阅读说明：本技术 共焦抛物面反射扩束镜 (Confocal paraboloid reflection beam expander ) 是由 陈和 孙雨婷 陈思颖 张寅超 郭磐 檀望舒 于 2021-09-13 设计创作，主要内容包括：本发明公开了一种共焦抛物面反射扩束镜,共焦抛物面反射扩束镜中,第一抛物面反射镜具有第一曲率半径,第二抛物面反射镜具有第二曲率半径,第二抛物面反射镜和第一抛物面反射镜共焦同轴,入射光束沿光轴入射到第一抛物面反射镜,光轴旋转90°后入射到第二抛物面反射镜,光轴旋转90°后与入射光束方向相反以第一次扩束,第一双平面反射镜接收且反射第一次扩束后的入射光束,并将光轴旋转90°,第二双平面反射镜接收且反射来自第一双平面反射镜的反射光束,并将其光轴旋转90°,使得反射光束沿光轴入射到第一抛物面反射镜,第一抛物面反射镜将光轴旋转90°后入射到第二抛物面反射镜,光轴旋转90°后与入射光束方向相反以第二次扩束。(The invention discloses a confocal paraboloid reflection beam expander, wherein in the confocal paraboloid reflection beam expander, a first paraboloid reflector has a first curvature radius, a second paraboloid reflector has a second curvature radius, the second paraboloid reflector and the first paraboloid reflector are in confocal and coaxial, an incident light beam enters the first paraboloid reflector along an optical axis, the incident light beam enters the second paraboloid reflector after the optical axis rotates 90 degrees, the incident light beam is expanded for the first time in a direction opposite to the incident light beam after the optical axis rotates 90 degrees, the first biplane reflector receives and reflects the incident light beam after the first time of expansion, the optical axis rotates 90 degrees, the second biplane reflector receives and reflects a reflected light beam from the first biplane reflector, the optical axis rotates 90 degrees, the reflected light beam enters the first paraboloid reflector along the optical axis, the first paraboloid reflector rotates 90 degrees and then enters the second paraboloid reflector, the optical axis rotates by 90 degrees and then is opposite to the incident beam direction to expand for the second time.)

1. A confocal paraboloid reflection beam expander is characterized by comprising,

a first parabolic reflector having a first radius of curvature,

a second parabolic reflector with a second curvature radius larger than the first curvature radius, the second parabolic reflector and the first parabolic reflector are confocal and coaxial, the distance between the vertex of the second parabolic reflector and the vertex of the first parabolic reflector is the sum of the focal lengths of the second parabolic reflector and the first parabolic reflector, an incident light beam enters the first parabolic reflector along the optical axis, enters the second parabolic reflector after the optical axis rotates by 90 degrees, and expands the beam for the first time after the optical axis rotates by 90 degrees and is opposite to the direction of the incident light beam,

a first biplane reflector for receiving and reflecting the first beam-expanded incident beam and rotating the optical axis by 90 degrees,

a second bi-planar mirror that receives and reflects the reflected beam from the first bi-planar mirror and rotates its optical axis by 90 DEG such that the reflected beam is incident on the first parabolic mirror along the optical axis,

the first parabolic reflector rotates the optical axis by 90 degrees and then enters the second parabolic reflector, and the optical axis rotates by 90 degrees and then is opposite to the incident beam direction to expand the beam for the second time.

2. A confocal parabolic reflecting beam expander according to claim 1, characterized in that preferably said first bi-planar mirror comprises,

a first plane mirror receiving an incident beam from the first reflected expanded beam,

and the second plane reflector receives the light beam from the first plane reflector and reflects the light beam, and the included angle between the first plane reflector and the second plane reflector is 45 degrees, so that the light beam is vertical to the incident light beam direction of the first reflected expanded beam.

3. A confocal parabolic reflecting beam expander according to claim 1, wherein the first planar mirror is angled at 30 ° from vertical.

4. A confocal parabolic reflecting beam expander according to claim 2, wherein said second bi-planar mirror comprises,

a third planar mirror receiving an incident light beam from the first dual planar mirror,

and the fourth plane mirror receives the light beam from the third plane mirror, reflects the light beam, enables the light beam to be opposite to the incident light beam expanded by the first reflection, and vertically irradiates the first paraboloid mirror.

5. A confocal parabolic reflecting beam expander according to claim 4, wherein said third and fourth planar mirrors are angled at 45 °.

6. A confocal parabolic reflecting beam expander according to claim 4, wherein said fourth plane mirror is angled 30 ° from vertical.

7. A confocal parabolic reflecting beam expander according to claim 1, wherein the second radius of curvature is 150mm and the first radius of curvature is 30 mm.

8. A confocal parabolic reflecting beam expander according to claim 1, wherein the first parabolic reflector or the second parabolic reflector satisfies the aspheric formula:where r is the radius of curvature, k-1, and c is the derivative of the radius of curvature.

9. The confocal parabolic reflecting beam expander of claim 4, wherein the central axis of the first parabolic reflector is collinear with the central axis of the second parabolic reflector, and the first and second bi-planar reflectors are symmetric with respect to the central axis of the first parabolic reflector or the central axis of the second parabolic reflector.

10. A confocal parabolic reflecting beam expander according to claim 9, wherein said first and fourth planar mirrors are symmetric with respect to the central axis of the first parabolic mirror or the central axis of the second parabolic mirror, and said second and third planar mirrors are symmetric with respect to the central axis of the first parabolic mirror or the central axis of the second parabolic mirror.

Technical Field

The invention relates to the technical field of optics, in particular to a confocal paraboloid reflection beam expander.

Background

Because the typical laser beam emitted by the laser has a small diameter and a certain divergence angle, in the fields of laser ranging, light source beam expansion and the like, the laser has the requirement of long-distance transmission and the emergent light spot is far larger than the light spot of the laser, so the beam expansion collimation needs to be carried out on the laser beam. The beam expanding systems widely used at present are of two types, one is a transmission type laser beam expanding system suitable for small-magnification beam expanding, when the aperture of laser is increased, the aperture of a lens is also increased, and therefore aberration related to the aperture of the lens, such as spherical aberration, coma aberration and the like, is increased. And secondly, the reflective beam expanding system without chromatic aberration can realize high-magnification beam expansion. Such as a common off-axis griighland reflective beam expanding system and a reflective beam expanding system consisting of an off-axis parabolic mirror. However, the horizontal distance between the primary and secondary mirrors of the off-axis griighbein system is relatively long, the lens barrel required for assembly and adjustment is very long, and the reflective beam expanding system consisting of two off-axis parabolic mirrors needs a large off-axis amount during high-multiple beam expansion, so that the cost is high and the volume is large.

The above information disclosed in this background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is well known to those of ordinary skill in the art.

Disclosure of Invention

The invention aims to provide a confocal paraboloid reflection beam expander, which overcomes the problem of aberration related to the aperture of a lens in a transmission type laser beam expanding system, realizes miniaturization of the reflection type beam expanding system through twice reflection beam expansion, greatly reduces the volume of the reflection type beam expander under the condition of the same beam expansion multiple, reduces the cost and can realize 25 times of collimation beam expansion of laser.

In order to achieve the above purpose, the invention provides the following technical scheme:

the invention discloses a confocal paraboloid reflection beam expander, which comprises a reflector,

a first parabolic reflector having a first radius of curvature,

a second parabolic reflector with a second curvature radius larger than the first curvature radius, the second parabolic reflector and the first parabolic reflector are confocal and coaxial, the distance between the vertex of the second parabolic reflector and the vertex of the first parabolic reflector is the sum of the focal lengths of the second parabolic reflector and the first parabolic reflector, an incident light beam enters the first parabolic reflector along the optical axis, enters the second parabolic reflector after the optical axis rotates by 90 degrees, and expands the beam for the first time after the optical axis rotates by 90 degrees and is opposite to the direction of the incident light beam,

a first biplane reflector for receiving and reflecting the first beam-expanded incident beam and rotating the optical axis by 90 degrees,

a second bi-planar mirror that receives and reflects the reflected beam from the first bi-planar mirror and rotates its optical axis by 90 DEG such that the reflected beam is incident on the first parabolic mirror along the optical axis,

the first parabolic reflector rotates the optical axis by 90 degrees and then enters the second parabolic reflector, and the optical axis rotates by 90 degrees and then is opposite to the incident beam direction to expand the beam for the second time.

In the confocal paraboloidal reflection beam expander, the first biplane reflector comprises,

a first plane mirror receiving an incident beam from the first reflected expanded beam,

and the second plane reflector receives the light beam from the first plane reflector and reflects the light beam, and the included angle between the first plane reflector and the second plane reflector is 45 degrees, so that the light beam is vertical to the incident light beam direction of the first reflected expanded beam.

In the confocal paraboloid reflection beam expander, the included angle between the first plane reflector and the vertical direction is 30 degrees.

In the confocal parabolic reflection beam expander, the second bi-planar reflector comprises,

a third planar mirror receiving an incident light beam from the first dual planar mirror,

and the fourth plane mirror receives the light beam from the third plane mirror, reflects the light beam, enables the light beam to be opposite to the incident light beam expanded by the first reflection, and vertically irradiates the first paraboloid mirror.

In the confocal paraboloid reflection beam expander, the included angle between the third plane reflector and the fourth plane reflector is 45 degrees.

In the confocal paraboloidal reflection beam expander, the included angle between the fourth plane reflector and the vertical direction is 30 degrees.

In the confocal paraboloid reflection beam expander, the second curvature radius is 150mm, and the first curvature radius is 30 mm.

In the confocal paraboloidal reflection beam expander, the first paraboloidal reflector or the second paraboloidal reflector meets an aspherical formula:where r is the radius of curvature, k-1, and c is the derivative of the radius of curvature.

In the confocal parabolic reflection beam expander, the central axis of the first parabolic reflector is collinear with the central axis of the second parabolic reflector, and the first and second double-plane reflectors are symmetrical relative to the central axis of the first parabolic reflector or the central axis of the second parabolic reflector.

In the confocal parabolic reflection beam expander, the first plane reflector and the fourth plane reflector are symmetrical relative to the central axis of the first parabolic reflector or the central axis of the second parabolic reflector, and the second plane reflector and the third plane reflector are symmetrical relative to the central axis of the first parabolic reflector or the central axis of the second parabolic reflector.

In the technical scheme, the confocal paraboloid reflection beam expander provided by the invention has the following beneficial effects: according to the confocal paraboloid reflection beam expander, the direction of emergent light is changed through the two biplane reflectors, the confocal paraboloid reflector can be repeatedly utilized for expanding beams for two times, the off-axis amount of the paraboloid reflector required by single reflection is greatly reduced, the size is reduced, and the processing cost is saved. The double-plane reflector mainly has the main function of reflecting light beams through the front surface and the back surface, and when the double-plane reflector rotates as a rigid body, the direction of emergent light rays cannot be changed as long as the direction of incident light rays is unchanged.

Drawings

In order to more clearly illustrate the embodiments of the present application or technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to the drawings.

FIG. 1 is a schematic diagram of an embodiment of a confocal parabolic reflecting beam expander;

FIG. 2 is a schematic diagram of a first beam expansion principle of one embodiment of a confocal parabolic reflector beam expander;

FIG. 3 is a schematic diagram of the operation of a first bi-planar mirror of an embodiment of a confocal parabolic reflector beam expander;

FIG. 4 is a schematic diagram of the working principle of a second bi-planar mirror of an embodiment of a confocal parabolic reflecting beam expander;

FIG. 5 is a schematic diagram of a second reflection beam expansion operation of an embodiment of a confocal parabolic reflection beam expander;

fig. 6 is a schematic diagram of an optical path structure of an embodiment of a confocal parabolic reflection beam expander.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be described in detail and completely with reference to fig. 1 to 6 of the drawings of the embodiments of the present invention, and it is apparent that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In order to make the technical solutions of the present invention better understood, those skilled in the art will now describe the present invention in further detail with reference to the accompanying drawings.

In one embodiment, as shown in fig. 1-6, a confocal parabolic reflective beam expander includes,

a first parabolic mirror 1 having a first radius of curvature,

a second parabolic reflector 2 with a second curvature radius larger than the first curvature radius, the second parabolic reflector 2 and the first parabolic reflector 1 are confocal and coaxial, the distance between the vertex of the second parabolic reflector 2 and the vertex of the first parabolic reflector 1 is the sum of the focal lengths of the second parabolic reflector and the first parabolic reflector, an incident light beam enters the first parabolic reflector 1 along an optical axis, enters the second parabolic reflector 2 after the optical axis rotates by 90 degrees, and expands the beam for the first time in the direction opposite to the direction of the incident light beam after the optical axis rotates by 90 degrees,

a first biplane reflector for receiving and reflecting the first beam-expanded incident beam and rotating the optical axis by 90 degrees,

a second bi-planar mirror which receives and reflects the reflected beam from the first bi-planar mirror and rotates its optical axis by 90 DEG such that the reflected beam is incident on the first parabolic mirror 1 along the optical axis,

the first parabolic reflector 1 rotates the optical axis by 90 degrees and then enters the second parabolic reflector 2, and the optical axis rotates by 90 degrees and then is opposite to the incident beam direction to expand the beam for the second time.

In a preferred embodiment of the confocal parabolic reflection beam expander, the first bi-planar reflector comprises,

a first plane mirror 3 receiving the incident beam from the first reflected expanded beam,

and the second plane mirror 4 receives the light beam from the first plane mirror 3 and reflects the light beam, and the included angle between the first plane mirror 3 and the second plane mirror 4 is 45 degrees, so that the light beam is perpendicular to the incident light beam direction of the first reflected expanded beam.

In the preferred embodiment of the confocal parabolic reflection beam expander, the included angle between the first plane reflector 3 and the vertical direction is 30 °.

In a preferred embodiment of the confocal parabolic reflection beam expander, the second bi-planar mirror comprises,

a third plane mirror 5 receiving an incident light beam from the first plane mirror,

and a fourth plane mirror 6 for receiving the light beam from the third plane mirror 5, reflecting the light beam so that the light beam is opposite to the incident light beam expanded by the first reflection and vertically incident on the first parabolic mirror 1.

In a preferred embodiment of the confocal parabolic reflection beam expander, an included angle between the third plane reflector 5 and the fourth plane reflector 6 is 45 °.

In a preferred embodiment of the confocal parabolic reflection beam expander, the angle between the fourth plane mirror 6 and the vertical direction is 30 °.

In the preferred embodiment of the confocal parabolic reflection beam expander, the second radius of curvature is 150mm, and the first radius of curvature is 30 mm.

In the preferred embodiment of the confocal parabolic reflection beam expander, the first parabolic reflector 1 or the second parabolic reflector 2 satisfies the aspheric formula:where r is the radius of curvature, k-1, and c is the derivative of the radius of curvature.

In the preferred embodiment of the confocal parabolic reflection beam expander, the central axis of the first parabolic reflector 1 is collinear with the central axis of the second parabolic reflector 2, and the first and second bi-planar reflectors are symmetrical with respect to the central axis of the first parabolic reflector 1 or the central axis of the second parabolic reflector 2.

In the preferred embodiment of the confocal parabolic reflection beam expander, the first plane mirror 3 and the fourth plane mirror 6 are symmetrical with respect to the central axis of the first parabolic mirror 1 or the central axis of the second parabolic mirror 2, and the second plane mirror 4 and the third plane mirror 5 are symmetrical with respect to the central axis of the first parabolic mirror 1 or the central axis of the second parabolic mirror 2.

In one embodiment, the confocal parabolic reflection beam expander structure of the present invention is shown in fig. 1, a first parabolic reflector 1 with a curvature radius of 30mm, a second parabolic reflector 2 with a curvature radius of 150mm, the first parabolic reflector 1 and the second parabolic reflector 2 are confocal and coaxial, a vertex distance is the sum of focal lengths of the two parabolic reflectors, an angle between a first plane reflector 3 and a vertical direction is 30 °, an angle between the first plane reflector 3 and a second plane reflector 4 is 45 °, an angle between a fourth plane reflector 6 and the vertical direction is 30 °, and an angle between a third plane reflector 5 and a fourth plane reflector 6 is 45 °. A laser beam with the beam radius of r0 enters the first parabolic reflector 1 along the optical axis, the laser beam enters the second parabolic reflector 2 after the optical axis rotates by 90 degrees, the optical axis rotates by 90 degrees and is opposite to the direction of the incident laser beam, the first reflection beam expansion is realized, and the radius of the emergent beam is r 1. The first double-plane reflector receives the light rays reflected and expanded for the first time and changes the direction of the light rays to enable emergent light to be emitted in the vertical direction, and the second double-plane reflector receives incident light from the first double-plane reflector and reflects the light beams, so that the light beams are opposite to the direction of the incident light beams reflected and expanded for the first time and vertically enter the first parabolic reflector 1. The light beam is reflected by the first parabolic reflector 1 and then enters the second parabolic reflector 2 to realize secondary beam expansion, the radius of the emergent light beam is r2, the direction of the emergent light beam is opposite to that of the incident light beam, and r2 is larger than r1 and is larger than r 0.

In one embodiment, the first parabolic mirror satisfies the aspheric formula:

radius of curvature R1 is 30mm, k-1,

the second is a parabolic reflector, and meets the aspheric formula:

radius of curvature R2 is 150mm, k-1,

fig. 2 shows a schematic diagram of the first beam expansion of the laser beam, wherein the focal points of the first parabolic mirror 1 and the second parabolic mirror 2 are coincident, the distance between the vertex of the first parabolic mirror 1 and the vertex of the second parabolic mirror 2 is d12, and d12 is numerically equal to the sum of the focal lengths of the first parabolic mirror 1 and the second parabolic mirror 2. The radius of an incident laser beam parallel to the optical axis is R0, the distance h1 between the incident laser beam and the optical axis is the curvature radius R1 of the first parabolic reflector 1, after the laser is reflected twice, the beam radius is R1, and the beam expansion multiple R is equal to₁/r₀＝R₂/R₁At 5, the vertex distance isThe first plane reflector 3 and the second plane reflector 4 form a first double plane reflector, wherein alpha is an included angle between the first plane reflector 3 and the vertical direction, and beta is a first plane reflectorThe angle β between the mirror 3 and the second plane mirror 4 is 45 °. When the double-plane reflector rotates as a rigid body, the alpha angle can be randomly changed within a certain range as long as the incident light beam and the emergent light beam are not shielded, and the direction of the emergent light beam is not influenced. The first bi-plane mirror is operative to receive the first reflected expanded incident beam, rotate its optical axis by 90 °, as shown in figure 3,

the third plane mirror 5 and the fourth plane mirror 6 form a second double plane mirror, wherein γ is an included angle between the fourth plane mirror 6 and the vertical direction, β is an included angle between the third plane mirror 5 and the fourth plane mirror 6, and β is 45 °. When the biplane mirror rotates as a rigid body, the gamma angle can be changed randomly within a certain range as long as the incident light beam and the emergent light beam are not shielded, and the direction of the emergent light beam is not influenced. The second bi-plane mirror is used for receiving the reflected light beam of the first bi-plane mirror, and rotating the optical axis of the reflected light beam by 90 °, the principle is as shown in fig. 4, the first parabolic mirror 1 receives the incident light beam from the second bi-plane mirror, the height h2 of the incident light beam is equal to the curvature radius of the first parabolic mirror 1 in value, the light beam is reflected and expanded by the first parabolic mirror 1 and then enters the surface of the second parabolic mirror 2 for reflection, and the direction of the emergent light beam is opposite to the direction of the laser emitted by the laser.

Fig. 6 is a schematic view of an optical path structure of the confocal parabolic reflection beam expander when the beam expansion multiple of the confocal parabolic reflection beam expander is 25 times and an angle between the first plane reflector 3 and the vertical direction is 30 °.

Finally, it should be noted that: the embodiments described are only a part of the embodiments of the present application, and not all embodiments, and all other embodiments obtained by those skilled in the art without making creative efforts based on the embodiments in the present application belong to the protection scope of the present application.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that the described embodiments may be modified in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are illustrative in nature and should not be construed as limiting the scope of the invention.