Optical cavity enhanced reaction cavity structure

Abstract

This invention belongs to the field of reaction chamber technology, specifically relating to a photocavity-enhanced reaction chamber structure. It includes: a cavity defining an internal chamber for containing a flowing medium, the cavity having one or more openings allowing the flowing medium to flow in and / or out; and at least one light source disposed within or optically coupled to the internal chamber for emitting light into the internal chamber. This invention enables long-term light confinement of the reaction chamber, enhancing the interaction between the fluid and light within the chamber. This invention is suitable for applications such as water purification and photocatalysis. This invention eliminates the need for complex molding or extensive welding, while ensuring the structural integrity and reflectivity of the cavity. This invention achieves a more uniform irradiance distribution, which is a significant advantage in processes requiring high uniformity of irradiance dose.

Description

Technical Field

[0001] This invention belongs to the field of reaction cavity technology, and specifically relates to an optical cavity enhanced reaction cavity structure. Background Technology

[0002] In many industrial and scientific research fields, such as ultraviolet (UV) air / water disinfection, photocatalytic pollutant degradation, and high-sensitivity spectroscopic analysis, the core processes all rely on a key device—the reaction chamber. In these applications, the flowing gas or liquid medium needs to be fully irradiated with light within the reaction chamber to trigger physical, chemical, or biological reactions such as disinfection, catalysis, or detection. Therefore, the performance of the reaction chamber directly determines the efficiency, effectiveness, and energy consumption of the entire system.

[0003] Traditionally, these reaction chambers have mostly adopted simple geometric shapes, such as cuboids, cylinders, or straight tubes. Their design primarily considers mechanical strength, corrosion resistance, and ease of manufacturing, often neglecting their optical performance as "optical cavities." Typically, their inner walls are made of metals such as stainless steel, which have very low reflectivity in the ultraviolet or visible light bands.

[0004] This leads to a fundamental problem: when a light source (such as a UV LED) emits light inside the cavity, the light travels in almost random directions. On the low-reflectivity inner walls, the light often undergoes only a few reflections before its energy is absorbed by the walls, or worse, escapes directly through openings provided for fluid flow. As a result, most of the light energy is wasted without being effectively utilized, and the light distribution within the cavity is extremely uneven, with obvious bright and dark areas. This is like turning on a lamp in a rough, dimly lit room; most of the light is absorbed by the walls, and only a few corners are illuminated, resulting in very low overall luminous efficiency.

[0005] To address this problem, an intuitive approach is to increase the reflectivity of the inner walls, such as by using high-reflectivity aluminum or applying a special coating. However, for cavities with traditional, simple geometries, simply increasing reflectivity yields minimal results. This is because their shape determines the "fate" of light propagation—openings are the natural escape routes for light. No matter how high the wall reflectivity, after a few simple specular reflections, light will easily find the opening and escape directly. This is analogous to a square hall with smooth walls but an open door; no matter how reflective the walls are, a ball can easily bounce directly out of the doorway and cannot remain inside for long.

[0006] A deeper problem lies in the fact that the design of traditional reaction cavities does not follow the physical principles of "optical cavities." The core purpose of an ideal optical cavity is to confine light within a limited space as much as possible, forcing it to repeatedly pass through the working medium, thereby significantly increasing the effective path length (i.e., optical path) of the light's interaction with the medium. This requires precise geometric design to ensure that the light forms stable and predictable reflection trajectories, such as oscillating along a specific family of "caustic surfaces" or following a "quasi-periodic" path, thus systematically preventing light from directly hitting the opening. Traditional box-shaped or cylindrical structures completely lack this ability to guide and control light, and therefore cannot fundamentally improve light confinement efficiency.

[0007] In summary, existing reaction chambers suffer from a long-standing unresolved contradiction: openings are necessary for fluid exchange, but these openings also become major bottlenecks hindering light escape and performance improvement. Therefore, there is an urgent need in this field for an innovative reaction chamber design that can overcome this limitation geometrically. This design, through a special chamber shape, actively guides light through multiple, orderly reflections within the chamber, significantly extending its residence time, while still retaining necessary openings for free fluid passage, thereby truly achieving a multiplier effect on the efficiency of light-matter interaction. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a photocavity-enhanced reaction chamber structure. This invention enables long-term light confinement within the reaction chamber, enhancing the interaction between fluid and light within the chamber. This invention is applicable to water purification, photocatalysis, and other applications. This invention eliminates the need for complex molding or extensive welding, while ensuring the structural integrity and reflectivity of the chamber. This invention achieves a more uniform irradiance distribution, which is a significant advantage in processes requiring high uniformity of irradiance dose.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A cavity-enhanced reactive cavity structure, comprising:

[0011] A cavity defining an internal chamber for containing the flowing medium, the cavity having one or more openings allowing the flowing medium to flow in and / or flow out;

[0012] At least one light source, wherein the light source is disposed within the internal cavity or optically coupled to the internal cavity, is used to emit light into the internal cavity;

[0013] Wherein, at least one inner wall of the cavity is a reflective surface, which is formed by mirror polishing or coating the surface of the material constituting the cavity with a reflective coating;

[0014] Furthermore, the internal geometry of the cavity is configured as an optical cavity, and the geometry of the optical cavity is designed such that the light emitted by the light source and reflected between the reflective surfaces forms a constrained, non-directly escaping reflection path, thereby extending the average optical path of the light in the internal cavity.

[0015] Furthermore, the optical cavity's geometry is a single quadratic surface optical cavity structure based on ellipsoidal quadratic surface segments, wherein the ellipsoidal quadratic surface segments are selected from ellipsoidal surface portions capable of forming A-type or C-type caustic surfaces.

[0016] The A-type caustic surface is a double-leaf hyperboloid, corresponding to light rays oscillating in a single direction; the C-type caustic surface is a single-leaf hyperboloid, corresponding to light rays oscillating in two mutually perpendicular directions.

[0017] The cavity is formed by truncating a complete ellipsoidal surface and retaining one or more openings, such that light is constrained and reflected within the region defined by the segment of the ellipsoidal quadratic surface.

[0018] Furthermore, the optical cavity has a hybrid quadric surface optical cavity structure, which is a confocal system;

[0019] The confocal system includes a first reflective wall and a second reflective wall, wherein the first reflective wall and the second reflective wall are confocal elliptic surfaces sharing at least one common focus, or are a combination of an elliptic surface and a hyperboloid sharing at least one common focus;

[0020] In this process, the light rays that intersect with the area near the common focal point are repeatedly reflected between the first reflective wall and the second reflective wall.

[0021] Furthermore, the confocal system is specifically an elliptical-elliptical configuration, wherein the first reflective wall and the second reflective wall are both elliptical surfaces, and the two elliptical surfaces share two focal points, and the internal cavity is formed between the two elliptical surfaces.

[0022] Furthermore, the confocal system is specifically an elliptical-hyperbolic configuration, wherein the first reflective wall is an elliptical surface, the second reflective wall is a hyperbolic surface, and the elliptical surface and the hyperbolic surface share a focal point;

[0023] The hyperboloid is used to capture and reflect light rays incident at large angles toward the shared focal region.

[0024] Furthermore, the optical cavity has a hybrid quadric surface optical cavity structure, which is a quadric surface-planar hybrid system;

[0025] The internal cavity of the quadric surface-planar hybrid system has a profile in at least one cross section including at least one elliptical profile segment, which forms part or all of the reflective wall, while the remaining profile segments in the cross section are composed of straight line segments.

[0026] The reflective wall surface corresponding to the at least one elliptical contour segment is used to guide light to its focal area and reflect it back to the internal cavity.

[0027] Furthermore, the internal cavity of the quadratic surface-planar hybrid system has elliptical contour segments on two mutually perpendicular cross-sections, resulting in multiple elliptical contour walls within the internal cavity. The quadratic surface-planar hybrid system is constructed through the following steps: drawing an ellipse in a plane and truncating a portion of its arc segments to form a truncated elliptical contour; stretching the truncated elliptical contour along a direction perpendicular to the plane to form a first prism structure; rotating the first prism structure by a certain angle and splicing it with itself or other prism structures, and then removing the end face to form the internal cavity.

[0028] Furthermore, the optical cavity has a hybrid quadric surface optical cavity structure, which is a ball court-shaped system;

[0029] The court-shaped system includes a first ellipsoidal half and a second ellipsoidal half, which are obtained by dividing a complete ellipsoid along a plane perpendicular to its major axis.

[0030] The first ellipsoidal hemisphere and the second ellipsoidal hemisphere are arranged opposite each other, such that one focus of the first ellipsoidal hemisphere is opposite to one focus of the second ellipsoidal hemisphere, thereby forming the internal cavity, and light emitted from near one of the focuses is reflected toward the opposite focus.

[0031] Furthermore, the court-type system is a composite court configuration, wherein the first ellipsoidal hemisphere and the second ellipsoidal hemisphere are connected by an additional connecting structure, so that the reflection trajectory of light in the internal cavity exhibits chaotic characteristics, thereby achieving a more uniform irradiance distribution.

[0032] Furthermore, the cavity is integrally formed from a metal sheet through cutting and bending processes, and the thickness of the metal sheet is 0.2mm to 1.0mm;

[0033] The reflective surface is achieved by selecting a high-reflectivity metal as the material of the metal plate and / or by applying a high-reflectivity coating to the inner surface of the metal plate.

[0034] The light source is a light-emitting diode, a laser diode, or a discharge lamp, and is located within the internal cavity or at a position where its optical path can be coupled into the internal cavity through a window.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) In this invention, a reaction cavity based on a single quadratic surface integrates selected ellipsoidal segments to form A-type and / or C-type caustic surfaces; these ellipsoidal segments serve as reflective inner walls of the cavity, defining the internal chamber. By truncating and opening the ellipsoidal surface along a selected direction, one or more openings are formed while maintaining the light trajectory of the target caustic surface, enabling fluid exchange between the internal chamber and the outside. Placing one or more light sources at positions where their emitted light intersects with the caustic surface support area allows the reaction cavity to achieve long-term light confinement, enhancing the interaction between the fluid and light within the cavity.

[0037] (2) The confocal assembly of the present invention is used to design the reflective inner wall of the cavity, forming a hybrid quadratic surface optical cavity structure with at least one fluid flow opening. In some embodiments, two ellipsoids are aligned along their major axis, share a focal point, and form a central channel in the internal cavity as a flow path for the liquid; the confocal reflective surface around the channel can achieve strong light confinement, while the open structure allows water or other liquids to pass through smoothly without significantly interfering with the light field. The confocal system constructed by this configuration includes elliptical-elliptical and / or elliptical-hyperbolic layouts, which are particularly suitable for applications such as water purification and photocatalysis.

[0038] (3) The typical construction method of the multi-elliptical planar quadric surface-planar hybrid optical cavity of the present invention ultimately forms a quadric surface-planar hybrid system, whose internal cavity contains multiple elliptical contour walls (usually four), and the remaining boundaries are open or planar. Compared with a simple box cavity, this multi-elliptical planar geometry can significantly increase the number of light reflections and the average optical path length, thereby improving the irradiance of the internal cavity. This geometry can be physically prepared by thin metal plates, using a cutting-folding process to cut, bend, and splice the aluminum plates; it does not require complex molding or a large amount of welding, and can ensure the structural integrity and reflectivity of the cavity.

[0039] (4) The invention improves the light trajectory by connecting the two ellipsoidal halves with an additional square structure, which makes the light trajectory exhibit chaotic characteristics, manifested as non-periodic reflection and complex propagation path, and the light can explore most of the internal cavity area; the chaotic dynamics can reduce light intensity hotspots and achieve a more uniform irradiance distribution, which has a significant advantage in processes with high requirements for irradiance dose uniformity. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the caustic surface family in a triaxial ellipsoidal system of an optical cavity-enhanced reactive cavity structure according to the present invention.

[0041] Figure 2This is a schematic diagram of an elliptical coordinate system and a confocal ellipse and a confocal hyperbola structure for an optical cavity-enhanced reactive cavity structure according to the present invention.

[0042] Figure 3 This is a schematic diagram illustrating the step-by-step construction process of a multi-elliptical planar quadric surface-planar hybrid reaction cavity structure, which is a cavity-enhanced reaction cavity structure according to the present invention.

[0043] Figure 4 This is a schematic diagram of the hybrid quadric surface structure configuration of an optical cavity enhanced reaction cavity structure according to the present invention;

[0044] Figure 5 This is a schematic diagram showing the material characterization data of the reflective surface used in the prototype of the optical cavity enhanced reaction cavity structure of the present invention.

[0045] Figure 6 This is a schematic diagram comparing the optical confinement effect / ray tracing of an elliptical-planar reactive cavity and a rectangular box-type reference cavity according to the optical cavity enhancement reactive cavity structure of the present invention.

[0046] Figure 7 This is a schematic diagram of the experimental measurement device and results of an optical cavity enhanced reaction cavity structure according to the present invention;

[0047] Figure 8 This is a schematic diagram showing the normalized optical gain of LEDs of different wavelengths as a function of reflectivity in a cavity-enhanced reactive cavity structure according to the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0049] Although the steps in this invention are arranged by reference numerals, this is not intended to limit the order of the steps. Unless the order of the steps is explicitly stated or the execution of a step requires other steps as a basis, the relative order of the steps can be adjusted. It is understood that the term "and / or" as used herein refers to and covers any and all possible combinations of one or more of the associated listed items.

[0050] Example

[0051] General structure of the reaction chamber:

[0052] In all embodiments, the reaction chamber includes a cavity that defines an internal chamber in which light interacts with matter; the cavity has one or more openings (such as inlets and outlets) that allow fluids such as air, mixed gases, and liquids to exchange between the internal chamber and the outside.

[0053] One or more inner walls of the cavity are reflective surfaces, which can be achieved by using reflective materials such as aluminum or by coating with a reflective coating; the shaping design of these reflective surfaces makes the internal geometry of the cavity form a light cavity.

[0054] At least one light source is disposed within the internal cavity, or optically coupled to the internal cavity, so that after the light enters the optical cavity region, it is reflected multiple times by the reflective inner wall and finally escapes from the opening. The resulting enhanced irradiance and extended effective optical path length can improve the interaction efficiency between the fluid flowing through the internal cavity and the light.

[0055] The general structure of an ideal optical cavity enhancement-type reactive cavity:

[0056] In an ideal optical cavity, light is continuously confined, and its intensity increases until a steady state is reached; at this point, the input power of the light source and the light loss are balanced. For a reflectivity of [missing information], [missing information]. The total power gain of the optical cavity can be approximated by an infinite geometric series, as shown in the formula: ,in This is the sum of the power of each reflection.

[0057] In practical double-mirror optical cavities, performance is limited by two major factors: first, beam divergence, where poor beam collimation causes the beam to propagate beyond the mirrors; and second, light trajectory loss, where light can escape from the edge of the cavity or through the entrance port.

[0058] Design based on a single quadratic surface structure:

[0059] To reduce the aforementioned losses, the reaction cavity disclosed in this invention employs a geometry based on integrable convex truncations. The caustic surfaces of integrable truncations such as circles and ellipses form non-empty internal regions, confining the light trajectory within these regions and thus enabling multiple reflections. According to the Birkhoff conjecture, circles and ellipses with smooth boundaries are the only integrable convex truncations, indicating that they are the optimal choices for designing optical cavities with stable light trajectories.

[0060] Quasi-periodic orbits are another important mechanism for reducing optical loss; the optical path can be rotated several times. Characterization ( For the number of turns, (The number of reflections). When the value is irrational, the ray trajectory is quasi-periodic and will not exactly repeat the original path. This means that the ray can propagate over a wide area without repeating itself within the allowed range, thus achieving long-term light confinement.

[0061] Two-dimensional Euclidean space In the middle, the semi-major axis is The semi-minor axis is The ellipse has the following rectangular coordinate equation: , ( (where angular parameters are used), the coordinates of the two foci are... Elliptical spherical tables exhibit three main types of ray trajectories: focal trajectories (passing through the focal points and oscillating between them), elliptical trajectories (intersecting the major axis outside the line connecting the two focal points and constrained by a confocal ellipse), and hyperbolic trajectories (intersecting the major axis inside the line connecting the two focal points and constrained by a confocal hyperbola). Among these, hyperbolic caustics are particularly important for designing dual-mirror optical cavities, as they can capture large-angle rays and reflect them back into the cavity.

[0062] Three-dimensional Euclidean space The ellipsoid in the image is a three-dimensional extension of the ellipse, with a semi-major axis of 1. , , The ellipsoid has the following rectangular coordinate parametric equation: , , ( , (Angular parameters used to control the orientation and shape of the ellipsoid).

[0063] In a triaxial ellipsoid, the motion of light rays can be described by invariant three-dimensional tori in phase space. Each tori corresponds to a class of ray trajectories, which are always constrained to a specific region of phase space and form unique caustic surfaces. Based on existing research on triaxial ellipsoidal quantum stages, four types of caustic surfaces (AD) can be identified, each associated with a specific type of ellipsoid.

[0064] A type I ellipsoid is formed by rotating an ellipse around the Y-axis. Any ray that intersects this ellipsoid will form a type A caustic surface (a hyperboloid with two leaves). The ray oscillation of a type A caustic surface is mainly along the Y-direction. Its corresponding ray dynamics are suitable for designing open optical cavities, but it is difficult to form a stable double-mirror optical cavity.

[0065] Type II ellipsoids are formed by rotating an ellipse, during which the ellipse's focus sweeps across a focal circle. Rays intersecting the outer edge of the focal circle form a Type B caustic surface (ellipsoid), which is a hollow region. Rays oscillate in all directions between the caustic surface and the boundary ellipsoid, making it unsuitable for open-cavity designs. Rays intersecting the inner edge of the focal circle form a Type C caustic surface (hyperboloid), where rays oscillate between the caustic surfaces in both the Y and Z directions. This type of surface can be used to realize open-cavity and dual-mirror cavities.

[0066] Type III ellipsoids lack rotational symmetry. Light rays intersecting this ellipsoid form Type D caustics (hyperbolic paraboloids). These caustics have a saddle-shaped geometry with two mutually perpendicular planes of symmetry. Light rays oscillate between the caustics along the Y and Z directions. Type D caustics can be used to construct dual-mirror optical cavities, and different light patterns will be formed when the mirror positions are adjusted. Figure 1 As shown.

[0067] In the embodiment of the reaction cavity based on a single quadratic surface of the present invention, the cavity integrates selected ellipsoidal segments to form A-type and / or C-type caustic surfaces; these ellipsoidal segments serve as reflective inner walls of the cavity, defining the internal chamber. By truncating and opening the ellipsoidal surface along a selected direction, one or more openings are formed while maintaining the light trajectory of the target caustic surface, enabling fluid exchange between the internal chamber and the outside environment. Placing one or more light sources at positions where their emitted light intersects with the caustic surface support region allows the reaction cavity to achieve long-term light confinement, enhancing the interaction between the fluid and light within the cavity.

[0068] Design based on hybrid confocal structure:

[0069] In another embodiment, the cavity employs a hybrid quadratic surface optical cavity structure based on confocal geometry. This confocal structure utilizes the characteristic that "a confocal ellipse and a hyperbola share the same focal point" to create an optical cavity with excellent optical confinement performance. For example... Figure 2 As shown, an elliptical coordinate system containing confocal elliptic families and confocal hyperbolic families is displayed, and their combinations can form a variety of optical cavity shapes.

[0070] In an elliptical-elliptical configuration, two confocal ellipses sharing a focal point form the relative boundaries of the internal cavity. Light rays intersecting the region connecting the two focal points are repeatedly reflected between the confocal boundaries, achieving light confinement. In an elliptical-hyperbolic configuration, the confocal ellipse and hyperbola share the same focal point, forming complementary boundaries: the divergent geometry of the hyperbola can capture large-angle light rays, guiding them to the focal point and reflecting them back into the optical cavity, while the ellipse further acts as a light-focusing element. Light rays intersecting the focal length are captured by the hyperbolic caustic surface, resulting in multiple reflections and increased irradiance.

[0071] The confocal combination described above is used to design the reflective inner wall of a cavity, forming a hybrid quadratic surface optical cavity structure with at least one fluid flow opening. In some embodiments, two ellipsoids are aligned along their major axis, sharing a focal point and forming a central channel within the internal cavity as a flow path for the liquid. The confocal reflective surface around the channel provides strong light confinement, while the open structure allows water or other liquids to pass through smoothly without significantly interfering with the light field. The confocal system constructed using this configuration includes elliptical-elliptical and / or elliptical-hyperbolic layouts, making it particularly suitable for applications such as water purification and photocatalysis.

[0072] Quadratic surface-planar hybrid system:

[0073] The quadric-planar hybrid system combines quadric surfaces and planar structures within a cavity, simplifying the manufacturing process while retaining the core optical properties of quadric surfaces. In this type of embodiment, the internal chamber defined by the cavity includes at least one elliptical profile wall in at least one plane cross-section, with the remaining walls being planar.

[0074] Even with only an elliptical contour wall, its light dynamics differ significantly from those of a pure rectangular box cavity: light interacting with the elliptical wall is directed to the focal point and reflected back into the internal cavity, rather than escaping rapidly.

[0075] like Figure 3 As shown, a typical construction method for a multi-elliptical planar quadric surface-planar hybrid optical cavity is demonstrated: First, an ellipse is drawn in the xy plane to form an elongated elliptical outline, and the segments at both ends of the ellipse are marked with two vertical lines; the ellipse is trimmed along the vertical lines, and the vertex region is removed, and the resulting truncated outline serves as the basis for the optical cavity cross section; the truncated ellipse is stretched along the z-axis by a selected distance to form a three-dimensional hollow prism with an elliptical cross section; the stretched prism can be rotated around the z-axis (e.g., 90°) and superimposed with the original prism or another rotated prism to form a composite structure; the two structures are spliced ​​together through a union operation, and then the front and rear end faces are removed to open the cavity and expose the internal cavity volume.

[0076] The resulting quadric-planar hybrid system has an internal cavity containing multiple elliptical profile walls (typically four), with the remaining boundaries being open or planar. Compared to a simple box cavity, this multi-elliptical planar geometry significantly increases the number of light reflections and the average optical path length, thereby enhancing the irradiance of the internal cavity.

[0077] This geometry can be physically fabricated using thin metal plates (such as aluminum plates with a thickness of about 0.4 mm). The aluminum plates are cut, bent, and spliced ​​using a cutting-folding process. This method does not require complex molding or a large amount of welding and can ensure the structural integrity and reflectivity of the cavity.

[0078] Stadium-type system:

[0079] The court-type system is another type of hybrid quadric surface optical cavity structure suitable for the reaction cavity of this invention. The preparation method of the double-hemispherical court configuration is as follows: the ellipsoid is divided along a plane approximately perpendicular to the major axis of the ellipsoid to obtain two ellipsoidal hemispheres, each hemisphere containing a focal point (denoted as...). , Each ellipsoidal hemisphere retains the reflective properties of the ellipsoid, from The emitted light will be reflected towards Conversely, this achieves efficient light transmission between the two halves. Placing the two ellipsoidal halves opposite each other creates a stadium-shaped internal cavity where light reflects back and forth, enhancing the irradiation effect of the fluid between the two halves.

[0080] The composite court configuration is an extension of the above concept, achieved by connecting two ellipsoidal hemispheres with additional structures or adjusting their relative orientation. This type of improvement results in chaotic light trajectories, characterized by non-periodic reflections and complex propagation paths, allowing light to explore most of the internal chambers. Chaotic dynamics reduce light intensity hotspots, achieving a more uniform irradiance distribution, which is a significant advantage in processes requiring high uniformity of irradiance dose.

[0081] like Figure 4 As shown, this paper summarizes hybrid quadric surface structures (including confocal systems, quadric-planar hybrid systems, and stadium-type systems), highlighting the geometric and optical properties of various structures.

[0082] Prototype Development:

[0083] To verify the performance of the quadric surface-planar hybrid reaction cavity, the researchers prepared a physical prototype of a multi-elliptical planar structure using thin aluminum plates and studied two types of inner wall surfaces: one is a high diffuse reflection surface, which can scatter incident light over a wide range; the other is a high specular reflection surface, which can achieve specular reflection.

[0084] The total reflectivity of diffuse reflective materials was measured using an integrating sphere, and specular reflective materials were characterized using a spectral ellipsometry. The Delta and Psi values ​​were obtained in the wavelength range of 190 nm to 1700 nm at incident angles of 45°, 65°, and 85°.

[0085] Researchers measured the reflectance curves of the two materials at eight representative wavelengths (270nm, 460nm, 520nm, 620nm, 900nm, 940nm, 980nm, and 1050nm), as follows: Figure 5 As shown, the results indicate that the reflectivity of the specular reflective material exceeds approximately 0.8 in most ultraviolet bands, including the far ultraviolet (UVC) region, and its overall reflectivity is significantly higher than that of diffuse reflective materials. These measurements provide a basis for predicting the achievable optical gain of reaction cavities with different surface treatments.

[0086] Simulation and numerical analysis:

[0087] Researchers conducted numerical ray tracing simulations to compare the differences in ray trajectories between the geometric structure designed in this invention and the traditional rectangular reaction cavity, and constructed two three-dimensional models: one is the elliptical-planar quadric-planar hybrid reaction cavity of this invention, and the other is a rectangular box-shaped cavity with similar external dimensions and opening size (as a reference cavity).

[0088] In both models, light is emitted from the light source region inside the cavity, and the angular distribution of the light simulates the characteristics of an LED emitter; it is assumed that the inner wall is a specular reflector, and the reflectivity value is consistent with the measured specular reflector material; the light continues to propagate until it hits the opening or the light power is lower than the numerical threshold.

[0089] like Figure 6 As shown, typical light trajectories in two geometric structures are illustrated: in an elliptical-planar reaction cavity, light is repeatedly reflected and guided by the elliptical walls, allowing it to explore most of the internal cavity before escaping; while in a rectangular box cavity, most light propagates along a simple trajectory and escapes the cavity after a finite number of reflections.

[0090] These qualitative simulations revealed the differences in the optical confinement mechanisms of the two designs: the elliptical-planar reaction cavity of this invention guides light away from the direct escape path through its curved quadratic surface wall, promoting multiple reflections, which is visually manifested as a longer and more complex light trajectory; while the rectangular cavity, due to the lack of a guiding curved surface structure, allows light to easily escape directly through the opening, resulting in limited photon recovery efficiency. This difference in light behavior became the basis for subsequent experiments comparing the optical gains of the two geometric structures.

[0091] Experimental verification:

[0092] Researchers experimentally compared the performance of an elliptical-planar reaction cavity prototype with a rectangular reference cavity prototype, measuring the light intensity distribution generated by the central LED light source within the cavity. Each prototype was equipped with 13 photodiodes, arranged at different positions within the cavity and near the exit: 1 at the top center, 2 at the top side, 2 at the bottom side, 2 on the side, 2 at the top exit, 2 at the bottom exit, and 2 at the side exit. The LED was installed at a reference position at or near the bottom of the cavity. The measurements of photodiodes at similar positions were averaged to reduce alignment and installation errors.

[0093] The experiment tested four configurations: diffuse reflection inner wall elliptical-planar type, specular inner wall elliptical-planar type, diffuse reflection inner wall rectangular box type, and specular inner wall rectangular box type. For example... Figure 7 As shown, a schematic diagram of the experimental setup is presented, along with normalized light intensity histograms for the four configurations at different locations.

[0094] The results show that the elliptical-planar reaction cavity with a mirror inner wall exhibits higher light intensity and a more rational light intensity distribution in most locations, demonstrating significant advantages over other configurations (especially rectangular box cavities). These results confirm that the elliptical-planar geometry enhances light confinement and optimizes light intensity distribution, thereby improving the efficiency of light-matter interaction.

[0095] Researchers combined the enhancement factor obtained from experiments with the normalized gain curves obtained from simulations to evaluate the performance of the reaction cavity under different reflectivities and wavelengths. Figure 8As shown, the normalized optical gain of LEDs at different wavelengths varies with reflectivity, including simulated curves for elliptical-planar and rectangular reference cavities, as well as experimental data points. The results show that the optical gain of the elliptical-planar reactive cavity is consistently higher than that of the rectangular reference cavity, and this advantage becomes more significant with increasing inner wall reflectivity.

[0096] Applications and variations:

[0097] The reaction chamber described in this invention can be implemented at various scales and can be designed with different internal dimensions. The core requirement is that the chamber retains the target quadratic surface or hybrid quadratic surface structure. The number, size, and layout of the chamber openings can be selected according to the required fluid velocity and flow pattern, while ensuring sufficient light confinement effect.

[0098] Any suitable light source can be selected, including point light sources, line light sources, LED arrays, laser diodes, discharge lamps, etc.; the installation position and orientation of the light source must ensure that its emitted light intersects with the caustic surface support area of ​​the internal cavity.

[0099] The ellipse and ellipsoid of the optical cavity can be constructed, and their eccentricity can be selected to any value less than 1. The characteristics of the optical cavity can be controlled by adjusting parameters such as the semi-axis length and relative orientation. Composite configurations that integrate the characteristics of a single quadratic surface, confocal, quadratic surface-plane hybrid, and stadium-shaped structure can be designed. The core requirement is that the final cavity can define a reflective internal chamber and retain one or more fluid exchange openings.

[0100] Typical applications of the reaction chamber of this invention include: ultraviolet sterilization irradiation of air and water, photocatalytic reactors requiring high photon flux, cavity-enhanced Raman spectroscopy analysis, optical cooling schemes, and other processes requiring improved light-matter interaction efficiency. This invention provides a general framework for integrating the optical cavity into practical reaction devices where fluids need to freely enter and exit the internal chamber.

[0101] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A cavity-enhanced reactive cavity structure, characterized in that, include: A cavity defining an internal chamber for containing the flowing medium, the cavity having one or more openings allowing the flowing medium to flow in and / or flow out; At least one light source, wherein the light source is disposed within the internal cavity or optically coupled to the internal cavity, is used to emit light into the internal cavity; Wherein, at least one inner wall of the cavity is a reflective surface, which is formed by mirror polishing or coating the surface of the material constituting the cavity with a reflective coating; Furthermore, the internal geometry of the cavity is configured as an optical cavity, and the geometry of the optical cavity is designed such that the light emitted by the light source and reflected between the reflective surfaces forms a constrained, non-directly escaping reflection path, thereby extending the average optical path of the light in the internal cavity.

2. The optical cavity enhanced reaction cavity structure according to claim 1, characterized in that, The optical cavity has a geometric structure based on a single quadratic surface optical cavity structure composed of ellipsoidal quadratic surface segments, wherein the ellipsoidal quadratic surface segments are selected from ellipsoidal surface portions that can form type A caustic surfaces or type C caustic surfaces. The A-type caustic surface is a double-leaf hyperboloid, corresponding to light rays oscillating in a single direction; the C-type caustic surface is a single-leaf hyperboloid, corresponding to light rays oscillating in two mutually perpendicular directions. The cavity is formed by truncating a complete ellipsoidal surface and retaining one or more openings, such that light is constrained and reflected within the region defined by the segment of the ellipsoidal quadratic surface.

3. The optical cavity enhanced reaction cavity structure according to claim 1, characterized in that, The optical cavity has a hybrid quadric surface optical cavity structure, which is a confocal system. The confocal system includes a first reflective wall and a second reflective wall, wherein the first reflective wall and the second reflective wall are confocal elliptic surfaces sharing at least one common focus, or are a combination of an elliptic surface and a hyperboloid sharing at least one common focus; In this process, the light rays that intersect with the area near the common focal point are repeatedly reflected between the first reflective wall and the second reflective wall.

4. The optical cavity enhanced reaction cavity structure according to claim 3, characterized in that, The confocal system is specifically an elliptical-elliptical configuration, wherein the first reflective wall and the second reflective wall are both elliptical surfaces, and the two elliptical surfaces share two focal points, and the internal cavity is formed between the two elliptical surfaces.

5. The optical cavity enhanced reaction cavity structure according to claim 3, characterized in that, The confocal system is specifically an elliptical-hyperbolic configuration, wherein the first reflective wall is an elliptical surface, the second reflective wall is a hyperbolic surface, and the elliptical surface and the hyperbolic surface share a focal point; The hyperboloid is used to capture and reflect light rays incident at large angles toward the shared focal region.

6. The optical cavity enhanced reaction cavity structure according to claim 1, characterized in that, The optical cavity has a hybrid quadric surface optical cavity structure, which is a quadric surface-planar hybrid system. The internal cavity of the quadric surface-planar hybrid system has a profile in at least one cross section including at least one elliptical profile segment, which forms part or all of the reflective wall, while the remaining profile segments in the cross section are composed of straight line segments. The reflective wall surface corresponding to the at least one elliptical contour segment is used to guide light to its focal area and reflect it back to the internal cavity.

7. The optical cavity enhanced reaction cavity structure according to claim 6, characterized in that, The internal cavity of the quadratic surface-planar hybrid system has elliptical contour segments on two mutually perpendicular cross sections, resulting in multiple elliptical contour walls within the internal cavity. The quadratic surface-planar hybrid system is constructed through the following steps: drawing an ellipse in a plane and truncating a portion of its arc segment to form a truncated elliptical contour; stretching the truncated elliptical contour along a direction perpendicular to the plane to form a first prism structure; rotating the first prism structure by a certain angle and splicing it with itself or other prism structures, and then removing the end face to form the internal cavity.

8. The optical cavity enhanced reaction cavity structure according to claim 1, characterized in that, The optical cavity has a hybrid quadric surface optical cavity structure, which is a ball court-shaped system. The court-shaped system includes a first ellipsoidal half and a second ellipsoidal half, which are obtained by dividing a complete ellipsoid along a plane perpendicular to its major axis. The first ellipsoidal hemisphere and the second ellipsoidal hemisphere are arranged opposite each other, such that one focus of the first ellipsoidal hemisphere is opposite to one focus of the second ellipsoidal hemisphere, thereby forming the internal cavity, and light emitted from near one of the focuses is reflected toward the opposite focus.

9. The optical cavity enhanced reaction cavity structure according to claim 8, characterized in that, The court-type system is a composite court configuration, wherein the first and second ellipsoidal halves are connected by an additional connecting structure, so that the reflection trajectory of light in the internal cavity exhibits chaotic characteristics, thereby achieving a more uniform irradiance distribution.

10. A cavity-enhanced reactive cavity structure according to any one of claims 1 to 9, characterized in that, The cavity is integrally formed from a metal sheet through cutting and bending processes, and the thickness of the metal sheet is 0.2mm to 1.0mm; The reflective surface is achieved by selecting a high-reflectivity metal as the material of the metal plate and / or by applying a high-reflectivity coating to the inner surface of the metal plate. The light source is a light-emitting diode, a laser diode, or a discharge lamp, and is located within the internal cavity or at a position where its optical path can be coupled into the internal cavity through a window.

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