KR102124077B1 - Assembling method of laser gain medium assembly solid-state solid lasers - Google Patents

Abstract

The present invention relates to a gain medium assembly for a solid-state laser and a method for assembling a gain medium assembly for a solid-state laser, in which a gain medium member is disposed within a gain medium casing member to receive no stress using metal with metallic malleability and ductility, the gain medium member is bonded to the gain medium casing member to prevent lowering of a laser beam space mode and a laser performance and accordingly to maintain a stable performance, the gain medium member has no axial change according to contraction and expansion of the gain medium casing member at a temperature change and can maintain a stable optical performance even under external vibration and mechanical impulse conditions, and a metal bonding member fixating a position of the gain medium member functions as a thermal conduction medium to facilitate transfer of heat, generated from the gain medium member, between the gain medium member and the gain medium casing member and accordingly to minimize thermal imbalance of a gain medium, thereby enhancing a laser performance, ensuring mechanical stability and generating a pulse laser with high energy.

Description

ASSEMBLING METHOD OF LASER GAIN MEDIUM ASSEMBLY SOLID-STATE SOLID LASERS

The present invention relates to a method for assembling a gain medium assembly for a solid laser and a gain medium assembly for a solid laser, and more specifically, a gain medium assembly for a solid laser and a solid laser for stably fixing the gain medium with a metal bonding member in a casing. The invention relates to a method of assembling a gain medium assembly.

In general, the laser diode-excited solid-state laser has high electro-optical conversion efficiency by matching the emission spectrum of the laser diode and the absorption spectrum of the laser gain medium, while the long lifetime (more than 100,000 hours) of the laser diode is also regarded as a great advantage.

Due to these advantages, laser diode-excited solid-state lasers are steadily developed for various purposes in industrial and military fields such as laser marking and cutting devices, environmental pollutant detection, non-destructive inspection, laser targeting and distance measuring devices.

Solid-state lasers (SSLs) with high energy use crystal or glass-based optical materials with rare earth ions added. The development of solid-state lasers that excite laser diodes for the purpose of high electro-optical conversion efficiency and small size and light weight is the main focus.

In particular, high-energy pulsed lasers are used for military purposes such as material detection and LIDAR light sources due to harmonic generation using equipment or non-linear optical devices that point or target a target in a surveillance and reconnaissance system.

The solid laser needs to be designed to be insensitive to external environmental changes depending on the purpose of use. Lasers used as military equipment are easily exposed to vibration and shock, and have a wide allowable temperature range.

In particular, when a stress is applied to the laser gain medium, the laser beam spatial mode is deteriorated, and thus an organic adhesive is generally used to fix the metal fixture to secure mechanical stability.

However, the organic adhesive is vulnerable to the environmental resistance of the gain medium assembly because the organic adhesive contaminates and damages the laser interior and degrades laser performance in a low temperature and high temperature environment for a long time.

On the other hand, the laser gain medium forms a reference axis of the laser resonator in the form of a cylinder, and the excitation light source is excited from the side to realize a high energy pulse laser.

At this time, heat imbalance occurs due to absorption of the beam by the excitation light source in the gain medium. This imbalance directly affects the beam quality and divergence angle of the laser and generates unstable energy.

Recently, high-energy solid-state lasers have been developed from water-cooling to air-cooling for the purpose of miniaturization and weight reduction, but generally have a disadvantage of low heat dissipation effect depending on the processing state of the contact surface of the gain medium mechanism and the side surface quality of the circular gain medium.

0001) Korea Patent Registration No. 1337523'Solid laser device for laser diode' (Registration on Nov. 4, 2013)

An object of the present invention is to provide a gain medium assembly for a solid laser and a method for assembling a gain medium assembly for a solid laser to stably fix the gain medium member with a metal bonding member and stably fix it in the casing member to have optical stability.

In order to achieve the above object of the present invention, an embodiment of a gain medium assembly for a solid laser according to the present invention is a gain medium member that absorbs an excitation beam emitted from a laser diode unit to emit photons, and the gain medium member is internal It characterized in that it comprises a metal member for fixing the position of the gain medium casing member, which is inserted into the position, is located inside the gain medium casing member to bond the gain medium member to the gain medium casing member to fix the position.

In the present invention, the metal bonding member may be a metal bonding layer cured after the metal thin plate is melted by heating.

In the present invention, the metal bonding member may be indium or an alloy containing indium.

In the present invention, the metal joining member may be spaced apart in the longitudinal direction of the gain medium member to be positioned in plural.

In the present invention, the gain medium casing member includes a lower casing in which a first gain medium inserting part for wrapping and supporting a portion of the circumferential circumference of the gain medium member is located above; And a second casing for inserting a second gain medium that surrounds and supports the rest of the circumferential circumference of the gain medium member, and an upper casing coupled to an upper part of the lower casing.

In the present invention, the gain medium casing member may further include a gain medium position adjustment block capable of moving up and down on the upper casing to wrap and fix the metal bonding member and adjust the position of the gain medium member. .

In the present invention, on the lower surface of the gain medium position adjustment block, a gain medium joint insertion part in which a metal joint member surrounding the upper side part of the gain medium member and an upper side part of the gain medium member is inserted and positioned therein is positioned. Can be.

In the present invention, a block inserting portion into which the gain medium positioning block is inserted may be located in the upper casing.

In the present invention, in the upper casing, a gain medium position fixing member for pressing the gain medium member to fix the position of the gain medium member may be located.

In the present invention, a gain medium position fixing member for fixing the position of the gain medium member by pressing the upper portion of the gain medium position adjustment block may be positioned on the upper casing.

In the present invention, the gain medium position fixing member may be a gain medium fixing bolt that is fastened through the upper casing.

In order to achieve the above object of the present invention, an embodiment of a method of assembling a gain medium assembly for a solid laser according to the present invention inserts a gain medium member into a gain medium casing, and a metal sheet is placed between the gain medium casing and the gain medium member. It characterized in that it comprises a step of inserting a gain medium to be positioned, a heating step to heat and melt the thin metal plate, and a gain medium bonding step to cool and secure the gain medium member to the metal bonding member within the gain medium casing member.

In the present invention, the step of inserting the gain medium is a process of locating the gain medium member in the first gain medium insert of the lower casing, and spaces the metal thin plate covering a part of the gain medium member protruding upward from the lower casing in the longitudinal direction. It may include a plurality of positioning process, the process of positioning the gain medium position adjustment block to the upper side of the thin metal plate and assembling the upper casing and the lower casing.

The step of inserting the gain medium may further include the step of pressing the gain medium position adjustment block with a predetermined pressure to a gain medium position fixing part located in the upper casing after the process of assembling the upper casing and the lower casing. .

One embodiment of a method of assembling a gain medium assembly for a solid laser according to the present invention may further include a parallelism inspection step of checking whether the parallelism of the two sides of the gain medium member is consistent after the gain medium bonding step.

One embodiment of a method of assembling a gain medium assembly for a solid laser according to the present invention further comprises a parallelism inspection step of checking whether the parallelism of the two sides of the gain medium member is consistent after the gain medium bonding step, and the gain medium bonding step is During cooling, the gain medium position fixing part may be moved up and down to include a parallelism adjustment process for adjusting the parallelism on both sides of the gain medium member.

One embodiment of a method for assembling a gain medium assembly for a solid laser according to the present invention includes a step of joining a gain medium including the heating step and the process of adjusting the parallelism when the parallelisms of the two sides of the gain medium member do not match in the parallelism inspection step. By repeating, the parallelism of both sides of the gain medium member can be matched.

The present invention uses a metal having metal malleability and ductility to arrange the gain medium member so as not to be stressed within the gain medium casing member, and bonds the gain medium member to the gain medium casing member to reduce laser beam spatial mode and laser performance. It has the effect of being prevented and maintaining stable performance.

In addition, the present invention has the effect of maintaining a stable optical performance even under external vibration and mechanical shock conditions without any change in the axis of the gain medium member due to contraction and expansion of the gain medium casing member at temperature changes.

In addition, the present invention, the metal bonding member for fixing the position of the gain medium member serves as a heat conduction medium, thereby facilitating heat transfer generated in the gain medium member between the gain medium member and the gain medium casing member to reduce the thermal imbalance of the gain medium. It has the effect of minimizing.

The present invention can improve the laser performance and secure mechanical stability, and has the effect of generating a high energy pulse laser.

1 is a perspective view showing an embodiment of a gain medium assembly for a solid laser according to the present invention.
Figure 2 is an exploded perspective view showing an embodiment of a gain medium assembly for a solid laser according to the present invention.
3 is a schematic diagram showing one embodiment of a gain medium assembly for a solid laser according to the present invention.
Figure 4 is a cross-sectional view showing an embodiment of a gain medium assembly for a solid laser according to the present invention.
Figure 5 is a process diagram showing a method of assembling a gain medium assembly for a solid laser according to the present invention.

The present invention will be described in more detail.

If described in detail by the accompanying drawings, preferred embodiments of the present invention. Prior to the detailed description of the present invention, terms or words used in the present specification and claims described below should not be interpreted as being limited to a conventional or dictionary meaning. Therefore, the configuration shown in the embodiments and drawings described in this specification are only the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, and thus can replace them at the time of application. It should be understood that there may be equivalents and variations.

1 is a perspective view showing an embodiment of a gain medium assembly for a solid laser according to the present invention, FIG. 2 is an exploded perspective view showing an embodiment of a gain medium assembly for a solid laser according to the present invention, and FIG. 3 is It is a schematic diagram showing an embodiment of a gain medium assembly for a solid laser according to the present invention, and FIG. 4 is a cross-sectional view showing an embodiment of a gain medium assembly for a solid laser according to the present invention.

An embodiment of a gain medium assembly for a solid laser according to the present invention will be described in detail below with reference to FIGS. 1 to 4.

One embodiment of a gain medium assembly for a solid laser according to the present invention includes a gain medium member 100 that absorbs an excitation beam emitted from a laser diode unit and emits photons.

As an example, the gain medium member 100 is formed in a rod shape having a round circumference, that is, a rod.

The gain medium member 100 is known to emit photons for laser generation by absorbing an excitation beam emitted from the laser diode unit to the gain medium member 100, and a detailed description thereof will be omitted.

The gain medium member 100 is inserted and positioned in the gain medium casing member 200, and the gain medium casing member 200 is penetrated in the longitudinal direction therein and a gain medium inserting part into which the gain medium member 100 is inserted is located. .

For example, the gain medium casing member 200 is made of a material having excellent thermal conductivity, that is, copper, aluminum, stainless steel, or the like, to rapidly dissipate heat generated during laser oscillation.

In addition, a beam transmission window 200a for opening the gain medium member 100 located therein in the circumferential direction is located in the gain medium casing member 200.

For example, the beam transmission window 200a is an open part so that the beam emitted from the laser diode is transmitted to the gain medium member 100 and is positioned in a plurality in the longitudinal direction of the gain medium casing member 200.

The gain medium casing member 200 includes a lower casing 210 in which a first gain medium inserting portion 211 which surrounds and supports a portion of the circumferential circumference of the gain medium member 100 is located at the upper portion, and a gain medium member ( A second gain medium insertion portion 221 surrounding and supporting the rest of the circumferential circumference of 100) is located and includes an upper casing 220 coupled to an upper portion of the lower casing 210.

A reflector (not shown) that reflects the excitation beam may be positioned on the inner surface of the first gain medium inserting portion 211 and the inner surface of the second gain medium inserting portion 221.

The reflecting portion includes a well-known reflecting member such as a reflective metal thin plate or a reflective layer formed by applying a reflective chemical, and includes the inner surface of the first gain medium inserting portion 211 and the second gain medium inserting part 221. The absorption of the excitation beam is increased by the gain medium member 100 by reflecting the excitation beam from the inner surface.

For example, the lower casing 210 and the upper casing 220 are assembled by bolting with the casing assembly bolt 200b.

On one side of the lower casing 210, a lower fastening portion 212 in which a plurality of lower bolt holes 212a are located is protruded, and on one side of the upper casing 220 overlaps the lower fastening portion 212 and lower bolts. The upper fastening part 222 in which a plurality of upper bolt holes 222a coinciding with the ball 212a are located is positioned.

As an example, at least one of the upper bolt hole 222a and the lower bolt hole 212a is formed with an inner circumferential surface in which a screw thread to which the casing assembly bolt 200b can be fastened is formed.

The casing assembly bolt 200b penetrates any one of the upper bolt hole 222a and the lower bolt hole 212a and is fastened to the other, thereby assembling the lower casing 210 and the upper casing 220 by bolting or upper bolt After passing through the ball 222a and the lower bolt hole 212a, they are fastened to separate nuts to assemble the lower casing 210 and the upper casing 220 by bolting.

The lower casing 210 and the upper casing 220 are assembled so that the first gain medium inserting part 211 and the second gain medium inserting part 221 are combined so that the gain medium member 100 is inserted and positioned. The insert is formed inside.

The plurality of beam transmitting windows 200a are positioned to face the laser diode of the laser diode unit so that the excitation beam emitted from the laser diode passes and can be irradiated to the gain medium member 100.

The beam transmission window 200a is formed in a size corresponding to the size of the laser diode of the laser diode unit, that is, a size corresponding to the emission range of the excitation beam emitted from the laser diode, and the excitation beam emitted from each laser diode unit is a gain medium member without loss. (100) to be absorbed as much as possible.

The gain medium member 100 is bonded to the gain medium casing by the metal joining member 300 inside the gain medium casing member 200 to fix the position.

For example, the metal bonding member 300 is a metal bonding layer that is cured after the metal thin plate is melted by heating.

Further, the metal bonding member 300 is an example of a metal having malleability and ductility, and an example of an indium or an alloy containing indium.

The metal bonding member 300 is positioned in plural in the longitudinal direction of the gain medium member 100 to stably fix the position of the gain medium member 100 within the gain medium casing member 200.

The gain medium casing member 200 is coupled to the upper casing 220 so that it can be moved up and down to wrap and fix the metal joining member 300 and to adjust the position of the gain medium to adjust the position of the gain medium member 100 ( 230) may be further included.

The gain medium position adjustment block 230 is spaced apart in the longitudinal direction of the upper casing 220 and positioned in plural.

The lower surface of the gain medium position adjustment block 230 is wrapped around the rest of the circumferential direction of the gain medium member 100 and the rest of the gain medium member 100, that is, the upper part of the gain medium member 100. The metal bonding member 300 is inserted into the gain medium is inserted into the insertion portion 231 is located.

The gain medium member 100 is positioned in the gain medium joint insertion portion 231 and is fixed to the gain medium position adjustment block 230 by a metal joint member 300.

For example, the metal bonding member 300 and the gain medium position adjusting unit are located in the center of the upper casing 220, at the front end side of the upper casing 220, and at the rear end side of the upper casing 220.

That is, the metal joining member 300 and the gain medium position adjusting unit are located at three or more points to be symmetrical at the top of the gain medium member 100 without interfering with the side excitation light source, that is, the laser diode part beam path. Yes.

In addition, the metal bonding member 300 is at least partially located between the lower casing 210 and the upper casing 220 on both sides of the gain medium member 100, thereby joining the lower casing 210 and the upper casing 220. Take it as an example.

A block inserting portion 223 into which the gain medium positioning block 230 is inserted is located in the upper casing 220.

The block inserting portion 223 is spaced apart in the longitudinal direction of the upper casing 220, and the gain medium position adjustment block 230 is fitted to be coupled to move up and down.

The upper casing 220 is positioned with a gain medium positioning member 240 for pressing the gain medium member 100 to fix the position of the gain medium member 100.

The gain medium position fixing member 240 presses the gain medium member 100 to fix the position of the gain medium member 100 to prevent distortion of the gain medium member 100.

The gain medium position fixing member 240 is positioned through the upper casing 220 to press the upper part of the gain medium position adjustment block 230 to adjust the position of the gain medium member 100, and gain medium at the adjusted position It is assumed that the member 100 is pressed and fixed.

The gain medium positioning member 240 is fastened through the upper casing 220 and presses the upper part of the gain medium positioning block 230 to secure the position of the gain medium fixing bolt 241 Take that as an example.

A bolt fastening hole 224 to which the block inserting portion 223 is connected and the gain medium fixing bolt 241 is fastened is located in the upper casing 220.

The gain medium fixing bolt 241 is fastened through the bolt fastening hole 224 to press the upper part of the gain medium positioning block 230 located in the block inserting portion 223.

When the gain medium member 100 is joined by a soft metal joining member 300, the optical axis may be twisted without being fixed.

The gain medium member 100 is fixed on the basis of the first gain medium inserting portion 211 of the lower casing 210 and receives heat and pressure while being pressed by the gain medium position adjustment block 230 to form a metal joining member ( 300) while being cured after bonding, the axial change due to the soft nature of the metal bonding member 300 is prevented.

On the other hand, some of the energy received from the side by the excitation light source is accumulated as heat in the gain medium member 100 and deteriorates the spatial mode and beam quality of the laser.

The metal joining member 300 is applied as a heat conduction medium that emits heat generated in the gain medium member 100, and heat generated by the gain medium member 100 is partially transferred to the gain medium casing member 200, thereby dissipating heat. The effect can be improved.

5 is a process diagram illustrating a method of assembling a gain medium assembly for a solid laser according to the present invention, and referring to FIGS. 2 and 5, an embodiment of a method of assembling a gain medium assembly for a solid laser according to the present invention is a gain medium Inserting member 100 into the gain medium casing and inserting a gain medium in which a metal sheet is positioned between the gain medium casing and the gain medium member 100 (S100), heating step of heating and melting the metal sheet (S200), cooling And a gain medium bonding step (S300) in which the gain medium member 100 is bonded and fixed in the gain medium casing member 200 to the metal bonding member 300.

The gain medium inserting step (S100) is a process of positioning the gain medium member 100 in the first gain medium inserting part 211 of the lower casing 210, and the gain medium member 100 protruding above the lower casing 210 ) A process of positioning a plurality of metal thin plates covering a portion of the metal spaced apart in the longitudinal direction, a process of positioning the gain medium positioning block 230 to the upper side of the metal thin plate, and a process of assembling the upper casing 220 and the lower casing. Includes.

In addition, the gain medium insertion step (S100) is based on the gain medium position fixing block located in the upper casing 220 after the process of assembling the upper casing 220 and the lower casing 110, the gain medium position adjustment block 230 It further includes a process of pressing at a set pressure.

The heating step (S200) is a gain medium inserting step (S100), in which the gain medium casing member 200 into which the gain medium member 100 is inserted is heated to a temperature at which the metal sheet can be melted to melt the metal sheet.

At this time, the gain medium member 100 receives heat and pressure between the gain medium position adjustment block 230 and the lower casing 210 inside the gain medium casing member 200, and then the metal bonding member is cured after the metal thin plate is melted and cured ( 300) can be stably fixed without distortion.

The method for assembling the gain medium assembly for a solid laser according to the present invention may further include a parallelism inspection step (S400) for checking whether the parallelism of both sides of the gain medium member 100 is consistent after the gain medium bonding step (S300).

And, the gain medium bonding step (S300) may include a parallelism adjustment process to adjust the parallelism of both sides of the gain medium member 100 by moving the gain medium position fixing part up and down during cooling.

In the process of adjusting the degree of parallelism, the gain medium member 100 joined by the plurality of metal joining members 300 is tightened or loosened by tightening or releasing the plurality of gain medium fixing bolts 241, respectively, which are the gain medium position fixing parts, and receiving the uniform force in the longitudinal direction. And prevent the distortion of the parallelism on both sides.

When the parallelism on both sides of the gain medium member 100 is wrong, there is a problem that directly affects the laser spatial mode.

If the parallelism of the two sides of the gain medium member 100 does not match in the parallelism inspection step (S400), the heating medium (S200) and the gain medium bonding step (S300) including the parallelism adjustment process are repeated, so that both sides of the gain medium member 100 are repeated. Make sure to match the parallelism accurately.

The gain medium member 100 can be pressurized under a uniform force in a state of being joined by a plurality of metal bonding members 300, and the position can be stably fixed without distortion of parallelism on both sides.

According to the present invention, the gain medium member 100 is disposed using the metal having metal malleability and ductility so as not to be stressed within the gain medium casing member 200, and the gain medium member 100 is gain medium casing member 200. It is bonded to the laser beam space mode and the laser performance is prevented from deteriorating to maintain stable performance.

In addition, according to the present invention, there is no axial change of the gain medium member 100 due to contraction and expansion of the gain medium casing member 200 at a temperature change, and stable optical performance can be maintained even under external vibration and mechanical shock conditions.

In addition, according to the present invention, the metal bonding member 300 for fixing the position of the gain medium member 100 serves as a heat conduction medium, and thus the gain medium member 100 between the gain medium member 100 and the gain medium casing member 200 is provided. ) To minimize heat imbalance of the gain medium by facilitating heat transfer.

The present invention makes it possible to improve laser performance and secure mechanical stability, and to generate a high energy pulse laser.

The present invention is not limited to the above-described embodiments, but can be carried out by variously changing within a range not departing from the gist of the present invention, and it is revealed that it is included in the configuration of the present invention.

100: gain medium member 200: gain medium casing member
200a: Beam transmission window 200b: Casing assembly bolt
210: lower casing 211: first gain medium insertion section
212: lower fastening portion 212a: lower bolt hole
220: upper casing 221: second gain medium insertion section
222: upper fastening portion 222a: upper bolt hole
223: block inserting section 230: gain medium position adjustment block
231: gain medium joint insertion part 240: gain medium position fixing member
300: metal bonding member
S100: Insertion step of gain medium
S200: heating stage
S300: bonding step of gain medium
S400: Parallelism inspection step

Claims (17)

delete delete delete delete delete delete delete delete delete delete delete A gain medium inserting step of inserting a gain medium member into a gain medium casing member separated into an upper casing and a lower casing and placing a thin metal plate between the gain medium casing member and the gain medium member;
A heating step of heating and melting the thin metal plate;
A cooling medium bonding step of cooling and bonding the gain medium member to the metal bonding member within the gain medium casing member; And
And a parallelism inspection step of inspecting whether the parallelism of both sides of the gain medium member is consistent after the bonding step of the gain medium,
The step of inserting the gain medium,
Positioning the gain medium member in the first gain medium insertion portion of the lower casing;
Placing a plurality of metal thin plates covering a portion of the gain medium member protruding upward from the lower casing to be spaced apart in the longitudinal direction;
Positioning a gain medium positioning block on an upper side of the thin metal plate;
Assembling the upper casing and the lower casing; And
After the step of assembling the upper casing and the lower casing, the step of pressing the gain medium position adjustment block with a predetermined pressure to a gain medium position fixing part located in the upper casing,
The method of assembling the gain medium assembly for a solid laser, wherein the gain medium bonding step includes a parallelism adjustment process to adjust the parallelism of both sides of the gain medium member by moving the gain medium position fixing part up and down during cooling.
delete delete delete delete The method according to claim 12,
If the parallelism of the two sides of the gain medium member is not coincident in the parallelism inspection step, the heating step and the gain medium bonding step including the parallelism adjustment process are repeated to match the parallelism of both sides of the gain medium member. How to assemble the dragon gain medium assembly.

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