Tunable single-frequency pulse fiber laser

Abstract

The invention discloses a tunable single-frequency pulse fiber laser, and belongs to the technical field of fiber lasers, the tunable single-frequency pulse fiber laser comprises a shell, a pumping source assembly, a gain assembly and a resonant cavity assembly are sequentially arranged in the shell from right to left, and the pumping source assembly comprises a plurality of upper pumping sources fixedly arranged on the top wall of the shell; the lower pumping sources are fixedly arranged on the bottom wall of the shell, and the upper pumping sources are obliquely and symmetrically arranged in two rows. According to the tunable single-frequency pulse optical fiber laser, simultaneous heat dissipation of the upper pumping source and the lower pumping source is achieved through the heat dissipation plate, cooling liquid is brought into the pumping sources through the second branch flow channels, the heat dissipation effect is improved, the pumping sources which are obliquely and symmetrically arranged reduce the bending degree of optical fibers, and meanwhile the heat pipes which are arranged in a penetrating mode are matched; heat dissipation of the heat pipe on the heat dissipation plate and the pumping source is achieved, and the heat dissipation effect is further improved. Compared with an existing device, the problem that the heat dissipation effect is not ideal when the pumping sources are stacked is solved. And the heat dissipation effect is optimized.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber lasers, and in particular relates to a tunable single-frequency pulse optical fiber laser. Background Art

[0002] Fiber lasers refer to lasers that use rare earth-doped glass optical fibers as gain media. They require multiple pump sources to generate pump light, and under the action of the pump light, the laser energy level of the laser working material is "inverted" to produce a coherent laser beam. The greater the output power of the fiber laser, the greater the pump source power it requires.

[0003] Most existing fiber lasers pursue greater power. Ordinary lasers need to be equipped with pump sources, gain media, and resonant cavities, while tunable single-frequency pulse fiber lasers need to be equipped with tunable optical filter components, Q-switching components, and optical couplers to achieve laser tuning and pulse output. In this way, the space allocated to heat dissipation components inside tunable single-frequency pulse fiber lasers is relatively limited, and the circulating cooling water commonly used in the prior art does not have an ideal heat dissipation effect.

[0004] For the above problem, an improved solution is a fiber laser as shown in the authorization publication number CN117559201B, including: a cooling plate and a pump source, a plurality of the pump sources form a pump source array and are arranged in a preset area of ​​the cooling plate. The above solution directly introduces circulating cooling water into the copper block at the bottom of the pump source to shorten the distance from the LD chip to the cooling water. However, this solution does not have an ideal heat dissipation effect when facing stacked pump sources.

[0005] To this end, we proposed a tunable single-frequency pulse fiber laser to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of unsatisfactory heat dissipation effect in the prior art, and to propose a tunable single-frequency pulse fiber laser.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A tunable single-frequency pulse fiber laser comprises a shell, wherein a pump source assembly, a gain assembly and a resonant cavity assembly are sequentially arranged inside the shell from right to left, wherein the pump source assembly comprises a plurality of upper pump sources fixedly arranged on the top wall of the shell, and a plurality of lower pump sources fixedly arranged on the bottom wall of the shell, wherein the upper pump sources are arranged in two rows obliquely and symmetrically, and the pigtails of the upper pump sources face the middle of the gain assembly, and the number and arrangement of the lower pump sources are consistent with those of the upper pump sources, wherein a heat sink is arranged in the middle of the shell, and the top surface of the heat sink is simultaneously attached to all the upper pump sources, and the bottom surface is simultaneously attached to all the lower pump sources, wherein a water pipe assembly and a plurality of heat pipes are arranged inside the heat sink, and both ends of the water pipe assembly extend to the outside of the shell;

[0009] The water pipe assembly includes an inlet pipe, an outlet pipe, a plurality of first branch flow channels, a plurality of second branch flow channels and a plurality of third branch flow channels that cooperate with each other. The first branch flow channel and the second branch flow channel on the same side are connected through two second branch flow channels. The second branch flow channel located above extends to the lower end of the upper pump source, and the branch flow channel located below extends to the upper end of the lower pump source. The coolant flows through the inlet pipe, the first branch flow channel, the second branch flow channel, the third branch flow channel and the outlet pipe in sequence.

[0010] The heat pipe is located between two second branch flow channels on the same side, and one end of the heat pipe away from the gain component extends to the outside of the heat dissipation plate.

[0011] Preferably, the inclination angle of the upper pump source is between 30° and 60°.

[0012] Preferably, the upper pump sources are arranged in a 2×4 arrangement, the lower pump sources correspond to the upper pump sources one by one, and the lower pump sources are located directly below the upper pump sources.

[0013] Preferably, the second branch flow channel includes a plate-shaped cavity in the pump source assembly and a shunt pipe in the heat sink, and two shunt pipes on the same side are connected to the cavity.

[0014] Preferably, the heat pipes are arranged in 2×2, and the top surface of the heat pipe located at the top is in contact with the bottom surface of the upper pump source, and the bottom surface of the heat pipe located at the bottom is in contact with the top surface of the lower pump source.

[0015] Preferably, one end of the plurality of heat pipes located outside the heat sink is commonly connected to a plurality of fins.

[0016] Preferably, a plurality of heat dissipation holes are formed at one end of the shell close to the fins.

[0017] In summary, the technical effects and advantages of the present invention are as follows: the tunable single-frequency pulse fiber laser achieves simultaneous heat dissipation of the upper pump source and the lower pump source through the heat sink, and the second branch flow channel brings the coolant to the inside of the pump source to improve the heat dissipation effect. The pump source arranged obliquely and symmetrically reduces the curvature of the optical fiber, and cooperates with the heat pipe arranged through it to achieve heat dissipation of the heat sink and the pump source by the heat pipe, further improving the heat dissipation effect. Compared with the existing device, it avoids the problem of unsatisfactory heat dissipation when the pump sources are stacked. The heat dissipation effect is optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the pump source component in the present invention after the heat sink is removed;

[0021] Figure 4 for Figure 3 A schematic diagram of a cross-sectional structure in which the heat pipe is removed;

[0022] Figure 5 It is a cross-sectional schematic diagram of the heat sink at the second branch flow channel in the present invention.

[0023] In the figure: 1. Shell; 2. Gain component; 3. Resonant cavity component; 4. Upper pump source; 5. Lower pump source; 6. Heat sink; 7. Heat pipe; 8. Water inlet pipe; 9. Water outlet pipe; 10. First branch flow channel; 11. Second branch flow channel; 12. Third branch flow channel; 13. Cavity; 14. Diverter pipe; 15. Fins; 16. Heat dissipation holes. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] Reference Figure 1-3A tunable single-frequency pulse fiber laser includes a housing 1, wherein a pump source component, a gain component 2, and a resonant cavity component 3 are sequentially arranged inside the housing 1 from right to left. The gain component 2 is a prior art, and includes a gain fiber doped with rare earth ions (such as erbium-doped, ytterbium-doped, etc.). The resonant cavity component 3 is a prior art, and includes a linear cavity and a ring cavity part. The linear cavity part is composed of a high-reflectivity chirped fiber grating, a high-gain fiber, and a low-reflectivity chirped fiber grating, and is used to form a resonant circuit of the laser. The ring cavity part includes an optical circulator, a tunable optical filter component, a Q-switching component, an optical coupler, etc., and is used to achieve laser tuning and pulse output. The pump source assembly includes a plurality of upper pump sources 4 fixed on the top wall of the shell 1, and a plurality of lower pump sources 5 fixed on the bottom wall of the shell 1. The upper pump sources 4 are arranged in two rows obliquely and symmetrically, and the pigtails of the upper pump sources 4 face the middle of the gain component 2. The number and arrangement of the lower pump sources 5 are consistent with those of the upper pump sources 4. A heat sink 6 is provided in the middle of the shell 1, and the top surface of the heat sink 6 is simultaneously attached to all the upper pump sources 4, and the bottom surface is simultaneously attached to all the lower pump sources 5. A water pipe assembly and a plurality of heat pipes 7 are provided inside the heat sink 6, and both ends of the water pipe assembly extend to the outside of the shell 1.

[0026] Reference Figure 3-5 The water pipe assembly includes an inlet pipe 8, an outlet pipe 9, a plurality of first branch channels 10, a plurality of second branch channels 11, and a plurality of third branch channels 12 that cooperate with each other. The first branch channel 10 and the third branch channel 12 on the same side are connected through two second branch channels 11. The second branch channel 11 located above extends to the lower end of the upper pump source 4, and the branch channel located below extends to the upper end of the lower pump source 5. The coolant flows through the inlet pipe 8, the first branch channel 10, the second branch channel 11, the third branch channel 12, and the outlet pipe 9 in sequence.

[0027] The heat pipe 7 is located between two second branch flow channels 11 on the same side, and one end of the heat pipe 7 away from the gain component 2 extends to the outside of the heat dissipation plate 6 .

[0028] A water pump should be provided outside the water pipe assembly, and the water pipe assembly should be filled with coolant. The coolant is driven by the water pump to circulate and dissipate heat. The above is the prior art and will not be described in detail.

[0029] In the case where the load of the tunable single-frequency pulse fiber laser is not high and the heat generation of the pump source component is not large, the water pipe component can be turned off and the heat can be dissipated only through the heat pipe 7. At this time, the heat pipe 7 transfers the heat of the pump source component to the outside of the heat sink 6.

[0030] When the load is high, turn on the water pump and let the coolant flow through the water inlet pipe 8, the first branch channel 10, the second branch channel 11, the third branch channel 12, and the water outlet pipe 9 in sequence. When the coolant flows through the first branch channel 10, it is divided into six, and when it flows through the second branch channel 11, it is divided into twelve. The coolant enters the lower end of the upper pump source 4 and the lower end of the upper pump source 4 at the same time, and takes away the heat of the pump source assembly. Since the upper pump source 4 and the lower pump source 5 are arranged in an inclined manner, the heat pipe 7 and the second branch channel 11 do not interfere with each other, and the heat pipe 7 can also perform auxiliary heat dissipation at this time.

[0031] Since the second branch flow channel 11 is located inside the pump source assembly, when heat is dissipated only through the heat pipe 7, it is also necessary to keep the coolant inside the water pipe full. If there is residual gas in the second branch flow channel 11, it will affect the heat exchange between the heat pipe 7 and the pump source assembly, affecting the heat dissipation efficiency. Therefore, the above-mentioned non-opening of the water pipe assembly only refers to not opening the water pump.

[0032] The inclination angle of the upper pump source 4 is between 30° and 60°. If the inclination angle of the pump source is too small, the heat pipe 7 and the second branch flow channel 11 will conflict with each other; if the inclination angle is too large, on the one hand, the curvature of the pigtail is increased, affecting the laser generation effect of the pump source, and on the other hand, the contact area between the pump source and the heat pipe 7 is reduced in disguise, affecting the heat dissipation effect.

[0033] like Figure 3-4 As shown, the upper pump sources 4 are arranged in 2×4, the lower pump sources 5 correspond to the upper pump sources 4 one by one, and the lower pump sources 5 are located directly below the upper pump sources 4. This facilitates the arrangement of the heat dissipation channel. The upper pump source 4 includes a pump source K 11 , Pump source K 21 , Pump source K 31 , Pump source K 41 , Pump source K 51 , Pump source K 61 , Pump source K 71 , Pump source K 81 ; The lower pump source 5 includes a pump source K 12 , Pump source K 22 , Pump source K 32 , Pump source K 42 , Pump source K 52 , Pump source K 62 , Pump source K 72 , Pump source K 82 ;

[0034] The third branch flow channel 12 includes a branch flow channel S1 and a branch flow channel S2;

[0035] In order to improve the heat dissipation effect and uniformity, it is necessary to make the coolant flow rate in different second branch channels 11 as similar as possible. That is, the resistance encountered by the coolant in different routes is roughly the same. Here, it can be simply understood that the lengths of different routes are roughly the same. Therefore, as shown in the figure, the branch channel S1 and the branch channel S2 merge in the middle.

[0036] Since the coolant will first pass through the right turn at the water inlet pipe, due to the influence of inertia and laminar flow, the coolant enters the pump source K 11 , Pump source K 21 , Pump source K 31 , Pump source K 41 , Pump source K 12 , Pump source K 22 , Pump source K 32 , Pump source K 42 When the corresponding resistance of the second branch channel 11 is greater than that of the pump source K 51 , Pump source K 61 , Pump source K 71 , Pump source K 81 , Pump source K 52 , Pump source K 62 , Pump source K 72 , Pump source K 82 The second branch flow channel 11 at the time.

[0037] It has been verified that when the length of branch channel S1 is between 1.05 and 1.15 times the length of branch channel S2, the flow rate of the coolant is roughly the same. 11 The flow rate is 27.2L / min; the pump source K 12 The flow rate is 27.0L / min; the pump source K 21 The flow rate is 26.6L / min; the pump source K 22 The flow rate is 26.5L / min; the pump source K 31 The flow rate is 26.2L / min; the pump source K 32 The flow rate is 25.8L / min; the pump source K 41 The flow rate is 26.1L / min; the pump source K 42 The flow rate is 25.8L / min; the pump source K 51 The flow rate is 26.8L / min; the pump source K 52 The flow rate is 26.4L / min; the pump source K 61 The flow rate is 26.2L / min; the pump source K 62 The flow rate is 26.3L / min; the pump source K 71 The flow rate is 26.0L / min; the pump source K 72The flow rate is 26.2L / min; the pump source K 81 The flow rate is 25.7L / min; the pump source K 82 The flow rate is 25.7L / min. It can be seen that the closer the pump source is to the water inlet pipe, the better the cooling effect of the coolant; and the farther the pump source is from the water inlet pipe 8, the worse the cooling effect of the coolant. However, due to the position of the heat pipe 7, the cooling effect of the heat pipe 7 is better when the pump source is farther away from the water inlet pipe 8, which makes up for the problem of uneven cooling effect caused by relying solely on water cooling.

[0038] The second branch flow channel 11 includes a plate-shaped cavity 13 in the pump source assembly and a shunt pipe 14 in the heat sink 6, and two shunt pipes 14 on the same side are connected to the cavity 13. The pump source is cooled by the coolant flowing in the cavity 13. The plate-shaped cavity 13 can increase the heat dissipation area of ​​the pump source heat source as much as possible under the premise of a certain coolant flow rate, thereby improving the heat dissipation effect.

[0039] The heat pipes 7 are arranged in 2×2, and the top surface of the heat pipe 7 located at the top is attached to the bottom surface of the upper pump source 4, and the bottom surface of the heat pipe 7 located at the bottom is attached to the top surface of the lower pump source 5. The heat pipe 7 can be attached to the pump source component in a direct contact manner, or it can be attached to the pump source component through a medium (heat sink 6). Regardless of the method, a phase change sheet or heat dissipation silicone grease should be provided between the pump source component and the heat pipe 7 to fill the gap and improve the heat dissipation effect.

[0040] The ends of the plurality of heat pipes 7 located outside the heat sink 6 are commonly connected to a plurality of fins 15. The fins 15 increase the contact area between the heat pipes 7 and the air, thereby improving the heat dissipation effect.

[0041] In order to facilitate ventilation and heat dissipation of the fins 15 and further improve the heat dissipation effect, a plurality of heat dissipation holes 16 for ventilation are opened at one end of the housing 1 close to the fins 15 .

[0042] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A tunable single-frequency pulsed fiber laser, comprising a housing (1), characterized in that: The housing (1) is provided with a pump source component, a gain component (2) and a resonant cavity component (3) from right to left in sequence. The pump source component comprises a plurality of upper pump sources (4) fixedly arranged on the top wall of the housing (1), and a plurality of lower pump sources (5) fixedly arranged on the bottom wall of the housing (1). The upper pump sources (4) are arranged in two rows in an oblique and symmetrical manner, and the tail fibers of the upper pump sources (4) face the middle of the gain component (2). The number and arrangement of the lower pump sources (5) are consistent with those of the upper pump sources (4). A heat sink (6) is provided in the middle of the housing (1), and the top surface of the heat sink (6) is simultaneously attached to all the upper pump sources (4), and the bottom surface is simultaneously attached to all the lower pump sources (5). A water pipe component and a plurality of heat pipes (7) are provided inside the heat sink (6), and both ends of the water pipe component extend to the outside of the housing (1); The water pipe assembly comprises a water inlet pipe (8), a water outlet pipe (9), a first branch flow channel (10), a second branch flow channel (11) and a third branch flow channel (12) which cooperate with each other. The second branch flow channel (11) located at the top extends to the lower end of the upper pump source (4), and the branch flow channel located at the bottom extends to the upper end of the lower pump source (5). The coolant flows through the water inlet pipe (8), the first branch flow channel (10), the second branch flow channel (11), the third branch flow channel (12) and the water outlet pipe (9) in sequence. The heat pipe (7) is located between two second branch flow channels (11) on the same side, and one end of the heat pipe (7) away from the gain component (2) extends to the outside of the heat dissipation plate (6).

2. A tunable single-frequency pulsed fiber laser according to claim 1, characterized in that: The inclination angle of the upper pump source (4) is between 30° and 60°.

3. A tunable single-frequency pulsed fiber laser according to claim 2, characterized in that: The upper pump sources (4) are arranged in a 2×4 pattern, the lower pump sources (5) correspond to the upper pump sources (4) one by one, and the lower pump sources (5) are located directly below the upper pump sources (4).

4. The tunable single-frequency pulsed fiber laser according to claim 3, characterized in that: The second branch flow channel (11) comprises a plate-shaped cavity (13) in the pump source component and a shunt pipe (14) in the heat sink (6), and two shunt pipes (14) on the same side are connected to the cavity (13).

5. The tunable single-frequency pulsed fiber laser according to claim 3, characterized in that: The heat pipes (7) are arranged in a 2×2 pattern, and the top surface of the heat pipe (7) located at the top is in contact with the bottom surface of the upper pump source (4), and the bottom surface of the heat pipe (7) located at the bottom is in contact with the top surface of the lower pump source (5).

6. The tunable single-frequency pulsed fiber laser according to claim 5, characterized in that: One end of the plurality of heat pipes (7) located outside the heat dissipation plate (6) is commonly connected to a plurality of fins (15).

7. The tunable single-frequency pulsed fiber laser according to claim 6, characterized in that: A plurality of heat dissipation holes (16) are provided at one end of the housing (1) close to the fins (15).

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