Laser diode linear stacking structure and laser

Abstract

The invention provides a laser diode linear stacking structure and a laser, the laser diode linear stacking structure comprises N laser diode groups, and N is a natural number greater than or equal to 2; the laser diode group comprises a heat sink, at least two laser diode chips arranged on the heat sink and a light beam adjusting module, and the light emitting directions of the laser diode chips are consistent; the light beam adjusting module is arranged on the light emitting side of each laser diode chip, and carries out collimation and light beam width adjustment on laser emitted by each laser diode chip; the laser diode sets are sequentially arranged in the light emitting direction of the light beam adjusting module, and the positions of light beams emitted by the laser diode sets are arranged in an offset mode in the arrangement direction of the laser diode chips so that the positions of the light beams emitted by the laser diode sets can be propagated in the same emitting plane in a staggered mode. And the same emergent direction is realized. The laser diode linear stacking structure and the laser have the advantages of being high in efficiency, small in size, high in heat dissipation efficiency, long in service life and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of lasers, and in particular, to a linear stacked structure of laser diodes and a laser. Background Art

[0002] Laser diodes have the advantages of high efficiency, low power consumption, small size, and low cost, and are widely used in fields such as aerospace, medicine, and scientific research. Typically, a single laser diode can emit a power of up to several tens of watts; an important application of high-power laser diodes is to pump solid-state lasers (PSSL; also known as pumped solid-state lasers) and fiber lasers (FL); another important application is laser material processing.

[0003] Hereinafter, a single laser diode will be referred to as a transmitter. In order to achieve the power required for various applications, for example, multiple transmitters are combined together in the form of a single-crystal diode laser bar; another method of increasing power is to optically aggregate the power of many single transmitters. The efficiency of laser diodes is about 55%, and heat must be dissipated effectively to ensure the normal operation of the laser diodes, and a microchannel cooler can be used to dissipate heat effectively; however, due to erosion and corrosion, the service life of the microchannel cooler is limited. In contrast, the configuration using many single transmitters has significant advantages in heat dissipation management; however, the size of the diode laser system constructed with many single transmitters is significantly larger than that of the diode laser system using a microchannel cooler.

[0004] Therefore, how to balance the issues of size, heat dissipation efficiency, and service life while achieving power expansion has become one of the problems that need to be urgently solved by those skilled in the art.

[0005] It should be noted that the above introduction of the technical background is only for the convenience of clearly and completely explaining the technical solution of the present invention and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art just because these solutions are described in the background art section of the present invention. Summary of the Invention

[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a linear stacked structure of laser diodes and a laser, which are used to solve the problems that the size, heat dissipation efficiency, and service life cannot be balanced in the application of expanding the power of lasers in the prior art.

[0007] To achieve the above object and other related objects, the present invention provides a linear stacked structure of laser diodes, characterized in that the linear stacked structure of laser diodes includes:

[0008] N laser diode groups, where N is a natural number greater than or equal to 2; each laser diode group includes a heat sink, at least two laser diode chips disposed on the heat sink, and a beam adjustment module, and the light-emitting directions of the laser diode chips are the same; the beam adjustment module is disposed on the light-emitting side of each laser diode chip and collimates and adjusts the beam width of the laser emitted by each laser diode chip;

[0009] The laser diode groups are arranged in sequence in the light-emitting direction of the beam adjustment module, and the positions of the beams emitted by the laser diode groups are offset in the arrangement direction of the laser diode chips, so that the positions of the beams emitted by the laser diode groups propagate alternately in the same emission plane and have the same emission direction.

[0010] Optionally, the beam adjustment module includes a first collimating lens and a second collimating lens arranged in sequence along the beam propagation direction. The first collimating lens collimates the beam emitted by the laser diode chip in the fast axis direction, and the second collimating lens collimates the beam in the slow axis direction.

[0011] Optionally, the beam adjustment module further includes a first type of beam guiding element disposed on the optical path after the first collimating lens; the first beam guiding element adjusts the beam propagation direction to be not parallel to the plane where the laser diode chips are located.

[0012] More optionally, the beam propagation direction after being adjusted by the beam adjustment module is perpendicular to the plane where the laser diode chips are located.

[0013] More optionally, the first beam guiding element is a mirror.

[0014] More optionally, the beam adjustment module further includes a second type of beam guiding element disposed on the optical path after the first collimating lens; the second beam guiding element adjusts the beam to propagate in a preset plane, and the preset plane is parallel to the plane where the laser diode chips are located.

[0015] More optionally, the second type of beam guiding element is a rhombic prism.

[0016] More optionally, the second type of beam guiding element includes a first mirror and a second mirror; the first mirror reflects the incident beam, and the second mirror reflects the beam reflected by the first mirror again;

[0017] The first reflector is arranged as a single reflector having alternately arranged reflection regions and transmission regions in sequence or as a plurality of reflectors corresponding to each laser diode chip one by one; the second reflector is arranged as a single reflector having alternately arranged reflection regions and transmission regions in sequence or as a plurality of reflectors corresponding to each laser diode chip one by one.

[0018] More preferably, the first reflector reflects the light beam by 90°, and the second reflector reflects the light beam by -90°.

[0019] More preferably, the second collimating lens is arranged between the first reflector and the second reflector.

[0020] More preferably, the beam adjustment module further includes a wavelength selective element disposed on the optical path after the first collimating lens.

[0021] More preferably, the width of the light beam of each laser diode chip in the slow axis direction after passing through the corresponding beam adjustment module is not greater than D / N; the offset of the light beam emitted by each laser diode group is not less than the width in the slow axis direction and not greater than D / N, where D is the distance between the central axes of two adjacent laser diode chips in the same laser diode group.

[0022] More preferably, each laser diode chip is packaged with COS.

[0023] More preferably, a positive contact and a negative contact are further arranged on the heat sink, and each laser diode chip is connected in series between the positive contact and the negative contact by a bonding wire.

[0024] More preferably, the positions of each laser diode group are offset in the arrangement direction of each laser diode chip; and / or, the beam adjustment module further includes a third type of beam guiding element, and the third type of beam guiding element is disposed on the optical path after the first collimating lens for offsetting the positions of the light beams emitted by each laser diode group in the arrangement direction of each laser diode chip.

[0025] More preferably, the beam adjustment module further includes an optical function unit, and the optical function unit is disposed on the optical path after the first collimating lens for rotating the light beam by 90° around the optical axis.

[0026] More preferably, the height of the light beam of each laser diode chip in the fast axis direction after passing through the corresponding beam adjustment module is not greater than D / N; the offset of the light beam emitted by each laser diode group is not less than the height in the fast axis direction and not greater than D / N, where D is the distance between the central axes of two adjacent laser diode chips in the same laser diode group.

[0027] More optionally, the positions of the laser diode groups are offset in the arrangement direction of the laser diode chips; and / or, the beam adjustment module further includes a third type of beam guiding element, which is disposed on the optical path after the first collimating lens and is used to offset the positions of the beams emitted by the laser diode groups in the arrangement direction of the laser diode chips.

[0028] More optionally, the laser diode linear stacking structure further includes a first optical device, which is disposed on the emission optical path of the N laser diode groups, divides the beam in the slow axis direction into K segments, and arranges the K segments of beams side by side in the fast axis direction; where K is a natural number greater than or equal to 4.

[0029] More optionally, the positions of the laser diode groups are offset in the arrangement direction of the laser diode chips; and / or, the beam adjustment module further includes a third type of beam guiding element, which is disposed on the optical path after the first collimating lens and is used to offset the beams emitted by the laser diode groups in the arrangement direction of the laser diode chips.

[0030] To achieve the above object and other related objects, the present invention further provides a laser, which at least includes: the above laser diode linear stacking structure.

[0031] Optionally, the laser further includes a second optical device, which is disposed on the optical path after the laser diode linear stacking structure and is used to couple the beam into the optical waveguide.

[0032] As described above, the laser diode linear stacking structure and the laser of the present invention have the following beneficial effects:

[0033] The laser diode linear stacking structure of the present invention uses at least two laser diode groups, and at least two laser diode chips are arranged side by side in each laser diode group, and the beams of the laser diode chips are unfolded in parallel; the laser diode groups are arranged in sequence in the light emission direction of the laser diode chips, so that the positions of the beams emitted by the laser diode groups are staggered, and the beams are parallel and located in the same plane; the efficiency is greatly improved by combining the beams in two directions.

[0034] In the laser diode linear stacking structure of the present invention, each laser diode chip is disposed on the heat sink, which greatly reduces the device size while ensuring the heat dissipation efficiency and the service life of the heat sink. Description of the Drawings

[0035] Figure 1 It shows a schematic diagram of the first laser diode group of the present invention in the XZ plane.

[0036] Figure 2 It shows a schematic diagram of the laser COS chip of the present invention in the YZ plane.

[0037] Figure 3 It shows a schematic diagram of the laser COS chip of the present invention in the XZ plane.

[0038] Figure 4 It shows an optical path diagram of the emitted light of the laser diode chip of the present invention collimated in the fast axis direction.

[0039] Figure 5 It shows an optical path diagram of the emitted light of the laser diode chip of the present invention collimated in the slow axis direction.

[0040] Figure 6 It shows a schematic structural diagram of the second laser diode group of the present invention in the XZ plane.

[0041] Figure 7 It shows a schematic diagram of the first laser diode linear stacking structure of the present invention in the XZ plane.

[0042] Figure 8 It shows a schematic diagram of the third laser diode group of the present invention in the XZ plane.

[0043] Figure 9 It shows a schematic diagram of the third laser diode group of the present invention in the YZ plane.

[0044] Figure 10 It shows a schematic diagram of the fourth laser diode group of the present invention in the XZ plane.

[0045] Figure 11 It shows a schematic diagram of the fourth laser diode group of the present invention in the XY plane.

[0046] Figure 12 It shows a schematic diagram of the fifth laser diode group of the present invention in the XZ plane.

[0047] Figure 13 It shows a schematic diagram of the fifth laser diode group of the present invention in the XY plane.

[0048] Figure 14 It shows a schematic diagram of the second laser diode linear stacking structure of the present invention in the XY plane.

[0049] Figure 15 It shows a schematic diagram of the sixth laser diode group of the present invention in the XZ plane.

[0050] Figure 16 It shows a schematic diagram of the sixth laser diode group of the present invention in the XY plane.

[0051] Figure 17 Schematic diagram of the sixth laser diode group of the present invention in the YZ plane.

[0052] Figure 18 Schematic diagram of the seventh laser diode group of the present invention in the XZ plane.

[0053] Figure 19 Schematic diagram of the seventh laser diode group of the present invention in the XY plane.

[0054] Figure 20 Schematic diagram of the seventh laser diode group of the present invention in the YZ plane.

[0055] Figure 21 Schematic diagram of the eighth laser diode group of the present invention in the XY plane.

[0056] Figure 22 Schematic diagram of the structure of the second mirror of the present invention.

[0057] Figure 23 Schematic diagram of the third laser diode linear stacking structure of the present invention in the XZ plane.

[0058] Figure 24 Schematic diagram of the third laser diode linear stacking structure of the present invention in the YZ plane.

[0059] Figure 25 Schematic diagram of the fourth laser diode linear stacking structure of the present invention in the XZ plane.

[0060] Figure 26 Schematic diagram of the light spot of the first optical device of the present invention before and after shaping.

[0061] Figure 27 Schematic diagram of the ninth laser diode group of the present invention in the XZ plane.

[0062] Figure 28 Schematic diagram of the ninth laser diode group of the present invention in the XY plane.

[0063] Figure 29 Schematic diagram of the ninth laser diode group of the present invention in the YZ plane.

[0064] Figure 30 Schematic diagram of the fifth laser diode linear stacking structure of the present invention in the XZ plane.

[0065] Figure 31 Schematic diagram of the tenth laser diode group of the present invention in the XZ plane.

[0066] Figure 32 Shows a schematic diagram of the tenth laser diode group of the present invention in the XY plane.

[0067] Figure 33 Shows a schematic diagram of the tenth laser diode group of the present invention in the YZ plane.

[0068] Figure 34 Shows a schematic diagram of the eleventh laser diode group of the present invention in the XZ plane.

[0069] Figure 35 Shows a schematic diagram of the eleventh laser diode group of the present invention in the XY plane.

[0070] Figure 36 Shows a schematic diagram of the eleventh laser diode group of the present invention in the YZ plane.

[0071] Figure 37 Shows a schematic diagram of the laser of the present invention in the XZ plane.

[0072] Description of component labels

[0073] 10 Linear stack structure of laser diodes

[0074] 1 Laser diode group

[0075] 11 Heat sink

[0076] 12 Laser diode chip

[0077] 12a Substrate

[0078] 12b Solder layer

[0079] 12c Electrode layer

[0080] 12d Emission end

[0081] 13 Beam adjustment module

[0082] 131 First collimating lens

[0083] 132 Second collimating lens

[0084] 133 Wavelength selective element

[0085] 134 First type of beam guiding element

[0086] 135 Second type of beam guiding element

[0087] 135a First mirror

[0088] 135b Second mirror

[0089] 136 Optical functional unit

[0090] 137 The third type of beam guiding element

[0091] 14 The first optical device

[0092] 14a Positive contact

[0093] 14b Negative contact

[0094] 15 Bonding wire

[0095] 16 The first optical device

[0096] 20 The second optical device

[0097] 30 Optical waveguide Detailed implementation manners

[0098] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0099] Please refer to Figures 1 to 37 . It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and ratios of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0100] The present invention arranges N laser diode groups in sequence in the light-emitting direction of the laser diode chip. The positions of the light beams emitted by each laser diode group are offset in the arrangement direction of each laser diode chip, so that the N groups of lasers emitted by the N laser diode groups are staggered. In this way, multiple single laser diode chips are used to efficiently expand the power in a compact structure, while taking into account issues such as size, heat dissipation efficiency, and service life. The laser diode linear stacking structure of the present invention can maintain the brightness of a single laser diode chip, so that the light beams combined by multiple laser diode chips can be coupled into an optical waveguide with the smallest diameter, or a pump source with the maximum brightness can be realized. The following specifically describes the implementation manner of the present invention.

[0101] The present invention proposes a laser diode linear stacking structure 10, including N laser diode groups 1, where N is a natural number greater than or equal to 2. As Figure 1As shown, each laser diode group 1 includes a heat sink 11, at least two laser diode chips 12 disposed on the heat sink 11, and a beam adjustment module 13. The light-emitting directions of the laser diode chips 12 are the same. The beam adjustment module 13 is disposed on the light-emitting side of each laser diode chip 12, and collimates and adjusts the beam width of the laser emitted by each laser diode chip 12. The laser diode groups 1 are arranged in sequence in the light-emitting direction of the beam adjustment module 13, and the positions of the beams emitted by the laser diode groups 1 are offset in the arrangement direction of the laser diode chips 12, so that the lasers emitted by the laser diode groups 1 propagate crosswise in the same emission plane and have the same emission direction.

[0102] Specifically, the heat sink 11 is located at the bottom of the laser diode group 1. The heat sink 11 is used for heat dissipation. In this example, the heat sink 11 is made of a material with high thermal conductivity, including but not limited to metals or alloys with high thermal conductivity. In actual use, the material of the heat sink 11 can be set according to needs, and any material and shape that can meet the heat dissipation requirements are applicable.

[0103] Specifically, as Figure 2 and Figure 3 shown, in this embodiment, a single laser diode chip 12 of the present invention uses COS (Chip on Submount) packaging to form a laser COS chip. As an example, the laser COS chip includes a substrate 12a and a laser diode chip 12 disposed on the substrate 12a. The substrate 12a is composed of a thin and thermally conductive ceramic plate and a conductive layer on the surface. The bottom electrode of the laser diode chip 12 is attached to the upper surface of the substrate 12a through a solder layer 12b and is electrically connected to the conductive layer on the upper surface of the substrate 12a. The top electrode of the laser diode chip 12 is led out through an electrode layer 12c on the top. The laser diode chip 12 emits a beam from the emission end 12d, and the emission width is d. For the convenience of description, a coordinate system is introduced in the present invention. Among them, the XZ plane is parallel to the plane where the laser diode chip 12 is located. The X axis is the laser slow axis direction (parallel to the pn junction direction), the Y axis is the laser fast axis direction (parallel to the stacking direction of each part in the laser COS chip 12, that is, the direction perpendicular to the pn junction on the XY plane), and the Z axis is parallel to the light-emitting direction of the laser diode chip 12. Due to the unique geometric shape of the laser diode chip 12, the beam of the laser diode chip 12 has a large divergence angle θfa in the fast axis direction and a small divergence angle θsa in the slow axis direction.

[0104] It should be noted that in actual use, the laser diode chip can use a bare chip or other packaging structures. Any laser diode chip that can be arranged side by side on the same heat sink is applicable to the present invention and is not limited to this embodiment.

[0105] As Figure 1As shown, in this embodiment, the number of laser diode chips 12 arranged side by side on each laser diode group 1 is set to 6, and is set according to actual needs during actual use, including but not limited to 3, 5, 7, 8, 10, 15, 20, and is not limited to this embodiment.

[0106] As Figure 1 shown, as an example, the beam adjustment module 13 includes a first collimating lens 131 and a second collimating lens 132 arranged in sequence along the beam propagation direction. The first collimating lens 131 collimates the beam emitted by the laser diode chip 12 in the fast axis direction, and the second collimating lens 132 collimates the beam emitted by the first collimating lens 131 in the slow axis direction; wherein, the beam emitted by the laser diode linear stacking structure 10 propagates in a straight line in the same plane. Specifically, each laser diode chip 12 in the same laser diode group 1 emits a beam of light, and the beam adjustment module 13 collimates and adjusts the width of the laser emitted by each laser diode chip 12 so that each beam of laser can be used in cooperation (parallelly emitted in the same plane and arranged in sequence to reduce brightness loss), achieving high power. As Figure 4 shown, a first collimating lens 131 is provided at the output end of a single laser diode chip 12 to collimate the beam in the fast axis direction, and the beam height is adjusted to Wy; as Figure 5 shown, in order to maintain the brightness, a second collimating lens 132 is further used to collimate the beam in the slow axis direction, and the beam width is adjusted to Wx; after collimation in two directions, the beam divergence angle is reduced, so that the beam of a single laser diode chip 12 has an approximately rectangular cross-section, and the cross-sectional area is Wx*Wy. As Figure 1 shown, when a single laser diode group 1 is used alone, it is set that the width Wx of the beam of each laser diode chip 12 in the slow axis direction after passing through the corresponding beam adjustment module 13 is not greater than D, then, the lasers emitted by each laser diode chip 12 are combined (the brightness after combination is the same as the emission brightness of a single laser diode chip 12); wherein, D is the distance between the central axes of two adjacent laser diode chips 12 in the same laser diode group 1, and Wx should be as close as possible to D to maintain the brightness of the total beam emitted by the laser diode group 1 (obtaining a beam that is as continuous as possible in the X-axis direction); the value of Wx can be set according to actual needs, including but not limited to D, 95% D, 92% D, 90% D, 88% D, 85% D, 80% D, 50% D, which will not be elaborated here one by one.

[0107] It should be noted that the first collimating lens 131 corresponding to each side-by-side laser diode chip 12 can be set according to the number of laser diode chips 12, and the number of the first collimating lens 131 is set in one-to-one correspondence with the number of side-by-side laser diode chips 12. Similarly, the second collimating lens 132 corresponding to each side-by-side laser diode chip 12 can also be set according to the number of laser diode chips 12, and can be one-to-one. Of course, the first collimating lens 131 and the second collimating lens 132 can also be set as a long lens respectively, that is, the lasers emitted by a row of laser diode chips 12 are collimated in the fast axis direction through a lens, and collimated in the slow axis direction through a lens group (replacing a microlens array composed of multiple collimating lenses), which is not limited to this embodiment. As an example, the first collimating lens 131 and the second collimating lens 132 are implemented using cylindrical microlenses, and any lens that can achieve collimation in the corresponding direction is applicable to the present invention, and will not be described one by one here.

[0108] As another example, Figure 6 As shown, the beam adjustment module 13 also includes a wavelength selective element 133 arranged on the optical path, and the wavelength selective element 133 is arranged on the optical path after the first collimating lens 131. The wavelength selective element 133 is used to set the wavelength of the laser emitted by each single laser diode chip 12, and can adopt a continuous long element or a plurality of elements corresponding to each laser diode chip 12. In this example, the wavelength selective element 133 is arranged on the optical path between the first collimating lens 131 and the second collimating lens 132; in actual use, the wavelength selective element 133 can also be arranged on the optical path after the second collimating lens 132, and the wavelength selection function can be realized. As an example, the wavelength selective element 133 includes but is not limited to a transmissive volume Bragg grating, a reflective volume Bragg grating, a transmissive holographic grating, and a reflective holographic grating. It should be noted that the wavelength selective element 133 is an optional element, and there is no need to set a wavelength selective element for occasions where there is no requirement for the wavelength or the wavelength has met the requirement. In this example, the beam width Wx is adjusted by adjusting the focal length of the second collimating lens 132 , so that the beam width Wx is smaller than D.

[0109] Specifically, as an example, the width Wx of the light beam of each laser diode chip 12 after passing through the corresponding beam adjustment module 13 in the slow axis direction is not greater than D / N; the offset S of the light beam emitted by each laser diode group 1 is not less than the width Wx in the slow axis direction, and is not greater than D / N; wherein, Wx should be as close to (or equal to) D / N as possible, and the offset S should also be as close to (or equal to) D / N as possible, so that the gaps between the laser diode chips 12 are filled with the laser beams in other laser diode groups 1, and the lasers emitted by each laser diode group 1 are combined, and all the light beams together form an approximately continuous linear light beam. Figure 7As shown, in this embodiment, the offset of each laser diode group 1 in position is used to achieve the offset of the light beams emitted by each laser diode group 1. N is set to 2, and the two laser diode groups 1 are arranged in sequence along the light-emitting direction (Z-axis) of the laser diode chip 12 in the XZ plane. The offset amount S of the two laser diode groups 1 is set to D / 2, and the width Wx in the slow axis direction after adjustment is set to D / 2. At this time, the light beam of one laser diode group 1 passes through the light beam gap of the other laser diode group 2, and the two rows of light beams intersect each other. In this example, the laser light emitted by each laser diode chip 12 always propagates parallel in the same plane.

[0110] By applying voltages to the upper and lower electrodes of each laser diode chip 12 to drive the laser diode chip 12 to emit light, each laser diode chip 12 on the laser diode group 1 can be respectively applied with voltages through leads; they can also be connected in series and voltages are applied at both ends of the series structure to reduce ohmic losses. As Figure 8 shown, as an example, bonding wires 15 are used to achieve the series connection of each laser diode chip 12. A positive contact 14a and a negative contact 14b are also provided on the heat sink 11. Each laser diode chip 12 is connected in series between the positive contact 14a and the negative contact 14b through the bonding wire 15. As Figure 9 shown, since each bonding wire is located between two adjacent laser diode chips 12, when the N laser diode groups 1 are arranged in sequence in the Z-axis direction, the gap between two adjacent laser diode chips 12 is occupied, and the light beam is blocked by the bonding wire and cannot propagate alternately and be combined. In view of this, the present invention improves the light beam adjustment module 13 so that the light beams of the N laser diode groups 1 can be emitted in the same plane.

[0111] As an example, as Figure 10 shown, the light beam adjustment module 13 includes a first collimating lens 131, a second collimating lens 132 and a first type of light beam guiding element 134 arranged along the optical path. The first type of light beam guiding element 134 adjusts the light beam propagation direction to be not parallel to the plane (XZ plane) where each laser diode chip 12 is located; the first collimating lens 131, the second collimating lens 132 and the first type of light beam guiding element 134 are arranged in sequence along the light beam propagation direction; in this embodiment, the first type of light beam guiding element 134 is implemented by a mirror, and thus the folded laser diode group 1 is obtained. The number of mirrors can correspond one-to-one to the number of laser diode chips 12, or one mirror can be used, and the mirror is set to have alternately arranged reflection regions and transmission regions. As Figure 11 shown, in this example, the light beam propagation direction after being adjusted by the light beam adjustment module 13 is perpendicular to the plane (Y-axis direction) where each laser diode chip 12 is located. As Figure 10As shown, when the first collimating lens 131, the second collimating lens 132, and the first type of beam guiding element 134 are arranged in sequence, the size of the laser diode group 1 in the emission beam direction (Z-axis) of the laser diode chip 12 is H; in order to reduce the size of the laser diode group 1 in the emission beam direction of the laser diode chip 12, the order of the second collimating lens 132 and the first type of beam guiding element 134 in the optical path is interchanged, that is, the first collimating lens 131, the first type of beam guiding element 134, and the second collimating lens 132 are arranged in sequence along the beam propagation direction, and the collimation in the slow direction is performed after the beam is reflected, as Figure 12 and Figure 13 shown. At this time, the size of the laser diode group 1 in the emission beam direction of the laser diode chip 12 can be reduced to h, and h is less than H. In this example, a wavelength selective element 133 can also be arranged on the optical path after the first collimating lens 131 (the wavelength selective element 133 can be arranged at any position on the optical path after the first collimating lens 131, not limited to this embodiment), and the wavelength selective element 133 and the first type of beam guiding element 134 can also be combined into one element to reduce the number of components. As Figure 14 shown, when the beam propagation direction is adjusted to the Y-axis direction based on the first type of beam guiding element 134, the laser diode groups 1 are stacked in the Y-axis direction and offset in the arrangement direction of the laser diode chips 12; at this time, since the beam is not blocked by the bonding wires, beam combination can be performed in the same plane. It should be noted that when the adjustment angle of the first type of beam guiding element 134 to the beam is not equal to 90°, the positions of the laser diode groups 1 can be adjusted according to actual needs as long as the emitted light of the laser diode groups 1 can be combined in the same plane, which will not be elaborated here one by one.

[0112] It should be noted that theoretically, the beams emitted by the laser diode chips 12 are parallel, and the beams after passing through the corresponding lenses are also parallel. However, due to process errors, there may be a certain deviation in the propagation angle of the beams; at this time, the first type of beam guiding element 134 is set to correspond one-to-one with the laser diode chips 12, and the first type of beam guiding element 134 can correct the propagation angle and / or position of the input beam so that the beams output by the first type of beam guiding elements 134 propagate parallel in the same plane.

[0113] As another example, as Figures 15 to 17As shown, the beam adjustment module 13 includes a first collimating lens 131, a second type of beam guiding element 135, and a second collimating lens 132 arranged along the optical path. The second type of beam guiding element 135 adjusts the beam to propagate in a preset plane in the form of a periscope, and the preset plane is parallel to the plane where each laser diode chip 12 is located. In this example, the first collimating lens 131, the second type of beam guiding element 135, and the second collimating lens 132 are arranged in sequence along the beam propagation direction. The second type of beam guiding element 135 is implemented by a rhombic prism to simplify the system. It should be noted that the first collimating lens 131 is arranged at the forefront of the optical path (i.e., closest to the emission end of the laser diode chip 12), and the order of the second collimating lens 132 and the second type of beam guiding element 135 on the optical path can be interchanged; in this example, a wavelength selective element 133 can also be added. At this time, the order of the second collimating lens 132, the second type of beam guiding element 135, and the wavelength selective element 133 on the optical path can be interchanged, which will not be elaborated one by one here. The positions of the N laser diode groups 1 are arranged in sequence along the light emission direction of the laser diode chip 12 in the XZ plane and have an offset in the arrangement direction of each laser diode chip 12. For details, please refer to the above text and will not be elaborated one by one here; at this time, since the plane where the emitted beams of each laser diode group 1 are located is not in the same plane as the bonding wire, the beam combination of the emitted beams of the N laser diode groups 1 can be achieved.

[0114] As another example, in order to increase the degree of freedom, the second type of beam guiding element 135 guides the beam to a higher plane. At this time, the second type of beam guiding element 135 is composed of a pair of reflectors. As Figures 18 to 20 shown, the second type of beam guiding element 135 includes a first reflector 135a and a second reflector 135b; the first reflector 135a reflects the incident beam, and the second reflector 135b reflects the beam reflected by the first reflector 135a again; the reflection angle can be set as needed, and finally, the incident beam and the emitted beam are arranged in parallel in different planes. Preferably, the first reflector 135a reflects the beam by 90° (rotating 90° counterclockwise), and the second reflector 135b reflects the beam by -90° (rotating 90° clockwise). In this example, the first collimating lens 131 is arranged at the forefront of the optical path, and the order of the second collimating lens 132, the first reflector 135a, and the second reflector 135b on the optical path can be interchanged; as an example, the second collimating lens 132 is arranged between the first reflector 135a and the second reflector 135b. Of course, a wavelength selective element 133 can also be added in this example, which will not be elaborated one by one here. As Figure 21 and Figure 22As shown, by way of example, the second mirror 135b is a mirror having reflection regions and transmission regions arranged at intervals, thereby reducing the optical components. Each reflection region corresponds to the light beam emitted from each laser diode chip 12 in the laser diode group 1, and each transmission region corresponds to the gap between adjacent laser diode chips 12; the second mirror 135b can also be arranged as a plurality of mirrors corresponding one by one to each laser diode chip 12. Similarly, the first mirror 135a can be arranged as a single mirror having reflection regions and transmission regions arranged at intervals or as a plurality of mirrors corresponding one by one to each laser diode chip 12. As Figure 23 and Figure 24 shown, the positions of the two laser diode groups 1 are arranged in sequence along the light-emitting direction of the laser diode chips 12 in the XZ plane, with an offset in the arrangement direction of each laser diode chip 12, and each laser diode group 1 is combined into a beam in another plane parallel to the plane where each laser diode chip 12 is located.

[0115] A typical single laser diode chip 12 emits a light beam with a width of 300 microns, corresponding to a beam quality M 2 of approximately 60. Then, the beam quality M 2 x of the laser diode linear stack structure composed of 4 laterally offset laser diode groups 1 in the slow axis direction is 1100; in contrast, the typical value of the beam quality M 2 y in the fast axis direction is about 1.1. The above laser diode linear stack structures can obtain a light beam with a rectangular cross-section (the width of the combined light beam in the slow axis direction is greater than the height in the fast axis direction), and exhibit an extremely asymmetric beam cross-section and beam quality. Such a light beam cannot be directly used in applications such as fiber coupling that require an approximately symmetric beam cross-section and beam quality. Therefore, the present invention further performs a symmetry treatment on the beam cross-section and beam quality.

[0116] As an example, the laser diode linear stack structure 10 of the present invention further includes a first optical device 16, such as Figure 25 shown, the first optical device 16 is arranged on the light-emitting path of the N laser diode groups 1 to shape the combined light beam. As Figure 26 shown, the first optical device 16 divides the light beam in the slow axis direction into K segments, and arranges the K segments of light beams side by side (i.e., superimposes) in the fast axis direction; the beam quality of each resulting segment of light beam in the slow axis direction is M 2 s = M 2 x / K, and the beam quality in the fast axis direction is M 2 f = M 2 y * K. When K is selected such that M 2 s is approximately equal to M 2When at f, a symmetric beam with approximately the same beam quality is generated. K is a natural number greater than or equal to 2. Preferably, K is set as a natural number greater than or equal to 4. In this example, K is set to 10.

[0117] As another example, the beam adjustment module 13 of the present invention further includes an optical function unit 136. The optical function unit 136 is disposed on the optical path after the first collimating lens 131 and is used to rotate the beam 90° around the optical axis. As Figures 27 to 29 shown, in this example, the first collimating lens 131, the first mirror 135a, the second collimating lens 132, the optical function unit 136, and the second mirror 135b are sequentially arranged along the beam propagation direction. The beams emitted by each laser diode chip 12 are collimated in the fast axis direction and then reflected by 90°. Subsequently, they are collimated in the slow axis direction, then rotated 90° around the optical axis, and finally reflected by -90°. At this time, the fast axis direction of the emitted beam is consistent with the X axis, and the slow axis direction is consistent with the Y axis. The beams emitted by each laser diode chip 12 are superposed side by side in the fast axis direction with Wy, thereby making the beam cross-section and beam quality have higher symmetry compared with the scheme using the first optical device 16; the symmetry is determined by the number of laser diode chips 12 arranged side by side and can be set according to actual needs, which will not be elaborated here one by one. In this example, the optical function unit 136 is implemented by a Dove prism. In actual use, any optical element that can rotate the beam 90° around the optical axis is applicable, including but not limited to being composed of a combination of 3 mirrors. As Figure 30 shown, at this time, the adjustment of the height Wy of the beam in the fast axis direction can be achieved by adjusting the focal length of the first collimating lens 131, so that the height Wy of the beams corresponding to each laser diode chip 12 in the fast axis direction is not greater than D / N, and the offset S of the beams emitted by each laser diode group 1 is not less than the height Wy in the fast axis direction and not greater than D / N; among them, Wy should be as close as possible (or equal to) D / N, and the offset S should also be as close as possible (or equal to) D / N to maintain the brightness of the beam.

[0118] It should be noted that for the scheme that does not use bonding wires to connect each laser diode chip 12 in series, the beam propagation path can also be changed through the beam adjustment module 13, thereby avoiding obstacles in the beam transmission path when N laser diode groups 1 are arranged staggeredly or improving the usage flexibility for a single laser diode group 1 used, which is not limited to this embodiment.

[0119] In the above example, an offset amount S is obtained by offsetting the positions of the respective laser diode groups 1 in the arrangement direction (X-axis direction) of the respective laser diode chips 12, so as to achieve the offset of the light beams emitted by the respective laser diode groups 1 in the arrangement direction of the respective laser diode chips 12. In other examples, the beam adjustment module 13 further includes a third type of beam guiding element 137, and the third type of beam guiding element 137 is disposed on the optical path after the first collimating lens 131, so that the positions of the light beams emitted by the respective laser diode groups 1 are offset in the arrangement direction of the respective laser diode chips 12. Specifically, as Figures 31 to 33 shown, in this example, the first collimating lens 131, the first reflecting mirror 135a, the second collimating lens 132, the second reflecting lens 135b, and the third type of beam guiding element 137 are sequentially arranged along the light beam propagation direction (in actual use, the order of the first reflecting mirror 135a, the second collimating lens 132, the second reflecting lens 135b, and the third type of beam guiding element 137 can be interchanged). Through the adjustment of the third type of beam guiding element 137, the light beam is translated in the XZ plane. The third type of beam guiding element 137 can be implemented by including but not limited to a rhombic prism ( Figure 31 ), a set of reflecting mirrors, etc. As Figures 34 to 36 shown, in this example, the first collimating lens 131, the first reflecting mirror 135a, the second collimating lens 132, the second type of beam guiding element 133, the third type of beam guiding element 137, and the second reflecting lens 135b are sequentially arranged along the light beam propagation direction (in actual use, the order of the first reflecting mirror 135a, the second collimating lens 132, the second type of beam guiding element 133, the third type of beam guiding element 137, and the second reflecting lens 135b can be interchanged). Through the adjustment of the third type of beam guiding element 137, the light beam is translated in the XY plane. The third type of beam guiding element 137 can be implemented by including but not limited to a rhombic prism, a set of reflecting mirrors ( Figure 35 ), etc. The third type of beam guiding element 137 can be disposed in any of the above beam adjustment modules 13, which will not be elaborated one by one here. In addition, when N is greater than or equal to 3, in a laser diode linear stacking structure 1, a part uses the offset of the positions of the laser diode groups 1, and another part uses the third type of beam guiding element 137, so as to achieve the offset of the light beams emitted by the laser diode groups 1 in the arrangement direction of the respective laser diode chips 12.

[0120] It should be noted that when the third type of beam guiding element 137 is a set of reflecting mirrors, the set of reflecting mirrors can correct the propagation angle and / or position of the input light beam to overcome the process error, so that the light beams output by the respective first type of beam guiding elements 134 propagate in parallel in the same plane.

[0121] As Figure 37As shown in the figure, the present invention also provides a laser, which at least includes the laser diode linear stacking structure 10 of the present invention. Further, in order to change or symmetrize the beam cross-section and beam quality of the total beam, the laser further includes a second optical device 20, which is arranged on the optical path after the laser diode linear stacking structure 10 and is used to couple the beam into the optical waveguide 30. The optical waveguide 30 includes, but is not limited to, optical fibers, and will not be elaborated one by one here.

[0122] The laser diode linear stacking structure and the laser of the present invention greatly improve the efficiency through the linear stacking of laser diodes; by adopting the arrangement of arranging the laser diode chips 12 side by side on the heat sink, while ensuring the heat dissipation efficiency and the service life of the heat sink, the device size can be greatly reduced.

[0123] In summary, the present invention provides a laser diode linear stacking structure and a laser, including N laser diode groups, where N is a natural number greater than or equal to 2; each laser diode group includes a heat sink, at least two laser diode chips arranged on the heat sink, and a beam adjustment module, and the light emitting directions of the laser diode chips are the same; the beam adjustment module is arranged on the light emitting side of each laser diode chip and collimates and adjusts the beam width of the laser emitted by each laser diode chip; each laser diode group is arranged in sequence in the light emitting direction of the beam adjustment module, and the positions of the beams emitted by each laser diode group are offset in the arrangement direction of the laser diode chips, so that the positions of the beams emitted by each laser diode group propagate alternately in the same emission plane and have the same emission direction. The laser diode linear stacking structure and the laser of the present invention have the advantages of high efficiency, small size, high heat dissipation efficiency, and long service life. Therefore, the present invention effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

[0124] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A linear stacked structure of laser diodes, characterized in that, The laser diode linear stacking structure includes: N laser diode groups, where N is a natural number greater than or equal to 2; each laser diode group includes a heat sink, at least two laser diode chips disposed on the heat sink, and a beam adjustment module, and the light-emitting directions of the laser diode chips are the same; the beam adjustment module is disposed on the light-emitting side of each laser diode chip and collimates and adjusts the beam width of the laser emitted by each laser diode chip; Each laser diode group is arranged in sequence in the light-emitting direction of the beam adjustment module, and the positions of the beams emitted by each laser diode group are offset in the arrangement direction of the laser diode chips, so that the positions of the beams emitted by each laser diode group propagate alternately in the same emission plane and have the same emission direction.

2. The laser diode linear stacking structure according to claim 1, wherein: The beam adjustment module includes a first collimating lens and a second collimating lens arranged in sequence along the beam propagation direction. The first collimating lens collimates the beam emitted by the laser diode chip in the fast axis direction, and the second collimating lens collimates the beam in the slow axis direction.

3. The laser diode linear stacking structure according to claim 2, characterized in that: The beam adjustment module further includes a first type of beam guiding element disposed on the optical path after the first collimating lens; the first type of beam guiding element adjusts the beam propagation direction to be not parallel to the plane where each laser diode chip is located.

4. The laser diode linear stacking structure according to claim 3, wherein: The beam propagation direction after being adjusted by the beam adjustment module is perpendicular to the plane where each laser diode chip is located.

5. The laser diode linear stacking structure according to claim 3, wherein: The first beam guiding element is a mirror.

6. The laser diode linear stacking structure according to claim 2, characterized in that: The beam adjustment module further includes a second type of beam guiding element disposed on the optical path after the first collimating lens; the second type of beam guiding element adjusts the beam to propagate in a preset plane, and the preset plane is parallel to the plane where each laser diode chip is located.

7. The laser diode linear stacking structure according to claim 6, characterized in that: The second type of beam guiding element is a rhombic prism.

8. The laser diode linear stack structure according to claim 6, characterized in that: The second type of beam guiding element includes a first mirror and a second mirror; the first mirror reflects the incident beam, and the second mirror reflects the beam reflected by the first mirror again; The first mirror is arranged as a single mirror with alternately arranged reflection regions and transmission regions or as a plurality of mirrors corresponding to each laser diode chip one by one; the second mirror is arranged as a single mirror with alternately arranged reflection regions and transmission regions or as a plurality of mirrors corresponding to each laser diode chip one by one.

9. The laser diode linear stacking structure according to claim 8, wherein: The first mirror reflects the beam by 90°, and the second mirror reflects the beam by -90°.

10. The laser diode linear stacking structure according to claim 8, wherein: The second collimating lens is disposed between the first mirror and the second mirror.

11. The laser diode linear stacking structure according to any one of claims 2-10, characterized in that: The beam adjustment module further includes a wavelength selective element disposed on the optical path after the first collimating lens.

12. The laser diode linear stacking structure according to any one of claims 1-10, characterized in that: The width of the beam of each laser diode chip in the slow axis direction after passing through the corresponding beam adjustment module is not greater than D / N; the offset of the beam emitted by each laser diode group is not less than the width in the slow axis direction and not greater than D / N, where D is the distance between the central axes of two adjacent laser diode chips in the same laser diode group.

13. The laser diode linear stacking structure according to any one of claims 1-10, characterized in that: Each laser diode chip is packaged by COS.

14. The laser diode linear stacking structure according to claim 13, characterized in that: Positive contacts and negative contacts are also provided on the heat sink, and each laser diode chip is connected in series between the positive contact and the negative contact by a bonding wire.

15. The laser diode linear stacking structure according to any one of claims 2-10, characterized in that: The positions of the laser diode groups are offset in the arrangement direction of the laser diode chips; and / or, the beam adjustment module further includes a third type of beam guiding element, which is arranged on the optical path after the first collimating lens and is used to offset the positions of the beams emitted by the laser diode groups in the arrangement direction of the laser diode chips.

16. The laser diode linear stacking structure according to any one of claims 2-10, characterized in that: The beam adjustment module further includes an optical functional unit, which is arranged on the optical path after the first collimating lens and is used to rotate the beam by 90° around the optical axis.

17. The laser diode linear stacking structure according to claim 16, wherein: The height of the beam of each laser diode chip in the fast axis direction after passing through the corresponding beam adjustment module is not greater than D / N; the offset of the beam emitted by each laser diode group is not less than the height in the fast axis direction and not greater than D / N, where D is the distance between the central axes of two adjacent laser diode chips in the same laser diode group.

18. The laser diode linear stacking structure according to claim 17, wherein: The positions of the laser diode groups are offset in the arrangement direction of the laser diode chips; and / or, the beam adjustment module further includes a third type of beam guiding element, which is arranged on the optical path after the first collimating lens and is used to offset the positions of the beams emitted by the laser diode groups in the arrangement direction of the laser diode chips.

19. The laser diode linear stacking structure according to any one of claims 2-10, characterized in that: The laser diode linear stacking structure further includes a first optical device, which is arranged on the output optical path of the N laser diode groups, divides the beam in the slow axis direction into K segments, and arranges the K segments of beams side by side in the fast axis direction; where K is a natural number greater than or equal to 4.

20. The laser diode linear stacking structure according to claim 19, wherein: The positions of the laser diode groups are offset in the arrangement direction of the laser diode chips; and / or, the beam adjustment module further includes a third type of beam guiding element, which is arranged on the optical path after the first collimating lens and is used to offset the positions of the beams emitted by the laser diode groups in the arrangement direction of the laser diode chips.

21. A laser, characterized in that, The laser at least includes: the laser diode linear stacking structure according to any one of claims 1-20.

22. The laser according to claim 21, wherein: The laser further includes a second optical device, which is arranged on the optical path after the laser diode linear stacking structure and is used to couple the beam into the optical waveguide.

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