Optical reflection cavity and detection equipment

Abstract

The utility model relates to the technical field of optical reflection cavities, and provides an optical reflection cavity and detection equipment. The optical reflection cavity comprises a concave surface reflecting mirror, a main plane reflecting mirror, a first sub plane reflecting mirror and a second sub plane reflecting mirror which are inclined relative to the main plane reflecting mirror along at least one of an x-axis direction and a y-axis direction, and a third sub plane reflecting mirror which is inclined relative to the main plane reflecting mirror along the y-axis direction or has an inclined component along the y-axis direction; the first sub-plane mirror, the second sub-plane mirror, the third sub-plane mirror and the main plane mirror are located on a focal plane, and a light beam is reflected into the optical reflection cavity through the first sub-plane mirror, is reflected for multiple times through the concave surface mirror, the main plane mirror and the third sub-plane mirror, and then is reflected into the optical reflection cavity. And the light is reflected to the outside of the optical reflection cavity through the second sub-plane mirror. The optical reflection cavity and the detection equipment in the embodiment of the utility model can meet the requirements of small volume, long optical path and flat form.

Description

Technical Field

[0001] This application relates to the field of optical reflective cavity technology, and more particularly to an optical reflective cavity and a detection device. Background Technology

[0002] Optical reflective cavities that enable multiple reflections of a light beam within a finite volume, allowing the beam to travel a relatively long optical path, have important applications in the field of optical sensing, especially in the sensing and analysis of special gases.

[0003] Existing optical reflector technologies, such as Herriot cells and White cells, cannot meet the industrial demand for small-volume, long-path, and flat optical reflectors. Utility Model Content

[0004] In view of this, embodiments of this application provide an optical reflection cavity and a detection device to solve the problem that existing optical reflection cavity technology cannot meet the industrial field's demand for small-volume, long-path, and flat-shaped optical reflection cavities.

[0005] A first aspect of this application provides an optical reflecting cavity, comprising:

[0006] A concave mirror has a focal plane, the distance from the focal plane to the concave mirror being the focal length f of the concave mirror;

[0007] The principal plane mirror is located on the focal plane and is parallel to the x-axis and y-axis of the Cartesian coordinate system. The origin of the Cartesian coordinate system is the intersection of the optical axes of the optical system composed of the concave mirror and the principal plane mirror on the focal plane. The z-axis of the Cartesian coordinate system is parallel to the optical axis.

[0008] The first sub-plane mirror and the second sub-plane mirror are located on the focal plane and are tilted relative to the main plane mirror in at least one of the x-axis and y-axis directions;

[0009] The third sub-plane mirror is located on the focal plane and is tilted relative to the main plane mirror along the y-axis or has a tilt component along the y-axis.

[0010] The light beam is reflected into the optical reflection cavity by the first sub-plane mirror, and after multiple reflections between the concave mirror, the main plane mirror and the third sub-plane mirror, it is reflected out of the optical reflection cavity by the second sub-plane mirror.

[0011] In one embodiment, the radius of the light beam incident on the first sub-plane reflector is A0, and the divergence half-angle is β0;

[0012] The distance by which the third sub-plane mirror deviates from the origin is greater than the product of the divergence half-angle and the focal length of the concave mirror, β0·f.

[0013] In one embodiment, the third sub-plane mirror is located at the position where the light beam reaches the focal plane after the first or third reflection by the concave mirror, and the light transmission diameter of the third sub-plane mirror is greater than 2β0·f.

[0014] In one embodiment, the tilt direction of the third sub-plane mirror relative to the main plane mirror is selected such that when the light beam reaches the focal plane after an even number of reflections by the concave mirror, the distance from the center of the light beam to the boundary of the third sub-plane mirror is greater than the radius A0 of the light beam.

[0015] In one embodiment, the first sub-plane mirror is disposed in the region where the origin is located on the main plane mirror;

[0016] The second sub-plane reflector is disposed in the region of the main plane reflector in the positive y-axis direction;

[0017] The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is inclined relative to the main plane reflector in the negative y-axis direction;

[0018] Alternatively, the first sub-plane reflector is disposed at the apex region of the main plane reflector in the negative x-axis and negative y-axis directions;

[0019] The second sub-plane reflector is disposed in the region of the main plane reflector in the negative x-axis direction and the positive y-axis direction;

[0020] The third sub-plane reflector is located at the apex of the main plane reflector in the negative x-axis and positive y-axis directions, adjacent to the second sub-plane reflector, and tilted relative to the main plane reflector in the negative y-axis direction.

[0021] Alternatively, the first sub-plane reflector is disposed at the apex region of the main plane reflector in the negative x-axis direction and the positive y-axis direction;

[0022] The second sub-plane reflector is disposed in the apex region of the main plane reflector in the positive x-axis and positive y-axis directions;

[0023] The third sub-plane reflector is disposed in the region of the main plane reflector adjacent to the origin in the positive y-axis direction and is tilted relative to the main plane reflector in the negative y-axis direction.

[0024] In one embodiment, the third sub-plane reflector is disposed at the edge region of the main plane reflector in the y-axis direction, is inclined relative to the main plane reflector in the y-axis direction, and has a length in the x-axis direction equal to m times the width of the trajectory of the light beam on the main plane reflector in the x-axis direction, where m ≥ 1.

[0025] In one embodiment, the trajectory spacing of the light beam along the y-axis on the main plane mirror is 2f·θ1, where θ1 is the tilt angle of the reflecting surface of the third sub-plane mirror relative to the main plane mirror along the y-axis.

[0026] In one embodiment, the first sub-plane mirror is disposed in the region of the main plane mirror adjacent to the origin in the negative x-axis direction;

[0027] The second sub-plane reflector is disposed in the region of the main plane reflector adjacent to the origin in the positive x-axis direction and is symmetrical to the first sub-plane reflector about the y-axis;

[0028] The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is inclined relative to the main plane reflector in the positive y-axis direction.

[0029] Alternatively, the first sub-plane mirror is disposed in the region where the origin is located on the main plane mirror;

[0030] The second sub-plane reflector is disposed in the apex region of the main plane reflector in the negative x-axis direction and the positive y-axis direction;

[0031] The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is inclined relative to the main plane reflector in the negative y-axis direction;

[0032] Alternatively, the first sub-plane mirror is disposed in the region where the origin is located on the main plane mirror;

[0033] The second sub-plane reflector is disposed in the apex region of the main plane reflector in the negative x-axis and negative y-axis directions;

[0034] The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction, adjacent to the second sub-plane reflector, and tilted relative to the main plane reflector in the positive y-axis direction.

[0035] Alternatively, the first sub-plane reflector is disposed at the apex region of the main plane reflector in the negative x-axis direction and the positive y-axis direction;

[0036] The second sub-plane reflector is disposed in the region of the main plane reflector in the positive x-axis and positive y-axis directions;

[0037] The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is tilted relative to the main plane reflector in the negative y-axis direction.

[0038] A second aspect of this application provides a detection device, including:

[0039] The first aspect of the embodiments of this application provides an optical reflecting cavity;

[0040] A light-emitting device for emitting a light beam reflected by the first sub-plane mirror into the optical reflection cavity;

[0041] A photoelectric detector for receiving a light beam reflected by the second sub-plane mirror to the outside of the optical reflection cavity;

[0042] A base is used to fix the optical reflecting cavity, the light-emitting device, and the photodetector.

[0043] The light-emitting device and the photodetector are positioned on the base without exceeding the boundary of the optical reflection cavity in the z-axis direction and without passing through the transmission optical path of the light beam within the optical reflection cavity.

[0044] In one embodiment, the optical reflecting cavity, the light-emitting device, and the photodetector are disposed on the top surface of the base in the negative x-axis direction;

[0045] Alternatively, the optical reflection cavity may be disposed on the top surface of the base in the negative x-axis direction;

[0046] The light-emitting device is disposed on the bottom surface of the base in the positive x-axis direction, and the light beam emitted by the light-emitting device is transmitted to the first sub-plane reflector through the first through hole opened in the base;

[0047] The photodetector is disposed on the bottom surface of the base in the positive x-axis direction, and the light beam reflected by the second sub-plane reflector is transmitted to the photodetector through the second through hole opened in the base.

[0048] In one embodiment, the light-emitting device and the photodetector are disposed on the bottom surface of the base in the positive x-axis direction, and the detection device further includes:

[0049] The first reflector is disposed on the top surface of the base in the negative x-axis direction, and the light beam emitted by the light-emitting device is transmitted to the first sub-plane reflector through the first through hole and the first reflector.

[0050] The second reflector is disposed on the top surface of the base in the negative x-axis direction. The light beam reflected by the second sub-plane reflector is transmitted to the photodetector through the second through hole and the second reflector.

[0051] In one embodiment, the orthographic projection of the base in the x-axis direction is a circle or a near-circular shape.

[0052] The optical reflecting cavity provided in the first aspect of this application introduces a first sub-plane mirror, a second sub-plane mirror, and a third sub-plane mirror into a plano-concave cavity. The first and second sub-plane mirrors are located on the focal plane and are tilted relative to the main plane mirror along at least one of the x-axis and y-axis directions. The third sub-plane mirror is located on the focal plane and is tilted relative to the main plane mirror along the y-axis direction or has a tilt component along the y-axis direction. This allows the light beam to be reflected into the plano-concave cavity by the first sub-plane mirror, and after multiple reflections between the concave mirror, the main plane mirror, and the third sub-plane mirror, it is reflected out of the plano-concave cavity by the second sub-plane mirror. Since the number of light beam trajectories in the y-axis direction is 1 to 4, the optical reflecting cavity can adopt a flat shape. Compared with Heriot-Lewis chambers and White chambers, it can achieve an optical reflecting cavity with more reflections (i.e., longer optical path) and a higher optical path-to-volume ratio.

[0053] The detection device provided in the second aspect of the embodiments of this application employs the optical reflection cavity provided in the first aspect of the embodiments of this application. Since the orthographic projection shape of the light beam in the x-direction is trapezoidal, the presence of the first sub-plane reflector and the second sub-plane reflector allows the light beam to enter and exit from one or both sides of the short side of the trapezoid. By fixing the light-emitting device and the photodetector on the base without exceeding the boundary of the optical reflection cavity in the z-axis direction and without passing through the transmission optical path of the light beam in the optical reflection cavity (e.g., one or both sides of the short side of the orthographic projection of the trapezoid in the x-direction), the detection device is comparable in size to the optical reflection cavity and has a compact structure. Attached Figure Description

[0054] To more clearly illustrate the technical applications in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] To more clearly illustrate the technical applications in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a schematic diagram of the optical reflection cavity provided in Embodiment 1 of this application;

[0057] Figures 2-4 This is a schematic diagram showing the positions of the light beam, the first sub-plane mirror, the second sub-plane mirror, and the third sub-plane mirror on the main plane mirror, as provided in Embodiment 1 of this application.

[0058] Figure 5 This is a schematic diagram of the tilt angle of the third sub-plane reflector provided in Embodiment 1 of this application;

[0059] Figures 6-9 This is a schematic diagram showing the positions of the light beam, the first sub-plane mirror, the second sub-plane mirror, and the third sub-plane mirror on the main plane mirror, as provided in Embodiment 2 of this application.

[0060] Figure 10 and Figure 11 This is a schematic diagram of the detection device provided in Embodiment 3 of this application. Detailed Implementation

[0061] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0062] To illustrate the technical application described in this application, specific embodiments will be used for further explanation below.

[0063] To enable those skilled in the art to better understand this application, the technical applications in the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0064] The term "comprising," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. Furthermore, the terms "first," "second," etc., are used to distinguish different objects, not to describe a particular order.

[0065] Example 1

[0066] like Figures 1-5 As shown, this application embodiment provides an optical reflecting cavity 100, including:

[0067] The concave mirror 101 has a focal plane 102, and the distance from the focal plane 102 to the concave mirror 101 is the focal length f of the concave mirror 101.

[0068] The principal plane mirror 103 is located on the focal plane 102 and parallel to the x-axis and y-axis of the Cartesian coordinate system, with the origin of the Cartesian coordinate system at 104. Figures 2-3 (The point marked with ×) is the intersection of the optical axis 105 of the optical system composed of the concave mirror 101 and the principal plane mirror 103 on the focal plane 102. The z-axis of the Cartesian coordinate system is parallel to the optical axis 105.

[0069] The first sub-plane mirror 106 and the second sub-plane mirror 107 are located on the focal plane 102 and are tilted relative to the main plane mirror 103 in at least one of the x-axis and y-axis directions.

[0070] The third subplane mirror 108 is located on the focal plane 102 and is tilted relative to the main plane mirror 103 along the y-axis or has a tilt component along the y-axis.

[0071] The light beam is incident on the first sub-plane mirror 106 (that is, the first sub-plane mirror 106 is the incident position of the light beam), reflected by the first sub-plane mirror 106 into the optical reflection cavity 100, and after multiple reflections between the concave mirror 101, the main plane mirror 103 and the third sub-plane mirror 108, it is reflected by the second sub-plane mirror 107 out of the optical reflection cavity 100 (that is, the second sub-plane mirror 107 is the exit position of the light beam).

[0072] In applications, the positive directions of each coordinate axis in the Cartesian coordinate system can be set according to actual needs. For example, the direction from the origin 104 to the concave mirror 101 on the z-axis can be defined as the positive z-axis direction, the anti-gravity direction can be defined as the positive y-axis direction, and then the positive x-axis direction can be determined according to the right-hand rule.

[0073] Figures 2-4Each rectangular grid represents a reflection area on the focal plane 102. The number in each rectangular grid represents the reflection sequence number of the light beam after being reflected by the concave mirror 101 and reaching the focal plane 102. The center of each rectangular grid represents the reflection position of the light beam.

[0074] In this diagram, the rectangular grid containing the number 0 represents the incident position of the light beam, which is also the position of the first sub-plane reflector 106. The number 1 indicates that the light beam reaches the focal plane 102 after the first reflection by the concave reflector 101, the number 2 indicates that the light beam reaches the focal plane 102 after the second reflection by the concave reflector 101, and so on. Figure 2 The number 8 indicates that the light beam reaches the focal plane 102 after the 8th reflection by the concave mirror 101. Figure 3 The number 20 indicates that the light beam reaches the focal plane 102 after the 20th reflection by the concave mirror 101. Figure 4 The number 26 indicates that the light beam reaches the focal plane 102 after the 26th reflection by the concave mirror 101;

[0075] Figure 2 The middle number 8 Figure 3 Chinese number 20 and Figure 4 The rectangular grid where the number 26 is located is the exit position of the light beam, which is also the position of the second sub-plane reflector 107;

[0076] The arrow "→" on the third subplane mirror 108 indicates its tilt direction relative to the main plane mirror 103.

[0077] In application, from an optical perspective, since the optical reflecting cavity 100 employs a confocal optical system, the radius and half-divergence angle of the light beam on the focal plane 102 will vary between two sets of values, independent of the number of reflections by the concave mirror 101, and only related to the parity of the number of reflections by the concave mirror 101. Let the radius of the light beam be A0 and the half-divergence angle be β0 when it is incident on the first sub-plane mirror 106, and the radius and half-divergence angle be A1 after one reflection by the concave mirror 101 to reach the focal plane 102. Then the following relationship holds:

[0078] A1=β0·f (1)

[0079] β1=A0 / f (2)

[0080] After being reflected twice by the concave mirrors 101, the radius of the light beam reaching the focal plane 102 is A2, and the divergence half-angle is β2. This can be obtained by applying equations (1) and (2) twice:

[0081] A2=β1·f=(A0 / f)·f=A0 (3)

[0082] β2=A1 / f=(β0·f) / f=β0(4)

[0083] Based on equations (3) and (4), it can be seen that after the beam is reflected twice by the concave mirror 101, it reaches the focal plane 102 and recovers the characteristics (A0, β0) of the beam when it was incident on the first sub-plane mirror 106. After an even number of reflections by the concave mirror 101, the characteristics of the beam will be the same as when it was incident on the first sub-plane mirror 106. For an odd number of reflections by the concave mirror 101, the characteristics of the beam are the radius and divergence half angle (A1, β1) obtained based on equations (1) and (2).

[0084] Regarding the transformation of the principal beam position and angle (relative to the optical axis 105), without the introduction of the third sub-plane mirror 108, after being reflected four times by the concave mirror 101 to reach the focal plane 102, the principal beam position coincides with the principal beam position when the beam is incident on the first sub-plane mirror 106, and the angle is mirror-symmetrical about the optical axis 105 with the principal beam angle when the beam is incident on the first sub-plane mirror 106. Since the principal beam position coincides with the principal beam position when the beam is incident on the first sub-plane mirror 106, the beam is no longer reflected by the principal plane mirror 103, but is reflected by the first sub-plane mirror 106 to the outside of the optical reflection cavity 100. Therefore, without the introduction of the third sub-plane mirror 108, the beam is reflected a maximum of four times by the concave mirror 101, and the total optical path is greatly limited.

[0085] In this embodiment, a third sub-plane mirror 108 is introduced into the confocal optical system composed of a concave mirror 101 and a main plane mirror 103. The third sub-plane mirror 108 is positioned at a certain distance from the origin 104 and is located at the position where the light beam reaches the focal plane 102 after the first or third reflection from the concave mirror 101. The third sub-plane mirror 108 changes the reflection angle of the light beam, so that after the light beam is reflected by the concave mirror 101, the position of the light beam in the focal plane 102 after the even-numbered reflections changes, while the position of the light beam in the focal plane 102 after the odd-numbered reflections remains unchanged. This ensures that the position of all the light beams no longer conflicts with the position of the main beam when the light beam is incident on the first sub-plane mirror 106, thus realizing multiple reflections of the light beam.

[0086] like Figures 2-4 As shown, after introducing the third sub-plane mirror 108, on the reflecting surface of the main plane mirror 103, i.e., the focal plane 102, after 1+4k (k=0,1,2,3,···) reflections by the concave mirror 101, the position of the light beam is in the same region. For example, Figure 2 The area containing the rectangular grid in the last row of the middle. Figure 3 The area containing the rectangular grid in the first row and first column of the middle. Figure 4The region containing the rectangular grid in the third row and second column from the bottom is denoted as P1. After 3+4k (k=0,1,2,3,...) reflections by the concave mirror 101, the beam's position is in the same region. For example, Figure 2 The area containing the rectangular grid in the first row of the text. Figure 3 The area containing the rectangular grid in the last row and second column of the middle. Figure 4 The region containing the rectangular grid in the third row and second column is denoted as P3. After 4+4k (k=0,1,2,3,···) reflections by the concave mirror 101, the position of the beam and the incident position of the beam are on a straight line. For example, Figure 2 The area containing the rectangular grid in the second and third rows of the middle section. Figure 3 The area containing the rectangular grid from the second row, first column to the second-to-last row, first column. Figure 4 The rectangular grid area from the second row, first column to the last row, first column; after 2+4k (k=0,1,2,3,...) reflections by the concave mirror 101, the position of the beam and the exit position of the beam are on a straight line, for example, Figure 2 The area containing the rectangular grid in the second-to-last and third-to-last rows. Figure 3 The area containing the rectangular grid from the second row and second column to the second row and second column from the bottom. Figure 4 The area containing the rectangular grid in the third column.

[0087] For ease of explanation, Figure 4 The third sub-plane reflector 108 is selected at the position of the light beam on the focal plane 102 after the third reflection by the concave reflector 101, such as... Figure 5 As shown, the normal 109 of the third sub-plane mirror 108 and the normal 110 of the main plane mirror 103 form an angle of inclination θ0. A vector is drawn along the direction of the edge formed by the intersection of the plane formed by the two normals and the focal plane 102, called the displacement vector ΔP (i.e., 111), and its length is defined by the following formula:

[0088] ΔP= tan(2θ0)·f (5)

[0089] It is easy to prove that... Figure 4 The beams distributed in the rectangular grids 2, 4, 6, ..., 26 in the third column and the rectangular grids 0, 4, 8, ..., 24 in the first column have a positional interval of ΔP given by equation (5), and the beam trajectories in these two columns are parallel to ΔP. It can be seen that ΔP includes the magnitude and direction of the tilt angle θ0 of the third subplane reflector 108.

[0090] As can be seen from the properties of confocal optical systems, Figure 4The rectangular grids at P1 and P3 are symmetrical about the origin 104 of the focal plane 102. In order to prevent the third sub-plane mirror 108 from interfering with the beam on P1, the distance of the third sub-plane mirror 108 from the origin 104 of the focal plane 102 is greater than the beam radius A1 on P1 or P3. As can be seen from the above equation (1), A1 = β0·f. At the same time, in order to ensure that the third sub-plane mirror 108 can reflect all the beam energy reaching it, its light transmission diameter is greater than the beam diameter 2·A1 on P1 or P3, that is, 2β0·f.

[0091] To avoid the third subplane mirror 108 pairs Figure 4 The interference from the beams in the first or third column, the selection of the tilt angle θ0 direction makes the direction of the shift vector ΔP not in the direction of the line connecting the first sub-plane mirror 106 and P3, but forming a certain angle with it. After an even number of reflections by the concave mirror 101, when the beam reaches the focal plane 102, the distance from the center of the incident beam to the boundary of the third sub-plane mirror 108 is greater than the radius A0 of the incident beam, thus making the beam... Figure 4 The light transmission band in the first or third column, with a width equal to the beam diameter, does not overlap with the third sub-plane reflector 108.

[0092] Figure 3 In this configuration, the first sub-plane mirror 106 and the second sub-plane mirror 107 can be positioned in the area of ​​the first or third column of rectangular grids on the focal plane 102. For example, the first sub-plane mirror 106 is located in the first row and first column of the rectangular grid, and the second sub-plane mirror 107 is located in the first row and third column of the rectangular grid. That is, the second sub-plane mirror 107 is located at the position where the light beam reaches the focal plane 102 after being reflected 2+4k times (k=0,1,2,3,···) by the concave mirror 101. This configuration of the second sub-plane mirror 107 makes the exit position and angle of the light beam insensitive to the positional deviation of the angle between the concave mirror 101 and the main plane mirror 103, and the optical system has high stability.

[0093] In one embodiment, the radius of the light beam incident on the first sub-plane reflector 106 is A0, and the divergence half-angle is β0;

[0094] The distance of the third sub-plane mirror 108 from the origin 104 is greater than the product of the divergence half angle and the focal length of the concave mirror 101, β0·f.

[0095] In one embodiment, the third sub-plane mirror 108 is located at the position where the light beam reaches the focal plane 102 after the first or third reflection of the concave mirror 101, and the light transmission diameter of the third sub-plane mirror 108 is greater than 2β0·f.

[0096] In one embodiment, the tilt direction of the third sub-plane mirror 108 relative to the main plane mirror 103 is selected such that when the light beam reaches the focal plane 102 after an even number of reflections by the concave mirror 101, the distance from the center of the light beam to the boundary of the third sub-plane mirror 108 is greater than the radius A0 of the light beam.

[0097] In application, the positions of the first sub-plane mirror 106, the second sub-plane mirror 107, and the third sub-plane mirror 108 on the main plane mirror 103 (or focal plane 102), the tilt angle of the first sub-plane mirror 106 and the second sub-plane mirror 107 relative to the main plane mirror 103 along the x-axis and y-axis, and the tilt angle or tilt component of the third sub-plane mirror 108 relative to the main plane mirror 103 along the y-axis can be set according to actual needs.

[0098] like Figure 2 As shown, an exemplary first sub-plane reflector 106 is provided in the region where the origin 104 is located on the main plane reflector 103;

[0099] The second sub-plane reflector 107 is disposed in the region of the main plane reflector 103 in the positive y-axis direction;

[0100] The third sub-plane reflector 108 is disposed in the edge region of the main plane reflector 103 in the negative y-axis direction and is tilted relative to the main plane reflector 103 in the negative y-axis direction.

[0101] like Figure 3 As shown, an exemplary first sub-plane reflector 106 is provided in the apex region of the main plane reflector 103 in the negative x-axis and negative y-axis directions;

[0102] The second sub-plane reflector 107 is disposed in the region of the main plane reflector 103 in the negative x-axis direction and the positive y-axis direction;

[0103] The third sub-plane reflector 108 is located in the apex region of the main plane reflector 103 in the negative x-axis and positive y-axis directions, adjacent to the second sub-plane reflector 107, and tilted relative to the main plane reflector 103 in the negative y-axis direction.

[0104] like Figure 4 As shown, an exemplary first sub-plane reflector 106 is provided in the apex region of the main plane reflector 103 in the negative x-axis direction and the positive y-axis direction;

[0105] The second sub-plane reflector 107 is disposed in the apex region of the main plane reflector 103 in the positive x-axis and positive y-axis directions;

[0106] The third sub-plane reflector 108 is located in the region of the main plane reflector 103 adjacent to the origin 104 in the positive y-axis direction and is tilted relative to the main plane reflector 103 in the negative y-axis direction.

[0107] The optical reflecting cavity 100 provided in Embodiment 1 of this application introduces a first sub-plane mirror 106, a second sub-plane mirror 107, and a third sub-plane mirror 108 into a plano-concave cavity. The first and second sub-plane mirrors 106 and 107 are located on the focal plane 102 and tilted relative to the main plane mirror 103 along at least one of the x-axis and y-axis directions. The third sub-plane mirror 108 is located on the focal plane 102 and tilted relative to the main plane mirror 103 along the y-axis direction or has a tilt component along the y-axis direction. The light beam is reflected by the first sub-plane mirror 106 into the plano-concave cavity. After multiple reflections between the concave mirror 101, the main plane mirror 103, and the third sub-plane mirror 108, it is reflected by the second sub-plane mirror 107 out of the plano-concave cavity. Since the number of light beam trajectories in the y-axis direction is 1 to 4, the optical reflection cavity 100 can adopt a flat shape. Compared with the Heriot-Lewis chamber and the White chamber, it can achieve more reflections (i.e., longer optical path) and a higher optical path-to-volume ratio.

[0108] Example 2

[0109] like Figures 6-9 As shown, in one embodiment, based on Embodiment 1, the third sub-plane reflector 108 is disposed in the edge region of the main plane reflector 103 in the y-axis direction, is inclined relative to the main plane reflector 103 in the y-axis direction, and has a length in the x-axis direction equal to m times the width of the trajectory of the light beam on the main plane reflector 103 in the x-axis direction, where m ≥ 1.

[0110] Figures 6-9 Each rectangular grid represents a reflection area on the focal plane 102. The number in each rectangular grid represents the reflection sequence number of the light beam after being reflected by the concave mirror 101 and reaching the focal plane 102. The center of each rectangular grid represents the reflection position of the light beam.

[0111] In this diagram, the rectangular grid containing the number 0 represents the incident position of the light beam, which is also the position of the first sub-plane reflector 106. The number 1 indicates that the light beam reaches the focal plane 102 after the first reflection by the concave reflector 101, the number 2 indicates that the light beam reaches the focal plane 102 after the second reflection by the concave reflector 101, and so on. Figure 6 The number 21 indicates that the light beam reaches the focal plane 102 after the 21st reflection by the concave mirror 101. Figure 7 The number 33 indicates that the light beam reaches the focal plane 102 after the 33rd reflection by the concave mirror 101. Figure 8 The number 35 indicates that the light beam reaches the focal plane 102 after the 35th reflection by the concave mirror 101. Figure 9 The number 47 indicates that the light beam reaches the focal plane 102 after the 47th reflection by the concave mirror 101;

[0112] Figure 6 The middle number 21 Figure 7 The middle number 33 Figure 8 The number 35 and Figure 9 The rectangular grid where the number 47 is located is the exit position of the light beam, which is also the position of the second sub-plane reflector 107;

[0113] The arrow "→" on the third subplane mirror 108 indicates its tilt direction relative to the main plane mirror 103.

[0114] In application, the value of m can be set to any value greater than or equal to 1 according to actual needs. By making the length of the third sub-plane reflector 108 in the x-axis direction equal to m times the width of the beam trajectory along the x-axis direction on the main plane reflector 103, the beam can be reflected more than once by the third sub-plane reflector 108 and the translation direction of the trajectory will be continuously changed after being reflected by the third sub-plane reflector 108. This increases the number of reflections of the beam in a finite volume, thereby increasing the optical path and also increasing the distribution density of the reflected light spot.

[0115] In one embodiment, the trajectory spacing of the light beam on the main plane mirror 103 along the y-axis is 2f·θ1, and the trajectory spacing of the light beam on the main plane mirror 103 along the x-axis is determined by the position of the first sub-plane mirror 106 relative to the optical axis 105.

[0116] In application, the tilt direction and tilt angle θ1 of the third subplane reflector 108 relative to the main plane reflector 103 on the y-axis can be set according to actual needs, and θ1 is not 0 or π.

[0117] In application, the positions of the first sub-plane mirror 106, the second sub-plane mirror 107, and the third sub-plane mirror 108 on the main plane mirror 103 (or focal plane 102), the tilt angle of the first sub-plane mirror 106 and the second sub-plane mirror 107 relative to the main plane mirror 103 along the x-axis and y-axis, and the tilt angle of the third sub-plane mirror 108 relative to the main plane mirror 103 along the y-axis can be set according to actual needs.

[0118] like Figure 6 As shown, an exemplary first sub-plane reflector 106 is provided in the region of the main plane reflector 103 adjacent to the origin 104 in the negative x-axis direction;

[0119] The second sub-plane reflector 107 is located in the region of the main plane reflector 103 adjacent to the origin 104 in the positive x-axis direction, and is symmetrical to the first sub-plane reflector 106 about the y-axis.

[0120] The third sub-plane reflector 108 is disposed in the edge region of the main plane reflector 103 in the negative y-axis direction and is tilted relative to the main plane reflector 103 in the positive y-axis direction.

[0121] like Figure 7 As shown, an exemplary first sub-plane reflector 106 is provided in the region where the origin 104 is located on the main plane reflector 103;

[0122] The second sub-plane reflector 107 is located in the apex region of the main plane reflector 103 in the negative x-axis direction and the positive y-axis direction;

[0123] The third sub-plane reflector 108 is disposed in the edge region of the main plane reflector 103 in the negative y-axis direction and is tilted relative to the main plane reflector 103 in the negative y-axis direction.

[0124] like Figure 8 As shown, an exemplary first sub-plane reflector 106 is provided in the region where the origin 104 is located on the main plane reflector 103;

[0125] The second sub-plane reflector 107 is disposed in the apex region of the main plane reflector 103 in the negative x-axis and negative y-axis directions;

[0126] The third sub-plane reflector 108 is located in the edge region of the main plane reflector 103 in the negative y-axis direction, adjacent to the second sub-plane reflector 107, and tilted relative to the main plane reflector 103 in the positive y-axis direction.

[0127] like Figure 9 As shown, an exemplary first sub-plane reflector 106 is provided in the apex region of the main plane reflector 103 in the negative x-axis direction and the positive y-axis direction;

[0128] The second sub-plane reflector 107 is disposed in the region of the main plane reflector 103 in the positive x-axis direction and the positive y-axis direction;

[0129] The third sub-plane reflector 108 is disposed in the edge region of the main plane reflector 103 in the negative y-axis direction and is tilted relative to the main plane reflector 103 in the negative y-axis direction.

[0130] The optical reflecting cavity 100 provided in Embodiment 2 of this application, based on Embodiment 1, defines the third sub-plane reflector 108 as being disposed on the edge region of the main plane reflector 103 in the y-axis direction, tilted relative to the main plane reflector 103 in the y-axis direction, and having a length in the x-axis direction equal to more than twice the width of the trajectory of the light beam on the main plane reflector 103 in the x-axis direction. This allows the light beam to be reflected more than once by the third sub-plane reflector 108, and the translation direction of the trajectory to be continuously changed after being reflected by the third sub-plane reflector 108. This increases the number of reflections of the light beam within a finite volume, thereby increasing the optical path and the distribution density of the reflected light spot. Compared with the Heriot-Litt chamber and the White chamber, it can achieve more reflections (i.e., a longer optical path), a higher optical path-to-volume ratio, and a higher density of light spot distribution.

[0131] Example 3

[0132] like Figure 10 or Figure 11 As shown, this application embodiment provides a detection device 200, including:

[0133] The optical reflection cavity 100 in Embodiment 1 or Embodiment 2;

[0134] The light-emitting device 201 is used to emit a light beam that is reflected by the first sub-plane mirror 106 into the optical reflection cavity 100;

[0135] The photoelectric detector 202 is used to receive the light beam reflected by the second sub-plane mirror 107 to the outside of the optical reflection cavity 100;

[0136] The base 203 is used to fix the optical reflecting cavity 100, the light-emitting device 201 and the photoelectric detector 202;

[0137] The light-emitting device 201 and the photodetector 202 are positioned on the base 203 without exceeding the boundary of the optical reflection cavity 100 in the z-axis direction and without passing through the transmission optical path of the light beam within the optical reflection cavity 100.

[0138] In applications, the light-emitting device 201 can be any type of tunable laser, such as a Fabry-Perot laser, a distributed feedback semiconductor laser, a distributed Bragg reflector laser, a vertical-cavity surface-emitting laser, and an external-cavity tunable semiconductor laser. The laser's operating parameters can be operating temperature, bias current, or bias voltage. The wavelength of the emitted laser beam can be adjusted by changing these operating parameters.

[0139] In applications, the photodetector 202 can be implemented based on photodiodes, photomultiplier tubes, and other photoelectric conversion devices.

[0140] In application, the shape and size of the base can be set according to actual needs. For example, it can be the same as the orthographic projection shape (i.e., trapezoid) of the optical reflector 100 in the x direction and have a comparable area (i.e., equal to or slightly larger than). Alternatively, it can be the same as the shape of the circumscribed rectangle or circumscribed circle (or near-circular shape) of the orthographic projection shape of the optical reflector 100 in the x direction and have a comparable area.

[0141] like Figure 9 or Figure 10 As shown, the orthographic projection of the base 203 in the x-axis direction is exemplarily a circle, the area of ​​which is equivalent to the area of ​​the circumscribed circle of the optical reflecting cavity 100 in the x-axis direction.

[0142] In the application, the optical reflection cavity 100 is disposed on the top surface of the base 203 in the negative x-axis direction. The light-emitting device 201 and the photodetector 202 can be disposed on the top surface of the base 203 in the negative x-axis direction or the bottom surface in the positive x-axis direction, without exceeding the boundary of the optical reflection cavity 100 in the z-axis direction, and without passing through any position of the transmission optical path of the light beam in the optical reflection cavity 100, for example, one or both sides of the short side of the trapezoidal orthogonal projection of the light beam in the x-direction.

[0143] like Figure 9 or Figure 10 As shown, an optical reflection cavity 100, a light-emitting device 201, and a photodetector 202 are exemplaryly arranged on the top surface of the base 203 in the negative x-axis direction; wherein, the light-emitting device 201 and the photodetector 202 are specifically arranged on both sides of the short side of the trapezoidal orthogonal projection of the light beam in the x-direction.

[0144] In one embodiment, the optical reflection cavity 100 is disposed on the top surface of the base 203 in the negative x-axis direction;

[0145] The light-emitting device 201 is disposed on the bottom surface of the base 203 in the positive x-axis direction. The light beam emitted by the light-emitting device 201 is transmitted to the first sub-plane reflector 106 through the first through hole opened in the base 203.

[0146] The photodetector 202 is disposed on the bottom surface of the base 203 in the positive x-axis direction. The light beam reflected by the second sub-plane reflector 107 is transmitted to the photodetector 202 through the second through hole opened in the base 203.

[0147] In application, by reasonably setting the position and tilt angle of the first sub-plane reflector 106 and the second sub-plane reflector 107, it is only necessary to open a through hole at the position of the first sub-plane reflector 106 and the second sub-plane reflector 107 on the base 203, so that the light beam can be incident or emitted between the top and bottom surfaces of the base 203. Furthermore, by setting the light-emitting device 201 and the photodetector 202 on the bottom surface of the base 203, the conflict between the light-emitting device 201 and the photodetector 202 and the various devices or optical paths in the optical reflection cavity 100 can be avoided, and the compact structure of the detection device 200 can be better realized.

[0148] In one embodiment, when the light-emitting device 201 and the photodetector 202 are disposed on the bottom surface of the base 203 in the positive x-axis direction, the detection device 200 further includes:

[0149] The first reflector is disposed on the top surface of the base 203 in the negative x-axis direction. The light beam emitted by the light-emitting device 201 is transmitted to the first sub-plane reflector 106 through the first through hole and the first reflector.

[0150] The second reflector is disposed on the top surface of the base 203 in the negative x-axis direction. The light beam reflected by the second sub-plane reflector 107 is transmitted to the photodetector 202 through the second through hole and the second reflector.

[0151] In application, by setting a first reflector in the incident light path between the light-emitting device 201 and the first sub-plane reflector 106, and setting a second reflector in the outgoing light path between the second sub-plane reflector 107 and the photodetector 202, and setting the position and tilt angle of the first and second reflectors according to actual needs (for example, tilting 45° relative to the top surface of the base 203 along the positive x-axis), the position and tilt angle of the first sub-plane reflector 106 and the second sub-plane reflector 107 can be set more flexibly.

[0152] In applications, the detection device 200 can be a gas detection device or a photoelectric detection device for physical quantities such as vibration, sound waves, stress, temperature, and distance.

[0153] The detection device 200 provided in Embodiment 3 of this application, by adopting the optical reflection cavity 100 in Embodiment 1 or Embodiment 2, since the orthographic projection shape of the light beam in the x-direction is trapezoidal, and with the presence of the first sub-plane reflector 106 and the second sub-plane reflector 107, allows the light beam to enter and exit from one or both sides of the short side of the trapezoid. By fixing the light-emitting device 201 and the photodetector 202 on the base 203 without exceeding the boundary of the optical reflection cavity 100 in the z-axis direction and without passing through the transmission optical path of the light beam in the optical reflection cavity 100 (e.g., one or both sides of the short side of the orthographic projection of the trapezoid in the x-direction), the detection device 200 is comparable to or slightly larger in volume than the optical reflection cavity 100, with a compact structure, and is especially suitable for application scenarios that require a flat shape or a flat circular (or near-circular) shape. For example, the detection device 200 can be a mobile robot with a main body shape of a flat circular (or near-circular) shape.

[0154] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An optical reflecting cavity, characterized in that, include: A concave mirror has a focal plane, the distance from the focal plane to the concave mirror being the focal length f of the concave mirror; The principal plane mirror is located on the focal plane and is parallel to the x-axis and y-axis of the Cartesian coordinate system. The origin of the Cartesian coordinate system is the intersection of the optical axes of the optical system composed of the concave mirror and the principal plane mirror on the focal plane. The z-axis of the Cartesian coordinate system is parallel to the optical axis. The first sub-plane mirror and the second sub-plane mirror are located on the focal plane and are tilted relative to the main plane mirror in at least one of the x-axis and y-axis directions; The third sub-plane mirror is located on the focal plane and is tilted relative to the main plane mirror along the y-axis or has a tilt component along the y-axis. The light beam is reflected into the optical reflection cavity by the first sub-plane mirror, and after multiple reflections between the concave mirror, the main plane mirror and the third sub-plane mirror, it is reflected out of the optical reflection cavity by the second sub-plane mirror.

2. The optical reflecting cavity as described in claim 1, characterized in that, The radius of the incident light beam on the first sub-plane mirror is A0, and the divergence half-angle is β0; The distance by which the third sub-plane mirror deviates from the origin is greater than the product of the divergence half-angle and the focal length of the concave mirror, β0·f.

3. The optical reflecting cavity as described in claim 2, characterized in that, The third sub-plane reflector is located at the position where the light beam reaches the focal plane after the first or third reflection by the concave reflector, and the light transmission diameter of the third sub-plane reflector is greater than 2β0·f.

4. The optical reflecting cavity as described in any one of claims 1 to 3, characterized in that, The first sub-plane reflector is disposed in the region where the origin is located on the main plane reflector; The second sub-plane reflector is disposed in the region of the main plane reflector in the positive y-axis direction; The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is inclined relative to the main plane reflector in the negative y-axis direction; Alternatively, the first sub-plane reflector is disposed at the apex region of the main plane reflector in the negative x-axis and negative y-axis directions; The second sub-plane reflector is disposed in the region of the main plane reflector in the negative x-axis direction and the positive y-axis direction; The third sub-plane reflector is located at the apex of the main plane reflector in the negative x-axis and positive y-axis directions, adjacent to the second sub-plane reflector, and tilted relative to the main plane reflector in the negative y-axis direction. Alternatively, the first sub-plane reflector is disposed at the apex region of the main plane reflector in the negative x-axis direction and the positive y-axis direction; The second sub-plane reflector is disposed in the apex region of the main plane reflector in the positive x-axis and positive y-axis directions; The third sub-plane reflector is disposed in the region of the main plane reflector adjacent to the origin in the positive y-axis direction and is tilted relative to the main plane reflector in the negative y-axis direction.

5. The optical reflecting cavity as described in any one of claims 1 to 3, characterized in that, The third sub-plane reflector is disposed on the edge region of the main plane reflector in the y-axis direction, is inclined relative to the main plane reflector in the y-axis direction, and has a length in the x-axis direction equal to m times the width of the trajectory of the light beam on the main plane reflector in the x-axis direction, where m ≥ 1.

6. The optical reflecting cavity as described in claim 5, characterized in that, The first sub-plane reflector is disposed in the region of the main plane reflector adjacent to the origin in the negative x-axis direction; The second sub-plane reflector is disposed in the region of the main plane reflector adjacent to the origin in the positive x-axis direction and is symmetrical to the first sub-plane reflector about the y-axis; The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is inclined relative to the main plane reflector in the positive y-axis direction. Alternatively, the first sub-plane mirror is disposed in the region where the origin is located on the main plane mirror; The second sub-plane reflector is disposed in the apex region of the main plane reflector in the negative x-axis direction and the positive y-axis direction; The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is inclined relative to the main plane reflector in the negative y-axis direction; Alternatively, the first sub-plane mirror is disposed in the region where the origin is located on the main plane mirror; The second sub-plane reflector is disposed in the apex region of the main plane reflector in the negative x-axis and negative y-axis directions; The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction, adjacent to the second sub-plane reflector, and tilted relative to the main plane reflector in the positive y-axis direction. Alternatively, the first sub-plane reflector is disposed at the apex region of the main plane reflector in the negative x-axis direction and the positive y-axis direction; The second sub-plane reflector is disposed in the region of the main plane reflector in the positive x-axis and positive y-axis directions; The third sub-plane reflector is disposed in the edge region of the main plane reflector in the negative y-axis direction and is tilted relative to the main plane reflector in the negative y-axis direction.

7. A detection device, characterized in that, include: The optical reflecting cavity as described in any one of claims 1 to 6; A light-emitting device for emitting a light beam reflected by the first sub-plane mirror into the optical reflection cavity; A photoelectric detector for receiving a light beam reflected by the second sub-plane mirror to the outside of the optical reflection cavity; A base is used to fix the optical reflecting cavity, the light-emitting device, and the photodetector. The light-emitting device and the photodetector are positioned on the base without exceeding the boundary of the optical reflection cavity in the z-axis direction and without passing through the transmission optical path of the light beam within the optical reflection cavity.

8. The detection device as described in claim 7, characterized in that, The optical reflection cavity, the light-emitting device, and the photodetector are disposed on the top surface of the base in the negative x-axis direction; Alternatively, the optical reflection cavity may be disposed on the top surface of the base in the negative x-axis direction; The light-emitting device is disposed on the bottom surface of the base in the positive x-axis direction, and the light beam emitted by the light-emitting device is transmitted to the first sub-plane reflector through the first through hole opened in the base; The photodetector is disposed on the bottom surface of the base in the positive x-axis direction, and the light beam reflected by the second sub-plane reflector is transmitted to the photodetector through the second through hole opened in the base.

9. The detection device as described in claim 8, characterized in that, The light-emitting device and the photodetector are disposed on the bottom surface of the base in the positive x-axis direction. The detection device further includes: The first reflector is disposed on the top surface of the base in the negative x-axis direction, and the light beam emitted by the light-emitting device is transmitted to the first sub-plane reflector through the first through hole and the first reflector. The second reflector is disposed on the top surface of the base in the negative x-axis direction. The light beam reflected by the second sub-plane reflector is transmitted to the photodetector through the second through hole and the second reflector.

10. The detection device according to any one of claims 7 to 9, characterized in that, The orthographic projection of the base along the x-axis is a circle or a near-circular shape.

Images