Laser light source and laser light source system

Abstract

The application discloses a laser light source, which comprises a laser device, the laser device comprises at least one laser for generating at least one light beam with different divergence angles in a first direction and a second direction; a light homogenizing rod, which comprises an entrance end surface and an exit end surface, and the entrance end surface and the exit end surface are square; the entrance end surface receives the at least one light beam with different divergence angles in the first direction and the second direction, the exit end surface outputs the light beam after homogenization, and one diagonal line of the entrance end surface is parallel to the first direction or the second direction. Thus, the intensity and color distribution of the outgoing light beam on the fluorescent light source surface are homogenized, the size of the required light homogenizing rod is small, and the effects of low loss and low cost are achieved.

Description

[0001] This application is a divisional application of application number 201910807941.9, filed on August 29, 2019, entitled "Laser Light Source and Laser Light Source System". Technical Field

[0002] This invention relates to the field of light sources, and in particular to a laser light source and a laser light source system. Background Technology

[0003] Lasers have advantages such as small chip size, high brightness, concentrated emission direction, high power, and good laser beam quality. When laser light is irradiated by a wavelength conversion device, a small spot size and high brightness lighting source can be obtained.

[0004] However, since the beam emitted by the laser has a Gaussian distribution and the power density at the center is very high, when it is incident on the wavelength conversion element, the local heat at the center is very high, which limits the overall output brightness and reduces the conversion efficiency of the laser fluorescence. In addition, the intensity and color of the light are not uniform on the surface of the fluorescence source.

[0005] Therefore, in order to obtain a light source with high brightness, high efficiency, and uniform beam intensity and color, the laser beam is usually homogenized before being incident on a wavelength conversion element to convert it into a fluorescent light source. Conventional homogenization methods mostly use square rods or compound eyes, which are placed next to the laser to focus the laser beam on the light-incident end face of the square rod or compound eye, so that the light is emitted from the light-out end face to obtain a uniform beam.

[0006] However, this technical solution has drawbacks. When using a square rod to homogenize the light, the beam is reflected multiple times inside. The more times it is reflected, the more uniform the beam becomes. At this time, the required length of the square rod is longer. However, if the square rod is too long, it will cause disadvantages such as high light loss, high cost, and large product size. Summary of the Invention

[0007] The main technical problem solved by this invention is to provide a laser light source and a laser light source system that can make the intensity and color distribution of the emitted beam uniform on the fluorescent light source surface, and require a small uniform rod size, so as to achieve the effect of low loss and low cost.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A laser light source is provided, comprising:

[0010] A laser device includes at least one laser for generating at least one beam with different divergence angles along a first direction and along a second direction;

[0011] A light-homing rod includes an incident end face and an exit end face, wherein the incident end face and the exit end face are square, the incident end face receives at least one light beam with different divergence angles along a first direction and along a second direction, and the exit end face outputs a light beam after homogenization, and one diagonal of the incident end face is parallel to the first direction or the second direction.

[0012] The laser device includes multiple lasers, each laser generating a beam with a different divergence angle along a first direction and along a second direction;

[0013] And the first direction is perpendicular to the second direction.

[0014] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is:

[0015] A laser source system is provided, including the laser source and wavelength conversion device described above. The laser source outputs a uniform light beam to the wavelength conversion device, and the wavelength conversion device receives the uniform light beam and generates stimulated light with a wavelength range different from that of the uniform light beam.

[0016] The beneficial effects of the present invention are as follows: Unlike the prior art, the present invention shortens the length of the beam homogenizing rod and makes the emitted beam uniform by setting the diagonal of the beam homogenizing rod parallel to the first or second direction of the laser beam, thereby achieving low loss and low cost. Attached Figure Description

[0017] Figures 1a-1c This is a schematic diagram of a structure in which the fast and slow axes of the laser beam are parallel to the edge of the uniform beam.

[0018] Figures 2a-2b This is a schematic diagram of a structure in which the fast and slow axes of the laser beam are parallel to the diagonal of the uniform beam.

[0019] Figure 3 This is a schematic diagram of the structure of the laser light source of the present invention;

[0020] Figure 4a This is a schematic diagram of the structure of the first embodiment of the uniform beam in the laser light source of the present invention;

[0021] Figure 4b and Figure 4c This is a schematic diagram of the structure of the second embodiment of the uniform beam in the laser light source of the present invention;

[0022] Figure 4d and Figure 4e This is a schematic diagram of the third embodiment of the uniform beam in the laser light source of the present invention;

[0023] Figure 4f This is a schematic diagram of the fourth embodiment of the uniform beam in the laser light source of the present invention;

[0024] Figure 5a This is a schematic diagram of the structure of a first embodiment of the laser source of the present invention, which includes multiple lasers and a beam homogenizer.

[0025] Figure 5b This is a schematic diagram of the structure of a second embodiment of the laser source of the present invention, which includes multiple lasers and a beam homogenizing rod.

[0026] Figure 5c This is a schematic diagram of the third embodiment of the laser source of the present invention, which includes multiple lasers and a beam homogenizing rod.

[0027] Figure 6 This is a schematic diagram of the structure of the first embodiment of the laser source system of the present invention;

[0028] Figure 7 This is a schematic diagram of the structure of the second embodiment of the laser source system of the present invention;

[0029] Figure 8a and Figure 8b This is a structural schematic diagram of the third embodiment of the laser source system of the present invention. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] This invention proposes a laser source and a laser fluorescence source system. The laser source includes a laser device, which includes at least one laser. The laser generates beams with different divergence angles in two directions: a first direction (X-axis) and a second direction (Y-axis). A uniform beam is also provided, and the line connecting the diagonals of the uniform beam is parallel or perpendicular to the X-axis or Y-axis.

[0032] The basic principle of uniform light distribution using a uniform light distribution rod is that the light beam is superimposed after multiple reflections on the inner wall of the uniform light distribution rod, so that the light spot at the exit of the uniform light distribution rod is uniform. The more reflections, the more uniform the light spot. When the length and width of the uniform light distribution rod are fixed, the larger the laser beam angle, the more reflections, and the more uniform the light spot.

[0033] The beam emitted from a laser typically has different divergence angles along the fast and slow axes. A shorter rod is needed to achieve uniform beam distribution along the direction with the larger divergence angle, while a relatively longer rod is required along the direction with the smaller divergence angle. To ensure uniform beam distribution across the entire beam, the required rod length needs to be designed according to the direction with the smaller divergence angle, resulting in a relatively longer rod.

[0034] However, longer square rods lead to greater power loss, higher costs, and larger product sizes, which are disadvantages. Therefore, the design aims to keep the square rods as short as possible while ensuring beam homogenization.

[0035] See Figure 1a A laser beam emitted from laser 101 has different divergence angles along its fast and slow axes, for example, a fast axis divergence angle of 45 degrees and a slow axis divergence angle of 14 degrees. This beam is focused by lens system 102 onto a homogenizing rod with sides of 0.4 mm and a length of 17 mm. When the fast and slow axes of the laser are parallel to the sides of the homogenizing rod 103, the beam spot at the exit of the homogenizing rod 103 is non-uniform in the left-right direction. Figure 1b As shown. Only when the length of the homogenizing rod is increased to 27mm will the light spot at the exit of the homogenizing rod be uniform, as... Figure 1c As shown.

[0036] See Figure 2a Optical path system and Figure 1a The same applies, but the fast and slow axes of the laser 101 are parallel to the diagonal of the homogenizing rod 103. When the length of the homogenizing rod is 17mm, the light spot at the exit of the homogenizing rod is already uniform, such as... Figure 2b As shown.

[0037] The above explains that when the divergence angle of the laser beam generated along the first direction (such as the X direction) and along the second direction (such as the Y direction) are different, when the diagonal direction of the uniform beam is parallel to the X or Y direction, a shorter uniform beam length can achieve the uniform beam effect compared to when the side of the uniform beam is parallel to the X or Y direction.

[0038] Please see Figure 3 This is a schematic diagram of the structure of the laser source of the present invention. The laser source includes a laser device, which includes at least one laser 301 for generating at least one beam with different divergence angles along a first direction and along a second direction;

[0039] A light-diffusing rod 303 includes an incident end face and an exit end face, and the incident and exit end faces are square. A diagonal X0 of the incident and exit end faces is parallel to the first direction or the second direction. The incident end face of the light-diffusing rod 303 receives light beams with different divergence angles along the first and second directions, and the exit end face outputs a light beam after light diffusing. The light beam is diffused by multiple reflections in the light-diffusing rod 303.

[0040] The laser source may further include a lens 302, which is disposed between the laser 301 and the beam homogenizer 303. The lens 302 is used to focus at least one beam of light generated by the laser 301, with different divergence angles along a first direction and a second direction, onto the incident surface of the beam homogenizer 303. The number of lenses 302 corresponds to the number of lasers 301, or a large lens can be used to converge the beams emitted by all lasers 301. The number of lasers is set as needed.

[0041] Please see Figure 4aThis is a schematic diagram of the structure of the first embodiment of the homogenizing rod in the laser source of the present invention. The homogenizing rod 3 is a solid square rod, including an incident end face and an exit end face, both of which are square. One diagonal of the incident and exit end faces of the homogenizing rod is set parallel to the first direction (such as the X-axis or fast axis) or the second direction (such as the Y-axis or slow axis), thereby achieving a homogenized beam output after the laser beam passes through the homogenizing rod.

[0042] Please see Figure 4b This is a schematic diagram of the structure of a second embodiment of the homogenizing rod in the laser beam of the present invention. The difference between the second embodiment and the first embodiment is that the homogenizing rod is an optical fiber, which includes a solid square core 31 and a cladding layer 32 covering the core.

[0043] Please see Figure 4c The optical fiber also includes a coating layer 33 covering the wrapping layer 32.

[0044] The square rod core includes an incident light end face and an exit light end face, both of which are square. One diagonal of the incident light end face and the exit light end face of the uniform light rod is set to be parallel to the first direction (such as the X-axis or fast axis) or the second direction (such as the Y-axis or slow axis), so that the light beam emitted by the laser is output as a uniform light beam after passing through the uniform light rod.

[0045] See Figure 4d and Figure 4e This is a schematic diagram of the third embodiment of the homogenizing rod in the laser light source of the present invention. Figure 4d The difference between the third embodiment shown and the first embodiment described above is that the light-diffusing rod 6 is conical, including an incident end face and an exit end face. The incident end face is smaller than the exit end face. At least one beam 1 emitted by the laser with different divergence angles along the first direction and the second direction converges on the incident end face of the light-diffusing rod 6. The diagonal of the light-diffusing rod 6 is parallel to the first direction (X-axis, fast axis) or the second direction (Y-axis, slow axis) of the beam.

[0046] like Figure 4e As shown, the light-diffusing rod 6 is conical, including an incident end face and an exit end face. The incident end face is larger than the exit end face. The light beams 1 emitted by the laser with different divergence angles along the first direction and the second direction converge on the incident end face of the light-diffusing rod 6. The diagonal of the light-diffusing rod is parallel to the X-axis or Y-axis of the light beam.

[0047] See Figure 4fThis is a schematic diagram of the fourth embodiment of the homogenizing rod in the laser source of the present invention. The difference between the fourth embodiment and the first embodiment is that the homogenizing rod 7 is a hollow rod, including an incident end face and an exit end face. A square hole 34 is formed by passing through the incident end face of the homogenizing rod to the exit end face. The square hole 34 and the homogenizing rod 7 have the same center line. The laser beams 1 emitted from the laser with different divergence angles along the first direction and the second direction converge on the incident end face of the homogenizing rod 7. The diagonal of the homogenizing rod is parallel to the X-axis or Y-axis of the laser beam.

[0048] The laser beam can be a beam synthesized from multiple lasers, wherein the fast and slow axes of the beams emitted from different lasers can be in the same direction or perpendicular to each other, and the diagonal of the uniform beam remains parallel to the fast and slow axes. Furthermore, because the number or spacing of the different lasers in the X and Y directions varies, the divergence angle of the beam incident on the square rod entrance differs in both the X and Y directions.

[0049] See Figure 5a This is a schematic diagram of the structure of a first embodiment of the laser source of the present invention, comprising multiple lasers and a beam homogenizing rod. The fast and slow axes of the beams emitted from different lasers are arranged in the same direction. That is, the fast axes of the beams emitted from multiple lasers are all parallel to the first direction. The emitted beams 1, which have different divergence angles along the first and second directions, converge onto the lens group 42, which focuses the emitted beams onto one end face of the beam homogenizing rod 41. The diagonal of the beam homogenizing rod is parallel to the X-axis or Y-axis of the emitted beam.

[0050] See Figure 5bThis is a schematic diagram of the structure of a second embodiment of the laser source of the present invention, comprising multiple lasers and a homogenizing rod. The fast axes and slow axes of different lasers are perpendicular to each other. That is, the fast axes of the emitted beams from some of the lasers are parallel to the first direction, while the fast axes of the emitted beams from the remaining lasers are perpendicular to the first direction. For example, in one embodiment, if the multiple lasers are arranged in two columns, the fast axes of the emitted beams from one column are parallel to the first direction, and the fast axes of the emitted beams from the other column are perpendicular to the first direction. In another embodiment, if the multiple lasers are arranged in two rows, the fast axes of the emitted beams from one row are parallel to the first direction, and the fast axes of the emitted beams from the other row are perpendicular to the first direction. In yet another embodiment, if the multiple lasers are arranged in two rows, the fast axes of the emitted beams from the odd-numbered lasers in one row are parallel to the first direction, and the fast axes of the emitted beams from the even-numbered lasers in the other row are perpendicular to the first direction, and the fast axes of the emitted beams from the even-numbered lasers in the other row are parallel to the first direction. Alternatively, in another embodiment, multiple lasers are arranged in two columns. In one column, the fast axis of the emitted beams from the odd-numbered lasers is parallel to the first direction, while the fast axis of the emitted beams from the even-numbered lasers is perpendicular to the first direction. In the other column, the fast axis of the emitted beams from the odd-numbered lasers is perpendicular to the first direction, while the fast axis of the emitted beams from the even-numbered lasers is parallel to the first direction. Beams 1 emitted from the multiple lasers along the first direction and along the second direction, with different divergence angles, converge onto a lens group 42. The lens group 42 then focuses the emitted beams onto one end face of a beam homogenizer 41. The diagonal of the beam homogenizer is parallel to the X-axis or Y-axis of the emitted beam.

[0051] See Figure 5c This is a schematic diagram of the third embodiment of the laser source of the present invention, comprising multiple lasers and a beam homogenizing rod. Multiple lasers are arranged in an array along a first direction and a second direction, with different numbers and / or spacings of lasers arranged along the first direction and those arranged along the second direction. For example, in one embodiment, the number of lasers arranged in the first direction is 'a' (e.g., 1, 2, 3…a-1, a), and the number of lasers arranged in the second direction is 'b' (e.g., 1, 2, 3…b-1, b). The distance between two adjacent lasers arranged in the first direction is 1 mm, and the distance between two adjacent lasers arranged in the second direction is 2 mm. Beams 1 from the multiple lasers, with different divergence angles along the first and second directions, converge onto a lens group 42, which focuses the emitted beams onto one end face of the beam homogenizing rod 41. The diagonal of the beam homogenizing rod is parallel to the X-axis or Y-axis of the emitted beam.

[0052] The laser homogenization scheme proposed in this invention can be applied to laser fluorescence light source systems.

[0053] See Figure 6 This is a schematic diagram of the structure of a first embodiment of the laser source system of the present invention. The laser source system includes the laser source and wavelength conversion device described in any of the above embodiments. The laser source outputs a uniform light beam to the wavelength conversion device, and the wavelength conversion device receives the uniform light beam and generates stimulated light with a wavelength range different from that of the uniform light beam.

[0054] In this embodiment, the laser source system further includes a lens 52 and a light collection component 53;

[0055] Lens 52 is used to converge the uniform light beam output from the laser source;

[0056] Wavelength conversion device 54, for receiving the converged homogenized light beam from the lens to generate a fluorescent light beam; and

[0057] The light-collecting component 53 is a reflector cup used to receive the fluorescent beam from the wavelength conversion device 54 and output it after reflection. The reflector cup is provided with a light-transmitting area for transmitting the uniform light beam emitted by the laser source. The light-transmitting area is a through hole provided in the reflector cup. The through hole is either hollowed out or has a film that transmits the uniform light beam emitted by the laser source and reflects fluorescence.

[0058] The light beams 1, which have different divergence angles along the first direction and the second direction, converge on the incident end face of the light homogenizing rod 51. After multiple reflections inside the light homogenizing rod 51, the uniform light beam is emitted from the exit end face of the light homogenizing rod 51. The diagonal of the light homogenizing rod 51 is parallel to the fast axis or slow axis of the emitted light beam. After being converged by the lens 52, the light beam passes through the through hole on the reflector cup and shines on the wavelength conversion device 54 to excite a fluorescent light beam. The fluorescent light beam is reflected by the light collection component 53 (and the reflector cup) and then output.

[0059] The power density distribution of the light spot on the wavelength conversion element 54 after being homogenized by the homogenizing rod 51 is uniform, which avoids the problem of decreased laser fluorescence conversion efficiency and decreased overall light source brightness caused by excessively high local power density.

[0060] See Figure 7 Figure 5 is a schematic diagram of the structure of the second embodiment of the laser source system of the present invention. The difference between the second embodiment and the first embodiment described above (as shown in Figure 5) is that the light collecting component 63 includes a regional diaphragm and a fluorescence collecting lens group 65. The laser source system includes:

[0061] Lens 62 is used to converge the uniform light beam output from the laser source.

[0062] Wavelength conversion device 66 is used to receive the converged uniform light beam to generate a fluorescent light beam, which is output after passing through the fluorescent collecting lens group and being reflected by the regional diaphragm.

[0063] A light-collecting component 63, comprising a regional diaphragm and a fluorescence-collecting lens group 65, is used to receive the fluorescence beam from the wavelength conversion device 66 and output a laser fluorescence light source after reflection. The regional diaphragm includes a central region capable of transmitting the uniform light beam emitted by the laser light source and a peripheral region disposed around the central region capable of reflecting fluorescence.

[0064] The light beams 1, which have different divergence angles along the first direction and the second direction, converge on the incident end face of the homogenizing rod 61. After multiple reflections inside the homogenizing rod 61, the uniform light beam is emitted from the exit end face of the homogenizing rod 61. The diagonal of the homogenizing rod is parallel to the fast axis or the slow axis. After being collimated by the lens 62, the light beam passes through the central region of the regional diaphragm, and then is converged onto the wavelength conversion device 66 by the fluorescence collecting lens group 65, which excites fluorescence. The fluorescence is then received by the fluorescence collecting lens group 65 and then reflected by the outer region of the regional diaphragm before being output.

[0065] See Figure 8a and Figure 8b Figure 5 is a schematic diagram of the structure of the third embodiment of the laser source system of the present invention. The difference between the third embodiment and the first embodiment (as shown in Figure 5) is that the wavelength conversion device is a transmission-type fluorescence wavelength conversion device.

[0066] Among them, such as Figure 8a As shown, the wavelength conversion device 72 is a transmission-type fluorescence wavelength conversion device, and the wavelength conversion device 72 is attached to the light-emitting end face of the light-diffusing rod 71.

[0067] Among them, such as Figure 8b As shown, the wavelength conversion device 72 is a transmissive fluorescent wavelength conversion device, and the wavelength conversion device 72 is attached to the light-emitting end face of the light-diffusing rod 71 through a transparent carrier 74.

[0068] Beams 1 with different divergence angles along the first and second directions converge at the incident end face of the homogenizing rod 71. After multiple reflections within the homogenizing rod 71, a uniform beam is obtained and emitted from the emitting end face of the homogenizing rod 71. The diagonal of the homogenizing rod is parallel to the fast or slow axis. A wavelength conversion device 72 (i.e., a fluorescence wavelength conversion device), such as a fluorescent sheet, is disposed next to the homogenizing rod 71. The fluorescent sheet can be directly attached to the homogenizing rod 71 (e.g., a fluorescent film). Figure 8a (As shown), a transition carrier 74 can also be provided between the homogenizing rod 71 and the phosphor sheet (e.g. Figure 8bAs shown, a uniform light beam illuminates the phosphor sheet, exciting fluorescence which is then output as the laser fluorescence source 73. The transition carrier 74 can be air or a transparent carrier.

[0069] In this embodiment, only some relevant solutions for the laser source are described. Other solutions are the same as those in the prior art and will not be described again here.

[0070] The laser source and laser source system achieve the advantages of low loss and low cost by setting the diagonal of the uniform beam parallel to the fast or slow axis of the laser beam, thereby shortening the length of the uniform beam and making the emitted beam more uniform.

[0071] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A laser light source, characterized in that, include: A laser device includes at least one laser for generating at least one beam with different divergence angles along a first direction and along a second direction; A light-homing rod includes an incident end face and an exit end face, wherein the incident end face and the exit end face are square, the incident end face receives at least one light beam with different divergence angles along a first direction and along a second direction, and the exit end face outputs a light beam after homogenization, and one diagonal of the incident end face is parallel to the first direction or the second direction. The laser device includes multiple lasers, each laser generating a beam with a different divergence angle along a first direction and along a second direction; And the first direction is perpendicular to the second direction.

2. The laser source according to claim 1, characterized in that, The laser source also includes a lens, which is disposed between the laser and the beam homogenizer to focus at least one beam generated by the laser device with different divergence angles along a first direction and a second direction onto the incident end face of the beam homogenizer.

3. The laser source according to claim 1, characterized in that, The light-diffusing rod is an optical fiber, comprising a square core and a cladding layer that wraps around the square core. The square core includes an incident light end face and an exit light end face.

4. The laser source according to claim 3, characterized in that, The optical fiber also includes a coating layer that surrounds the cladding layer.

5. The laser source according to claim 1, characterized in that, The light-diffusing rod is square, and the area of ​​its incident light-facing end face is equal to the area of ​​its emitting light-facing end face; or The light-diffusing rod is conical, and the area of ​​the light-incident end face of the light-diffusing rod is greater than the area of ​​the light-exit end face, or the area of ​​the light-exit end face of the light-diffusing rod is greater than the area of ​​the light-incident end face.

6. The laser source according to claim 1, characterized in that, The light-diffusing rod is hollow, and a square hole is formed by passing through the light-incident end face of the light-diffusing rod to the light-exit end face. The square hole and the light-diffusing rod have the same center line.

7. The laser source according to claim 1, characterized in that, The fast axes of the beams generated by the plurality of lasers are all parallel to the first direction.

8. The laser source according to claim 1, characterized in that, The fast axis of the beams generated by some of the lasers is parallel to the first direction, while the fast axis of the beams generated by the remaining lasers is perpendicular to the first direction.

9. The laser source according to claim 1, characterized in that, The plurality of lasers are arranged in an array along a first direction and along a second direction, and the number and / or spacing of the lasers arranged along the first direction are different from those arranged along the second direction.

10. A laser source system, characterized in that, The laser source system includes a laser source and a wavelength conversion device as described in any one of claims 1 to 9, wherein the laser source outputs a uniform light beam to the wavelength conversion device, and the wavelength conversion device receives the uniform light beam and generates stimulated light with a wavelength range different from that of the uniform light beam.

11. The laser source system according to claim 10, characterized in that, The laser source system also includes lenses and light collection components; The lens is used to converge the uniform light beam output by the laser source; The wavelength conversion device is used to receive the converged homogenized light beam from the lens to generate a fluorescence light beam; and The light collection component is used to receive the fluorescent light beam from the wavelength conversion device and output it after reflection.

12. The laser source system according to claim 10, characterized in that, The wavelength conversion device is a transmission type wavelength conversion device, and the wavelength conversion device is disposed on the light-emitting end face of the light-dispersing rod.

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