A laser

Abstract

This utility model discloses a laser, comprising: a laser source for emitting a fundamental frequency beam; an optical fiber splitter for splitting the fundamental frequency beam into at least two fundamental frequency sub-beams for output, wherein the at least two fundamental frequency sub-beams are emitted in parallel; multiple frequency doubling units located on the propagation paths of each fundamental frequency sub-beam for receiving the fundamental frequency sub-beams and outputting frequency-doubled sub-beams; at least one reflection unit located on the propagation paths of some of the frequency-doubled sub-beams for reflecting the frequency-doubled sub-beams and outputting reflected frequency-doubled sub-beams, wherein the polarization directions of the reflected frequency-doubled sub-beams and the frequency-doubled sub-beams are perpendicular; and at least one polarization combining unit located on the propagation paths of the frequency-doubled sub-beams and the reflected frequency-doubled sub-beams for combining the frequency-doubled sub-beams and the reflected frequency-doubled sub-beams and outputting a green laser beam. By setting multiple frequency-doubled sub-beams and reflected frequency-doubled sub-beams and using the polarization combining unit for polarization combining, a high-brightness green laser beam is output.

Description

Technical Field

[0001] This utility model relates to the field of laser technology, and in particular to a laser. Background Technology

[0002] Fiber lasers with frequency doubling have advantages such as simple structure, narrow linewidth, and good beam quality. Currently, high-power green lasers above kW are mainly based on fiber and disk single-pass frequency doubling. The beam quality of the disk scheme is relatively poor. Fiber lasers can achieve high-power single transverse mode output due to their inherent advantages. However, when fiber lasers maintain higher single-mode output, they will face problems such as mode instability, stimulated Raman scattering (SRS), and time-domain pulses. At high power, the weak absorption of LBO crystals will also be more obvious, leading to unstable green light power and crystal damage. Utility Model Content

[0003] This invention provides a laser for outputting a high-brightness green laser beam.

[0004] This utility model provides a laser, comprising:

[0005] Laser source, used to emit a fundamental frequency beam;

[0006] An optical fiber splitter is used to split the fundamental frequency beam into at least two fundamental frequency sub-beams for output, wherein the at least two fundamental frequency sub-beams are emitted in parallel.

[0007] Multiple frequency doubling units are located on the propagation path of each of the fundamental frequency sub-beams, and are used to receive the fundamental frequency sub-beams and output the frequency doubling sub-beams;

[0008] At least one reflecting unit is located on the propagation path of a portion of the frequency-doubled sub-beam, for reflecting the frequency-doubled sub-beam and outputting a reflected frequency-doubled sub-beam, wherein the polarization direction of the reflected frequency-doubled sub-beam is perpendicular to that of the frequency-doubled sub-beam;

[0009] At least one polarization beam combiner is located on the propagation path of the frequency-doubled sub-beam and the reflected frequency-doubled sub-beam, for combining the frequency-doubled sub-beam and the reflected frequency-doubled sub-beam and outputting a green laser beam.

[0010] Optionally, the frequency doubling unit includes a frequency doubling crystal and a dichroic mirror;

[0011] The frequency doubling crystal is used to double the frequency of the fundamental frequency sub-beam to generate a frequency doubling sub-beam;

[0012] The dichroic mirror is used to transmit the frequency-doubled sub-beam to the reflection unit or the polarization beam combiner unit and to reflect the fundamental frequency sub-beam.

[0013] Optionally, the laser further includes multiple fundamental frequency optical amplifiers, which are located on the propagation path of each of the fundamental frequency sub-beams and are used to amplify the fundamental frequency sub-beams.

[0014] Optionally, the laser further includes multiple collimation units, which are located on the propagation path of each fundamental frequency sub-beam and are used to collimate the fundamental frequency sub-beam.

[0015] Optionally, the laser further includes a plurality of first half-wave plates, which are respectively located on the propagation path of each fundamental frequency sub-beam, for adjusting the polarization state of the fundamental frequency sub-beam.

[0016] Optionally, the laser further includes multiple focusing units, which are located on the propagation path of each fundamental frequency sub-beam and are used to focus the fundamental frequency sub-beam and emit it to the frequency doubling unit.

[0017] Optionally, the laser further includes a plurality of second half-wave plates located on the propagation path of the frequency-doubled sub-beam for adjusting the polarization state of the frequency-doubled sub-beam.

[0018] Optionally, the multiple frequency multiplier units include a first frequency multiplier unit and a second frequency multiplier unit;

[0019] At least one reflective unit includes a first reflective unit;

[0020] At least one polarization beam combiner unit includes a first polarization beam combiner unit;

[0021] The first frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a first frequency doubling sub-beam;

[0022] The second frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a second frequency doubling sub-beam to the first reflection unit. The first reflection unit reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling sub-beam. The first polarization beam combining unit receives the first frequency doubling sub-beam and the first reflected frequency doubling sub-beam and combines them to generate a green laser beam.

[0023] Optionally, the plurality of frequency multiplication units include a first frequency multiplication unit, a second frequency multiplication unit, and a third frequency multiplication unit;

[0024] At least one reflective unit includes a first reflective unit and a second reflective unit;

[0025] At least one polarization beam combiner unit includes a first polarization beam combiner unit and a second polarization beam combiner unit;

[0026] The first frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a first frequency doubling sub-beam;

[0027] The second frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a second frequency doubling sub-beam to the first reflection unit, and the first reflection unit reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling sub-beam;

[0028] The first polarization beam combining unit receives the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam, combines them, and generates a first sub-green laser beam;

[0029] The third frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a third frequency doubling sub-beam to the second reflection unit. The second reflection unit reflects the third frequency doubling sub-beam and outputs a second reflected frequency doubling sub-beam. The polarization direction of the second reflected frequency doubling sub-beam is perpendicular to that of the first green laser beam.

[0030] The second polarization beam combiner receives the first sub-green laser beam and the second reflected frequency-doubled sub-beam to generate a green laser beam.

[0031] Optionally, the plurality of frequency multiplication units include a first frequency multiplication unit, a second frequency multiplication unit, a third frequency multiplication unit, and a fourth frequency multiplication unit;

[0032] At least one reflective unit includes a first reflective unit and a second reflective unit;

[0033] At least one polarization beam combiner unit includes a first polarization beam combiner unit, a second polarization beam combiner unit, and a third polarization beam combiner unit;

[0034] The first frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a first frequency doubling sub-beam;

[0035] The second frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a second frequency doubling sub-beam to the first reflection unit, and the first reflection unit reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling sub-beam;

[0036] The first polarization beam combining unit receives the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam, combines them, and generates a first sub-green laser beam;

[0037] The third frequency harmonic unit receives one of the fundamental frequency sub-beams and outputs a third frequency harmonic sub-beam;

[0038] The fourth frequency harmonic unit receives one of the fundamental frequency sub-beams and outputs a fourth frequency harmonic sub-beam to the second reflection unit, and the second reflection unit reflects the fourth frequency harmonic sub-beam and outputs a second reflected frequency harmonic sub-beam;

[0039] The second polarization beam combining unit receives the third frequency-doubled sub-beam and the second reflected frequency-doubled sub-beam, combines them, and generates a second sub-green laser beam;

[0040] The third polarization beam combining unit receives the first sub-green laser beam and the second sub-green laser beam to generate a green laser beam.

[0041] The technical solution of this utility model embodiment provides a laser, comprising: a laser source for emitting a fundamental frequency beam; an optical fiber splitter for splitting the fundamental frequency beam into at least two fundamental frequency sub-beams for output, wherein the at least two fundamental frequency sub-beams are emitted in parallel; multiple frequency doubling units located on the propagation paths of each fundamental frequency sub-beam for receiving the fundamental frequency sub-beam and outputting frequency-doubled sub-beams; at least one reflection unit located on the propagation paths of some of the frequency-doubled sub-beams for reflecting the frequency-doubled sub-beams and outputting reflected frequency-doubled sub-beams, wherein the polarization directions of the reflected frequency-doubled sub-beams and the frequency-doubled sub-beams are perpendicular; and at least one polarization combining unit located on the propagation paths of the frequency-doubled sub-beams and the reflected frequency-doubled sub-beams for combining the frequency-doubled sub-beams and the reflected frequency-doubled sub-beams to output a green laser beam. By setting multiple frequency-doubled sub-beams and reflected frequency-doubled sub-beams and using the polarization combining unit for polarization combining, a high-brightness green laser beam is output.

[0042] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic diagram of the structure of a laser provided in an embodiment of this utility model;

[0045] Figure 2 This is a schematic diagram of another laser provided in an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of another laser provided in an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram of another laser provided in an embodiment of the present invention. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0050] Figure 1 A schematic diagram of a laser structure provided for an embodiment of this utility model is shown below. Figure 1 As shown, the laser includes: a laser source 101 for emitting a fundamental frequency beam; an optical fiber splitter 102 for splitting the fundamental frequency beam into at least two fundamental frequency sub-beams for output, wherein the at least two fundamental frequency sub-beams are emitted in parallel; multiple frequency doubling units 103 located on the propagation path of each fundamental frequency sub-beam for receiving the fundamental frequency sub-beam and outputting the frequency-doubled sub-beam; at least one reflection unit 104 located on the propagation path of a portion of the frequency-doubled sub-beam for reflecting the frequency-doubled sub-beam and outputting a reflected frequency-doubled sub-beam, wherein the polarization directions of the reflected frequency-doubled sub-beam and the frequency-doubled sub-beam are perpendicular; and at least one polarization combining unit 105 located on the propagation path of the frequency-doubled sub-beam and the reflected frequency-doubled sub-beam for combining the frequency-doubled sub-beam and the reflected frequency-doubled sub-beam and outputting a green laser beam.

[0051] The laser source 101 emits a fundamental frequency beam with a wavelength of 1064 nm. The fiber optic splitter 102 includes one input end and multiple output ends. The number of output ends can be set according to the number of subsequent frequency doubling units 103, and this embodiment of the invention does not impose a specific limitation. In the exemplary figure, the fiber optic splitter 102 includes one output end and two output ends. The fiber optic splitter 102 receives the fundamental frequency beam and outputs two fundamental frequency sub-beams through the two output ends. Two frequency doubling units 103 are correspondingly provided, each corresponding to one of the two fundamental frequency sub-beams. One frequency doubling unit 103 receives one fundamental frequency sub-beam, doubles the frequency of the fundamental frequency sub-beam, and outputs a frequency doubling sub-beam with half the wavelength and doubled in frequency, so that the 1064 nm fundamental frequency sub-beam becomes a 532 nm green frequency doubling sub-beam. The reflection unit 104 is located on the propagation path of part of the frequency doubling sub-beam to adjust the propagation direction of the frequency doubling sub-beam. The polarization beam combiner 105 can be a polarization beam combiner or a polarization beam splitter. When two laser beams with perpendicular polarization directions are incident on the polarization beam combiner, one of the polarization states (such as S-polarized light) undergoes total internal reflection, while the other polarization state (such as P-polarized light) undergoes total transmission. Through precisely designed optical thin films and interference effects, the two beams achieve phase matching and energy superposition within the polarization beam combiner, ultimately combining into a high-power, high-quality laser beam. Specifically, the polarization beam combiner 105 is located on the propagation paths of the frequency-doubled sub-beams and the reflected frequency-doubled sub-beams, enabling it to combine the reflected and frequency-doubled sub-beams with perpendicular polarization directions, thereby forming a high-brightness green laser beam. The brightness of the green laser beam can be achieved by adjusting the number of frequency-doubled and reflected sub-beams; generally, the more frequency-doubled and reflected sub-beams, the higher the brightness of the green laser beam.

[0052] This invention provides a laser comprising a laser source for emitting a fundamental frequency beam; an optical fiber splitter for splitting the fundamental frequency beam into at least two fundamental frequency sub-beams, which are emitted in parallel; multiple frequency doubling units located on the propagation paths of each fundamental frequency sub-beam for receiving and outputting frequency-doubled sub-beams; at least one reflection unit located on the propagation paths of some of the frequency-doubled sub-beams for reflecting the frequency-doubled sub-beams and outputting reflected frequency-doubled sub-beams, the polarization directions of the reflected and frequency-doubled sub-beams being perpendicular; and at least one polarization combining unit located on the propagation paths of the frequency-doubled and reflected frequency-doubled sub-beams for combining the frequency-doubled and reflected frequency-doubled sub-beams and outputting a green laser beam. By setting multiple frequency-doubled and reflected frequency-doubled sub-beams and using the polarization combining unit for polarization combining, a high-brightness green laser beam is output.

[0053] Optional, continue to refer to Figure 1The frequency doubling unit 103 includes a frequency doubling crystal 106 and a dichroic mirror 107; the frequency doubling crystal 106 is used to double the frequency of the fundamental frequency sub-beam to generate a frequency doubling sub-beam; the dichroic mirror 107 is used to transmit the frequency doubling sub-beam to the reflection unit 104 or the polarization beam combining unit 105 and to reflect the fundamental frequency sub-beam.

[0054] The frequency doubling unit 103 includes a frequency doubling crystal 106 and a dichroic mirror 107. The frequency doubling crystal 106 can be a lithium triborate (LBO) crystal, a low-temperature phase barium metaborate (BBO) crystal, or a potassium titanium phosphate (KTP) crystal. The phase matching mode of the frequency doubling crystal 106 is NCPM (non-critical phase matching mode or temperature phase matching). The crystal cutting angle of the frequency doubling crystal 106 includes a first crystal cutting angle and a second crystal cutting angle. The first crystal cutting angle is the angle θ between the normal of the crystal cutting surface and the optical axis of the crystal, and the second crystal cutting angle is the rotation angle φ of the crystal cutting surface in a plane perpendicular to the optical axis, where θ = 90° and φ = 0°. By setting... A frequency-doubling crystal 106, with a temperature around 150℃, can achieve phase matching in the 1064 band, offering advantages such as high frequency doubling efficiency and no walk-off effect. A high-quality green frequency-doubled sub-beam is generated by single-pass frequency doubling of the fundamental sub-beam. A dichroic mirror 107 is positioned in the propagation path of the frequency-doubled sub-beam. The dichroic mirror 107 reflects a portion of the fundamental sub-beam that has not passed through the frequency-doubling crystal 106, effectively filtering it out and preventing its continued propagation, which could affect the quality of the subsequent green laser beam. The dichroic mirror 107 also transmits the received frequency-doubled sub-beam, ensuring it can be received by the reflection unit 104 or the polarization combining unit 105.

[0055] Optional, continue to refer to Figure 1 The laser also includes multiple fundamental frequency optical amplifiers 108, which are located on the propagation path of each fundamental frequency sub-beam and are used to amplify the fundamental frequency sub-beam.

[0056] A fundamental frequency optical amplifier 108 is provided between the fiber optic splitter 102 and the frequency multiplier unit 103. The number of fundamental frequency optical amplifiers 108 can be the same as the number of output ends of the fiber optic splitter 102, so that each fundamental frequency optical amplifier 108 is used to enhance the fundamental frequency sub-beam emitted from the output end of each fiber optic splitter 102 to a higher power level, thereby improving the beam transmission distance and quality.

[0057] Optional, continue to refer to Figure 1 The laser also includes multiple collimation units 109, which are located on the propagation path of each fundamental frequency sub-beam and are used to collimate the fundamental frequency sub-beam.

[0058] A collimation unit 109 is provided between the fundamental frequency optical amplifier 108 and the frequency doubling unit 103. The number of collimation units 109 can be the same as the number of fundamental frequency optical amplifiers 108, so that each fundamental frequency optical amplifier 108 is provided with a collimation unit 109. The collimation unit 109 can be a collimation lens. The collimation lens can collimate the fundamental frequency sub-beam output by the fundamental frequency optical amplifier 108, adjust the diverging fundamental frequency sub-beam into a parallel fundamental frequency sub-beam, avoid energy diffusion, and reduce transmission loss.

[0059] Optional, continue to refer to Figure 1 The laser also includes multiple first half-wave plates 110, which are located on the propagation path of each fundamental frequency sub-beam and are used to adjust the polarization state of the fundamental frequency sub-beam.

[0060] A first half-wave plate 110 is provided between the collimation unit 109 and the frequency doubling unit 103. The number of first half-wave plates 110 can be the same as the number of collimation units 109, so that each collimation unit 109 is provided with a first half-wave plate 110. The first half-wave plate 110 can change the polarization state of light by delaying the phase difference of the light, that is, converting linearly polarized light into linearly polarized light with different polarization directions, thereby realizing the adjustment of the polarization state of the fundamental frequency sub-beam.

[0061] Optional, continue to refer to Figure 1 The laser also includes multiple focusing units 111, which are located on the propagation path of each fundamental frequency sub-beam and are used to focus the fundamental frequency sub-beam and emit it to the frequency doubling unit 103.

[0062] A focusing unit 111 is provided between the first half-wave plate 110 and the frequency doubling unit 103. The number of focusing units 111 can be the same as the number of first half-wave plates 110. The focusing unit 111 can be a focusing lens. The focusing lens can focus the parallel fundamental frequency sub-beam to form a small spot with high energy density, which is convenient to be incident on the center of the frequency doubling crystal 106 in the frequency doubling unit 103, so as to ensure the energy of the generated frequency doubling sub-beam.

[0063] Optional, continue to refer to Figure 1 The laser also includes multiple second half-wave plates 112 located in the propagation path of the frequency-doubled sub-beam for adjusting the polarization state of the frequency-doubled sub-beam.

[0064] A second half-wave plate 112 is disposed between the dichroic mirror 107 and the polarization combining unit 105, or between the dichroic mirror 107 and the reflecting unit 104. The number of second half-wave plates 112 can be the same as the number of frequency doubling units 103, thereby adjusting the polarization state of the frequency-doubled sub-beams output by each frequency doubling unit 103. The first half-wave plate 110, the second half-wave plate 112, the focusing unit 111, and the collimating unit 109 in this application can all be coated with a dual-band anti-reflection film to increase the transmission of the fundamental and frequency-doubled sub-beams, reduce energy loss, and ensure efficient output of lasers of different wavelengths.

[0065] Optional, continue to refer to Figure 1 Multiple frequency doubling units 103 include a first frequency doubling unit 1031 and a second frequency doubling unit 1032; at least one reflection unit 104 includes a first reflection unit 1041; at least one polarization beam combining unit 105 includes a first polarization beam combining unit 1051; the first frequency doubling unit 1031 receives a fundamental frequency sub-beam and outputs a first frequency doubling sub-beam; the second frequency doubling unit 1032 receives a fundamental frequency sub-beam and outputs a second frequency doubling sub-beam to the first reflection unit 1041; the first reflection unit 1041 reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling sub-beam; the first polarization beam combining unit 1051 receives the first frequency doubling sub-beam and the first reflected frequency doubling sub-beam, combines them, and generates a green laser beam.

[0066] The laser includes two fundamental frequency sub-beam outputs, corresponding to two frequency doubling units 103, two fundamental frequency optical amplifiers 108, two focusing units 111, two collimating units 109, two first half-wave plates 110, two second half-wave plates 112, and a reflection unit 104. One fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimating unit 109, first half-wave plate 110, focusing unit 111, first frequency doubling unit 1031, and second half-wave plate 112 to form an incident beam at the first polarization combining unit 104. The first frequency-doubled sub-beam (51) and the other fundamental frequency sub-beam sequentially pass through the corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, second frequency-doubled unit 1032, second half-wave plate 112, and first reflection unit 1041 to form a first reflected frequency-doubled sub-beam incident on the first polarization combining unit 1051. The polarization directions of the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam are perpendicular, and then polarization combining is performed by the first polarization combining unit 1051 to obtain a high-brightness green laser beam output. The brightness of the final green laser beam can be ensured by adjusting the number of fundamental frequency sub-beams, and correspondingly setting the number of frequency-doubled units 103, fundamental frequency optical amplifier 108, focusing unit 111, collimation unit 109, first half-wave plate 110, second half-wave plate 112, reflection unit 104, and polarization combining unit 105.

[0067] Optional, Figure 2 A schematic diagram of another laser structure provided in this embodiment of the present invention is shown below. Figure 2 As shown, the multiple frequency doubling units 103 include a first frequency doubling unit 1031, a second frequency doubling unit 1032, and a third frequency doubling unit 1033; at least one reflection unit 104 includes a first reflection unit 1041 and a second reflection unit 1042; at least one polarization beam combining unit 105 includes a first polarization beam combining unit 1051 and a second polarization beam combining unit 1052; the first frequency doubling unit 1031 receives one fundamental frequency sub-beam and outputs a first frequency doubling sub-beam; the second frequency doubling unit 1032 receives one fundamental frequency sub-beam and outputs a second frequency doubling sub-beam to the first reflection unit 1041, and the first reflection unit 1041 reflects the second frequency doubling sub-beam. The frequency-doubled sub-beam outputs a first reflected frequency-doubled sub-beam; the first polarization beam combining unit 1051 receives the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam and combines them to generate a first sub-green laser beam; the third frequency-doubled unit 1033 receives a fundamental frequency sub-beam and outputs a third frequency-doubled sub-beam to the second reflection unit 1042, and the second reflection unit 1042 reflects the third frequency-doubled sub-beam and outputs a second reflected frequency-doubled sub-beam; the polarization directions of the second reflected frequency-doubled sub-beam and the first sub-green laser beam are perpendicular; the second polarization beam combining unit 1052 receives the first sub-green laser beam and the second reflected frequency-doubled sub-beam to generate a green laser beam.

[0068] The laser features three fundamental frequency sub-beam outputs, corresponding to three frequency doubling units 103, three fundamental frequency optical amplifiers 108, three focusing units 111, three collimating units 109, three first half-wave plates 110, three second half-wave plates 112, and two reflection units 104. A third half-wave plate 113 is also provided between the first polarization combining unit 1051 and the second polarization combining unit 1052. Each fundamental frequency sub-beam sequentially passes through its corresponding fundamental frequency optical amplifier 108, collimating unit 109, first half-wave plate 110, focusing unit 111, and first frequency doubling unit 1031. The second half-wave plate 112 forms a first frequency-doubled sub-beam incident on the first polarization combining unit 1051. Another fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, second frequency-doubled unit 1032, second half-wave plate 112, and first reflection unit 1041 to form a first reflected frequency-doubled sub-beam incident on the first polarization combining unit 1051. The polarization directions of the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam are perpendicular, and then polarized and combined by the first polarization combining unit 1051 to form a first sub-green laser beam. The first sub-green laser beam undergoes polarization state adjustment by the third half-wave plate 113. Another fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, third frequency doubling unit 1033, second half-wave plate 112, and second reflection unit 1042 to form a second reflected frequency doubling sub-beam incident on the second polarization combining unit 1052. The polarization direction of the second reflected frequency doubling sub-beam is perpendicular to that of the first sub-green laser beam after polarization state adjustment. Then, it undergoes polarization combining by the second polarization combining unit 1052 to form a beam that is polarized compared to the first green laser beam. Figure 1 A green laser beam with higher brightness.

[0069] Furthermore, the laser can be equipped with multiple fundamental frequency sub-beam outputs; the specific number can be selected according to actual design requirements, and this embodiment of the invention does not impose a specific limitation. For example, Figure 3 A schematic diagram of another laser structure provided in this embodiment of the present invention is shown below. Figure 3As shown, the laser can also be configured with four fundamental frequency sub-beam outputs, corresponding to four frequency doubling units 103, four fundamental frequency optical amplifiers 108, four focusing units 111, four collimating units 109, four first half-wave plates 110, four second half-wave plates 112, three reflection units 104, and three polarization combining units 105. The four frequency doubling units 103 include a first frequency doubling unit 1031, a second frequency doubling unit 1032, a third frequency doubling unit 1033, and a fourth frequency doubling unit 1034. The three polarization combining units 105 include a first polarization combining unit 1051, a second polarization combining unit 1052, and a fourth polarization combining unit 105. The three reflection units 104 include a first reflection unit 1041, a second reflection unit 1042, and a third reflection unit 1043. A third half-wave plate is also provided between the first polarization combining unit 1051 and the second polarization combining unit 1052. A fourth half-wave plate 114, located between the second polarization beam combiner unit 1052 and the third polarization beam combiner unit 1053, forms a first frequency-doubled sub-beam incident on the first polarization beam combiner unit 1051. One fundamental frequency sub-beam sequentially passes through a corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, first frequency-doubled unit 1031, and second half-wave plate 112. The other fundamental frequency sub-beam sequentially passes through a corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, second frequency-doubled unit 1032, second half-wave plate 112, and first reflection unit 1041 to form a first reflected frequency-doubled sub-beam incident on the first polarization beam combiner unit 1051. The polarization directions of the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam are perpendicular, and then they are polarized and combined by the first polarization beam combiner unit 1051 to form a first sub-green laser beam. The first sub-green laser beam undergoes polarization state adjustment by the third half-wave plate 113. Another fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, third frequency doubling unit 1033, second half-wave plate 112, and second reflection unit 1042 to form a second reflected frequency doubling sub-beam incident on the second polarization combining unit 1052. The polarization direction of the second reflected frequency doubling sub-beam is perpendicular to that of the first sub-green laser beam after polarization state adjustment. Then, it is polarized and combined by the second polarization combining unit 1052 to form a second sub-green laser beam. Another fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, fourth frequency doubling unit 1034, second half-wave plate 112, and third reflection unit 1043 to form a third reflected frequency doubling sub-beam incident on the third polarization combining unit 1053. The second sub-green laser beam undergoes polarization state adjustment by the fourth half-wave plate 114.The polarization directions of the third reflection frequency-doubled sub-beam and the second sub-green laser beam after polarization state adjustment are perpendicular, and then they are polarized and combined by the third polarization combining unit 1053 to form a beam that is polarized relative to the second sub-green laser beam. Figure 2 It has a brighter green laser beam.

[0070] Optional, Figure 4 A schematic diagram of another laser structure provided in this embodiment of the present invention is shown below. Figure 4 As shown, multiple frequency doubling units 103 include a first frequency doubling unit 1031, a second frequency doubling unit 1032, a third frequency doubling unit 1033, and a fourth frequency doubling unit 1034; at least one reflection unit 104 includes a first reflection unit 1041 and a second reflection unit 1042; at least one polarization beam combining unit 105 includes a first polarization beam combining unit 1051, a second polarization beam combining unit 1052, and a third polarization beam combining unit 1053; the first frequency doubling unit 1031 receives a fundamental frequency sub-beam and outputs a first frequency doubling sub-beam; the second frequency doubling unit 1032 receives a fundamental frequency sub-beam and outputs a second frequency doubling sub-beam to the first reflection unit 1041, and the first reflection unit 1041 reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling. Sub-beams; the first polarization beam combining unit 1051 receives the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam, combines them, and generates the first sub-green laser beam; the third frequency-doubled unit 1033 receives one fundamental frequency sub-beam and outputs the third frequency-doubled sub-beam; the fourth frequency-doubled unit 1034 receives one fundamental frequency sub-beam and outputs the fourth frequency-doubled sub-beam to the second reflection unit 1042, the second reflection unit 1042 reflects the fourth frequency-doubled sub-beam and outputs the second reflected frequency-doubled sub-beam; the second polarization beam combining unit 1052 receives the third frequency-doubled sub-beam and the second reflected frequency-doubled sub-beam, combines them, and generates the second sub-green laser beam; the third polarization beam combining unit 1053 receives the first sub-green laser beam and the second sub-green laser beam to generate the green laser beam.

[0071] The laser can also be configured with four fundamental frequency sub-beam outputs, corresponding to four frequency doubling units 103, four fundamental frequency optical amplifiers 108, four focusing units 111, four collimating units 109, four first half-wave plates 110, four second half-wave plates 112, two reflection units 104, and three polarization combining units 105. A third half-wave plate 113 is also provided between the first polarization combining unit 1051 and the second polarization combining unit 1052. The two reflection units 104 include a first reflection unit 1041 and a second reflection unit 102. One fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimating unit 109, first half-wave plate 100, second half-wave plate 102, and third half-wave plate 103. Half-wave plate 110, focusing unit 111, first frequency doubling unit 1031 and second half-wave plate 112 form a first frequency-doubled sub-beam incident on the first polarization beam combining unit 1051. Another fundamental frequency sub-beam passes sequentially through the corresponding fundamental frequency optical amplifier 108, collimating unit 109, first half-wave plate 110, focusing lens, second frequency doubling unit 1032, second half-wave plate 112 and first reflection unit 1041 to form a first reflected frequency-doubled sub-beam incident on the first polarization beam combining unit 1051. The polarization directions of the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam are perpendicular, and then the first polarization beam combining unit 1051 is used to polarize and synthesize the first green laser beam. Another fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, third frequency doubling unit 1033, and second half-wave plate 112 to form a second frequency doubling sub-beam incident on the second polarization beam combining unit 1052. Another fundamental frequency sub-beam sequentially passes through the corresponding fundamental frequency optical amplifier 108, collimation unit 109, first half-wave plate 110, focusing unit 111, fourth frequency doubling unit 1034, second half-wave plate 112, and first reflection unit 1041 to form a second reflected frequency doubling sub-beam incident on the second polarization beam combining unit 1052. The polarization directions of the second frequency doubling sub-beam and the second reflected frequency doubling sub-beam are perpendicular, and then the second polarization beam combining unit 1052 is used to polarize and synthesize a second sub-green laser beam. The reflection unit also includes a fourth reflection unit 1044 located on the propagation path of the second sub-green laser beam. The second sub-green laser beam is reflected by the fourth reflection unit 104 and incident on the third polarization beam combining unit 1053. The polarization state of the first sub-green laser beam is adjusted by the third half-wave plate 113. The polarization directions of the adjusted first sub-green laser beam and the second sub-green laser beam are perpendicular. The third polarization beam combining unit 1053 polarizes and generates a high-brightness green laser beam.The number of fundamental frequency sub-beams can be selected according to the actual design requirements. Usually, the number of fundamental frequency sub-beams is even. Every two fundamental frequency sub-beams are adjusted to form two frequency-doubled sub-beams, which are then combined into a green laser beam by a polarization combining unit. Every two green laser beams can be combined again by a polarization combining unit to form a high-brightness green laser beam. This process can be continuously superimposed and combined to form a green laser beam with the target brightness.

[0072] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A laser, characterized by, include: Laser source, used to emit a fundamental frequency beam; An optical fiber splitter is used to split the fundamental frequency beam into at least two fundamental frequency sub-beams for output, wherein the at least two fundamental frequency sub-beams are emitted in parallel. Multiple frequency doubling units are located on the propagation path of each of the fundamental frequency sub-beams, and are used to receive the fundamental frequency sub-beams and output the frequency doubling sub-beams; At least one reflecting unit is located on the propagation path of a portion of the frequency-doubled sub-beam, for reflecting the frequency-doubled sub-beam and outputting a reflected frequency-doubled sub-beam, wherein the polarization direction of the reflected frequency-doubled sub-beam is perpendicular to that of the frequency-doubled sub-beam; At least one polarization beam combiner is located on the propagation path of the frequency-doubled sub-beam and the reflected frequency-doubled sub-beam, for combining the frequency-doubled sub-beam and the reflected frequency-doubled sub-beam and outputting a green laser beam.

2. The laser of claim 1, wherein, The frequency doubling unit includes a frequency doubling crystal and a dichroic mirror; The frequency doubling crystal is used to double the frequency of the fundamental frequency sub-beam to generate a frequency doubling sub-beam; The dichroic mirror is used to transmit the frequency-doubled sub-beam to the reflection unit or the polarization beam combiner unit and to reflect the fundamental frequency sub-beam.

3. The laser of claim 1, wherein, The laser also includes multiple fundamental frequency optical amplifiers, which are located on the propagation path of each fundamental frequency sub-beam and are used to amplify the fundamental frequency sub-beam.

4. The laser of claim 1, wherein, The laser also includes multiple collimation units, which are located on the propagation path of each fundamental frequency sub-beam and are used to collimate the fundamental frequency sub-beam.

5. The laser of claim 1, wherein, The laser also includes a plurality of first half-wave plates, which are respectively located on the propagation path of each fundamental frequency sub-beam and are used to adjust the polarization state of the fundamental frequency sub-beam.

6. The laser of claim 1, wherein, The laser also includes multiple focusing units, which are located on the propagation path of each fundamental frequency sub-beam and are used to focus the fundamental frequency sub-beam and emit it to the frequency doubling unit.

7. The laser according to claim 1, characterized in that, The laser also includes multiple second half-wave plates located on the propagation path of the frequency-doubled sub-beam, used to adjust the polarization state of the frequency-doubled sub-beam.

8. The laser of claim 1, wherein, Multiple frequency multiplier units include a first frequency multiplier unit and a second frequency multiplier unit; At least one reflective unit includes a first reflective unit; At least one polarization beam combiner unit includes a first polarization beam combiner unit; The first frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a first frequency doubling sub-beam; The second frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a second frequency doubling sub-beam to the first reflection unit. The first reflection unit reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling sub-beam. The first polarization beam combining unit receives the first frequency doubling sub-beam and the first reflected frequency doubling sub-beam and combines them to generate a green laser beam.

9. The laser according to claim 1, characterized in that, The plurality of frequency multiplication units include a first frequency multiplication unit, a second frequency multiplication unit, and a third frequency multiplication unit; At least one reflective unit includes a first reflective unit and a second reflective unit; At least one polarization beam combiner unit includes a first polarization beam combiner unit and a second polarization beam combiner unit; The first frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a first frequency doubling sub-beam; The second frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a second frequency doubling sub-beam to the first reflection unit, and the first reflection unit reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling sub-beam; The first polarization beam combining unit receives the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam, combines them, and generates a first sub-green laser beam; The third frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a third frequency doubling sub-beam to the second reflection unit. The second reflection unit reflects the third frequency doubling sub-beam and outputs a second reflected frequency doubling sub-beam. The polarization direction of the second reflected frequency doubling sub-beam is perpendicular to that of the first green laser beam. The second polarization beam combiner receives the first sub-green laser beam and the second reflected frequency-doubled sub-beam to generate a green laser beam.

10. The laser according to claim 1, characterized in that, The plurality of frequency multiplication units include a first frequency multiplication unit, a second frequency multiplication unit, a third frequency multiplication unit, and a fourth frequency multiplication unit; At least one reflective unit includes a first reflective unit and a second reflective unit; At least one polarization beam combiner unit includes a first polarization beam combiner unit, a second polarization beam combiner unit, and a third polarization beam combiner unit; The first frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a first frequency doubling sub-beam; The second frequency doubling unit receives one of the fundamental frequency sub-beams and outputs a second frequency doubling sub-beam to the first reflection unit, and the first reflection unit reflects the second frequency doubling sub-beam and outputs a first reflected frequency doubling sub-beam; The first polarization beam combining unit receives the first frequency-doubled sub-beam and the first reflected frequency-doubled sub-beam, combines them, and generates a first sub-green laser beam; The third frequency harmonic unit receives one of the fundamental frequency sub-beams and outputs a third frequency harmonic sub-beam; The fourth frequency harmonic unit receives one of the fundamental frequency sub-beams and outputs a fourth frequency harmonic sub-beam to the second reflection unit, and the second reflection unit reflects the fourth frequency harmonic sub-beam and outputs a second reflected frequency harmonic sub-beam; The second polarization beam combining unit receives the third frequency-doubled sub-beam and the second reflected frequency-doubled sub-beam, combines them, and generates a second sub-green laser beam; The third polarization beam combining unit receives the first sub-green laser beam and the second sub-green laser beam to generate a green laser beam.

Images