is within a predetermined number of concentric circular light spots and whose circular spacing is within a predetermined circular spacing range as candidate concentric circular light spots includes: selecting concentric circular light spots whose number of concentric circular light spots is within a predetermined number of concentric circular light spots, whose circular spacing is within a predetermined circular spacing range, and whose corresponding number of reflections is within a predetermined number of reflections range as candidate concentric circular light spots.

[0019] Optionally, in the method for determining the formation of concentric circular light spots in the nested air chamber according to the present invention, selecting concentric circular light spots whose number of rings n is within a predetermined number of rings and whose inter-circular spacing is within a predetermined inter-circular spacing range as candidate concentric circular light spots includes: selecting concentric circular light spots whose major axis of the ellipse containing the unit semi-elliptical light spot is smaller than the radius of the outer concave mirror as initial concentric circular light spots; and selecting concentric circular light spots from all initial concentric circular light spots whose number of rings is within a predetermined number of rings and whose inter-circular spacing is within a predetermined inter-circular spacing range as candidate concentric circular light spots.

[0020] Optionally, in the method for determining the formation of concentric circular light spots in nested air chambers according to the present invention, setting the light rays to be incident from a predetermined incident point and determining the concentric circular light spots formed by the light rays on the first mirror and the second mirror according to the optical model includes: setting the light rays to be incident from the predetermined incident point, exiting from the predetermined incident point, and determining the concentric circular light spots formed by the light rays on the first mirror and the second mirror according to the optical model.

[0021] According to one aspect of the present invention, a computing device is provided, comprising: at least one processor; and a memory storing program instructions, wherein the program instructions are configured to be executed by the at least one processor, the program instructions including instructions for performing the methods described above.

[0022] According to one aspect of the present invention, a readable storage medium storing program instructions is provided, which, when read and executed by a computing device, causes the computing device to perform the method described above.

[0023] This invention provides a nested gas chamber and a method for determining the formation of concentric circular light spots within the nested gas chamber. The nested gas chamber has two coaxially arranged mirrors facing each other. Each mirror includes a coaxially nested outer concave mirror and an inner concave mirror. After light enters the nested gas chamber, it undergoes multiple reflections to form concentric circular light spots on the two mirrors. By forming concentric circular light spot patterns on the two mirrors of the nested gas chamber, the axial symmetry and rotational symmetry of the concentric circular light spots ensure uniform distribution on the mirrors, high mirror utilization, and improved optical path-to-volume ratio, thereby enhancing detection sensitivity. Furthermore, the beam quality is high and stability is good. Additionally, the distance between the two mirrors can be set relatively large, making it suitable for long optical paths. Moreover, the method for determining the formation of concentric circular light spots within the nested gas chamber according to this invention can determine various patterns of concentric circular light spots that can be formed in a multi-reflector gas chamber. Thus, in practical applications, the optimal concentric circular light spot pattern can be selected based on the required optical path conditions.

[0024] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0025] To achieve the foregoing and related objectives, certain illustrative aspects are described herein in conjunction with the following description and accompanying drawings. These aspects indicate various ways in which the principles disclosed herein may be practiced, and all aspects and their equivalents are intended to fall within the scope of the claimed subject matter. The foregoing and other objectives, features, and advantages of this disclosure will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings. Throughout this disclosure, the same reference numerals generally refer to the same parts or elements.

[0026] Figure 1 A structural block diagram of a computing device 100 according to an embodiment of the present invention is shown;

[0027] Figure 2 A schematic diagram of the structure of a nested air chamber 200 according to an embodiment of the present invention is shown;

[0028] Figure 3a A schematic projection of a nested air chamber 200 along the xz direction is shown according to an embodiment of the present invention;

[0029] Figure 3b A schematic projection of a nested air chamber 200 along the xy direction is shown according to an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the Herriott air chamber is shown.

[0031] Figures 5a-5c A schematic diagram illustrating the principle of nested air chambers forming concentric circular light spots is shown.

[0032] Figure 6 A schematic diagram of concentric circular light spots with the same total number of reflections but different density of light spot distribution is shown in one embodiment of the present invention;

[0033] Figure 7 A schematic diagram of concentric circular light spots corresponding to the same major axis A value of the ellipse, similar number of reflections, and different (n, K, m) according to an embodiment of the present invention is shown.

[0034] Figure 8 This shows that the incident angle of the incident light is shifted in the positive y-axis direction, causing the second point P1 to change by +0.01A in the y-direction. Figure 7 A schematic diagram illustrating the changes in the concentric circular light spot pattern;

[0035] Figure 9 A flowchart illustrating a method 900 for determining the formation of concentric circular light spots in nested air chambers according to an embodiment of the present invention is shown. Detailed Implementation

[0036] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0037] According to the multi-reflection chamber proposed in this invention, the two side mirrors are arranged coaxially opposite each other. Each side mirror includes a coaxially nested outer concave mirror and an inner concave mirror. After light enters the nested chamber, it undergoes multiple reflections to form concentric circular light spots on the two side mirrors. Based on the axial symmetry and rotational symmetry of the concentric circular light spots, the light spots are evenly distributed on the mirrors, resulting in high mirror utilization and improving the optical path-to-volume ratio. Furthermore, in the method for determining the formation of concentric circular light spots within the nested chamber in this invention, a computational device is used to perform an extended analysis of the types of concentric circular light spots that can be formed by the nested chamber of this invention, so as to select the optimal concentric circular light spot pattern according to the actual optical path conditions required in practical applications. An example of a computational device is shown below.

[0038] Figure 1 A structural block diagram of a computing device 100 according to an embodiment of the present invention is shown.

[0039] like Figure 1 As shown, in the basic configuration 102, the computing device 100 typically includes system memory 106 and one or more processors 104. Memory bus 108 can be used for communication between processor 104 and system memory 106.

[0040] Depending on the desired configuration, processor 104 can be any type of processor, including but not limited to: microprocessor (μP), microcontroller (μC), digital information processor (DSP), or any combination thereof. Processor 104 may include one or more levels of cache such as L1 cache 110 and L2 cache 112, processor core 114, and registers 116. Example processor core 114 may include an arithmetic logic unit (ALU), floating-point unit (FPU), digital signal processing core (DSP core), or any combination thereof. Example memory controller 118 may be used with processor 104, or in some implementations, memory controller 118 may be an internal part of processor 104.

[0041] Depending on the desired configuration, system memory 106 can be any type of memory, including but not limited to volatile memory (such as RAM), non-volatile memory (such as ROM, flash memory, etc.), or any combination thereof. System memory 106 may include operating system 120, one or more applications 122, and program data 124. In some embodiments, application 122 may be arranged to execute instructions on the operating system using program data 124 by one or more processors 104.

[0042] The computing device 100 may also include an interface bus 140 that facilitates communication from various interface devices (e.g., output devices 142, peripheral interfaces 144, and communication devices 146) to the basic configuration 102 via a bus / interface controller 130. Example output devices 142 include a graphics processing unit 148 and an audio processing unit 150. They may be configured to facilitate communication with various external devices such as displays or speakers via one or more A / V ports 152. Example peripheral interfaces 144 may include a serial interface controller 154 and a parallel interface controller 156, which may be configured to facilitate communication with external devices such as input devices (e.g., keyboards, mice, pens, voice input devices, touch input devices) or other peripherals (e.g., printers, scanners, etc.) via one or more I / O ports 158. Example communication devices 146 may include a network controller 160, which may be arranged to facilitate communication with one or more other computing devices 162 via a network communication link through one or more communication ports 164.

[0043] A network communication link can be an example of a communication medium. A communication medium can typically be embodied in a modulated data signal, such as a carrier wave or other transmission mechanism, and can include any information delivery medium. A “modulated data signal” can be a signal whose data set, or whose modifications, can be encoded with information within the signal. As a non-limiting example, a communication medium can include wired media such as wired networks or leased lines, and various wireless media such as sound, radio frequency (RF), microwave, infrared (IR), or other wireless media. The term “computer-readable medium” as used herein can include both storage media and communication media.

[0044] The computing device 100 can be implemented as a personal computer, including desktop and laptop computer configurations. Of course, the computing device 100 can also be implemented as part of a small-sized portable (or mobile) electronic device, such as a cellular phone, digital camera, personal digital assistant (PDA), personal media player device, wireless network browsing device, personal head-mounted device, application-specific device, or a hybrid device that may include any of the above functions. It can even be implemented as a server, such as a file server, database server, application server, and web server. The embodiments of the present invention do not limit this.

[0045] In an embodiment of the invention, computing device 100 is configured to execute a method 900 according to the invention for determining the formation of concentric circular light spots in nested air chambers. Application 122 of computing device 100 includes multiple program instructions for executing the method 900 according to the invention for determining the formation of concentric circular light spots in nested air chambers.

[0046] Figure 2 A schematic diagram of the structure of a nested air chamber 200 according to an embodiment of the present invention is shown. Figure 3a A schematic projection of a nested air chamber 200 along the xz direction according to an embodiment of the present invention is shown. Figure 3b A schematic projection of a nested air chamber 200 along the xy direction is shown according to an embodiment of the present invention.

[0047] like Figure 2 , Figure 3a As shown, the nested air chamber 200 includes a first mirror 210 and a second mirror 220 arranged coaxially opposite to each other. The first mirror 210 and the second mirror 220 each include a coaxially nested outer concave mirror and an inner concave mirror, both of which are circular. Specifically, the concave mirror can be a concave spherical reflector.

[0048] See Figure 2 This invention establishes a coordinate axis with the midpoint of the line connecting the geometric centers of the first mirror 210 and the second mirror 220 (i.e., the axis along which they lie) as the origin O, and with the straight line connecting the geometric centers of the first mirror 210 and the second mirror 220 as the z-axis. Figure 3b It can be seen that the projected shapes (projected shapes along the xy direction) of the first mirror 210 and the second mirror 220 are circular.

[0049] In one embodiment of the present invention, the mirror parameters (including radius of curvature and size) of the first mirror 210 and the second mirror 220 are the same. Therefore, the first mirror 210 and the second mirror 220 are symmetrically arranged on both sides. Correspondingly, the concave mirror in the first mirror 210 and the concave mirror in the second mirror 220 are symmetrical to each other and have the same mirror parameters, and the concave mirror in the first mirror 210 and the concave mirror in the second mirror 220 are symmetrical to each other and have the same mirror parameters. Specifically, the radius of curvature of the concave mirror on each side can be represented as R1, and the size radius can be represented as r1; the radius of curvature of the concave mirror can be represented as R2, and the size radius can be represented as r2.

[0050] According to the nested air chamber 200 of the present invention, an entrance hole is provided on the first mirror 210 or the second mirror 220. Light rays incident through the entrance hole can be reflected multiple times between the first mirror 210 and the second mirror 220 before exiting. Furthermore, as... Figure 2 As shown, after multiple reflections, light can form concentric circular light spots on the first mirror 210 and the second mirror 220. Here, according to the principle of reversibility of light, light can form concentric circular light spots on the first mirror 210 and the second mirror 220 respectively, and the concentric circular light spots formed on the first mirror 210 and the second mirror 220 are symmetrical to each other.

[0051] It should be noted that the concentric circular light spot includes multiple light spots (i.e., reflection points) distributed on the concentric circles. Here, the present invention does not limit the number of concentric circles, which may be, for example, n. In other words, all the light spots in the concentric circular light spot are distributed on concentric circles (with n concentric circles). In addition, the center of the concentric circles is located on the axis of the first mirror 210 and the second mirror 220 (i.e., the z-axis connecting the geometric centers).

[0052] In one embodiment of the present invention, such as Figure 2 , Figure 3a As shown, the first mirror surface 210 includes a first concave outer mirror 211 and a first concave inner mirror 212 coaxially nested together. A first central hole is formed at the center of the first concave outer mirror 211, and the first concave inner mirror 212 is nested within this central hole, thus enabling the first concave outer mirror 211 and the first concave inner mirror 212 to be coaxially nested together, forming a complete first mirror surface 210. Here, the radius of curvature of the first concave outer mirror 211 can be represented as R1, and its dimensional radius can be represented as r1. The radius of curvature of the first concave inner mirror 212 can be represented as R2, and its dimensional radius can be represented as r2.

[0053] The second mirror 220 includes a second concave outer mirror 221 and a second concave inner mirror 222, which are coaxially nested. Since the mirror parameters of the first mirror 210 and the second mirror 220 are the same and symmetrical, the mirror parameters (radius of curvature and radius of dimension) of the second concave outer mirror 221 are the same as those of the first concave outer mirror 211, and they are symmetrically arranged; similarly, the mirror parameters (radius of curvature and radius of dimension) of the second concave inner mirror 222 are the same as those of the first concave inner mirror 212, and they are symmetrically arranged.

[0054] In other words, the second mirror surface 220 includes a second outer concave mirror 221 and a second inner concave mirror 222 coaxially nested together. A second central hole is formed at the center of the second outer concave mirror 221, and the second inner concave mirror 222 is nested within this central hole, thus enabling the second outer concave mirror 221 and the second inner concave mirror 222 to be coaxially nested together, forming a complete second mirror surface 220. Here, the radius of curvature of the second outer concave mirror 221 can also be expressed as R1, and the dimensional radius of the second outer concave mirror 221 can be expressed as r1. The radius of curvature of the second inner concave mirror 222 can be expressed as R2, and the dimensional radius of the second inner concave mirror 222 can be expressed as r2.

[0055] In addition, such as Figure 3a As shown, C1, C2, C3, and C4 are the curvature centers of the first concave mirror 211, the first concave mirror 212, the second concave mirror 221, and the second concave mirror 222, respectively.

[0056] It should be noted that in other embodiments, concave mirrors and concave mirrors with different radii of curvature can also be realized on the first mirror surface and the second mirror surface by machine grinding, thus eliminating the need for drilling holes.

[0057] In one embodiment of the invention, after light is reflected by two concave mirrors on both sides (between the first concave mirror 211 and the second concave mirror 221), a unit semi-elliptical light spot can be formed on the first mirror surface 210 and the second mirror surface 220. Then, after light is reflected by two concave mirrors on both sides (between the first concave mirror 212 and the second concave mirror 222), the unit semi-elliptical light spot can rotate multiple times around its center of curvature, thereby forming multiple semi-elliptical light spots that are rotationally symmetrical to the (initially formed) unit semi-elliptical light spot on the first mirror surface 210 and the second mirror surface 220. Thus, based on all the semi-elliptical light spots formed above, concentric circular light spots (containing a total of K semi-elliptical light spots) can be combined to form a single circular light spot.

[0058] It should be pointed out that the concentric circular light spot pattern is an axially symmetric and rotationally symmetric figure. The axially symmetric and rotationally symmetric figure makes the light spot evenly distributed on the mirror surface and the mirror surface utilization rate is high.

[0059] It is understandable that the specific distribution of concentric circular light spots can be determined based on the pattern of the unit semi-elliptical light spot and the number of rotations (the total number of semi-elliptical light spots). In other words, the pattern of the concentric circular light spots is jointly determined by the pattern of the unit semi-elliptical light spot and the number K of the semi-elliptical light spots.

[0060] It should be noted that the present invention does not limit the position of the light emission point. For example, an emission hole can be opened on the first mirror 210 or the second mirror 220. The light rays that enter through the emission hole can be reflected multiple times between the first mirror 210 and the second mirror 220 and then exit from the emission hole on the first mirror 210 or the second mirror 220.

[0061] In one embodiment, light rays incident through the entrance aperture are adapted to undergo multiple reflections between the first mirror surface 210 and the second mirror surface 220 before exiting through the entrance aperture. Thus, the light rays satisfy the re-entry condition, meaning the exit point and incident point of the light rays coincide. It can be understood that when the re-entry condition is met, the concentric circular light spots formed on both mirror surfaces are identical. Furthermore, for re-entering concentric circular light spots, the light spots are evenly distributed on the mirror surfaces, resulting in higher mirror surface utilization.

[0062] To explain the principle of forming concentric circular light spots on the mirrors on both sides of the nested gas chamber, the principle of the Herriott gas chamber will be explained first below.

[0063] Figure 4 A schematic diagram of the Herriott chamber (double spherical mirror chamber) is shown.

[0064] like Figure 4 As shown, the Herriott chamber comprises two coaxially placed spherical mirrors. When the radii of curvature of the two spherical mirrors are the same, if the light ray incident on the chamber along the paraxial direction intersects the mirror surface at point P... i Furthermore, the projections of all intersection points (reflection points) onto the mirror surface form elliptical or circular light spot patterns. Here, intersection point P... i The coordinates are represented as (x i ,y i ), where the indices i represent the i-th reflection, then the coordinates of the intersection point (x i ,y i The initial incident point coordinates P0(x0,y0), incident angle θ, first reflection point coordinates P1(x1,y1), distance d between the two mirrors, and radius of curvature R can be expressed as follows:

[0065]

[0066]

[0067] Among them, according to the following formula:

[0068] cosθ=1-d / R. (3)

[0069] Formulas (1) and (2) can be rewritten as:

[0070] x i =Asin(iθ+γ) (4)

[0071] y i =βsin(iθ+β) (5)

[0072] The parameters (A, B, β, γ) in formulas (4) and (5) can be represented by six variables (x0, y0, x1, y1, d, R). When the incident angle θ and the total number of reflections i total When the product of and is an integer multiple of 2π, it is expressed by the following formula:

[0073] i total θ=2kpi, (6)

[0074] So, light passes through i total After the second reflection, the light eventually returns to the incident light position P0, satisfying the reentry condition.

[0075] Furthermore, when the curvatures of the two spherical mirrors are different, the coordinates of point jth can no longer be described by formulas (4) and (5), but can only be obtained by a single reflection, i.e.:

[0076]

[0077]

[0078] Wherein, the radius of curvature R is the radius of curvature of the mirror at the (j-1)th reflection point.

[0079] According to formula (3), cosθ and sinθ are expressed in terms of d and R, and substituted into formulas (6) and (7), formulas (6) and (7) can be simplified to:

[0080]

[0081]

[0082] According to formulas (9) and (10), the coordinates of the point reflected by a spherical mirror of arbitrary curvature can be obtained from the coordinates of the (j-1)th reflection point P. j-1 The coordinates of the reflection point P (j-2)th j-2 P j-2 The radius of curvature P of the spherical mirror at a given location and the distance d between the mirrors are represented by this.

[0083] Figures 5a-5cA schematic diagram illustrating the principle of nested air chambers forming concentric circular light spots is shown.

[0084] The following will combine Figures 5a-5c This will explain the principle of forming concentric circular light spots on the mirrors on both sides of the nested air chamber.

[0085] As described above, when light undergoes multiple reflections within a double-spherical mirror chamber with a radius of curvature R1, a complete elliptical light spot can be formed on both mirror surfaces. For example... Figure 5a As shown, for ease of calculation, the complete elliptical light spot is required to be symmetrical about its major and minor axes. The symmetry ensures that every four reflection points (light spots) in the elliptical light spot are located on the same circle centered at the origin, forming a total of n concentric circles. Therefore, the total number of reflections corresponding to the above elliptical light spot is 4n.

[0086] Considering the case where there are no other reflection points between two consecutive reflection points, i.e., the case where k=1 in formula (6), and setting the initial point P0 at the point in the first quadrant on the outermost circle, then the 1st to nth reflection points are exactly located on the 1st to nth concentric circles (from the outside to the inside). According to the intersection point P of formulas (4) and (5) i Projected coordinates on the mirror surface (x i ,y i This can be represented as:

[0087]

[0088]

[0089] in:

[0090]

[0091] A and B represent the major and minor axes of the ellipse containing the unit semielliptical light spot, respectively. The radius of curvature R1 of the concave mirror is related to the distance d between the two mirrors and the incident angle θ by the following equation:

[0092]

[0093] It should be noted that the radius of the concave mirror must meet the following condition: the radius (r1) of the concave mirror should be greater than the major axis (A) of the ellipse containing the unit semi-elliptical light spot. That is, r1 > A.

[0094] like Figure 5a As shown, the unit semi-elliptical light spot formed by the light rays on the concave mirror is symmetrical about the major axis of the ellipse, and the unit semi-elliptical light spot contains a total of 2n reflection points (formed on the two mirrors).

[0095] like Figure 5bAs shown, the symmetry and rotation of a unit semi-elliptical light spot can be achieved by reflecting the light through a concave mirror. The straight line l in the figure is the axis of symmetry, and the angle α is the rotation angle.

[0096] Figure 5c The diagram shows a concentric circular light spot pattern with k = 5, m = 2, and α = 4π / 5.

[0097] As can be understood from the above, in the nested air chamber 200 of the present invention, light can form a unit semi-elliptical light spot after being reflected by the outer concave mirror, and after being reflected by the inner concave mirror, the unit semi-elliptical light spot can rotate multiple times around the center of curvature, thereby continuing to form multiple semi-elliptical light spots that are rotationally symmetrical to the (initially formed) unit semi-elliptical light spot on the first mirror surface 210 and the second mirror surface 220. In this way, concentric circular light spots can be obtained by combining all the semi-elliptical light spots.

[0098] Within a single semi-elliptical light spot, every four light spots (reflection points) that are symmetrical about the major and minor axes of the ellipse are located on the same circle centered at the origin.

[0099] A single semi-elliptical light spot contains 2n light spots. The total number of reflections (i.e., the total number of reflection points contained in a concentric circular light spot) is 2nk. Here, n represents the number of concentric circular light spots, and k represents the number of semi-elliptical light spots contained in a concentric circular light spot.

[0100] It can be understood that each concentric circle has 4 reflection points of a complete elliptical light spot. Therefore, a complete elliptical light spot includes 4n reflection points (corresponding to 4n reflection times), and a unit semi-elliptical light spot includes 2n reflection points.

[0101] It should also be noted that, according to an embodiment of the present invention, the circumference of the concave mirror (radius r2) should be located at the midpoint between the two innermost circles of the concentric circular light spot (i.e., the midpoint between the nth and (n-1)th circles). That is, the following equation is satisfied. Let be the distance from the i-th point to the center of the mirror. It should be noted that the n-th point is the intersection point formed when the light beam first reaches the concave mirror, which, after reflection, produces a new reflection point P'. i When the nth point and the (n+1)th point are equidistant from the axis, the two semi-elliptical light spots formed according to the principle of reversibility of light are axially symmetric. Furthermore, since the semi-elliptical light spots themselves are also axially symmetric, these two semi-elliptical light spots have a rotational symmetry relationship (see [link to article]). Figure 5b This symmetry ensures that the semi-elliptical light spot can rotate multiple times.

[0102] The new coordinates of point (n+1) P′ n+1 (x′n+1 ,y′ n+1 The reflection points (n-1)th and nth can be represented by the radius of curvature R2 of the concave mirror and the distance d between the first mirror 210 and the second mirror 220:

[0103]

[0104]

[0105] like Figure 5b As shown, based on the rotational symmetry between the two semi-elliptical light spots, semi-elliptical light spot 1 can coincide with semi-elliptical light spot 2 by rotating it about the z-axis by α, P′ n+1 The coordinates can be represented as:

[0106] x′ n+1 =x 3n+1 cosα-y 3n+1 sinα (17)

[0107] y′ n+1 =x 3n+1 sinα+y 3n+1 cosα (18)

[0108] Combine equations (15)(16) with equations (17)(18), and use equations (11)(12) to determine the position coordinates (x). i ,y i Let (A, B, θ) represent the concave mirror. Finally, the relationship between the radius of curvature R² of the concave mirror and the ratio B / A of the minor and major axes of the ellipse can be solved as follows:

[0109]

[0110]

[0111] Since |B / A| < 1, and the stability condition is d < 2R, therefore:

[0112]

[0113] To satisfy the reentrancy condition, the product of the angular interval α between any two consecutive semi-elliptical light spots and the integer K should be an integer multiple of 2π, i.e., satisfying the following formula:

[0114] Kα=2mπ, (21)

[0115] Where K and m are coprime. The angular interval between two adjacent semi-ellipses is 2π / K. Two consecutive semi-elliptical light spots are separated by m angular intervals (m-1 semi-ellipses). The angle α between two consecutive semi-elliptical light spots is 2mπ / K. Figure 5cThe image shows the re-entry concentric circular light spot pattern when K=5, m=2, α=4π / 5.

[0116] In summary, the parameters (r1, r2, R1, R2, P0, P1) of the nested air chambers can all be represented by variables (A, α, θ, d). Variables A, α, and θ are parameters that characterize the features of concentric circular light spots. They respectively characterize the size of the pattern, the density of the dots, and the number of concentric circles.

[0117] According to the above formula As can be seen from the formula Kα=2mπ, α and θ can be expressed as functions of (n,K,m). Therefore, in the process of nested air chamber design, appropriate air chamber parameters can be selected for air chamber design based on the specific concentric circular light spot pattern.

[0118] It should be noted that mirror utilization, beam quality of the emitted light, and mechanical robustness of the gas chamber are important indicators for evaluating the application of a gas chamber in TDLAS gas measurement. Higher mirror utilization can improve the accuracy of gas detection, while the mechanical robustness of the gas chamber measures its ability to maintain equipment performance under environmental changes. Therefore, these are important issues to consider in the practical application of gas chambers. Based on the correspondence between the characteristic parameters of the concentric circular spot and the gas chamber parameters described above, the major axis A of the parameter ellipse only proportionally scales the spot size and does not affect gas chamber performance such as mirror utilization. Therefore, the following section explores the impact of the characteristic parameters (n, K, m) of the concentric circular spot on gas chamber performance and presents the results clearly and intuitively through numerical simulation.

[0119] High mirror utilization can improve the optical path-to-volume ratio while avoiding spot overlap, and is mainly determined by the total number of spots and their distribution on the mirror. The total reflection number corresponding to concentric circular spots is obtained by multiplying the number of spots 2n contained in a unit semi-elliptical spot by the number of semi-elliptical spots K, i.e., i total =2nK. When the number of semi-elliptical light spots K is constant, the larger the number of concentric circular light spots n, the more light spots 2n are on a unit semi-elliptical light spot, and the more reflections are performed. When the number of light spots 2n contained in a unit semi-elliptical light spot and the number of semi-elliptical light spots K are constant, that is, under the same number of reflections, if the ratio of the major and minor axes B / A of the ellipse containing the unit semi-elliptical light spot is different, the pattern distribution of the concentric circular light spots will also be different (the spacing between the concentric circles will be different).

[0120] Figure 6The illustration shows concentric circular light spots with the same total number of reflections but different density of light spot distribution according to one embodiment of the present invention. The reason for the different mirror utilization rates of the concentric circular light spots is that the value of the variable B / A is a function of the rotation angle α. Based on the re-entry condition, and according to the formula Kα = 2mπ, when the number K of semi-elliptical light spots is determined, the light spots may correspond to multiple re-entry modes.

[0121] Taking n=4 and K=11 as an example, the value of m can be from 2 to 5. Figure 6 The image shows the concentric circular spot patterns under different re-entry conditions when m takes values ​​of 2, 3, 4, and 5. It can be seen that when m is as close to K as possible within its range, the smaller the corresponding B / A value, the larger the intercircular spacing of the concentric circular spots, the more uniform the spot distribution, and the higher the mirror utilization rate.

[0122] in addition, Figure 7 The illustration shows a pattern of concentric circular light spots with the same major axis A value, similar number of reflections, and different (n, K, m) according to an embodiment of the present invention, wherein the corresponding number of reflections are 128, 132, 128, and 130, respectively.

[0123] also, Figure 8 This shows that the incident angle of the incident light is shifted in the positive y-axis direction, causing the second point P1 to change by +0.01A in the y-direction. Figure 7 A schematic diagram illustrating the variation of the concentric circular light spot pattern. Similar results are observed when the incident angle deviates in other directions. It is evident that for the concentric circular light spot pattern that satisfies the re-entry condition, the stability of the outgoing light position is excellent, exhibiting strong anti-interference capabilities. However, for the overall light spot, a smaller n results in less overall spot deformation. Therefore, the number of concentric circular light spots, n, should not be chosen too large to avoid a decrease in the robustness of the gas chamber.

[0124] Based on this, the present invention proposes a method 900 for determining the formation of concentric circular light spots in nested air chambers.

[0125] Figure 9 A schematic flowchart of a method 900 for determining the formation of concentric circular light spots in a nested gas chamber according to an embodiment of the present invention is shown. The nested gas chamber is the nested gas chamber 200 as described above. The method 900 is adapted to be executed in a computing device (e.g., the aforementioned computing device 100).

[0126] like Figure 9 As shown, the method begins at step 910.

[0127] In step 910, an optical model of the nested air chamber is established based on the mirror parameters of the first mirror 210 and the second mirror 220 of the nested air chamber 200. Here, the mirror parameters of the first mirror 210 and the second mirror 220 are the same, as described above, including: the radius of curvature R1 and the size radius r1 of the outer concave mirror, and the radius of curvature R2 and the size radius r2 of the inner concave mirror.

[0128] Subsequently, in step 920, an array of inter-mirror distances d between the first mirror 210 and the second mirror 220 can be constructed based on a predetermined inter-mirror distance interval. In one embodiment, the inter-mirror distance d can be in the range of d < 2R1, where R1 represents the radius of curvature of the concave mirror.

[0129] In step 930, an incident angle array can be constructed for the incident angle θ of the light rays based on a predetermined angular interval.

[0130] Next, in step 940, for each inter-mirror distance in the inter-mirror distance array and each incident angle in the incident angle array, the light can be set to enter from a predetermined incident point, and the pattern of the concentric circular light spots formed by the light on the first mirror and the second mirror can be determined according to the optical model established above.

[0131] Next, in step 950, from all the concentric circular light spots of the various patterns determined above, concentric circular light spots with the number of rings n within a predetermined number of rings and the inter-circle spacing within a predetermined inter-circle spacing range can be selected. All concentric circular light spots selected according to the above conditions are taken as candidate concentric circular light spots, and a candidate concentric circular light spot set is generated based on all candidate concentric circular light spots.

[0132] Here, the predetermined circle spacing range is set based on the following: when the re-entry condition is met, m should be as close to K as possible within the range of values. The smaller the corresponding B / A value, the larger the circle spacing of the concentric circular light spots, which can make the light spot distribution more uniform and the mirror utilization rate higher.

[0133] Finally, in step 960, the optical path length corresponding to each candidate concentric circular spot in the candidate concentric circular spot set is determined according to the above optical model, and then the candidate concentric circular spot that meets the fixed optical path condition can be selected as the optimal concentric circular spot.

[0134] Here, it can be understood that candidate concentric circular light spots that meet the optical path conditions can be candidate concentric circular light spots whose corresponding optical path is within the target optical path range. The target optical path range can be set according to actual needs, and by reasonably setting the target optical path range, the optical path-to-volume ratio of the nested gas chambers can be made as high as possible.

[0135] In one embodiment, the selection criteria for candidate concentric circular light spots can be further limited based on the number of reflections. As mentioned above, the number of reflections corresponding to a concentric circular light spot is 2nK (that is, the number of light spots contained in the concentric circular light spot), and the number of reflections can be set within a predetermined range. It can be understood that the number of reflections 2nK is related to the number of concentric circular light spots n and the number of semi-elliptical light spots K.

[0136] Specifically, in step 950, concentric circular light spots with the number of rings n within a predetermined number of rings, the inter-circular spacing within a predetermined inter-circular spacing, and the corresponding number of reflections 2nK within a predetermined number of reflections can be selected from all the concentric circular light spots of the various patterns determined above, as candidate concentric circular light spots.

[0137] Here, when setting the range of predetermined number of revolutions and the range of predetermined number of reflections, it is necessary to consider that when the number of reflections is similar, the larger the number of revolutions n of the concentric circular light spots, the more uniform the distribution of the light spots in each revolution, and the larger the spacing between the light spots. However, it should be noted that if n is too large, it will lead to a decrease in the robustness of the air chamber. Therefore, the value of the number of revolutions n should not be too large or too small. In addition, when setting the range of predetermined number of reflections, it is also necessary to consider the problem that too many reflections will lead to optical path overlap.

[0138] In other embodiments, the range of the number K of semi-elliptical spots (related to the rotation angle and m of the semi-elliptical spots) can also be directly defined. For example, from all the concentric circular spots of the various patterns determined above, concentric circular spots with the number of rings n within a predetermined number of rings, the inter-circular spacing within a predetermined inter-circular spacing, and the number K of semi-elliptical spots contained in the concentric circular spots within a predetermined number range can be selected as candidate concentric circular spots.

[0139] It should also be noted that in order to ensure that complete concentric circular light spots can be formed on both mirror surfaces, the basic conditions that need to be met include: the radius (r1) of the outer concave mirror should be greater than the major axis (A) of the ellipse in which the unit semi-elliptical light spot is located, that is, r1 > A.

[0140] Based on this, in one embodiment, in step 950, concentric circular spots whose major axis A of the ellipse containing the unit semi-elliptical spot is smaller than the radius r1 of the concave mirror can be selected as initial concentric circular spots (satisfying the above basic conditions). Furthermore, from all the initial concentric circular spots, concentric circular spots whose number of concentric circles n is within a predetermined range and whose inter-circular spacing is within a predetermined range can be selected as candidate concentric circular spots.

[0141] In this embodiment, concentric circular light spots can also be selected from all the initially selected concentric circular light spots. These concentric circular light spots have a number of rings n within a predetermined number of rings, a circular spacing between concentric circular light spots within a predetermined circular spacing, and a corresponding number of reflections 2nK within a predetermined number of reflections, and can be used as candidate concentric circular light spots.

[0142] In this embodiment, concentric circular spots can also be selected from all the initially selected concentric circular spots. These concentric circular spots have a number of rings n within a predetermined number of rings, a circle spacing within a predetermined circle spacing, and a number K of semi-elliptical spots included in the concentric circular spots within a predetermined number range, and can be selected as candidate concentric circular spots.

[0143] Furthermore, considering that the stability of the emitted light position is very good and the anti-interference ability is strong for the concentric circular light spot pattern that satisfies the re-entry condition, in one embodiment, in order to ensure that the re-entry condition is met, in step 940, for each inter-mirror distance in the inter-mirror distance array and each incident angle in the incident angle array, the light can be set to enter from a predetermined incident point and exit from the predetermined incident point, and the concentric circular light spot formed by the light on the first mirror and the second mirror is determined according to the optical model.

[0144] According to the nested gas chamber and the method for determining the formation of concentric circular light spots in the nested gas chamber of the present invention, the mirrors on both sides of the nested gas chamber are arranged coaxially opposite to each other. Each mirror includes an outer concave mirror and an inner concave mirror arranged coaxially nested. After light enters the nested gas chamber, it can form concentric circular light spots on the mirrors on both sides after multiple reflections. By forming concentric circular light spot patterns on the mirrors on both sides of the nested gas chamber, based on the axial symmetry and rotational symmetry of the concentric circular light spots, the light spots are evenly distributed on the mirrors, resulting in high mirror utilization and improving the optical path-to-volume ratio, thereby improving detection sensitivity. Furthermore, the beam quality is high and the stability is good. In addition, the distance between the mirrors on both sides can be set to be large, making it suitable for long optical paths. Moreover, according to the method for determining the formation of concentric circular light spots in the nested gas chamber of the present invention, various patterns of concentric circular light spots that can be formed in a multi-reflector gas chamber can be determined. Thus, in practical applications, the optimal concentric circular light spot pattern can be selected according to the actual required optical path conditions.

[0145] A8. A nested air chamber as described in any one of A1-A7, wherein light incident through the entrance aperture is adapted to be reflected multiple times between the first mirror and the second mirror before exiting from the entrance aperture.

[0146] A9. The nested air chamber as described in any one of A1-A8, wherein the distance d between the first mirror and the second mirror is in the range of d < 2R1, where R1 represents the radius of curvature of the concave mirror.

[0147] B11. The method as described in B10, wherein selecting concentric circular spots whose number of concentric circular spots is within a predetermined number of circles and whose inter-circular spacing is within a predetermined inter-circular spacing range as candidate concentric circular spots includes: selecting concentric circular spots whose number of concentric circular spots is within a predetermined number of circles, whose inter-circular spacing is within a predetermined inter-circular spacing range, and whose corresponding number of reflections is within a predetermined number of reflections range as candidate concentric circular spots.

[0148] B12. The method as described in B10 or B11, wherein selecting concentric circular spots whose number of concentric circular spots n is within a predetermined number of concentric circles and whose inter-circular spacing is within a predetermined inter-circular spacing range as candidate concentric circular spots includes: selecting concentric circular spots whose major axis of the ellipse containing the unit semi-elliptical spot is smaller than the radius of the concave mirror as initial concentric circular spots; and selecting concentric circular spots from all initial concentric circular spots whose number of concentric circular spots is within a predetermined number of concentric circles and whose inter-circular spacing is within a predetermined inter-circular spacing range as candidate concentric circular spots.

[0149] B13. The method of any one of B10-B12, wherein setting the light ray to be incident from a predetermined incident point and determining the concentric circular light spots formed by the light ray on the first mirror and the second mirror according to the optical model includes: setting the light ray to be incident from the predetermined incident point, exiting from the predetermined incident point, and determining the concentric circular light spots formed by the light ray on the first mirror and the second mirror according to the optical model.

[0150] The various techniques described herein can be implemented in combination with hardware or software, or a combination thereof. Thus, the methods and apparatus of the present invention, or certain aspects or portions thereof, can take the form of program code (i.e., instructions) embedded in a tangible medium, such as a removable hard disk, USB flash drive, floppy disk, CD-ROM, or any other machine-readable storage medium, wherein when the program is loaded into and executed by a machine such as a computer, the machine becomes an apparatus for practicing the present invention.

[0151] When the program code is executed on a programmable computer, the mobile terminal generally includes a processor, a processor-readable storage medium (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. The memory is configured to store program code; the processor is configured to execute, according to instructions in the program code stored in the memory, the method of the present invention for determining the formation of concentric circular light spots in nested air chambers.

[0152] By way of example, and not limitation, readable media include readable storage media and communication media. Readable storage media stores information such as computer-readable instructions, data structures, program modules, or other data. Communication media generally embodies computer-readable instructions, data structures, program modules, or other data in the form of modulated data signals such as carrier waves or other transmission mechanisms, and includes any information delivery medium. Any combination of the above is also included within the scope of readable media.

[0153] In the specification provided herein, the algorithms and displays are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used with the examples of this invention. The required structure for constructing such systems is apparent from the above description. Furthermore, this invention is not directed to any particular programming language. It should be understood that the contents of the invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the invention.

[0154] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0155] Similarly, it should be understood that, in order to streamline this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof.

[0156] Those skilled in the art will understand that modules, units, or components of the devices disclosed in the examples herein can be arranged in the devices described in this embodiment, or alternatively, can be located in one or more devices different from the devices in this example. The modules in the foregoing examples can be combined into a single module or, in addition, can be divided into multiple sub-modules.

[0157] Those skilled in the art will understand that the modules in the device of the embodiment can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiment can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components.

[0158] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention and form different embodiments.

[0159] Furthermore, some of the embodiments described herein are methods or combinations of method elements that can be implemented by a processor of a computer system or by other means of performing the functions. Therefore, a processor having the necessary instructions for implementing the methods or method elements forms means for implementing the methods or method elements. Furthermore, the elements described herein in the apparatus embodiments are examples of means for implementing the functions performed by elements for the purposes of carrying out the invention.

[0160] As used herein, unless otherwise specified, the use of ordinal numbers such as “first,” “second,” “third,” etc., to describe ordinary objects merely indicates different instances of similar objects and is not intended to imply that the objects being described must have a given order in time, space, ordering, or any other manner.

[0161] Although the invention has been described with respect to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and edibility purposes, and not for the purpose of explaining or limiting the subject matter of the invention.

Claims

1. A nested air chamber, comprising a first mirror and a second mirror arranged coaxially opposite to each other, wherein, The mirror parameters of the first mirror and the second mirror are the same; The first mirror and the second mirror each include a coaxially nested outer concave mirror and an inner concave mirror, both of which are circular. An entrance hole is provided on the first or second mirror surface. Light rays incident through the entrance hole are adapted to be reflected multiple times between the first and second mirror surfaces before being emitted, and are adapted to form concentric circular light spots on the first and second mirror surfaces. Wherein, after being reflected by the concave mirror, the light is adapted to form a unit semi-elliptical light spot on the first mirror surface and the second mirror surface, and after being reflected by the concave mirror, it is adapted to form a plurality of semi-elliptical light spots that are rotationally symmetrical with the unit semi-elliptical light spot on the first mirror surface and the second mirror surface, so as to form the concentric circular light spot based on the combination of all the semi-elliptical light spots.

2. The nested air chamber as described in claim 1, wherein, The first mirror includes a first outer concave mirror and a first inner concave mirror coaxially nested together, wherein the first outer concave mirror is provided with a first central hole, and the first inner concave mirror is nested in the first central hole; The second mirror includes a second outer concave mirror and a second inner concave mirror that are coaxially nested, wherein the second outer concave mirror has a second central hole, and the second inner concave mirror is nested in the second central hole.

3. The nested air chamber as described in claim 1, wherein, In the unit semi-elliptical light spot, every four light spots, symmetrical about the major and minor axes of the ellipse, are located on the same circle. The unit semi-elliptical light spot contains 2n light spots, where n represents the number of concentric circular light spots; The number of reflections corresponding to the concentric circular light spots is 2nk, where k represents the number of semi-elliptical light spots contained in the concentric circular light spots.

4. The nested gas chamber as described in any one of claims 1-3, wherein, The radius of the concave mirror is larger than the major axis of the ellipse containing the unit semi-elliptical light spot.

5. The nested gas chamber as described in any one of claims 1-3, wherein, All the light spots in the concentric circular light spots are distributed on concentric circles, and the center of the circle is located on the axis of the first mirror and the second mirror.

6. The nested gas chamber as described in any one of claims 1-3, wherein, The perimeter of the concave mirror is located between the two innermost circles of the concentric circular light spots.

7. The nested gas chamber as described in any one of claims 1-3, wherein, The light rays incident through the entrance aperture are adapted to undergo multiple reflections between the first mirror and the second mirror before exiting through the entrance aperture.

8. The nested gas chamber as described in any one of claims 1-3, wherein, The range of the distance d between the first mirror and the second mirror is: d < 2R1, where R1 represents the radius of curvature of the concave mirror.

9. A method for determining the formation of concentric circular light spots in a nested air chamber, performed in a computing device, said nested air chamber being a nested air chamber as described in any one of claims 1-8, the method comprising: An optical model of the nested air chamber is established based on the mirror parameters of the first and second mirrors of the nested air chamber. Based on the predetermined inter-mirror distance interval, construct an inter-mirror distance array for the inter-mirror distance between the first mirror and the second mirror; Based on a predetermined angular interval, construct an array of incident angles for the incident angles of light rays; For each inter-mirror distance in the inter-mirror distance array and each incident angle in the incident angle array, the light is set to enter from a predetermined incident point, and the concentric circular light spots formed by the light on the first and second mirror surfaces are determined according to the optical model. Concentric circular light spots with a number of concentric circles within a predetermined range and a circle spacing within a predetermined range are selected as candidate concentric circular light spots. A set of candidate concentric circular light spots is generated based on all candidate concentric circular light spots. The optical path length corresponding to each candidate concentric circular spot is determined according to the optical model, so as to select the candidate concentric circular spot that meets the fixed optical path length condition as the optimal concentric circular spot.

10. The method of claim 9, wherein, Concentric circular light spots with a number of revolutions within a predetermined range and a spacing between them within a predetermined range are selected as candidate concentric circular light spots, including: Candidate concentric circular light spots are selected if the number of concentric circular light spots is within a predetermined range, the inter-circular spacing of the concentric circular light spots is within a predetermined range, and the corresponding number of reflections is within a predetermined range.

11. The method of claim 9, wherein, Concentric circular light spots whose number of revolutions (n) is within a predetermined range and whose inter-circular spacing is within a predetermined range are selected as candidate concentric circular light spots, including: Select concentric circular spots whose major axis of the ellipse containing the unit semi-elliptical spot is smaller than the radius of the concave mirror as the initial concentric circular spots. From all the initially selected concentric circular light spots, select concentric circular light spots whose number of concentric circles is within a predetermined range and whose inter-circular spacing is within a predetermined range, and these will be selected as candidate concentric circular light spots.

12. The method according to any one of claims 9-11, wherein, Setting the light to incident from a predetermined incident point, and determining the concentric circular light spots formed by the light on the first and second mirror surfaces according to the optical model, including: The light rays are set to enter from a predetermined incident point and exit from the predetermined incident point, and the concentric circular light spots formed by the light rays on the first mirror and the second mirror are determined according to the optical model.

13. A computing device, comprising: At least one processor; and A memory storing program instructions configured to be executed by the at least one processor, the program instructions including instructions for performing the method as described in any one of claims 9-12.

14. A readable storage medium storing program instructions that, when read and executed by a computing device, cause the computing device to perform the method as described in any one of claims 9-12.

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