Ultrafast laser heat dissipation method based on efficient cold bonding and ultrafast laser system

Abstract

The invention relates to an ultrafast laser heat dissipation method based on efficient cold bonding and an ultrafast laser system, the method comprises a plurality of laser gain media arranged along a light path, each laser gain medium is provided with a corresponding pumping module, and the output of the pumping module is input into the corresponding laser gain medium after being shaped by a shaping lens; on a laser light path, except for the last laser gain medium, the output of the laser gain medium is shaped by the shaping lens and then is input into the next-stage laser gain medium; the laser gain medium is in cold bonding with the heat dissipation part, a water cooling channel is arranged in the heat dissipation part, and heat dissipation is carried out on the heat dissipation part through cooling water arranged in the water cooling channel. According to the invention, a cold bonding method is adopted between the laser gain crystal and the heat dissipation component, so that heat is efficiently and stably transmitted to the heat dissipation component. Meanwhile, it is guaranteed that the laser gain medium is stably and reliably fixed to the heat dissipation bottom plate or the heat dissipation component, the stress can be almost ignored, and the quality of output light beams of lasers reaches the best.

Description

Technical Field

[0001] The present disclosure relates to an ultrafast laser heat dissipation method and an ultrafast laser system based on efficient cold bonding, and belongs to the technical field of solid-state lasers. Background Art

[0002] For solid-state lasers, especially ultrafast lasers, thermal management is crucial for laser output power and performance. Solid-state laser generation occurs through a pump source exciting electrons in a laser gain crystal, which then undergoes energy level transitions. This energy transition is then enhanced by the resonant cavity, ultimately resulting in laser output. Within the laser system, the laser gain crystal is responsible for converting the pump light into the desired laser output. However, not all of the pump light energy is converted into useful laser output, but rather a significant portion is converted into heat, leading to thermal effects. Thermal effects primarily arise from the following: 1. Quantum loss: In a laser system, not all absorbed energy is effectively converted into laser output during each excitation transition. For example, in a four-level system, two photons are required to generate a single laser photon, resulting in energy loss, which is released as heat. 2. Non-radiative transitions: In addition to emitting photons through radiative transitions, electrons may also undergo non-radiative transitions during their return to the ground state. These transitions involve electrons jumping directly from an excited state back to the ground state, releasing excess energy into the surrounding environment as heat. 3. Scattering loss: Impurities or defects in the laser medium can cause photons to scatter, resulting in energy loss and conversion into heat energy. 4. Conduction loss: In some cases, the interaction between activated ions can also cause energy to be dissipated in the form of heat.

[0003] Thermal effects can have a significant impact on the performance of lasers, as follows: 1. Optical components are distorted, beam quality deteriorates, and laser stability deteriorates: Excessively high temperatures can cause thermal expansion or thermal deformation of the laser medium and optical components (such as reflectors), affecting the optical path and reducing the output beam quality and stability of the laser. 2. The threshold increases and the laser output power is limited: Temperature increases will increase the pumping threshold required for population inversion, reducing the efficiency of the laser, which in turn intensifies the thermal effect and ultimately reduces the laser output power, and even causes the entire laser system to enter an unstable state, limiting the maximum output power of the laser. 3. Wavelength change: Temperature changes can also cause the laser wavelength to drift, which is an unfavorable factor for applications that require precise wavelengths (such as spectral analysis, precision measurement, etc.). 4. Shortened life: Long-term high-temperature operation will accelerate material aging and shorten the working life of the laser.

[0004] Therefore, effective thermal management of solid-state ultrafast lasers is crucial to improving their performance.

[0005] Thermal management of the laser gain medium has become a top priority. Existing laser heat dissipation methods include indium packaging, compaction heat dissipation, and thermal welding.

[0006] There is an air layer between the indium layer crystal heat dissipation components that are wrapped and compressed to dissipate heat, which affects the heat dissipation. After long-term use, it is easy for the indium layer to become loose, which makes the thermal conductivity worse. After a long time, the indium layer is also easy to oxidize, which makes the thermal conductivity worse.

[0007] Thermal welding can easily contaminate the crystal, causing damage and reducing its lifespan. At the same time, high welding stress can easily cause crystal damage and light spot distortion. Summary of the Invention

[0008] In order to overcome the above problems, the present disclosure provides an ultrafast laser heat dissipation method and an ultrafast laser system based on efficient cold bonding.

[0009] The technical solutions disclosed in this disclosure are as follows:

[0010] In a first aspect, the present disclosure provides an ultrafast laser heat dissipation method based on efficient cold bonding, comprising the following steps:

[0011] Several laser gain media are arranged along the optical path, each laser gain medium being equipped with a corresponding pump module. The output of the pump module is shaped by a shaping lens and then input into the corresponding laser gain medium. In the laser optical path, except for the last laser gain medium, the output of each laser gain medium is shaped by a shaping lens and then input into the next-stage laser gain medium. After being shaped by the shaping lens, the output of the laser gain medium matches the pattern and size of the laser spot after being shaped by the shaping lens with the output of the next-stage pump module.

[0012] The laser gain medium is cold-bonded to the heat dissipation component, and a water cooling channel is provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel;

[0013] The cold bonding comprises the following steps:

[0014] In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal;

[0015] In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal;

[0016] gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0;

[0017] Fill the vacuum environment with nitrogen and release the vacuum.

[0018] Furthermore, the metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2um, 0.5um, 0.3um, and 1um, respectively;

[0019] The vacuum degree of the vacuum environment during coating is less than 100pa;

[0020] The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours;

[0021] Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm 2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

[0022] Furthermore, it also includes a seed source, an electric drive module, a control module, a temperature control module and a sensor module;

[0023] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation component.

[0024] Furthermore, the heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, each laser gain medium is cold-bonded to the heat dissipation base plate, and each laser gain medium is also cold-bonded to at least one heat sink;

[0025] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate;

[0026] The water cooling channel is arranged inside the heat sink and the heat dissipation base plate.

[0027] Furthermore, the heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink;

[0028] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate;

[0029] The water cooling channel is arranged inside the heat sink and the heat dissipation base plate.

[0030] Furthermore, part of the heat sink is connected to the heat dissipation base plate through thermal welding of the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat dissipation base plate through thermal welding.

[0031] In a second aspect, the present disclosure further provides an ultrafast laser system based on efficient cold bonding, comprising a seed source and a plurality of laser gain media sequentially arranged along an optical path propagation direction, each laser gain medium being configured with a corresponding pump module, the output of the seed source and the pump module being shaped by a shaping lens and then input into the laser gain medium; except for the laser gain medium of the last stage, the output of each laser gain medium is shaped by a shaping lens and then input into the laser gain medium of the next stage; after the output of the laser gain medium is shaped by the shaping lens, the pattern and size of the laser spot after the output of the pump module of the next stage is matched;

[0032] The heat dissipation component further comprises a water cooling channel provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel;

[0033] The laser gain medium is cold-bonded to the heat dissipation component, and the cold bonding is specifically:

[0034] In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal;

[0035] In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal;

[0036] gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0;

[0037] Fill the vacuum environment with nitrogen and release the vacuum.

[0038] The ultrafast laser system based on high-efficiency cold bonding according to claim 8, characterized in that the metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2 μm, 0.5 μm, 0.3 μm, and 1 μm, respectively;

[0039] The vacuum degree of the vacuum environment during coating is less than 100pa;

[0040] The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours;

[0041] Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

[0042] Furthermore, it also includes an electric drive module, a control module, a temperature control module and a sensor module;

[0043] The heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink;

[0044] Part of the heat sink is connected to the heat sink base plate through thermal welding of the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat sink base plate through thermal welding;

[0045] The electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate.

[0046] Furthermore, the electric drive module is connected to the seed source, control module, temperature control module, sensor module, and pump module to provide electric drive; the control module is connected to other modules to provide overall control for the laser system; the temperature control module is connected to the electric drive, sensor module, and semiconductor cooler to achieve precise temperature control of the laser gain crystal; the sensor module is connected to the electric drive module, control module, and various sensors in the cavity to monitor parameters in the laser system and achieve feedback control.

[0047] The present disclosure has the following beneficial effects:

[0048] This paper combines a laser gain medium with a shaping lens system and a Pu module to form an amplification module for multi-stage seed amplification, achieving high-power ultrafast laser output. Through specialized metallization treatment of the laser gain medium crystal and the heat sink surface, and cold bonding between the laser gain crystal and the heat sink, heat is efficiently and stably transferred to the heat sink.

[0049] The present disclosure also provides a heat sink and a semiconductor cooler that are efficiently connected and heat-conducted by metal thermal welding. The semiconductor cooler is then connected and heat-conducted by metal welding. A water-cooling channel is set up inside the heat-conducting base plate. Through the above heat transfer path, the waste heat generated in the laser gain medium is finally efficiently transferred to the heat-conducting base plate. There is a high-speed circulating cooling water flow in the water-cooling channel in the heat-conducting base plate. The heat is quickly and continuously taken away through the water-cooling refrigeration system, ensuring that the entire laser system is under efficient cooling conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 FIG. 1 is a schematic diagram of a laser system according to an embodiment of the present disclosure.

[0051] Figure 2 FIG. 1 is a schematic diagram of a laser system according to another embodiment of the present disclosure.

[0052] Figure 3 This is the beneficial effect of the present disclosure on laser output power. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0054] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In order to keep the following description of the embodiments of the present disclosure clear and concise, the present disclosure omits detailed descriptions of some known functions and known components.

[0055] The present disclosure will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0056] In the first aspect, the present disclosure provides an ultrafast laser heat dissipation method based on efficient cold bonding, referring to Figure 2 , including the following steps:

[0057] Several laser gain media are arranged along the optical path, each laser gain medium being equipped with a corresponding pump module. The output of the pump module is shaped by a shaping lens and then input into the corresponding laser gain medium. In the laser optical path, except for the last laser gain medium, the output of each laser gain medium is shaped by a shaping lens and then input into the next-stage laser gain medium. After being shaped by the shaping lens, the output of the laser gain medium matches the pattern and size of the laser spot after being shaped by the shaping lens with the output of the next-stage pump module.

[0058] The laser gain medium is cold-bonded to the heat dissipation component, and a water cooling channel is provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel;

[0059] The cold bonding comprises the following steps:

[0060] In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal;

[0061] In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal;

[0062] gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0;

[0063] Fill the vacuum environment with nitrogen and release the vacuum.

[0064] In one embodiment of the present disclosure, the metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2um, 0.5um, 0.3um, and 1um, respectively;

[0065] The vacuum degree of the vacuum environment during coating is less than 100pa;

[0066] The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours;

[0067] Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm 2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

[0068] In a specific embodiment, a 3mm*3mm*8mm laser crystal is cold-bonded to a Cu heat sink according to the method. The bonding strength (shear force) test values ​​are shown in Table 1, indicating high firmness.

[0069] Table 1 Shear force test values ​​after cold bonding between laser crystal and Cu heat sink

[0070] Test samples Shear force test value (N) P-55 12.12 P-56 11.85 P-57 10.4 P-58 12.43 average value 11.70 Standard deviation 0.90

[0071] The output power of the picosecond laser system prepared by this cold bonding method is less affected by heat dissipation issues and can maintain stable output under high power conditions. Figure 3 The figure shows the variation of the output power of the picosecond laser with the pump power when the cold bonding method is used and when the cold bonding method is not used. It is obvious that the picosecond ultrafast laser using this heat dissipation method can obtain higher laser output.

[0072] In one embodiment of the present disclosure, it further includes a seed source, an electric drive module, a control module, a temperature control module and a sensor module;

[0073] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation component.

[0074] In one embodiment of the present disclosure, the heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, each laser gain medium is cold-bonded to the heat dissipation base plate, and each laser gain medium is also cold-bonded to at least one heat sink;

[0075] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate;

[0076] The water cooling channel is arranged inside the heat sink and the heat dissipation base plate.

[0077] The laser gain medium is cold-bonded to a heat sink, which is then welded to a semiconductor refrigerator. The semiconductor refrigerator directly controls the heat sink and the cold-bonded laser gain medium, thereby achieving high-precision temperature control. The semiconductor refrigerator, seed source, pump module, shaping lens, electric drive module, control module, temperature control module, and sensor module are fixed to a heat dissipation base plate by welding or screws. A water-cooling channel is provided in the heat sink at the upper end of the laser gain crystal and the heat dissipation base plate, and cooling water provided in the water-cooling channel is connected to a water-cooling refrigeration system to dissipate heat from the heat dissipation components.

[0078] refer to Figure 1In one embodiment of the present disclosure, the heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink;

[0079] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate;

[0080] The water cooling channel is arranged inside the heat sink and the heat dissipation base plate, and the cooling water arranged in the water cooling channel is connected to the water cooling refrigeration system to dissipate heat from the heat dissipation component.

[0081] In one embodiment of the present disclosure, part of the heat sink is connected to the heat dissipation base plate by thermal welding through the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat dissipation base plate by thermal welding.

[0082] In a second aspect, the present disclosure further provides an ultrafast laser system based on efficient cold bonding, comprising a seed source and a plurality of laser gain media sequentially arranged along an optical path propagation direction, each laser gain medium being configured with a corresponding pump module, the output of the seed source and the pump module being shaped by a shaping lens and then input into the laser gain medium; except for the laser gain medium of the last stage, the output of each laser gain medium is shaped by a shaping lens and then input into the laser gain medium of the next stage; after the output of the laser gain medium is shaped by the shaping lens, the pattern and size of the laser spot after the output of the pump module of the next stage is matched;

[0083] The heat dissipation component further comprises a water cooling channel provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel;

[0084] The laser gain medium is cold-bonded to the heat dissipation component, and the cold bonding is specifically:

[0085] In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal;

[0086] In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal;

[0087] gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0;

[0088] Fill the vacuum environment with nitrogen and release the vacuum.

[0089] In one embodiment of the present disclosure, the metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2um, 0.5um, 0.3um, and 1um, respectively;

[0090] The vacuum degree of the vacuum environment during coating is less than 100pa;

[0091] The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours;

[0092] Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm 2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

[0093] In one embodiment of the present disclosure, it further includes an electric drive module, a control module, a temperature control module and a sensor module;

[0094] The heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink;

[0095] Part of the heat sink is connected to the heat sink base plate through thermal welding of the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat sink base plate through thermal welding;

[0096] The electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate.

[0097] In one embodiment of the present disclosure, the electric drive module is connected to the seed source, the control module, the temperature control module, the sensor module, and the pump module to provide electric drive; the control module is connected to the other modules to provide overall control for the laser system; the temperature control module is connected to the electric drive, the sensor module, and the semiconductor cooler to achieve precise temperature control of the laser gain crystal; the sensor module is connected to the electric drive module, the control module, and the sensors in the cavity to monitor the parameters in the laser system and achieve feedback control.

[0098] The laser gain medium is cold-bonded to a heat sink, which is then welded to a semiconductor cooler. The semiconductor cooler directly controls the heat sink and the bonded laser gain medium, achieving high-precision temperature control. The semiconductor cooler, seed source, pump module, shaping lens, electric drive module, control module, temperature control module, and sensor module are secured to the heat sink baseplate by welding or screws. A water-cooling channel is provided within the heat sink on the laser gain crystal and the heat sink baseplate. Cooling water in this channel connects to a water-cooled refrigeration system to dissipate heat from the heat sink components. The electric drive module is connected to the seed source, control module, temperature control module, sensor module, and pump module, providing electrical drive for them. The control module is connected to the other modules to provide overall control for the entire laser system. The temperature control module is connected to the electric drive, sensor module, and semiconductor cooler to achieve precise temperature control of the laser gain crystal. The sensing module is connected to the electric drive module, the control module, and various sensors in the cavity to monitor various parameters in the entire laser system, such as temperature and humidity, and to achieve feedback control. The present invention performs specialized metallization treatment on the surface of the laser gain medium crystal and the heat sink, and adopts a cold bonding method between the laser gain crystal and the heat sink to efficiently and stably transfer heat to the heat sink. At the same time, it ensures that the laser gain medium is stably and reliably fixed on the heat sink base plate or the heat sink, and the stress it is subjected to is almost negligible, so that the output beam quality of the laser is optimized.

[0099] In the first aspect, the present disclosure provides an ultrafast laser heat dissipation method based on efficient cold bonding, referring to Figure 1 ,include:

[0100] Several laser gain media are arranged along the optical path, each laser gain medium is equipped with a corresponding pump module, and the output of the pump module is shaped by a shaping lens and then input into the corresponding laser gain medium; in the laser optical path, except for the last laser gain medium, the output of each laser gain medium is shaped by a shaping lens and then input into the next level laser gain medium;

[0101] The laser gain medium is cold-bonded to the heat dissipation component. A water cooling channel is provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel.

[0102] In one embodiment of the present disclosure, the cold bonding comprises the following steps:

[0103] In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal;

[0104] In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal;

[0105] gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0;

[0106] Fill the vacuum environment with nitrogen and release the vacuum.

[0107] When the laser gain medium is a crystal, the cold bonding method has a better bonding effect.

[0108] In one embodiment of the present disclosure, the metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2um, 0.5um, 0.3um, and 1um, respectively;

[0109] The vacuum degree of the vacuum environment during coating is less than 100pa;

[0110] The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours;

[0111] Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm 2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

[0112] In a specific embodiment, a 3mm*3mm*8mm laser crystal was cold-bonded to a Cu heat sink according to the method, and the bonding strength (shear force) test values ​​are shown in Table 1.

[0113] Table 1 Shear force test values ​​after cold bonding between laser crystal and Cu heat sink

[0114]

[0115]

[0116] The output power of the picosecond laser system prepared by this cold bonding method is less affected by heat dissipation issues and can maintain stable output under high power conditions. Figure 3 The figure shows the variation of the output power of the picosecond laser with the pump power when the cold bonding method is adopted and when the cold bonding method is not adopted.

[0117] In one embodiment of the present disclosure, it further includes a seed source, an electric drive module, a control module, a temperature control module and a sensor module;

[0118] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation component.

[0119] In one embodiment of the present disclosure, the heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, each laser gain medium is cold-bonded to the heat dissipation base plate, and each laser gain medium is also cold-bonded to at least one heat sink;

[0120] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate;

[0121] The water cooling channel is arranged inside the heat sink and the heat dissipation base plate.

[0122] In one embodiment of the present disclosure, the heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink;

[0123] The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate;

[0124] The water cooling channel is arranged inside the heat sink and the heat dissipation base plate.

[0125] In one embodiment of the present disclosure, part of the heat sink is connected to the heat dissipation base plate by thermal welding through the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat dissipation base plate by thermal welding.

[0126] In a second aspect, the present disclosure further provides an ultrafast laser system based on efficient cold bonding, comprising a seed source and a plurality of laser gain media sequentially arranged along the optical path propagation direction, each laser gain medium being configured with a corresponding pump module, the output of the seed source and the pump module being shaped by a shaping lens and then input into the laser gain medium; except for the laser gain medium of the last stage, the output of each laser gain medium is shaped by a shaping lens and then input into the laser gain medium of the next stage;

[0127] The heat dissipation component further comprises a water cooling channel provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel;

[0128] The laser gain medium is cold-bonded to the heat dissipation component, and the cold bonding is specifically:

[0129] In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal;

[0130] In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal;

[0131] gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0;

[0132] Fill the vacuum environment with nitrogen and release the vacuum.

[0133] In one embodiment of the present disclosure, the metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2um, 0.5um, 0.3um, and 1um, respectively;

[0134] The vacuum degree of the vacuum environment during coating is less than 100pa;

[0135] The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours;

[0136] Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm 2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

[0137] In one embodiment of the present disclosure, it further includes an electric drive module, a control module, a temperature control module and a sensor module;

[0138] The heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink;

[0139] Part of the heat sink is connected to the heat sink base plate through thermal welding of the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat sink base plate through thermal welding;

[0140] The electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate.

[0141] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the module, program segment, or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of the boxes in the block diagram and / or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0142] The units involved in the embodiments described in this disclosure may be implemented in software or hardware, wherein the name of a unit does not necessarily limit the unit itself.

[0143] The functions described above herein may be performed, at least in part, by one or more hardware logic components. For example, and without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chip (SOCs), complex programmable logic devices (CPLDs), and the like.

[0144] The above description is merely a preferred embodiment of the present disclosure and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also includes other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned disclosed concepts. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this disclosure.

[0145] In addition, although each operation is described in a specific order, this should not be understood as requiring these operations to be performed in the specific order shown or in a sequential order. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details have been included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination mode.

[0146] Although the subject matter has been described in language specific to structural features and / or methodological logical acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are merely example forms of implementing the claims.

[0147] Regarding this disclosure, the following points need to be explained:

[0148] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure. Other structures may refer to conventional designs.

[0149] (2) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to form new embodiments.

[0150] The above descriptions are merely embodiments of the present disclosure and are not intended to limit the patent scope of the present disclosure. Any equivalent structures made using the contents of the present disclosure and the drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present disclosure.

Claims

1. An ultrafast laser heat dissipation method based on efficient cold bonding, characterized in that: The following steps are involved: Several laser gain media are arranged along the optical path, each laser gain medium being equipped with a corresponding pump module. The output of the pump module is shaped by a shaping lens and then input into the corresponding laser gain medium. In the laser optical path, except for the last laser gain medium, the output of each laser gain medium is shaped by a shaping lens and then input into the next-stage laser gain medium. After being shaped by the shaping lens, the output of the laser gain medium matches the pattern and size of the laser spot after being shaped by the shaping lens with the output of the next-stage pump module. The laser gain medium is cold-bonded to the heat dissipation component, and a water cooling channel is provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel; The cold bonding comprises the following steps: In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal; In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal; gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0; Fill the vacuum environment with nitrogen and release the vacuum.

2. The ultrafast laser heat dissipation method based on efficient cold bonding according to claim 2, characterized in that: The metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2um, 0.5um, 0.3um, and 1um respectively; The vacuum degree of the vacuum environment during coating is less than 100pa; The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours; Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm 2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

3. The ultrafast laser heat dissipation method based on efficient cold bonding according to claim 1, characterized in that: It also includes a seed source, an electric drive module, a control module, a temperature control module and a sensor module; The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation component.

4. The ultrafast laser heat dissipation method based on efficient cold bonding according to any one of claims 1 to 4, characterized in that: The heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, each laser gain medium is cold-bonded to the heat dissipation base plate, and each laser gain medium is also cold-bonded to at least one heat sink; The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate; The water cooling channel is arranged inside the heat sink and the heat dissipation base plate.

5. The ultrafast laser heat dissipation method based on efficient cold bonding according to any one of claims 1 to 4, characterized in that: The heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink; The seed source, the electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate; The water cooling channel is arranged inside the heat sink and the heat dissipation base plate.

6. The ultrafast laser heat dissipation method based on efficient cold bonding according to claim 6, characterized in that: Part of the heat sink is connected to the heat dissipation base plate through thermal welding of the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat dissipation base plate through thermal welding.

7. An ultrafast laser system based on efficient cold bonding, characterized in that: The system comprises a seed source and a plurality of laser gain media arranged in sequence along the optical path propagation direction, each laser gain medium being equipped with a corresponding pump module. The outputs of the seed source and the pump modules are shaped by a shaping lens and then input into the laser gain medium. Except for the laser gain medium of the last stage, the outputs of the laser gain media are shaped by a shaping lens and then input into the laser gain medium of the next stage. After the outputs of the laser gain media are shaped by the shaping lens, the pattern and size of the laser spot of the output of the pump module of the next stage after being shaped by the shaping lens are matched. The heat dissipation component further comprises a water cooling channel provided in the heat dissipation component, and the heat dissipation component is cooled by cooling water provided in the water cooling channel; The laser gain medium is cold-bonded to the heat dissipation component, and the cold bonding is specifically: In a vacuum environment, a metal film layer is plated on the surface of the laser gain medium and the heat dissipation component, wherein the surface of the heat dissipation component plated with the metal film layer is metal; In a vacuum environment, the laser gain medium and the coating surface of the heat dissipation component are placed opposite each other, and the laser gain medium and the heat dissipation component are pressed tightly together for a preset time; during the pressing process, the pressure at all locations on the contact surface is equal; gradually reducing the pressure applied to the laser gain medium and the heat dissipation component until the pressure reaches 0; Fill the vacuum environment with nitrogen and release the vacuum.

8. The ultrafast laser system based on high-efficiency cold bonding according to claim 8, characterized in that: The metal film layers are Cr, Cu, Au, and In metal film layers arranged in sequence, with thicknesses of 0.2um, 0.5um, 0.3um, and 1um respectively; The vacuum degree of the vacuum environment during coating is less than 100pa; The laser gain medium and the heat dissipation component are subjected to a pressure of 50 kg / cm 2 Press tightly with a pressure of 100°C and keep it for 12 hours; Gradually reduce the pressure applied to the laser gain medium and the heat dissipation component, specifically, the pressure is reduced from 50kg / cm 2 Reduced to 40kg / cm 2 、30kg / cm 2 , 20kg / cm 2 、10kg / cm 2 and 0kg / cm 2 , and maintain at each pressure value for 30 minutes.

9. The ultrafast laser system based on high-efficiency cold bonding according to claim 8, characterized in that: It also includes an electric drive module, a control module, a temperature control module and a sensor module; The heat dissipation component includes a plurality of heat sinks and a heat dissipation base plate, some of the heat sinks are cold-bonded to the laser gain medium, and the laser gain medium is heat-conducted with the heat dissipation base plate through at least one heat sink; Part of the heat sink is connected to the heat sink base plate through thermal welding of the semiconductor cooler, and the semiconductor cooler is connected to the heat sink and the heat sink base plate through thermal welding; The electric drive module, the control module, the temperature control module and the sensor module are all arranged on the heat dissipation base plate.

10. The ultrafast laser system based on high-efficiency cold bonding according to claim 9, characterized in that: The electric drive module is connected to the seed source, control module, temperature control module, sensor module, and pump module to provide electric drive; the control module is connected to other modules to provide overall control for the laser system; the temperature control module is connected to the electric drive, sensor module, and semiconductor cooler to achieve precise temperature control of the laser gain crystal; the sensor module is connected to the electric drive module, control module, and various sensors in the cavity to monitor the parameters within the laser system and achieve feedback control.

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