Solid-state amplification module and hybrid active-cooling amplification laser device including same

Abstract

The present disclosure relates to a solid-state amplification module which provides a pump beam through an optical fiber coupler, arranges a solid gain medium in a multi-stage structure or a bypass structure to amplify a seed beam, and arranges a compressor inside an amplification stage so that output loss due to the compressor is compensated for through the solid gain medium.

Description

Solid-state amplification module and hybrid active cooling amplification laser device including the same

[0001] The present disclosure relates to a laser device, and more specifically, to a solid-state amplification module and a hybrid active cooling amplification laser device including the same.

[0002] Amplified laser devices can be classified into crystal type and optical fiber type depending on the laser amplification medium.

[0003] Generally, crystal types have the advantage of enabling the formation of narrow and clean pulse widths due to minimal non-linear phenomena, but they have the disadvantage of being relatively vulnerable to changes in the surrounding environment and having poor heat dissipation, making them difficult to apply to high-power systems.

[0004] On the other hand, in the case of fiber-based ultrashort pulse lasers using optical fibers as an amplification medium, the pulse shape is relatively poor due to the higher-order dispersion and nonlinear characteristics of the optical fibers; however, since the optical path is composed of optical fibers, it is insensitive to environmental changes and stable.

[0005] In addition, due to the structural characteristics of the amplification medium, heat dissipation is easy, making it possible to secure a relatively high average output. These advantages of fiber-based ultrashort pulse lasers meet the needs of industrial sectors requiring stability and productivity.

[0006] Meanwhile, laser amplification modules are divided into two types based on their heat dissipation type. The first is an air-cooled version system that dissipates heat through conduction and radiation; however, due to limitations in heat dissipation, the maximum pumping capacity is typically limited to the level of tens of watts (W). For higher outputs, a water-cooled version system is utilized, which cools the heat-generating parts with water and exhibits at least twice the heat dissipation efficiency compared to the air-cooled version. However, a circulation system and additional pumps are required to circulate the water, and caution is required in selection and use because the impact on surrounding systems is significant in the event of a leak.

[0007] Meanwhile, amplified laser devices typically include a compressor at the output stage to compress the amplified signal and produce the final output. However, there was a limitation in that some loss occurred in the final output due to the compressor provided at the output stage.

[0008] The embodiments disclosed in this disclosure pump a beam (L) through an optical fiber coupler. p ) provides, and arranges the solid gain medium in a multistage or bypass structure to provide a seed beam (L s A solid-state amplification module is disclosed that amplifies ) and places a compressor inside the amplification stage so that output loss caused by the compressor is compensated through a solid-state gain medium.

[0009] The problems that this disclosure aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0010] A solid-state amplification module according to the present disclosure for achieving the above-described technical problem comprises: a compressor for compressing a laser beam; at least one solid-state gain medium for amplifying the compressed laser beam; and at least one optical fiber coupler that provides a pump beam to the at least one solid-state gain medium, wherein the coupler comprises a plurality of optical fibers to provide the pump beam of different wavelengths.

[0011] Meanwhile, the above-mentioned at least one solid gain medium can be arranged in a multi-stage structure to sequentially amplify the compressed laser beam.

[0012] Additionally, it may further include a Faraday isolator that provides the laser beam to the compressor; a pair of half-wave plates disposed at both ends of the Faraday isolator; a polarizing beam splitter that passes the laser beam from the Faraday isolator toward the compressor and reflects the compressed laser beam emitted from the compressor toward the at least one solid gain medium; and a quarter-wave plate disposed between the polarizing beam splitter and the compressor.

[0013] Additionally, it may further include a mirror disposed at the rear end of the at least one solid gain medium to reflect the laser beam that has passed through the at least one solid gain medium so that it can be incident back onto the at least one solid gain medium and amplified.

[0014] Additionally, it may further include a Faraday isolator that provides the laser beam to the compressor; a pair of first half-wave plates disposed at both ends of the Faraday isolator; a first polarization beam splitter that passes the laser beam from the Faraday isolator toward the compressor and reflects the compressed laser beam emitted from the compressor toward the at least one solid gain medium; a first quarter-wave plate disposed between the first polarization beam splitter and the compressor; a second polarization beam splitter that passes the compressed laser beam reflected by the first polarization beam splitter toward the at least one solid gain medium and reflects it so that a laser beam amplified by the at least one solid gain medium can be output; a second half-wave plate disposed between the first polarization beam splitter and the second polarization beam splitter; and a second quarter-wave plate disposed between the at least one solid gain medium and the mirror.

[0015] Additionally, it may further include an O-ring fixed to both ends of the at least one solid gain medium and controlling the temperature of the at least one solid gain medium through contact with cooling water.

[0016] In addition, the above at least one solid gain medium may be coated with a metal material.

[0017] In addition, the at least one solid gain medium can be coated with the metal material in a polished state.

[0018] In addition, the pump beam can be provided to the at least one solid gain medium by adjusting the angle of incidence so as to satisfy the total reflection condition of the at least one solid gain medium.

[0019] Meanwhile, the hybrid active cooling amplification laser device according to the present disclosure comprises: an oscillation module that emits a laser beam; a fiber amplification module that first amplifies the laser beam through at least one fiber gain medium; and a solid amplification module that secondarily amplifies the first amplified laser beam through at least one solid gain medium; wherein the solid amplification module comprises: a compressor that compresses the first amplified laser beam; the at least one solid gain medium that amplifies the compressed laser beam; and at least one fiber coupler that provides a pump beam to the at least one solid gain medium, wherein the pump beam has different wavelengths and includes a plurality of optical fibers.

[0020] According to the aforementioned means for solving the problem of the present disclosure, a laser beam (L) provided as a seed beam s By arranging a compressor and at least one solid gain medium so as to compress and then amplify ) a laser beam (L) produced by the compressor s The loss of ) can be compensated by at least one solid gain medium, thereby increasing the output power and expecting an improvement in overall efficiency.

[0021] The effects of the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below.

[0022] FIG. 1 is a drawing showing a solid-state amplification module according to one embodiment of the present disclosure.

[0023] FIG. 2 is a drawing showing a solid-state amplification module according to another embodiment of the present disclosure.

[0024] FIGS. 3 to 5 are drawings showing solid gain media according to various embodiments of the present disclosure.

[0025] FIG. 6 is a drawing showing an optical fiber coupler according to various embodiments of the present disclosure.

[0026] Figure 7 is a graph showing the power of the laser beam output from the solid-state amplification module illustrated in Figure 1.

[0027] FIG. 8 is a drawing showing a hybrid active cooling amplification laser device according to one embodiment of the present disclosure.

[0028] Throughout this disclosure, the same reference numerals denote the same components. This disclosure does not describe all elements of the embodiments, and general content in the art to which this disclosure pertains or content that overlaps between embodiments is omitted. The terms 'part, module, component, block' as used in the specification may be implemented in software or hardware, and depending on the embodiments, a plurality of 'parts, modules, components, blocks' may be implemented as a single component, or a single 'part, module, component, block' may include a plurality of components.

[0029] Throughout the specification, when a part is described as being "connected" to another part, this includes not only cases where they are directly connected but also cases where they are indirectly connected, and indirect connections include connections made via a wireless communication network.

[0030] Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0031] Throughout the specification, when it is stated that a component is located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0032] The terms first, second, etc. are used to distinguish one component from another, and the components are not limited by the aforementioned terms.

[0033] Singular expressions include plural expressions unless there is an obvious exception in the context.

[0034] In each step, identification codes are used for convenience of explanation and do not describe the order of the steps; the steps may be performed differently from the specified order unless a specific order is clearly indicated in the context.

[0035] The operating principles and embodiments of the present disclosure will be described below with reference to the attached drawings.

[0036] In this specification, the term "device according to the present disclosure" includes all various devices capable of performing computational processing and providing results to a user. For example, the device according to the present disclosure may include all of a computer, a server device, and a portable terminal, or may be in the form of any one of these.

[0037] Here, the computer may include, for example, a notebook, desktop, laptop, tablet PC, slate PC, etc. equipped with a web browser.

[0038] The above server device is a server that processes information by communicating with an external device, and may include an application server, a computing server, a database server, a file server, a game server, a mail server, a proxy server, and a web server.

[0039] The above portable terminal may include, for example, all types of handheld-based wireless communication devices such as PCS (Personal Communication System), GSM (Global System for Mobile communications), PDC (Personal Digital Cellular), PHS (Personal Handyphone System), PDA (Personal Digital Assistant), IMT (International Mobile Telecommunication)-2000, CDMA (Code Division Multiple Access)-2000, W-CDMA (W-Code Division Multiple Access), WiBro (Wireless Broadband Internet) terminals, smartphones, etc., as well as wearable devices such as watches, rings, bracelets, anklets, necklaces, glasses, contact lenses, or head-mounted devices (HMDs).

[0040] Functions related to artificial intelligence according to the present disclosure are operated through a processor and memory. The processor may be composed of one or more processors. In this case, the one or more processors may be general-purpose processors such as CPUs, APs, and DSPs (Digital Signal Processors), graphics-dedicated processors such as GPUs and VPUs (Vision Processing Units), or artificial intelligence-dedicated processors such as NPUs. The one or more processors control the processing of input data according to predefined operation rules or artificial intelligence models stored in memory. Alternatively, if the one or more processors are artificial intelligence-dedicated processors, the artificial intelligence-dedicated processors may be designed with a hardware structure specialized for processing a specific artificial intelligence model.

[0041] FIG. 1 is a drawing showing a solid-state amplification module according to one embodiment of the present disclosure.

[0042] Referring to FIG. 1, a solid-state amplification module (100) according to one embodiment of the present disclosure may include a Faraday isolator (110), a compressor (120), a polarizing beam splitter (PBS) (130), a solid-state gain medium (Yb:YAG) (140), and a fiber combiner (150).

[0043] The Faraday isolator (110) is a laser beam (L s ) can be transmitted in a specific direction. In this embodiment, the laser beam (L s ) can be provided through a photonic crystal fiber (PCF) and can be a picosecond pulse laser beam in a state amplified by a fiber gain medium.

[0044] For example, the Faraday isolator (110) is a laser beam (L s ) is transmitted toward the compressor (120), and the laser beam (L) returning in the reverse direction is transmitted. s It can block ).

[0045] Meanwhile, a solid-state amplification module (100) according to one embodiment of the present disclosure may further include a pair of half-wave plates (HW) (113, 115) disposed at both ends of a Faraday isolator (110).

[0046] A pair of half-wave plates (113, 115) are laser beams (L s The polarization direction of ) can be rotated 90°.

[0047] For example, a half-wave plate (113) placed at the input end of a Faraday isolator (110) is a laser beam (L in the horizontal direction) s) is rotated in a vertical direction so that it can pass through the Faraday isolator (110), and the half-wave plate (115) placed at the output end of the Faraday isolator (110) is aligned with the polarization direction of the compressor (120) and a vertical laser beam (L s ) can be rotated back horizontally.

[0048] Meanwhile, a solid-state amplification module (100) according to one embodiment of the present disclosure may further include a lens (L) disposed at the input end of a Faraday isolator (110).

[0049] The lens (L) provides a laser beam (L) through a photonic crystal optical fiber (PCF). s ) can be adjusted to a parallel beam.

[0050] The compressor (120) is a laser beam (L s It can compress and output the ) In this embodiment, the compressor (120) can be applied as a VBG (Volume Bragg Grating).

[0051] For example, the compressor (120) is provided with a laser beam (L) from the Faraday isolator (110). s ) can be compressed and output to the polarization beam splitter (130).

[0052] Meanwhile, a solid-state amplification module (100) according to one embodiment of the present disclosure may further include a quarter-wave plate (QW) (125) disposed between a compressor (120) and a polarizing beam splitter (130).

[0053] The quarter-wave plate (125) is a laser beam (L s The polarization direction of ) can be rotated 45°.

[0054] For example, the quarter-wave plate (125) is a horizontal laser beam (L) incident on the compressor (120). s Rotate ) 45°, and the laser beam (L) output from the compressor (120)s Rotate ) 45° to have a vertical direction.

[0055] The polarization beam splitter (130) separates the laser beam (L) according to the polarization state s It can pass or reflect the ) s Pass ) through, and a vertical laser beam (L s It can reflect ).

[0056] For example, the polarization beam splitter (130) is a horizontal laser beam (L) from the Faraday isolator (110) toward the compressor (120). s ) passes through, and a vertical laser beam (L) output from the compressor (120) s ) can be reflected to at least one solid gain medium (140).

[0057] The solid gain medium (140) is a laser beam (L in a compressed state) reflected from the polarization beam splitter (130). s ) can be amplified and output. In FIG. 1, the solid gain medium (140) is illustrated as being applied as Yb:YAG with a doping concentration of 1% to 2%, but is not limited thereto and may be applied as Nd:YVO4 or Nd:YAG, etc.

[0058] For example, the solid gain medium (140) is a pump beam (L p Exciting ions in the medium by ) a laser beam (L s It can amplify ).

[0059] A plurality of solid gain media (140) may be provided, and the plurality of solid gain media (140) are arranged in a multi-stage structure as shown in FIG. 1 to form a laser beam (L s It can sequentially amplify and output ).

[0060] The optical fiber coupler (150) pumps the beam (L) into the solid gain medium (140).p It can provide ).

[0061] For example, the optical fiber coupler (150) is a pump beam (L) emitted from a pump light source (not shown). p ) can be transferred to a solid gain medium (140).

[0062] The optical fiber coupler (150) can be formed in a shape in which a plurality of single optical fibers are woven together, and a pump beam (L) having at least one wavelength band through the plurality of single optical fibers p ) can be provided as a solid gain medium (140). In this case, a pump beam (L) having a single wavelength band. p Compared to the amplification method by ), the effect of increasing amplification efficiency can be expected.

[0063] For example, the optical fiber coupler (150) may be formed by weaving together three to seven single optical fibers. In this case, the NA of the single optical fiber may be 0.22 and the core may be 105 µm. The optical fiber coupler (150) comprises a plurality of optical fibers and a pump beam (L) having at least one different wavelength band (e.g., 969 nm and 940 nm). p It can simultaneously transmit ) and the pump beam (L) output from such optical fiber coupler (150) p ) can have a power of 300W or more. In addition, the pump beam (L) output from the optical fiber coupler (150) p The laser beam (L) is incident on the solid gain medium (140) by adjusting the angle of incidence (e.g., 45° or more) to satisfy the total reflection condition of the solid gain medium (140). s It enables ) to be amplified efficiently.

[0064] The optical fiber coupler (150) may be provided in multiple numbers corresponding to the number of multiple solid gain media (140), and each pump beam (L) to the multiple solid gain media (140). p By providing a laser beam (L s ) this pump beam (Lp Allows it to be amplified by ).

[0065] Meanwhile, a solid-state amplification module (100) according to one embodiment of the present disclosure is a laser beam (L s ) or pump beam (L p A plurality of lenses (L) and a laser beam (L) for focusing or defocusing ) s ) or pump beam (L p It may further include a plurality of dichroic mirrors (DM) for reflecting ) along a specific path.

[0066] A solid-state amplification module (100) according to one embodiment of the present disclosure has a laser beam (L) amplified through at least one solid-state gain medium (140). s It outputs '), and the laser beam (L) provided as the seed beam. s By arranging a compressor (120) and at least one solid gain medium (140) so as to compress and then amplify the laser beam (L) produced by the compressor (120), s The loss of ) can be compensated by at least one solid gain medium (140) to increase output power, thereby expecting an improvement in overall efficiency.

[0067] FIG. 2 is a drawing showing a solid-state amplification module according to another embodiment of the present disclosure.

[0068] Referring to FIG. 2, a solid-state amplification module (100') according to another embodiment of the present disclosure may include a Faraday isolator (110), a compressor (120), a first polarization beam splitter (130), a second polarization beam splitter (135), a solid-state gain medium (140), a fiber optic coupler (150), and a mirror (160).

[0069] The Faraday isolator (110) is a laser beam (L s ) can be transmitted in a specific direction. In this embodiment, the laser beam (L s) can be provided through a photonic crystal optical fiber (PCF) and can be a picosecond pulse laser beam in a state amplified by a first-order amplification by an optical fiber gain medium.

[0070] For example, the Faraday isolator (110) is a laser beam (L s ) is transmitted toward the compressor (120), and the laser beam (L) returning in the reverse direction is transmitted. s It can block ).

[0071] Meanwhile, a solid-state amplification module (100') according to another embodiment of the present disclosure may further include a pair of first half-wave plates (HW) (113, 115) disposed at both ends of a Faraday isolator (110).

[0072] A pair of first half-wave plates (113, 115) are laser beams (L s The polarization direction of ) can be rotated 90°.

[0073] For example, a first half-wave plate (113) positioned at the input end of a Faraday isolator (110) is a horizontal laser beam (L s ) is rotated in a vertical direction so that it can pass through the Faraday isolator (110), and the first half-wave plate (115) placed at the output end of the Faraday isolator (110) is aligned with the polarization direction of the compressor (120) and a vertical laser beam (L s ) can be rotated back horizontally.

[0074] Meanwhile, a solid-state amplification module (100') according to another embodiment of the present disclosure may further include a lens (L) disposed at the input end of a Faraday isolator (110).

[0075] The lens (L) provides a laser beam (L) through a photonic crystal optical fiber (PCF). s ) can be adjusted to a parallel beam.

[0076] The compressor (120) is a laser beam (Ls It can compress and output the ) In this embodiment, the compressor (120) can be applied as a VBG (Volume Bragg Grating).

[0077] For example, the compressor (120) is provided with a laser beam (L) from the Faraday isolator (110). s ) can be compressed and output to the first polarization beam splitter (130).

[0078] The first polarization beam splitter (130) separates the laser beam (L) according to the polarization state s It can pass or reflect the ) s ) passes through, and the laser beam (L) flowing in the opposite direction s It can reflect ).

[0079] For example, the first polarization beam splitter (130) is a laser beam (L) in a horizontal direction from the Faraday isolator (110) toward the compressor (120). s ) passes through, and the laser beam (L) output from the compressor (120) s ) can be reflected to at least one solid gain medium (140).

[0080] Meanwhile, a solid-state amplification module (100') according to another embodiment of the present disclosure may further include a first quarter-wave plate (125) disposed between a compressor (120) and a polarizing beam splitter (130).

[0081] The first quarter wave plate (125) is a laser beam (L s The polarization direction of ) can be rotated 45°.

[0082] For example, the first quarter-wave plate (125) is a horizontal laser beam (L) incident on the compressor (120). s Rotate ) 45°, and the laser beam (L) output from the compressor (120) sRotate ) 45° to have a vertical direction.

[0083] A second polarization beam splitter (135) can be positioned between the first polarization beam splitter (130) and at least one solid gain medium (140), and depending on the polarization state, a laser beam (L s It can pass or reflect the ) s ) passes through, and the laser beam (L) flowing in the opposite direction s It can reflect ).

[0084] For example, the second polarization beam splitter (135) is a laser beam (L) reflected from the first polarization beam splitter (130). s ) is passed to at least one solid gain medium (140), and a laser beam (L) amplified by at least one solid gain medium (140) is passed to at least one solid gain medium (140). s It can be reflected so that ') can be output.

[0085] Meanwhile, a solid-state amplification module (100') according to another embodiment of the present disclosure may further include a second half-wave plate (133) disposed between a first polarization beam splitter (130) and a second polarization beam splitter (135).

[0086] The second half-wave plate (133) is a laser beam (L s The polarization direction of ) can be rotated 90°.

[0087] For example, the second half-wave plate (133) is a vertical laser beam (L) reflected from the first polarization beam splitter (130). s ) can be rotated in a horizontal direction. Accordingly, the second polarization beam splitter (135) can rotate a horizontal laser beam (L s ) can be passed to at least one solid gain medium (140).

[0088] The solid gain medium (140) is the laser beam (L) in a compressed state that has passed through the second polarization beam splitter (135). s ) can be amplified and output. In FIG. 2, the solid gain medium (140) is illustrated as being applied as Yb:YAG with a doping concentration of 1% to 2%, but is not limited thereto and may be applied as Nd:YVO4 or Nd:YAG, etc.

[0089] For example, the solid gain medium (140) is a pump beam (L p Exciting ions in the medium by ) a laser beam (L s It can amplify ).

[0090] The optical fiber coupler (150) pumps the beam (L) into the solid gain medium (140). p It can provide ).

[0091] For example, the optical fiber coupler (150) is a pump beam (L) emitted from a pump light source (not shown). p ) can be transferred to a solid gain medium (140).

[0092] The optical fiber coupler (150) can be formed in a shape in which a plurality of single optical fibers are woven together, and a pump beam (L) having at least one wavelength band through the plurality of single optical fibers p ) can be provided as a solid gain medium (140). In this case, a pump beam (L) having a single wavelength band. p Compared to the amplification method by ), the effect of increasing amplification efficiency can be expected.

[0093] For example, the optical fiber coupler (150) may be formed by weaving together three to seven single optical fibers. In this case, the NA of the single optical fiber may be 0.22 and the core may be 105 µm. The optical fiber coupler (150) includes a plurality of optical fibers and pump beams (L) having different wavelength bands (e.g., 969 nm and 940 nm). pIt can simultaneously transmit ) and the pump beam (L) output from such optical fiber coupler (150) p ) can have a power of 300W or more. In addition, the pump beam (L) output from the optical fiber coupler (150) p The laser beam (L) is incident on the solid gain medium (140) by adjusting the angle of incidence (e.g., 45° or more) to satisfy the total reflection condition of the solid gain medium (140). s It enables ) to be amplified efficiently.

[0094] The mirror (160) can be placed at the rear end of the solid gain medium (140).

[0095] The mirror (160) passes through the solid gain medium (140) and amplifies the laser beam (L s ) can be reflected so that it is incident back onto the solid gain medium (140) and amplified.

[0096] For example, a laser beam (L) output to the rear end after passing through a solid gain medium (140). s ) is reflected by the mirror (160) and incident again at the rear end of the solid gain medium (140), and can be amplified again while passing through the solid gain medium (140) and output at the front end of the solid gain medium (140). In this case, the solid gain medium (140) is provided with a pump beam (L) to the optical fiber coupler (150). p ) can be reused. A laser beam (L) that is amplified again by the solid gain medium (140) and output to the front of the solid gain medium (140). s The ') can be reflected by the second polarization beam splitter (135) and output to the output terminal.

[0097] Meanwhile, a solid amplification module (100') according to another embodiment of the present disclosure may further include a second quarter-wave plate (165) disposed between a solid gain medium (140) and a mirror (160).

[0098] The second quarter wave plate (165) is a laser beam (Ls The polarization direction of ) can be rotated 45°.

[0099] For example, the second quarter-wave plate (165) is a laser beam (L) output from the solid gain medium (140) and incident on the mirror (160). s Rotate ) 45° and the laser beam (L) reflected by the mirror (160) s ) is rotated 45° to have a vertical direction. In this case, the laser beam (L) re-incident on the solid gain medium (140) is rotated 45°. s ) can have a vertical direction.

[0100] Meanwhile, a solid-state amplification module (100') according to another embodiment of the present disclosure is a laser beam (L s ) or pump beam (L p A plurality of lenses (L) and a laser beam (L) for focusing or defocusing ) s ) or pump beam (L p It may further include a plurality of dichroic mirrors (DM) for reflecting ) along a specific path.

[0101] A solid-state amplification module (100') according to another embodiment of the present disclosure outputs a laser beam (Ls') amplified through at least one solid-state gain medium (140), wherein the laser beam (L) provided as a seed beam is s By arranging a compressor (120) and at least one solid gain medium (140) so as to compress and then amplify the laser beam (L) produced by the compressor (120), s The output power can be increased so that the loss of ) can be compensated by at least one solid gain medium (140). Furthermore, a solid amplification module (100') according to another embodiment of the present disclosure can increase the output power by a laser beam (L) amplified by the solid gain medium (140). s A pump beam (L) further including a mirror (160) for re-inciding ) pIn terms of enabling the reuse of ), the effect of improving the efficiency of the entire system can be expected.

[0102] FIGS. 3 to 5 are drawings showing solid gain media according to various embodiments of the present disclosure.

[0103] Referring to FIG. 3, a solid gain medium (140) according to one embodiment of the present disclosure may include an O-ring (145).

[0104] The O-ring (145) can be fixed to both ends of the solid gain medium (140) and the temperature of the solid gain medium (140) can be controlled by direct water cooling through contact with cooling water. In this embodiment, the O-ring (145) can be applied as at least one O-ring among Viton, silicon, FFKM, and Teflon.

[0105] A solid gain medium (140) according to one embodiment of the present disclosure may include a coating layer (147) made of a metal material. In this embodiment, the coating layer (147) made of a metal material may be formed by coating one of gold, silver, copper, nickel, and aluminum to a thickness of 100 nm or more.

[0106] Meanwhile, it is preferable that the solid gain medium (140) according to one embodiment of the present disclosure be coated with a metal material in a polished state to form a metal coating layer (147).

[0107] A solid gain medium (140) according to one embodiment of the present disclosure as described above is a pump beam (L p Through total internal reflection, the laser beam (L s ) amplifies the pump beam (L) by means of a metal coating layer (147). p It can enhance total reflection of the O-ring (145), and can also be expected to improve the durability of the O-ring.

[0108] Referring to FIG. 4, a solid gain medium (140') according to another embodiment of the present disclosure may further include a polyimide coating layer (148) in the solid gain medium (140) shown in FIG. 3.

[0109] In this embodiment, the polyimide coating layer (148) can be formed by coating the polyimide to a thickness of 100 nm or more.

[0110] In another embodiment of the present disclosure, the solid gain medium (140') can be expected to improve the durability of the O-ring (145) by means of the polyimide coating layer (148).

[0111] Referring to FIG. 5, a solid gain medium (140'') according to another embodiment of the present disclosure may include an O-ring (145).

[0112] The O-ring (145) can be fixed to both ends of the solid gain medium (140) and the temperature of the solid gain medium (140'') can be controlled by direct water cooling through contact with cooling water. In this embodiment, the O-ring (145) can be applied as at least one O-ring among Viton, silicon, FFKM, and Teflon.

[0113] Meanwhile, the O-ring (145) may include a metal coating layer (146). In this embodiment, the metal coating layer (146) may be formed by coating one of the metals gold, silver, copper, nickel, and aluminum to a thickness of 100 nm or more.

[0114] According to another embodiment of the present disclosure, the solid gain medium (140'') is a pump beam (L p Through total internal reflection, the laser beam (L s It amplifies the pump beam (L) due to the fact that the refractive index of water is lower than that of crystal. p It enables total reflection of the O-ring (145), and by forming a metal coating layer (146) on the O-ring (145), the effect of improving the durability of the O-ring (145) can also be expected.

[0115] FIG. 6 is a drawing showing an optical fiber coupler according to various embodiments of the present disclosure.

[0116] Referring to FIG. 6(a), an optical fiber coupler (150) according to one embodiment of the present disclosure may be formed by weaving three single optical fibers together.

[0117] At least one of the three single optical fibers is a pump beam (L) having a wavelength of 969 nm. p It transmits ), and the remaining optical fiber is a pump beam (L) having a wavelength of 940 nm. p It can transmit ). In this case, the NA of a single optical fiber is 0.22 and the core can be 105 µm.

[0118] Referring to FIG. 6(b), a fiber coupler (150') according to another embodiment of the present disclosure may be formed by weaving four single optical fibers together.

[0119] At least one of the four single optical fibers is a pump beam (L) having a wavelength of 969 nm. p It transmits ), and the remaining optical fiber is a pump beam (L) having a wavelength of 940 nm. p It can transmit ). In this case, the NA of a single optical fiber is 0.22 and the core can be 105 µm.

[0120] Figure 7 is a graph showing the power of the laser beam output from the solid-state amplification module illustrated in Figure 1.

[0121] Referring to FIG. 7, the pump beam (L) from the optical fiber coupler (150) p Output laser beam (L) according to the output power (Pump Power of combined LDs) of ) s You can check the power of ')

[0122] As can be seen in FIG. 7, a solid-state amplification module (100) according to one embodiment of the present disclosure has amplification efficiency through a plurality of single optical fibers constituting an optical fiber coupler (150), and it can be confirmed that the power of the output laser beam (Ls') increases as the number of single optical fibers constituting the optical fiber coupler (150) increases (LD1→LD3).

[0123] FIG. 8 is a drawing showing a hybrid active cooling amplification laser device according to one embodiment of the present disclosure.

[0124] Referring to FIG. 8, a hybrid active cooling amplification laser device (1) according to one embodiment of the present disclosure has a laser beam (L S1 An oscillation module (10) that emits by stretching ) and a stretched laser beam (L S2 A fiber optic amplification module (20) that first amplifies ) through at least one fiber optic gain medium and a first amplified laser beam (L S3 ) pump beam(L p It may include a solid-state amplification module (100, 100') that outputs a second amplification through ).

[0125] The oscillation module (10) is a picosecond laser beam (L) generated from a pico light source. S1 It can output by amplifying and stretching )

[0126] For example, the oscillation module (10) is a picosecond laser beam (L S1 A pico seed generating ), a picosecond laser beam (L S1 Circulator and chirp fiber Bragg grating (CFBG) that extend the pulse width of ), picosecond laser beam (L S1 A preamplifier that amplifies ) and a picosecond laser beam (L S1 It may include a pulse picker that modulates ).

[0127] The optical fiber amplification module (20) is a laser beam (L) emitted from the oscillation module (10) through at least one optical fiber gain medium. S2 ) can be amplified once and output to a solid-state amplification module (100, 100').

[0128] For example, the optical fiber amplification module (20) is a laser beam (L S2 At least one optical fiber gain medium (YB PM (Polarization-Maintaining) fiber) that amplifies ), a first-order amplified laser beam (L S3 A filter that removes noise from ) and a first-order amplified laser beam (L S3 It may include a photonic crystal optical fiber (PCF) that transmits ) to a solid-state amplification module (100, 100').

[0129] At least one of the solid amplification modules (100, 100') illustrated in FIG. 1 and FIG. 2 may be applied, and a pump beam (L) provided to the solid gain medium (140) as described above p The laser beam (L) amplified by the first amplification through total internal reflection of ) S3 It can output ) by amplifying it by a second order.

[0130] The description of the solid-state amplification module (100, 100') is replaced with that described above according to FIGS. 1 and FIGS. 2.

[0131] A hybrid active cooling amplification laser device (1) according to one embodiment of the present disclosure has a laser beam (L S1 A laser beam (L) hybridly amplified by a fiber gain medium and a solid gain medium (140) from ) S The output is '), and as described above, the arrangement features of the compressor (120) and solid gain medium (140) of the solid amplification module (100, 100') can be expected to improve amplification efficiency.

[0132] Meanwhile, the disclosed embodiments may be implemented in the form of a recording medium that stores instructions executable by a computer. The instructions may be stored in the form of program code and, when executed by a processor, may generate a program module to perform the operation of the disclosed embodiments. The recording medium may be implemented as a computer-readable recording medium.

[0133] Computer-readable recording media include all types of recording media that store instructions that can be decoded by a computer. Examples include ROM (Read Only Memory), RAM (Random Access Memory), magnetic tape, magnetic disk, flash memory, optical data storage devices, etc.

[0134] As described above, the disclosed embodiments have been explained with reference to the attached drawings. Those skilled in the art will understand that the present disclosure may be practiced in forms different from the disclosed embodiments without changing the technical spirit or essential features of the present disclosure. The disclosed embodiments are illustrative and should not be interpreted restrictively.

Claims

1. A compressor that compresses a laser beam; At least one solid gain medium for amplifying the above-mentioned compressed laser beam; and A solid-state amplification module comprising: at least one optical fiber coupler that provides a pump beam to the above-mentioned at least one solid-state gain medium, wherein the coupler comprises a plurality of optical fibers to provide the pump beam of different wavelengths.

2. In Paragraph 1, The above at least one solid gain medium is, A solid-state amplification module arranged in a multi-stage structure to sequentially amplify the compressed laser beam.

3. In Paragraph 2, A Faraday isolator that provides the laser beam using the above compressor; A pair of half-wave plates disposed at both ends of the above-mentioned Faraday isolator; A polarization beam splitter that passes the laser beam from the Faraday isolator toward the compressor and reflects the compressed laser beam emitted from the compressor toward the at least one solid gain medium; and A solid-state amplification module further comprising a quarter-wave plate disposed between the polarization beam splitter and the compressor.

4. In Paragraph 1, A solid amplification module further comprising: a mirror disposed at the rear end of the at least one solid gain medium, which reflects the laser beam that has passed through the at least one solid gain medium so that it can be incident back onto the at least one solid gain medium and amplified.

5. In Paragraph 4, A Faraday isolator that provides the laser beam using the above compressor; A pair of first half-wave plates disposed at both ends of the above-mentioned Faraday isolator; A first polarization beam splitter that passes the laser beam from the Faraday isolator toward the compressor and reflects the compressed laser beam emitted from the compressor toward the at least one solid gain medium; A first quarter-wave plate disposed between the first polarizing beam splitter and the compressor; A second polarization beam splitter that passes the compressed laser beam reflected by the first polarization beam splitter toward the at least one solid gain medium and reflects the laser beam amplified by the at least one solid gain medium so that it can be output; A second half-wave plate disposed between the first polarization beam splitter and the second polarization beam splitter; and A solid-state amplification module further comprising: a second quarter-wave plate disposed between the at least one solid-state gain medium and the mirror.

6. In Paragraph 1, A solid amplification module further comprising: an O-ring fixed to both ends of the at least one solid gain medium and controlling the temperature of the at least one solid gain medium through contact with cooling water.

7. In Paragraph 1, The above at least one solid gain medium is, Solid-state amplifier module coated with metal material.

8. In Paragraph 7, The above at least one solid gain medium is, A solid amplification module coated with the above metal material in a polished state.

9. In Paragraph 1, The above pump beam is, A solid amplification module provided to the at least one solid gain medium, wherein the angle of incidence is adjusted to satisfy the total reflection condition of the at least one solid gain medium.

10. An oscillation module that emits a laser beam; A fiber optic amplification module that first amplifies the laser beam through at least one fiber optic gain medium; and A solid-state amplification module that secondarily amplifies the firstly amplified laser beam through at least one solid-state gain medium; comprising The above solid-state amplification module is, A compressor for compressing the above-mentioned first-amplified laser beam; The at least one solid gain medium for amplifying the compressed laser beam; and A hybrid active cooling amplification laser device comprising: at least one optical fiber coupler that provides a pump beam to the above-mentioned at least one solid gain medium, wherein the coupler comprises a plurality of optical fibers to provide the pump beam of different wavelengths.

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