A laser light source

Abstract

The present invention relates to a laser light source, comprising: a blue laser light source assembly for generating parallel linearly polarized blue laser, a dichroic polarization beam splitter, a quarter wave plate, a reflector and a wavelength converter; the polarization direction of the blue laser forms an angle θ with the Y axis of the XOY plane; the blue laser is reflected and transmitted by the dichroic polarization beam splitter to form reflected blue light and transmitted blue light, the reflected blue light converges on the wavelength converter to generate excitation yellow light, the transmitted blue light is wavelength-converted by the quarter wave plate and then reflected by the reflector to pass through the quarter wave plate again to perform a secondary wavelength conversion to form S-polarized blue light, the S-polarized blue light is mixed with the excitation yellow light to generate output white light; the angle θ is set based on a preset light energy ratio of the blue S-polarized light to the excitation yellow light. The present invention can simultaneously meet the requirements of stable color temperature, simple manufacturing and reduced energy loss.

Description

Technical Field

[0001] The present invention relates to the field of laser light sources, and more particularly to a laser light source. Background Art

[0002] Laser has the characteristics of concentrated energy and good collimation, which makes laser a new type of light source, widely used in various lighting fields, such as laser projection, stage lighting, etc. The application of laser light source in the lighting field is often not simple monochromatic light illumination but multi-color light mixing.

[0003] Figure 1 A laser light source of the prior art is shown. The blue laser light 101 emitted by the laser 1 becomes a blue light 201 after passing through a half wave plate 2. The blue light 201 is divided into an S-polarized blue light 301 and a P-polarized blue light 401 after passing through a dichroic polarization beam splitter 3. The dichroic polarization beam splitter 3 fully reflects the S-polarized blue light 301 and fully transmits the P-polarized blue light 401, and fully transmits the yellow light. The S-polarized blue light 301 passes through two condensers and is incident on a wavelength converter 5 to excite the yellow phosphor to produce yellow light. The yellow light passes through two condensers to form a collimated output yellow light 601. The yellow light 601 is fully transmitted through the dichroic polarization beam splitter 3. The P-polarized blue light 401 passes through a quarter wave plate 4 and is converted into a circularly polarized light. The circularly polarized light passes through two condensers and converges to a Lambertian diffuse reflection surface 6. The circularly polarized light passes through the quarter wave plate 4 again after being reflected by the Lambertian diffuse reflection surface 6, and the circularly polarized light becomes an S-polarized blue light 701. The S-polarized blue light 701 is totally reflected at the dichroic polarization beam splitter 3. The yellow light 601 and the S-polarized blue light 701 are combined into white light. Figure 1 In the laser light source shown, the ratio of the finally emitted yellow light 601 to the S-polarized blue light 701 can be adjusted by adjusting the angle between the fast axis of the half-wave plate 2 and the light vector of the blue laser 101, thereby adjusting the color temperature of the laser light source.

[0004] However, the defect of this solution is that although the ratio of the final emitted yellow light 601 to the S-polarized blue light 701 can be adjusted by adjusting the angle between the fast axis of the half-wave plate 2 and the light vector of the blue laser 101, the half-wave plate 2 is easily expanded by heat, which causes the ratio of the yellow light 601 to the S-polarized blue light 701 to fluctuate, thereby causing the color temperature of the output white light to fluctuate. This can only be achieved by using a zero-order wave plate or introducing a full-wave plate, in which the optical axis of the full-wave plate is perpendicular to the optical axis of the half-wave plate. However, the zero-order wave plate is difficult to process or has a low processing yield due to its thin thickness, resulting in excessively high cost of the zero-order wave plate, and the introduction of a full-wave plate not only increases the cost, but also causes a portion of light energy loss.

[0005] Figure 2Another laser light source of the prior art is shown. The blue laser light 202 emitted by the laser 1 is partially reflected and partially transmitted after passing through the dichroic mirror 7 to generate reflected blue light 302 and transmitted blue light 402. A regional reflective film is plated on the dichroic mirror 7 to reflect blue light and transmit yellow light to generate reflected blue light 302. A perforation treatment is performed on the dichroic mirror 7 corresponding to the spot of the blue laser light 202, so that part of the blue light can directly pass through the dichroic mirror 7 to form the transmitted blue light 402. The transmitted blue light 402 is converged on the Lambertian diffuse reflection surface 6 through two condensing mirrors, and after being reflected by the Lambertian diffuse reflection surface 6, the reflected blue light 702 is generated. The reflected blue light 302 is converged on the wavelength converter 5 through two condensing mirrors to excite the yellow phosphor to generate yellow light. The yellow light passes through the two condensing mirrors to form a collimated outgoing yellow light 602. The outgoing yellow light 602 and the reflected blue light 702 are converged into white light. By controlling the ratio between the perforation area and the total area of ​​the blue laser 202 spot, the ratio between the final emitted yellow light 602 and the reflected blue light 702 can be accurately controlled.

[0006] However, the drawback of this solution is that the dichroic mirror 7 needs to be perforated before being plated with a beam splitting film in different regions, so the processing technology of the dichroic mirror 7 is difficult, and when the reflected blue light 702 enters the dichroic mirror 7, part of the blue light will pass through the perforations again, causing energy waste. At the same time, when the emitted yellow light 602 passes through the dichroic mirror 7, the perforations actually play the role of a diffuse reflection surface, which will also cause some energy waste to the yellow light. Summary of the invention

[0007] The technical problem to be solved by the present invention is that, with respect to the laser light sources in the prior art, either color temperature fluctuations are easily generated or the structure is complex, the design cost is high and there is energy loss. A laser light source is provided which can reduce energy loss and has a simple structural design and stable color temperature.

[0008] The technical solution adopted by the present invention to solve the technical problem is: construct a laser light source, including: a blue laser light source assembly for generating parallel linearly polarized blue laser, a dichroic polarization beam splitter, a quarter wave plate, a reflector and a wavelength converter;

[0009] The blue laser light source assembly is arranged on the XOY plane and emits the blue laser along the Z-axis direction. The dichroic polarization beam splitter is arranged at an angle of 45 degrees to the XOY plane. The blue laser light source assembly is arranged so that the polarization direction of the blue laser forms an angle nθ with the Y-axis of the XOY plane. The blue laser is reflected and transmitted by the dichroic polarization beam splitter to form reflected blue light and transmitted blue light, respectively. The quarter wave plate and the reflector are arranged along the propagation direction of the transmitted blue light. The wavelength converter is arranged along the propagation direction of the reflected blue light.

[0010] The reflected blue light converges on the wavelength converter to generate excitation yellow light, the transmitted blue light is wavelength-converted by the quarter-wave plate and then reflected by the reflector to pass through the quarter-wave plate again for secondary wavelength conversion to form S-polarized blue light, and the S-polarized blue light is mixed with the excitation yellow light to generate output white light;

[0011] The angle θ is set based on a preset light energy ratio of the blue S-polarized light to the excitation yellow light, where n=1 or 2.

[0012] In the laser light source of the present invention, the blue laser light source assembly comprises a blue laser light source, and the blue laser light source is rotated clockwise from the Y axis in the XOY plane by the angle θ so that the polarization direction of the blue laser forms an angle θ with the Y axis of the XOY plane; the dichroic polarization beam splitter completely transmits P-polarized blue light, completely reflects S-polarized blue light, and completely transmits yellow light;

[0013] The angle θ is calculated based on the following equation:

[0014] sin 2 θ+cos 2 θ=1

[0015]

[0016] Wherein, a represents the preset light energy of the excitation yellow light, and b represents the preset light energy of the blue S-polarized light.

[0017] In the laser light source described in the present invention, the P-polarized blue light completely transmitted through the dichroic polarization beam splitter is converted into circularly polarized blue light after wavelength conversion through the quarter-wave plate, and the circularly polarized blue light is reflected by the reflector to pass through the quarter-wave plate again to form the S-polarized blue light; the S-polarized blue light completely reflected through the dichroic polarization beam splitter is converged on the wavelength converter to generate the excitation yellow light, and the excitation yellow light is mixed with the S-polarized blue light after being completely transmitted through the dichroic polarization beam splitter to generate the output white light.

[0018] In the laser light source of the present invention, the blue laser light source assembly comprises a blue laser light source, and the blue laser light source is rotated clockwise from the Y axis in the XOY plane by the angle θ so that the polarization direction of the blue laser forms an angle θ with the Y axis of the XOY plane; the dichroic polarization beam splitter completely reflects S-polarized blue light, partially reflects and partially transmits P-polarized blue light, and completely transmits yellow light;

[0019] The angle θ is calculated based on the following equation:

[0020] sin 2θ+cos 2 θ=1

[0021]

[0022] Wherein, a represents the preset light energy of the excitation yellow light, b represents the preset light energy of the blue S-polarized light, and R1 represents the reflectivity of the dichroic polarization beam splitter to the P-polarized blue light.

[0023] In the laser light source described in the present invention, the P-polarized blue light partially transmitted by the dichroic polarization beam splitter is converted into circularly polarized blue light after wavelength conversion by the quarter-wave plate, and the circularly polarized blue light is reflected by the reflector to pass through the quarter-wave plate again to form the S-polarized blue light; the S-polarized blue light completely reflected by the dichroic polarization beam splitter and the partially reflected P-polarized blue light are converged on the wavelength converter to generate the excitation yellow light, and the excitation yellow light is mixed with the S-polarized blue light after being completely transmitted by the dichroic polarization beam splitter to generate the output white light.

[0024] In the laser light source described in the present invention, the blue laser light source assembly includes a blue laser light source and a half wave plate, the blue laser light source is arranged along the Y-axis direction, the fast axis of the half wave plate is arranged at an angle θ with the polarization direction of the blue laser so that the polarization direction of the blue laser passing through the half wave plate forms an angle 2θ with the Y-axis of the XOY plane; the dichroic polarization beam splitter completely reflects S-polarized blue light, partially reflects and partially transmits P-polarized blue light, and completely transmits yellow light;

[0025] The angle θ is calculated based on the following equation:

[0026]

[0027] sin 2 2θ+cos 2 2θ=1

[0028] Wherein, a represents the preset light energy of the excitation yellow light, b represents the preset light energy of the blue S-polarized light, and R1 represents the reflectivity of the dichroic polarization beam splitter to the P-polarized blue light.

[0029] In the laser light source described in the present invention, the P-polarized blue light partially transmitted by the dichroic polarization beam splitter is converted into circularly polarized blue light after wavelength conversion by the quarter-wave plate, and the circularly polarized blue light is reflected by the reflector to pass through the quarter-wave plate again to form the S-polarized blue light; the S-polarized blue light completely reflected by the dichroic polarization beam splitter and the partially reflected P-polarized blue light are converged on the wavelength converter to generate the excitation yellow light, and the excitation yellow light is mixed with the S-polarized blue light after being completely transmitted by the dichroic polarization beam splitter to generate the output white light.

[0030] The laser light source described in the present invention further includes a first converging component and a second converging component, wherein the first converging component is arranged between the dichroic polarization beam splitter and the wavelength converter along the propagation direction of the reflected blue light, and the second converging component is arranged between the dichroic polarization beam splitter and the reflector along the propagation direction of the transmitted blue light.

[0031] In the laser light source described in the present invention, the first focusing component and the second focusing component respectively include two condensing mirrors arranged in parallel and spaced apart.

[0032] In the laser light source described in the present invention, the reflector comprises a Lambertian diffuse reflector.

[0033] The laser light source implementing the present invention cleverly sets the angle between the propagation direction of the blue laser and the vertical direction according to a preset light energy ratio of the blue S-polarized light and the excitation yellow light. It can simultaneously meet the requirements of stable color temperature, simple manufacturing and reduced energy loss by using a very simple structure and design. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0035] Figure 1 A laser light source of the prior art is shown;

[0036] Figure 2 Another laser light source of the prior art is shown;

[0037] Figure 3 is a schematic diagram of the optical path of a first preferred embodiment of the laser light source of the present invention;

[0038] Figure 4 yes Figure 3 A schematic diagram of the setting of a blue laser light source of the laser light source shown;

[0039] Figure 5 is a schematic diagram of the optical path of a second preferred embodiment of the laser light source of the present invention;

[0040] Figure 6 is a schematic diagram of the optical path of the third preferred embodiment of the laser light source of the present invention;

[0041] Figure 7 yes Figure 6 Schematic diagram of the setup of the blue laser light source of the laser light source shown. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0043] The present invention relates to a laser light source, comprising: a blue laser light source assembly for generating parallel linearly polarized blue laser light, a dichroic polarization beam splitter, a quarter wave plate, a reflector and a wavelength converter; the blue laser light source assembly is arranged on an XOY plane and emits the blue laser light along a Z-axis direction, the dichroic polarization beam splitter is arranged at an angle of 45 degrees to the XOY plane, and the blue laser light source assembly is arranged so that the polarization direction of the blue laser light forms an angle θ or 2θ with the Y-axis of the XOY plane; the blue laser light is respectively reflected and transmitted by the dichroic polarization beam splitter to form reflected blue light and transmitted blue light. The blue light is emitted, the quarter wave plate and the reflector are arranged along the propagation direction of the transmitted blue light, and the wavelength converter is arranged along the propagation direction of the reflected blue light; the reflected blue light converges on the wavelength converter to generate the excitation yellow light, the transmitted blue light is wavelength-converted by the quarter wave plate and then reflected by the reflector to pass through the quarter wave plate again for secondary wavelength conversion to form S-polarized blue light, and the S-polarized blue light is mixed with the excitation yellow light to generate output white light; the angle θ is set based on the preset light energy ratio of the blue S-polarized light to the excitation yellow light. The present invention ingeniously sets the angle between the propagation direction of the blue laser and the vertical direction according to the preset light energy ratio of the blue S-polarized light to the excitation yellow light, and adopts a very simple structure and design to simultaneously meet the requirements of stable color temperature, simple manufacturing and reduced energy loss.

[0044] Figure 3 1 is a schematic diagram of the first preferred embodiment of the laser light source of the present invention. Figure 3 As shown, the laser light source of the present invention comprises: a blue laser light source 1 for generating parallel linearly polarized blue laser light, a dichroic polarization beam splitter 8, a quarter wave plate 4, a reflector 6 and a wavelength converter 5. Figure 3 In the preferred embodiment shown, the laser light source further includes a first converging component 11 and a second converging component 12 .

[0045] The blue laser light source 1 is arranged on the XOY plane and emits the blue laser 203 along the Z-axis direction. The dichroic polarization beam splitter 8 is arranged at an angle of 45 degrees to the XOY plane. The blue laser light source 1 is arranged so that the polarization direction of the blue laser forms an angle θ with the Y-axis of the XOY plane. The blue laser 203 is reflected and transmitted by the dichroic polarization beam splitter 8 to form a reflected blue light 303 and a transmitted blue light 403, respectively. The quarter wave plate 4 and the reflector 6 are arranged along the propagation direction of the transmitted blue light 403, and the wavelength converter 5 is arranged along the propagation direction of the reflected blue light 303. The first converging component 11 is arranged between the dichroic polarization beam splitter 8 and the wavelength converter 5 along the propagation direction of the reflected blue light, and the second converging component 12 is arranged between the dichroic polarization beam splitter 8 and the reflector 6 along the propagation direction of the transmitted blue light. The first converging component 11 and the second converging component 12 respectively include two condensers arranged in parallel and spaced apart.

[0046] like Figure 3 As shown, the blue laser light source 1 is arranged on the XOY plane and emits the blue laser 203 along the Z axis. Figure 4 As shown, the blue laser light source 1 rotates clockwise from the Y axis in the XOY plane by the angle θ so that the polarization direction F of the blue laser forms an angle θ with the Y axis of the XOY plane. The dichroic polarization beam splitter 8 is set at a 45-degree angle with the XOY plane. The dichroic polarization beam splitter 8 completely transmits P-polarized blue light, completely reflects S-polarized blue light, and completely transmits yellow light. Therefore, the blue laser 203 is reflected and transmitted by the dichroic polarization beam splitter 8 to form reflected blue light 303 and transmitted blue light 403. The transmitted blue light 403 continues to propagate along the Z axis. The reflected blue light 303 propagates downward along the Y axis. In this embodiment, the transmitted blue light 403 is P-polarized blue light, and the reflected blue light 303 is S-polarized blue light. The angle between the fast axis of the quarter wave plate 4 and the polarization direction of the P-polarized blue light is set to 45 degrees. Therefore, the P-polarized blue light 403 completely transmitted by the dichroic polarization beam splitter 8 is converted into circularly polarized blue light after wavelength conversion by the quarter wave plate 4. After the circularly polarized blue light is converged by the second converging component 12, it is reflected by the reflector 6 to pass through the quarter wave plate 4 again to form S-polarized blue light 703.

[0047] At the same time, the S-polarized blue light 303 completely reflected by the dichroic polarization beam splitter 8 is converged on the wavelength converter 5 through the first convergence component 11 to generate the excitation yellow light 603. The excitation yellow light 603 propagates upward along the Y-axis direction. After the excitation yellow light 603 is completely transmitted by the dichroic polarization beam splitter 8, the S-polarized blue light 703 is completely reflected by the dichroic polarization beam splitter 8, and thus propagates upward along the Y-axis at the same time to be mixed to form output white light.

[0048] By rotating the angle θ of the blue laser light source 1, the direction of the light vector of the linearly polarized blue laser 203 is adjusted, that is, the angle θ between the polarization direction of the blue laser and the Y axis of the XOY plane is adjusted, so that the ratio of the blue S-polarized light to the excitation yellow light in the output white light can be adjusted. In this way, when the conversion ratio of the S-polarized blue light 303 to generate the excitation yellow light 603 is set to 1:1, the corresponding rotation angle θ of the blue laser light source 1 can be obtained according to the preset light energy ratio of the blue S-polarized light 703 to the excitation yellow light 603 to be obtained. In this way, there is no need to use a half-wave plate, and a very simple structure and design can simultaneously meet the requirements of stable color temperature, simple manufacturing and reduced energy loss.

[0049] The specific principle process is as follows:

[0050] A coordinate system is established based on the dichroic polarization beam splitter 8. The blue laser light source 1 is set on the XOY plane and emits the blue laser 203 along the Z axis. The blue laser 203 is a blue linear polarized light, and the light vector direction is along the wire direction. The angle between the dichroic polarization beam splitter 8 and the XOY plane is 45°. The blue laser light source 1 rotates the angle θ clockwise from the Y axis in the XOY plane so that the polarization direction F of the blue laser forms an angle θ with the Y axis of the XOY plane. Therefore, the Jones matrix corresponding to the blue laser 203 is Assuming that the blue light excites the yellow light in an ideal state, that is, the blue light and the yellow light are converted in a 1:1 ratio, without considering other factors, assuming that the output energy of the blue laser light source 1 is 1, the light energy of the reflected blue light 303 is cos 2 θ and the light energy of the transmitted blue light 403 is sin 2 θ, in the output white light, the preset light energy ratio of the blue S-polarized light to the excitation yellow light is a:b, that is, the simultaneous equations are obtained:

[0051] sin 2 θ+cos 2 θ=1

[0052]

[0053] Wherein, a represents the preset light energy of the excitation yellow light, and b represents the preset light energy of the blue S-polarized light.

[0054] By calculating the above equation, the value of the angle θ can be obtained. By rotating the blue laser light source 1 according to the value, a very simple structure and design can be used to simultaneously meet the requirements of stable color temperature, simple manufacturing and reduced energy loss. That is, the solution of the present invention reduces energy loss compared to solution 2 in the background technology, while reducing the difficulty of production and processing of the dichroic beam splitter and reducing the use of wave plates, and can effectively stabilize the color temperature compared to solution 1 in the background technology.

[0055] Figure 5 FIG. 2 is a schematic diagram of the optical path of the second preferred embodiment of the laser light source of the present invention. Figure 5 As shown, the laser light source of the present invention comprises: a blue laser light source 1 for generating parallel linearly polarized blue laser light, a dichroic polarization beam splitter 9, a quarter wave plate 4, a reflector 6 and a wavelength converter 5. Figure 5 In the preferred embodiment shown, the laser light source further comprises a first focusing component 11 and a second focusing component 12. The reflector is preferably a Lambertian diffuse reflector.

[0056] The blue laser light source 1 is arranged on the XOY plane and emits the blue laser 204 along the Z-axis direction. The dichroic polarization beam splitter 9 is arranged at an angle of 45 degrees to the XOY plane. The blue laser light source 1 is arranged so that the polarization direction of the blue laser forms an angle nθ with the Y-axis of the XOY plane. The blue laser 204 is reflected and transmitted by the dichroic polarization beam splitter 9 to form a reflected blue light 304 and a transmitted blue light 404, respectively. The quarter wave plate 4 and the reflector 6 are arranged along the propagation direction of the transmitted blue light 404, and the wavelength converter 5 is arranged along the propagation direction of the reflected blue light 304. The first converging component 11 is arranged between the dichroic polarization beam splitter 9 and the wavelength converter 5 along the propagation direction of the reflected blue light, and the second converging component 12 is arranged between the dichroic polarization beam splitter 9 and the reflector 6 along the propagation direction of the transmitted blue light. The first converging component 11 and the second converging component 12 respectively include two condensers arranged in parallel and spaced apart.

[0057] In this preferred embodiment, Figure 4As shown, the blue laser light source 1 rotates clockwise from the Y axis in the XOY plane by the angle θ so that the polarization direction F of the blue laser forms an angle θ with the Y axis of the XOY plane. The dichroic polarization beam splitter 9 is set at a 45-degree angle to the XOY plane. In this preferred embodiment, the dichroic polarization beam splitter 9 completely reflects the S-polarized blue light, partially reflects and partially transmits the P-polarized blue light, and completely transmits the yellow light. Therefore, the blue laser 204 forms a reflected blue light 304 and a transmitted blue light 404 after passing through the dichroic polarization beam splitter 9. The transmitted blue light 404 continues to propagate along the Z axis direction. And the reflected blue light 304 propagates downward along the Y axis direction. That is, the reflected blue light 304 includes the S-polarized blue light completely reflected by the dichroic polarization beam splitter 9 and the P-polarized blue light partially reflected, and the transmitted blue light 404 includes the P-polarized blue light partially transmitted by the dichroic polarization beam splitter 9. The angle between the fast axis of the quarter wave plate 4 and the polarization direction of the P-polarized blue light is set to 45 degrees. Therefore, the P-polarized blue light 404 partially transmitted by the dichroic polarization beam splitter 9 is converted into circularly polarized blue light after wavelength conversion by the quarter wave plate 4. After the circularly polarized blue light is converged by the second converging component 12, it is reflected by the reflector 6 to pass through the quarter wave plate 4 again to form S-polarized blue light 704.

[0058] At the same time, the reflected blue light 304 composed of the S-polarized blue light completely reflected by the dichroic polarization beam splitter 9 and the P-polarized blue light partially reflected is converged on the wavelength converter 5 through the first convergence component 11 to generate the excitation yellow light 604. The excitation yellow light 604 propagates upward along the Y-axis direction. After the excitation yellow light 604 is completely transmitted by the dichroic polarization beam splitter 9, the S-polarized blue light 704 is completely reflected by the dichroic polarization beam splitter 8, thereby propagating upward along the Y-axis at the same time to mix and form output white light.

[0059] By rotating the angle θ of the blue laser light source 1, the direction of the light vector of the linearly polarized blue laser 204 is adjusted, that is, the angle θ between the polarization direction of the blue laser and the Y axis of the XOY plane is adjusted, so that the ratio of the blue S-polarized light to the excitation yellow light in the output white light can be adjusted. In this way, when the conversion ratio of the S-polarized blue light 204 to generate the excitation yellow light 604 is set to 1:1, the corresponding rotation angle θ of the blue laser light source 1 can be obtained according to the preset light energy ratio of the blue S-polarized light 704 to the excitation yellow light 604 to be obtained. In this way, there is no need to use a half-wave plate, and a very simple structure and design can simultaneously meet the requirements of stable color temperature, simple manufacturing and reduced energy loss.

[0060] The specific principle process is as follows:

[0061] A coordinate system is established based on the dichroic polarization beam splitter 8. The blue laser light source 1 is set on the XOY plane and emits the blue laser 204 along the Z axis. The blue laser 204 is a blue linear polarized light, and the light vector direction is along the wire direction. The dichroic polarization beam splitter 9 and the XOY plane have an angle of 45°. The blue laser light source 1 rotates the angle θ clockwise from the Y axis in the XOY plane so that the polarization direction F of the blue laser forms an angle θ with the Y axis of the XOY plane. Therefore, the Jones matrix corresponding to the blue laser 204 is: Assuming that the blue light excites the yellow light in an ideal state, that is, the blue light and the yellow light are converted in a 1:1 ratio, without considering other factors, assuming that the output energy of the blue laser light source 1 is 1, and the reflectivity of the dichroic polarization beam splitter 9 to the P-polarized blue light is R1, the light energy of the reflected blue light 304 is cos 2 θ+R1*sin 2 θ, and the light energy of the transmitted blue light 404 is (1-R1)*sin 2 θ, in the output white light, the preset light energy ratio of the blue S-polarized light to the excitation yellow light is a:b, that is, the simultaneous equations are obtained:

[0062] sin 2 θ+cos 2 θ=1

[0063]

[0064] Wherein, a represents the preset light energy of the excitation yellow light, b represents the preset light energy of the blue S-polarized light, and R1 represents the reflectivity of the dichroic polarization beam splitter to the P-polarized blue light.

[0065] By calculating the above equation, the value of the angle θ can be obtained. By rotating the blue laser light source 1 according to the value, a very simple structure and design can be used to simultaneously meet the requirements of stable color temperature, simple manufacturing and reduced energy loss. That is, the solution of the present invention reduces energy loss compared to solution 2 in the background technology, while reducing the difficulty of production and processing of the dichroic beam splitter and reducing the use of wave plates, and can effectively stabilize the color temperature compared to solution 1 in the background technology.

[0066] The above two embodiments can achieve stable output of white light with stable color temperature at low cost by rotating the blue laser light source 1 and / or redesigning the dichroic polarization beam splitter, without causing energy loss, and can also reduce the difficulty of production and processing of the dichroic beam splitter and reduce the use of wave plates. Figure 6 FIG. 1 is a schematic diagram of the optical path of the third preferred embodiment of the laser light source of the present invention. Figure 6In the preferred embodiment shown, instead of rotating the blue laser light source 1, a half-wave plate is used, and by rotating the half-wave plate, the fast axis of the half-wave plate is made to form an angle θ with the polarization direction F of the blue laser, thereby achieving that the polarization direction of the blue laser forms an angle 2θ with the Y axis of the XOY plane only after passing through the half-wave plate.

[0067] Figure 7 yes Figure 6 The schematic diagram of the setting of the blue laser light source of the laser light source shown in FIG. Figure 7 As shown, the blue laser light source is arranged perpendicular to the Y axis, that is, the polarization direction F of the blue laser emitted by the blue laser light source does not form an angle θ with the Y axis but is parallel to the Y axis, and only forms an angle 2θ with the Y axis of the XOY plane after passing through the half wave plate.

[0068] like Figure 6 As shown, the laser light source of the present invention comprises: a blue laser light source 1 for generating parallel linearly polarized blue laser light, a half wave plate 2, a dichroic polarization beam splitter 9, a quarter wave plate 4, a reflector 6 and a wavelength converter 5. Figure 6 In the preferred embodiment shown, the laser light source further includes a first converging component 11 and a second converging component 12 .

[0069] The blue laser light source 1 is arranged on the XOY plane and emits the blue laser 105 along the Z-axis direction. The dichroic polarization beam splitter 9 is arranged at an angle of 45 degrees to the XOY plane. The blue laser light source 1 is arranged parallel to the Y-axis of the XOY plane, and the fast axis of the half-wave plate 2 is arranged at an angle θ with the polarization direction F of the blue laser 105, so that the blue laser 105 becomes a blue laser 205 after passing through the half-wave plate 2, and the polarization direction of the blue laser 205 forms an angle 2θ with the Y-axis of the XOY plane. The blue laser 205 is reflected and transmitted by the dichroic polarization beam splitter 9 to form a reflected blue light 305 and a transmitted blue light 405, respectively. The quarter-wave plate 4 and the reflector 6 are arranged along the propagation direction of the transmitted blue light 405, and the wavelength converter 5 is arranged along the propagation direction of the reflected blue light 305. The first converging component 11 is arranged between the dichroic polarization beam splitter 9 and the wavelength converter 5 along the propagation direction of the reflected blue light, and the second converging component 12 is arranged between the dichroic polarization beam splitter 9 and the reflector 6 along the propagation direction of the transmitted blue light. The first converging component 11 and the second converging component 12 respectively include two condensers arranged in parallel and spaced apart.

[0070] In this preferred embodiment, Figure 7As shown, the blue laser light source 1 is arranged on the XOY plane and emits the blue laser 105 along the Z-axis direction. The dichroic polarization beam splitter 9 is arranged at a 45-degree angle to the XOY plane. The blue laser light source 1 is arranged parallel to the Y-axis of the XOY plane, and the fast axis of the half-wave plate 2 is arranged at an angle θ to the polarization direction F of the blue laser 105, so that the blue laser 105 becomes a blue laser 205 after passing through the half-wave plate 2, and the polarization direction of the blue laser 205 forms an angle 2θ with the Y-axis of the XOY plane. In this preferred embodiment, the dichroic polarization beam splitter 9 completely reflects the S-polarized blue light, partially reflects and partially transmits the P-polarized blue light, and completely transmits the yellow light. Therefore, the blue laser 205 forms a reflected blue light 305 and a transmitted blue light 405 after passing through the dichroic polarization beam splitter 9. The transmitted blue light 405 continues to propagate along the Z-axis direction. And the reflected blue light 305 propagates downward along the Y-axis direction. That is, the reflected blue light 305 includes the S-polarized blue light fully reflected by the dichroic polarization beam splitter 9 and the P-polarized blue light partially reflected, and the transmitted blue light 405 includes the P-polarized blue light partially transmitted by the dichroic polarization beam splitter 9. The angle between the fast axis of the quarter wave plate 4 and the polarization direction of the P-polarized blue light is set to 45 degrees, so the P-polarized blue light 405 partially transmitted by the dichroic polarization beam splitter 9 is converted into circularly polarized blue light after the wavelength is converted by the quarter wave plate 4, and the circularly polarized blue light is converged by the second converging component 12, and then reflected by the reflector 6 to pass through the quarter wave plate 4 again to form the S-polarized blue light 705.

[0071] At the same time, the reflected blue light 305 composed of the S-polarized blue light completely reflected by the dichroic polarization beam splitter 9 and the P-polarized blue light partially reflected is converged on the wavelength converter 5 through the first convergence component 11 to generate the excitation yellow light 605. The excitation yellow light 605 propagates upward along the Y-axis direction. After the excitation yellow light 605 is completely transmitted by the dichroic polarization beam splitter 9, the S-polarized blue light 705 is completely reflected by the dichroic polarization beam splitter 8, thereby propagating upward along the Y-axis at the same time to be mixed to form the output white light.

[0072] By adjusting the angle θ between the fast axis of the half wave plate 2 and the polarization direction F of the blue laser 105, the light vector direction of the linearly polarized blue laser 205 can be adjusted, that is, by adjusting the angle 2θ between the polarization direction of the blue laser and the Y axis of the XOY plane, the ratio of the blue S-polarized light to the excitation yellow light in the output white light can be adjusted. In this way, when the conversion ratio of the S-polarized blue light 205 to generate the excitation yellow light 605 is set to 1:1, the angle θ can be obtained according to the preset light energy ratio of the blue S-polarized light 705 to the excitation yellow light 605 to be obtained.

[0073] The specific principle process is as follows:

[0074] A coordinate system is established based on the dichroic polarization beam splitter 8. The blue laser light source 1 is set on the XOY plane and emits the blue laser 105 along the Z axis. The blue laser 105 is a blue linear polarized light, and the light vector direction is along the wire direction. The dichroic polarization beam splitter 9 is at an angle of 45° to the XOY plane. The blue laser light source 1 is set parallel to the Y axis of the XOY plane. Therefore, the Jones matrix corresponding to the blue laser 105 is The Jones matrix of the half wave plate 2 is: Where θ is the angle between the fast axis of the half-wave plate 2 and the polarization direction F of the blue laser 105. Then the Jones matrix of the blue laser 205 is E2=G1*E1, To simplify the calculation, it is assumed that the energy of the blue laser 205 after passing through the half-wave plate 2 is 1. Then the light energy of the reflected blue light 305 is cos 2 2θ+R1*sin 2 2θ, and the light energy of the transmitted blue light 405 is (1-R1)sin 2 2θ, in the output white light, the preset light energy ratio of the blue S-polarized light to the excitation yellow light is a:b, that is, the simultaneous equations are obtained:

[0075]

[0076] sin 2 2θ+cos 2 2θ=1

[0077] Wherein, a represents the preset light energy of the excitation yellow light, b represents the preset light energy of the blue S-polarized light, and R1 represents the reflectivity of the dichroic polarization beam splitter 9 to the P-polarized blue light.

[0078] By calculating the above equation, the value of angle θ can be obtained. Due to the coating characteristics of the dichroic polarization beam splitter 9, the constant reflectivity of the P-polarized blue light is R1. Although the half-wave plate 2 still causes optical path difference due to thermal expansion, since R1 < 1, the influence of thermal expansion of the wave plate on color temperature fluctuation is less than Figure 1 The prior art shown is still an order of magnitude lower.

[0079] Although the present invention is described by specific embodiments, it should be understood by those skilled in the art that various changes and equivalent substitutions may be made to the present invention without departing from the scope of the present invention. In addition, various modifications may be made to the present invention for specific situations or materials without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but should include all implementation methods falling within the scope of the claims of the present invention.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser light source, characterized in that: include: A blue laser light source assembly, a dichroic polarization beam splitter, a quarter wave plate, a reflector and a wavelength converter for generating parallel linearly polarized blue laser light; The blue laser light source assembly is arranged on the XOY plane and emits the blue laser along the Z-axis direction. The dichroic polarization beam splitter is arranged at an angle of 45 degrees to the XOY plane. The blue laser light source assembly is arranged so that the polarization direction of the blue laser forms an angle θ with the Y-axis of the XOY plane. The blue laser is reflected and transmitted by the dichroic polarization beam splitter to form reflected blue light and transmitted blue light, respectively. The quarter wave plate and the reflector are arranged along the propagation direction of the transmitted blue light. The wavelength converter is arranged along the propagation direction of the reflected blue light. The reflected blue light converges on the wavelength converter to generate excitation yellow light, the transmitted blue light is wavelength-converted by the quarter-wave plate and then reflected by the reflector to pass through the quarter-wave plate again for secondary wavelength conversion to form S-polarized blue light, and the S-polarized blue light is mixed with the excitation yellow light to generate output white light; The angle θ is set based on a preset light energy ratio of the S-polarized blue light to the excitation yellow light; The blue laser light source assembly comprises a blue laser light source, and the blue laser light source is rotated clockwise from the Y axis in the XOY plane by the angle θ so that the polarization direction of the blue laser forms an angle θ with the Y axis of the XOY plane; the dichroic polarization beam splitter completely transmits P-polarized blue light, completely reflects S-polarized blue light, and completely transmits yellow light; The angle θ is calculated based on the following equation: Wherein, a represents the preset light energy of the excitation yellow light, and b represents the preset light energy of the S-polarized blue light.

2. The laser light source according to claim 1, characterized in that: The P-polarized blue light completely transmitted through the dichroic polarization beam splitter is converted into circularly polarized blue light after wavelength conversion through the quarter wave plate, and the circularly polarized blue light is reflected by the reflector to pass through the quarter wave plate again to form the S-polarized blue light; the S-polarized blue light completely reflected through the dichroic polarization beam splitter is converged on the wavelength converter to generate the excitation yellow light, and the excitation yellow light is mixed with the S-polarized blue light after being completely transmitted through the dichroic polarization beam splitter to generate the output white light.

3. A laser light source, characterized in that: include: A blue laser light source assembly, a dichroic polarization beam splitter, a quarter wave plate, a reflector and a wavelength converter for generating parallel linearly polarized blue laser light; The blue laser light source assembly is arranged on the XOY plane and emits the blue laser along the Z-axis direction. The dichroic polarization beam splitter is arranged at an angle of 45 degrees to the XOY plane. The blue laser light source assembly is arranged so that the polarization direction of the blue laser forms an angle θ with the Y-axis of the XOY plane. The blue laser is reflected and transmitted by the dichroic polarization beam splitter to form reflected blue light and transmitted blue light, respectively. The quarter wave plate and the reflector are arranged along the propagation direction of the transmitted blue light. The wavelength converter is arranged along the propagation direction of the reflected blue light. The reflected blue light converges on the wavelength converter to generate excitation yellow light, the transmitted blue light is wavelength-converted by the quarter-wave plate and then reflected by the reflector to pass through the quarter-wave plate again for secondary wavelength conversion to form S-polarized blue light, and the S-polarized blue light is mixed with the excitation yellow light to generate output white light; The angle θ is set based on a preset light energy ratio of the S-polarized blue light to the excitation yellow light; The blue laser light source assembly comprises a blue laser light source, and the blue laser light source is rotated clockwise from the Y axis in the XOY plane by the angle θ so that the polarization direction of the blue laser forms an angle θ with the Y axis of the XOY plane; the dichroic polarization beam splitter completely reflects S-polarized blue light, partially reflects and partially transmits P-polarized blue light, and completely transmits yellow light; The angle θ is calculated based on the following equation: Wherein, a represents the preset light energy of the excitation yellow light, b represents the preset light energy of the S-polarized blue light, and R1 represents the reflectivity of the dichroic polarization beam splitter to the P-polarized blue light.

4. The laser light source according to claim 3, characterized in that: The P-polarized blue light partially transmitted through the dichroic polarization beam splitter is converted into circularly polarized blue light after wavelength conversion through the quarter-wave plate, and the circularly polarized blue light is reflected by the reflector to pass through the quarter-wave plate again to form the S-polarized blue light; the S-polarized blue light completely reflected through the dichroic polarization beam splitter and the partially reflected P-polarized blue light are converged on the wavelength converter to generate the excitation yellow light, and the excitation yellow light is mixed with the S-polarized blue light after being completely transmitted through the dichroic polarization beam splitter to generate the output white light.

5. A laser light source, characterized in that: include: A blue laser light source assembly, a dichroic polarization beam splitter, a quarter wave plate, a reflector and a wavelength converter for generating parallel linearly polarized blue laser light; The blue laser light source assembly is arranged on the XOY plane and emits the blue laser along the Z-axis direction. The dichroic polarization beam splitter is arranged at an angle of 45 degrees to the XOY plane. The blue laser light source assembly is arranged so that the polarization direction of the blue laser forms an angle of 2θ with the Y-axis of the XOY plane. The blue laser is reflected and transmitted by the dichroic polarization beam splitter to form reflected blue light and transmitted blue light, respectively. The quarter wave plate and the reflector are arranged along the propagation direction of the transmitted blue light. The wavelength converter is arranged along the propagation direction of the reflected blue light. The reflected blue light converges on the wavelength converter to generate excitation yellow light, the transmitted blue light is wavelength-converted by the quarter-wave plate and then reflected by the reflector to pass through the quarter-wave plate again for secondary wavelength conversion to form S-polarized blue light, and the S-polarized blue light is mixed with the excitation yellow light to generate output white light; The angle 2θ is set based on a preset light energy ratio of the S-polarized blue light to the excitation yellow light. The blue laser light source assembly includes a blue laser light source and a half-wave plate. The blue laser light source is arranged along the Y-axis direction. The fast axis of the half-wave plate is arranged at an angle θ with the polarization direction of the blue laser so that the polarization direction of the blue laser passing through the half-wave plate forms an angle 2θ with the Y-axis of the XOY plane. The dichroic polarization beam splitter completely reflects the S-polarized blue light, partially reflects and partially transmits the P-polarized blue light, and completely transmits the yellow light. The angle 2θ is calculated based on the following equation: Wherein, a represents the preset light energy of the excitation yellow light, b represents the preset light energy of the S-polarized blue light, and R1 represents the reflectivity of the dichroic polarization beam splitter to the P-polarized blue light.

6. The laser light source according to claim 5, characterized in that: The P-polarized blue light partially transmitted through the dichroic polarization beam splitter is converted into circularly polarized blue light after wavelength conversion through the quarter-wave plate, and the circularly polarized blue light is reflected by the reflector to pass through the quarter-wave plate again to form the S-polarized blue light; the S-polarized blue light completely reflected through the dichroic polarization beam splitter and the partially reflected P-polarized blue light are converged on the wavelength converter to generate the excitation yellow light, and the excitation yellow light is mixed with the S-polarized blue light after being completely transmitted through the dichroic polarization beam splitter to generate the output white light.

7. The laser light source according to any one of claims 1 to 6, characterized in that: It further includes a first converging component and a second converging component, wherein the first converging component is arranged between the dichroic polarization beam splitter and the wavelength converter along the propagation direction of the reflected blue light, and the second converging component is arranged between the dichroic polarization beam splitter and the reflector along the propagation direction of the transmitted blue light.

8. The laser light source according to claim 7, characterized in that: The first focusing component and the second focusing component respectively include two condensing mirrors arranged in parallel and spaced apart.

9. The laser light source according to claim 8, characterized in that: The reflective element includes a Lambertian diffuse reflective element.

Images