CN111880315A - Laser lighting equipment - Google Patents

Abstract

The present application discloses a laser lighting device, comprising: a laser for emitting a laser beam, which is coupled into an optical fiber; an optical fiber for transmitting the laser beam; a collimating optical system for collimating the laser beam emitted from the optical fiber, And illuminate the surface of the random microlens array; the random microlens array is used to homogenize and shape the laser beam, emit a beam with a fixed divergence angle, and enter the angle adjustment optical system; the angle adjustment optical system is used to The outgoing beam from the lens array is adjusted to the required divergence angle and then outgoing. The invention adopts random microlens array to homogenize and shape the laser beam, which can make the outgoing beam within a fixed divergence angle range, improve the utilization rate of light energy, and reduce the coherence of the beam to a certain extent, thereby reducing the speckle effect and further improving the The quality of the light spot after shaping, and at the same time, the angle adjustment optical system is used to adjust the outgoing beam of the random microlens array to control the final outgoing beam angle.

Description

a laser lighting device

technical field

The present invention relates to the field of optical technology, in particular to a laser lighting device.

Background technique

Laser has the characteristics of high brightness, narrow spectral width, good directionality, etc., and it has its own unique advantages for lighting. Laser lighting technology is widely used in national defense engineering, aerospace engineering, night vision monitoring, laser display and other fields. However, due to the good monochromaticity of the laser and the strong coherence, laser speckle will be generated when illuminated to the surface of the object. At the same time, due to the large difference in the divergence angle between the fast and slow axes of the laser output by the commonly used semiconductor laser, a uniform circular light spot cannot be output. Generally, the light spot output by the method of coupling into the optical fiber for output shows a Gaussian distribution, which cannot show good uniformity on the required illumination surface.

In view of the problem of uniformity in laser illumination, the current methods of laser homogenization and shaping mainly use ground glass, aspheric lens groups, microlens arrays, diffractive optical elements, birefringent lens groups, and homogenizing rods. The ground glass homogenizes the laser light by random scattering formed by the microstructure on the glass surface; the aspheric lens group shapes the Gaussian beam through one or more aspheric lenses, and then collimates the output by another lens; the microlens array divides the incident beam The sub-beams are formed into several sub-beams, and the sub-beams are overlapped on the handle surface by a plurality of spherical mirrors; the diffractive optical element is processed by the continuous relief structure of the multi-step phase structure approximating the hologram, and the beam shaping is performed by using diffractive optics. The beam is shaped into square, ring or even any shape; the homogenizing rod homogenizes the laser light through multiple total reflections of the light source inside the glass. However, due to the random scattering of ground glass, the coherence of each sub-beam output by the aspheric lens and the microlens array is high, and the speckle phenomenon is serious, and the diffractive optical element can only achieve the required spot shape and uniformity within a certain distance range. The overall effect is not ideal.

Therefore, how to reduce the laser speckle and improve the quality of the shaped light spot is a technical problem to be solved urgently by those skilled in the art.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a laser lighting device, which can improve the utilization rate of light energy, reduce the speckle effect, improve the quality of the light spot after shaping, and realize the outgoing beam of any divergence angle. Its specific plan is as follows:

A laser lighting device, comprising:

A laser, for emitting a laser beam, which is coupled into an optical fiber;

the optical fiber for transmitting the laser beam;

a collimating optical system for collimating the laser beam emitted from the optical fiber and illuminating the surface of the random microlens array;

The random microlens array is used to homogenize and shape the laser beam, emit a beam with a fixed divergence angle, and enter the angle adjustment optical system;

The angle adjustment optical system is used for adjusting the outgoing beam of the random microlens array to a desired divergence angle and then outgoing.

Preferably, in the above-mentioned laser lighting device provided in the embodiment of the present invention, the collimating optical system includes a lens group consisting of a first meniscus lens, a second meniscus lens, and a third meniscus lens.

Preferably, in the above-mentioned laser lighting device provided by the embodiment of the present invention, one side of the surface of the random microlens array is a plane, and the other side is a microlens array with random radii.

Preferably, in the above-mentioned laser lighting device provided in the embodiment of the present invention, the fixed divergence angle of the light beams emitted by the random microlens array is in the range of 1° to 20°.

Preferably, in the above-mentioned laser illuminating device provided by the embodiment of the present invention, the angle adjustment optical system adopts a near double telecentric structure.

Preferably, in the above-mentioned laser lighting device provided in the embodiment of the present invention, the angle adjustment optical system includes a lens group consisting of a first lenticular lens, a second lenticular lens and a fourth meniscus lens.

Preferably, in the above-mentioned laser lighting device provided by the embodiment of the present invention, the selected wavelength of the laser is in the range of 400nm to 1500nm, and the power range is in the range of 0.1W to 60W.

Preferably, in the above-mentioned laser lighting device provided by the embodiment of the present invention, the diameter of the optical fiber is in the range of 50 μm to 400 μm, and the NA is in the range of 0.12 to 0.25.

It can be seen from the above technical solutions that a laser lighting device provided by the present invention includes: a laser, which is used to emit a laser beam and is coupled into an optical fiber; an optical fiber, which is used to transmit the laser beam; and a collimating optical system, which is used to The laser beam emitted by the optical fiber is collimated and illuminated to the surface of the random microlens array; the random microlens array is used to homogenize and shape the laser beam, emit a beam with a fixed divergence angle, and enter the angle adjustment optical system; angle The optical system is adjusted to adjust the outgoing beam from the random microlens array to the desired divergence angle and then outgoing.

The invention uses a random microlens array to homogenize and shape the laser beam, which can make the outgoing beam within a fixed divergence angle range, improve the utilization rate of light energy, and reduce the coherence of the beam to a certain extent, thereby reducing the speckle effect. The desired shape and uniformity can be maintained at any distance, and the quality of the light spot after shaping is further improved. At the same time, the angle adjustment optical system is used to adjust the outgoing beam of the random microlens array to control the final outgoing beam angle and realize the outgoing beam of any divergence angle.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the accompanying drawings required for the description of the embodiments or related technologies. Obviously, the accompanying drawings in the following description are only the For the embodiments of the invention, for those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a laser lighting device provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The present invention provides a laser lighting device, as shown in Figure 1, comprising:

The laser is used to emit a laser beam, which is coupled into the fiber 1;

Fiber 1, used to transmit the laser beam;

The collimating optical system 2 is used for collimating the laser beam emitted from the optical fiber 1 and illuminating the surface of the random microlens array 3;

The random microlens array 3 is used to homogenize and shape the laser beam, emit a beam with a fixed divergence angle, and enter the angle adjustment optical system 4;

The angle adjustment optical system 4 is used to adjust the emitted light beam from the random microlens array 3 to a desired divergence angle and then emit the light.

In the above-mentioned laser illuminating device provided by the embodiment of the present invention, the laser beam emitted by the laser is coupled into one end of the optical fiber, output through the other end of the optical fiber, and then collimates and illuminates the rear surface of the random microlens array through the collimating optical system, and passes through the random microlens array. After shaping the beam, a beam with a fixed divergence angle is emitted, and then the beam output is controlled by an angle adjustment optical system. In this way, a random microlens array is used to homogenize and shape the laser beam, which can make the emitted beam within the range of the fixed divergence angle and improve the light output. Energy utilization, and reduce the coherence of the beam to a certain extent, thereby reducing the speckle effect, maintaining the desired shape and uniformity at any distance, and further improving the quality of the light spot after shaping. The outgoing beam of the array is adjusted to control the final outgoing beam angle to realize an outgoing beam of any divergence angle.

During specific implementation, in the above-mentioned laser lighting device provided by the embodiment of the present invention, as shown in FIG. 1 , the collimating optical system 2 may include a first meniscus lens 21 , a second meniscus lens 22 , and a third meniscus lens 22 . A lens group composed of lenses 23 . Preferably, the focal length of the lens group may be 28.64 mm, and the divergence angle after collimation may be 1°. It should be noted that the collimating optical system 2 achieves the effect of the collimation angle ≤ 2° according to the selected optical fibers, and the specific design parameters can be determined according to the actual situation, which is not limited here.

In the specific implementation, in the above-mentioned laser lighting device provided by the embodiment of the present invention, as shown in FIG. 1 , one side of the surface of the random microlens array 3 may be set as a plane, and the other side may be set as a microlens with a random radius array. Specifically, the fixed divergence angle range of the light beam emitted by the random microlens array 3 can be 1° to 20°, that is to say, the divergence angle of the random microlens array 3 can be arbitrarily selected from 1° to 20°, and the thickness and diameter are not specified. Require. Preferably, the full angle of divergence of the random microlens array is 10°, the shape is circular, the thickness is 2mm, the diameter is 13mm, and the material is quartz glass.

In the specific implementation, in the above-mentioned laser lighting device provided by the embodiment of the present invention, in order to ensure that the uniformity of the light spot emitted by the random microlens array remains unchanged after passing through the angle adjustment optical system, the angle adjustment optical system 4 can adopt the near and double distances. heart structure. As shown in FIG. 1 , the angle adjustment optical system 4 may include a lens group consisting of a first lenticular lens 41 , a second lenticular lens 42 and a fourth meniscus lens 43 . Preferably, the exit angle of the angle adjustment optical system 4 is 30° in full angle, and the exit window is 3.73 mm. Such an angle adjustment optical system is carefully designed according to the telecentricity of the object side (the side of the random microlens array) and the near-telecentric structure of the image side, which can maintain the brightness uniformity of the light spot emitted by the random microlens array unchanged. It should be noted that, different specific design parameters can be selected for the angle adjustment optical system according to the selected random microlens array size and outgoing beam divergence angle, as well as the final required outgoing beam divergence angle.

In the specific implementation, in the above-mentioned laser lighting device provided by the embodiment of the present invention, the selected wavelength of the laser can be in the range of 400nm to 1500nm, and the power range can be from 0.1W to 60W, that is, the selected wavelength of the laser can be from 400nm to 1500nm The power can be arbitrarily selected in the range of 0.1W to 60W. Preferably, the wavelength of the laser is 850 nm and the power is 1W.

In the specific implementation, in the above-mentioned laser lighting device provided by the embodiment of the present invention, the diameter of the optical fiber can be in the range of 50 μm to 400 μm, and the NA can be in the range of 0.12 to 0.25, that is, the diameter of the optical fiber can be arbitrarily selected between 50 μm and 400 μm , NA can be arbitrarily selected between 0.12 and 0.25. Preferably, the core diameter of the optical fiber is 100 μm, and the NA value is 0.22.

A laser lighting device provided by an embodiment of the present invention includes: a laser for emitting a laser beam, which is coupled into an optical fiber; an optical fiber for transmitting the laser beam; and a collimating optical system for collimating the laser beam emitted from the optical fiber straight, and illuminate to the surface of the random microlens array; the random microlens array is used to homogenize and shape the laser beam, emit a beam with a fixed divergence angle, and enter the angle adjustment optical system; the angle adjustment optical system is used to The outgoing beam from the random microlens array is adjusted to the required divergence angle and then outgoing. The invention uses a random microlens array to homogenize and shape the laser beam, which can make the outgoing beam within a fixed divergence angle range, improve the utilization rate of light energy, and reduce the coherence of the beam to a certain extent, thereby reducing the speckle effect. The desired shape and uniformity can be maintained at any distance, and the quality of the light spot after shaping is further improved. At the same time, the angle adjustment optical system is used to adjust the outgoing beam of the random microlens array to control the final outgoing beam angle and realize the outgoing beam of any divergence angle.

Finally, it should also be noted that in this document, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply these entities or that there is any such actual relationship or sequence between operations. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

The laser lighting equipment provided by the present invention has been introduced in detail above, and the principles and implementations of the present invention are described with specific examples in this paper. The descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific embodiments and application scope. To sum up, the content of this specification should not be construed as a limitation to the present invention.

Claims (8)

1. a laser lighting equipment, is characterized in that, comprises: A laser, for emitting a laser beam, which is coupled into an optical fiber; the optical fiber for transmitting the laser beam; a collimating optical system for collimating the laser beam emitted from the optical fiber and illuminating the surface of the random microlens array; The random microlens array is used to homogenize and shape the laser beam, emit a beam with a fixed divergence angle, and enter the angle adjustment optical system; The angle adjustment optical system is used for adjusting the outgoing beam of the random microlens array to a desired divergence angle and then outgoing. 2 . The laser lighting device according to claim 1 , wherein the collimating optical system comprises a lens group consisting of a first meniscus lens, a second meniscus lens, and a third meniscus lens. 3 . 3 . The laser lighting device according to claim 1 , wherein one side of the surface of the random microlens array is a plane, and the other side is a microlens array with random radii. 4 . 4 . The laser lighting device according to claim 3 , wherein the fixed divergence angle of the light beams emitted from the random microlens array ranges from 1° to 20°. 5 . 5 . The laser lighting device according to claim 1 , wherein the angle adjustment optical system adopts a near double telecentric structure. 6 . 6 . The laser lighting device according to claim 5 , wherein the angle adjustment optical system comprises a lens group consisting of a first biconvex lens, a second biconvex lens and a fourth meniscus lens. 7 . 7 . The laser lighting device according to claim 1 , wherein the selected wavelength of the laser is in the range of 400nm to 1500nm, and the power range is in the range of 0.1W to 60W. 8 . 8 . The laser lighting device according to claim 1 , wherein the diameter of the optical fiber ranges from 50 μm to 400 μm, and the NA ranges from 0.12 to 0.25. 9 .

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