Laser amplification device

Abstract

The utility model discloses a laser amplification device, which comprises a first half-wave plate and a polarization beam splitter which are horizontally arranged in sequence, and a Faraday rotator, a second half-wave plate, a first laser gain medium and a dichroic mirror which are arranged along the transmission direction of the polarization beam splitter in sequence, the first half-wave plate is used for receiving the seed light and adjusting the polarization direction of the seed light to be horizontal; the polarization beam splitter transmits the seed light; the polarization direction of the seed light is rotated by 45 degrees by the Faraday rotator, and the polarization direction of the seed light is rotated by-45 degrees by the second half-wave plate; the dichroic mirror is used for receiving and transmitting the first pump light and reflecting the seed light; the first laser gain medium is used for receiving the first pump light to amplify the energy of the seed light, and after the seed light is reflected by the dichroic mirror, the seed light passes through the first laser gain medium again; wherein after the amplified seed light passes through the second half-wave plate and the Faraday rotator, the seed light is reflected by the polarization beam splitter. The scheme aims to simplify the arrangement of a laser amplification light path and improve the laser amplification effect.

Description

Technical Field

[0001] The utility model relates to the technical field of lasers, in particular to a laser amplification device. Background Art

[0002] Lasers are widely used in modern industry and scientific research, especially high-power lasers are in growing demand in the fields of precision machining and scientific research. The core component of a high-power laser is a laser amplifier. An invention patent application with application number CN201880025715.9 in the published Chinese invention patent application database discloses a laser amplifier device, which includes a seed beam light source, a seed beam adjustment device, and a solid-state amplifier 140. The specific solid-state amplifier 140 has similar functions to the laser amplifier device provided by the technical solution of the present application. More specifically, this public document discloses that the solid-state amplifier 140 may include a laser medium 145, a first pump beam light source 141, a first pump beam reflector 147, a plurality of dichroic mirrors, and a plurality of mirrors, etc. As Figure 1 As shown, the solid-state amplifier 140 described in this disclosed technical document has a complex optical path configuration, making optical path adjustment difficult, and the amplification process is easily interfered with by external factors. Consequently, existing laser amplification devices often suffer from issues such as insufficient gain, complex structure, and poor stability. Therefore, it is particularly important to provide a laser amplification device with a simple structure, good amplification effect, and high stability. Utility Model Content

[0003] The purpose of the utility model is to provide a laser amplification device, aiming to simplify the optical path setting and improve the laser amplification effect.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] A laser amplification device, comprising

[0006] A first half-wave plate and a polarization beam splitter are sequentially arranged horizontally and spaced apart from each other, wherein the first half-wave plate is used to receive the seed light and can adjust the polarization direction of the seed light to be horizontal; and the polarization beam splitter transmits the seed light;

[0007] and a Faraday rotator, a second half-wave plate, a first laser gain medium, and a dichroic mirror, which are sequentially arranged along the transmission direction of the polarization beam splitter; the Faraday rotator is incident on the seed light in the forward direction and is capable of rotating the polarization direction of the seed light by 45°; the second half-wave plate rotates the polarization direction of the seed light again by -45° to restore the polarization direction of the seed light to be horizontal; the first laser gain medium is used to amplify the energy of the seed light; the dichroic mirror is used to receive and transmit the first pump light, and reflect the seed light in the incident direction of the seed light, so that the seed light passes through the first laser gain medium again;

[0008] Among them, after amplification, the seed light passes through the second half-wave plate to rotate the polarization direction of the seed light by -45° again; the Faraday rotator injects the seed light in the opposite direction and rotates the polarization direction of the seed light by -45°, so that the polarization direction of the seed light is adjusted to vertical; the polarization beam splitter reflects the seed light to reflect the amplified seed light with a vertical polarization direction.

[0009] In one embodiment, a first focusing lens is further arranged between the second half-wave plate and the first laser gain medium;

[0010] The first focusing lens is used to focus the seed beam onto the first laser gain medium.

[0011] In one embodiment, it further comprises a first 45° reflecting mirror and a second laser gain medium which are horizontally spaced apart in sequence;

[0012] The first 45° reflector is used to reflect the seed light reflected by the polarization beam splitter and transmit the second pump light incident in the horizontal direction;

[0013] The second laser gain medium receives the seed light and the second pump light in the same direction, so as to secondary amplify the seed light.

[0014] In one embodiment, the device further comprises a third laser gain medium and a second 45° reflecting mirror arranged in sequence and horizontally spaced apart;

[0015] The second 45° reflector is used to reflect the seed light and transmit the third pump light incident in the horizontal direction;

[0016] The second laser gain medium receives the seed light and the third pump light emitted by the laser gain medium in reverse order to amplify the seed light three times.

[0017] In one embodiment, the system further includes a third 45° reflector and an acousto-optic Q switch disposed at intervals;

[0018] The third 45° reflector is used to reflect the seed light reflected by the second 45° reflector, and the acousto-optic Q switch is used to modulate the seed light.

[0019] In one embodiment, a second focusing lens is further provided between the polarization beam splitter and the first 45° reflecting mirror, and the second focusing lens is used to focus the seed beam onto the second laser gain medium;

[0020] A third focusing lens is further provided between the second laser gain medium and the third laser gain medium. The third focusing lens is used to focus the seed beam onto the third laser gain medium.

[0021] In one embodiment, the first 45° reflecting mirror, the second laser gain medium, the third focusing lens, the third laser gain medium and the second 45° reflecting mirror are horizontally arranged in sequence.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The technical solution of the utility model is to sequentially arrange a first half-wave plate and a polarization beam splitter at intervals horizontally, and sequentially arrange a Faraday rotator, a second half-wave plate, a first laser gain medium and a dichroic mirror at intervals along the transmission direction of the polarization beam splitter; Figure 1 As shown, specifically, the components can be arranged collinearly or horizontally. Therefore, compared with the prior art, the technical solution of the utility model simplifies the setting of the amplification light path, and the horizontal arrangement of the optical components facilitates the adjustment of the light path to optimize the light beam amplification effect. In a specific embodiment, after the first half-wave plate receives the seed light, the first half-wave plate can adjust the polarization direction of the seed light to be horizontal. After the polarization beam splitter transmits the seed light; the seed light is incident on the Faraday rotator, and the Faraday rotator is controlled to rotate the polarization direction of the seed light by 45°, and then the second half-wave plate rotates the polarization direction of the seed light by -45° to restore the polarization direction of the seed light to be horizontal. The dichroic mirror is used to receive and transmit the first pump light in the opposite direction of the seed light's incidence, and to reflect the seed light in the direction of the seed light's incidence. The first laser gain medium is used to receive the seed light and the first pump light, so that the seed light's energy is enhanced by the gain effect of the first pump light. After the seed light is reflected by the dichroic mirror, the seed light passes through the first laser gain medium again, and the energy of the seed light is further amplified, thereby achieving laser amplification and improving the amplification effect of the seed light under the action of the single first pump light. Furthermore, the amplified seed light passes through the second half-wave plate, and the polarization direction of the seed light is rotated by -45° again. The seed light is then injected into the Faraday rotator in the opposite direction, and the polarization direction of the seed light is rotated by -45° again, so that the polarization direction of the seed light is adjusted to vertical. The polarization beam splitter can reflect the amplified seed light with a vertical polarization direction, thereby obtaining an amplified laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] The structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in this specification so as to facilitate understanding and reading by those familiar with this technology. They are not intended to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modifications, changes in proportional relationships, or adjustments in size, without affecting the efficacy and objectives that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed in the present invention.

[0026] Figure 1 It is a structural diagram of a solid-state amplifier in the prior art;

[0027] Figure 2 This is a schematic structural diagram of an embodiment of the laser amplification device of the present utility model;

[0028] Illustration: 10. Laser amplification device;

[0029] H1, first half-wave plate; H2, second half-wave plate;

[0030] P1, polarizing beam splitter; F1, Faraday rotator; DM, dichroic mirror; Q1, acousto-optic Q switch;

[0031] L1, first focusing lens; L2, second focusing lens; L3, third focusing lens;

[0032] M1, first 45° reflector; M2, second 45° reflector; M3, third 45° reflector

[0033] G1, first laser gain medium; G2, second laser gain medium; G3, third laser gain medium;

[0034] S1, seed light; PL1, first pump light; PL2, second pump light; PL3, third pump light. DETAILED DESCRIPTION

[0035] In order to make the technical objectives, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally located component.

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0038] In the prior art, Figure 1 The optical path of the solid-state amplifier 140 shown is complex, the optical path adjustment is difficult, and the amplification process is easily disturbed by external factors.

[0039] An embodiment of the present utility model provides a laser amplification device 10 .

[0040] See also Figure 2 The laser amplification device 10 includes a first half-wave plate H1 and a polarization beam splitter P1 that are sequentially arranged horizontally at intervals, and a Faraday rotator F1, a second half-wave plate H2, a first laser gain medium G1, and a dichroic mirror DM that are sequentially arranged at intervals along the transmission direction of the polarization beam splitter P1;

[0041] The first half-wave plate H1 is used to receive the seed light S1 and adjust the polarization direction of the seed light S1 to be horizontal; the polarization beam splitter P1 transmits the seed light S1;

[0042] The Faraday rotator F1 receives the incident seed light S1 in the forward direction and is able to rotate the polarization direction of the seed light S1 by 45°. The second half-wave plate H2 rotates the polarization direction of the seed light S1 again by -45° to restore the polarization direction of the seed light S1 to the horizontal. The first laser gain medium G1 is used to amplify the energy of the seed light S1. The dichroic mirror DM is used to receive and transmit the first pump light PL1, and reflect the seed light S1 in the incident direction of the seed light S1, so that the seed light S1 passes through the first laser gain medium G1 again.

[0043] Among them, the amplified seed light S1 passes through the second half-wave plate H2 to rotate the polarization direction of the seed light S1 by -45° again; the Faraday rotator F1 injects the seed light S1 in the opposite direction and rotates the polarization direction of the seed light S1 by -45°, so that the polarization direction of the seed light S1 is adjusted to vertical; the polarization beam splitter P1 reflects the seed light S1 to reflect the amplified seed light S1 with a vertical polarization direction.

[0044] It can be understood that the technical solution of the present invention is to sequentially arrange the first half-wave plate H1 and the polarization beam splitter P1 at intervals in the horizontal direction, and sequentially arrange the Faraday rotator F1, the second half-wave plate H2, the first laser gain medium G1 and the dichroic mirror DM at intervals along the transmission direction of the polarization beam splitter P1; Figure 1As shown, specifically, the various components can be arranged collinearly or horizontally. Therefore, compared with the prior art, the technical solution of the present invention simplifies the setting of the amplification optical path, and the horizontal arrangement of the optical components facilitates the adjustment of the optical path to optimize the beam amplification effect. In a specific embodiment, after the first half-wave plate H1 receives the seed light S1, the first half-wave plate H1 can adjust the polarization direction of the seed light S1 to be horizontal. After the polarization beam splitter P1 transmits the seed light S1; the seed light S1 is incident on the Faraday rotator F1, and the Faraday rotator F1 is controlled to rotate the polarization direction of the seed light S1 by 45°. Then the second half-wave plate H2 rotates the polarization direction of the seed light S1 again by -45° to restore the polarization direction of the seed light S1 to be horizontal. The dichroic mirror DM is used to receive and transmit the first pump light PL1 in the opposite direction of the incident direction of the seed light S1, and to reflect the seed light S1 in the direction of the incident direction of the seed light. The first laser gain medium G1 is used to receive the first pump light PL1 to enhance the energy of the seed light S1. After the dichroic mirror DM reflects the seed light S1, the seed light S1 passes through the first laser gain medium G1 again, and the energy of the seed light S1 is further amplified, thereby achieving laser amplification and improving the amplification effect of the seed light S1 under the action of the single first pump light. Furthermore, the amplified seed light S1 passes through the second half-wave plate H2, which rotates the polarization direction of the seed light S1 by -45° again. The Faraday rotator F1 injects the seed light S1 in the opposite direction and rotates the polarization direction of the seed light S1 by -45° again, adjusting the polarization direction of the seed light S1 to vertical. The polarization beam splitter P1 reflects the seed light S1 and reflects the amplified seed light S1 with a vertical polarization direction, thereby obtaining the amplified laser.

[0045] It should also be noted that, along the incident direction of the seed light, after the seed light S1 passes through the polarization beam splitter P1, it passes through the Faraday rotator F1, which can rotate the polarization direction of the seed light S1 by 45°. Then, the second half-wave plate H2 rotates the polarization direction of the seed light S1 by -45°. Along the return path of the seed light, the amplified seed light S1 passes through the second half-wave plate H2, which again rotates the polarization direction of the seed light S1 by -45°. The Faraday rotator F1 then injects the seed light S1 in the opposite direction and rotates the polarization direction of the seed light S1 by -45° again, so that the polarization direction of the seed light S1 is adjusted to vertical. The terms "rotate 45°" and "rotate -45°" are used only to indicate that the polarization directions represented by the two are opposite, and the polarization angles are both 45°.

[0046] like Figure 2 As shown, in this embodiment, in the incident path of the seed light S1, the Faraday rotator F1 rotates the polarization direction of the seed light S1 by 45° clockwise, and the second half-wave plate H2 can rotate the polarization direction of the seed light S1 by 45° counterclockwise, thereby restoring the polarization direction of the seed light to the horizontal direction.

[0047] On the return path of the seed light S1, the second half-wave plate H2 rotates the polarization direction of the seed light S1 by 45° counterclockwise. Due to its inherent working principle, the Faraday rotator F1 can rotate the polarization direction of the seed light S1 by 45° counterclockwise, thereby adjusting the polarization direction of the seed light from horizontal to vertical.

[0048] Therefore, the Faraday rotator F1 is mainly provided to adjust the polarization direction of the seed light in the return path, so that when the seed light S1 passes through the polarization beam splitter P1 in the reverse direction, the polarization beam splitter P1 is used to emit the amplified seed light S1 with a vertical polarization direction.

[0049] It can also be understood that the second half-wave plate H2 is mainly provided to restore the polarization direction of the seed light S1 to be horizontal, thereby preparing for the subsequent amplification process of the seed light S1.

[0050] It should also be understood that the seed light S1 is a pulsed seed laser. In a specific embodiment, the seed light S1 is a picosecond pulsed laser.

[0051] It should also be emphasized that in this embodiment, on the basis of simplifying the optical path design, the polarization beam splitter P1 can split or combine the light beams according to their polarization states, so that they transmit horizontally polarized light and reflect vertically polarized light, thereby guiding the light into different beam paths.

[0052] It should also be noted that the first laser gain medium G1 provides energy through the first pump light PL1, so that the energy of the seed light S1 is gained, so that the light beam can be further amplified each time it passes through the first laser gain medium G1.

[0053] It should also be noted that the dichroic mirror DM is used to reflect the seed light S1 of a specific wavelength and transmit pump light of different wavelengths to ensure accurate light beam transmission and energy coupling.

[0054] In a specific embodiment, Figure 2 As shown, a first focusing lens L1 is interposed between the second half-wave plate H2 and the first laser gain medium G1. The first focusing lens L1 is used to focus the seed light S1 beam onto the first laser gain medium G1. This improves the energy coupling of the light beam in the first laser gain medium G1 and enhances the amplification efficiency.

[0055] In a further embodiment, the laser amplifying device 10 further includes a first 45° reflecting mirror M1 and a second laser gain medium G2 that are horizontally spaced apart in sequence;

[0056] The first 45° reflector M1 reflects the seed light S1 reflected by the polarization beam splitter P1 and transmits the second pump light PL2 incident in the horizontal direction; the second laser gain medium G2 receives the seed light S1 and the second pump light PL2 in the same direction to amplify the seed light S1 twice.

[0057] It can be understood that the arrangement of the 45° reflecting mirror and the second laser gain medium G2 further achieves energy amplification of the seed laser.

[0058] On the basis of the above embodiment, the laser amplifying device 10 further includes a third laser gain medium G3 and a second 45° reflecting mirror M2 which are horizontally spaced in sequence;

[0059] The second 45° reflector M2 reflects the seed light S1 and transmits the third pump light PL3 ​​incident horizontally. The second laser gain medium G2 receives the seed light S1 and the third pump light PL3 ​​emitted by the laser gain medium in reverse, amplifying the seed light S1 three times and further amplifying the energy of the seed laser.

[0060] like Figure 2 As shown, in a specific embodiment, the laser amplification device 10 also includes a third 45° reflector M3 and an acousto-optic Q switch Q1 arranged at intervals; the third 45° reflector M3 is used to reflect the seed light S1 amplified by the third laser gain medium and reflected by the second 45° reflector M2, and the acousto-optic Q switch Q1 is used to modulate the amplified seed light S1.

[0061] It is understood that the third 45° reflector M3 is primarily used to adjust the propagation direction of seed light S1. The acousto-optic Q switch Q1 can achieve on-off control of the seed light S1 beam through diffraction modulation, ensuring that the laser beam is blocked or allowed to pass when needed, ultimately achieving modulation of the output laser.

[0062] In a specific embodiment, a second focusing lens L2 is further provided between the polarization beam splitter P1 and the first 45° reflecting mirror M1, and the second focusing lens L2 is used to focus the seed light S1 beam onto the second laser gain medium G2;

[0063] A third focusing lens L3 is further provided between the second laser gain medium G2 and the third laser gain medium G3 . The third focusing lens L3 is used to focus the seed light S1 beam onto the third laser gain medium G3 .

[0064] The configuration of the second focusing lens L2 and the third focusing lens L3 can both optimize the light beam and improve the amplification efficiency of the seed light S1.

[0065] Furthermore, the first 45° reflecting mirror M1, the second laser gain medium G2, the third focusing lens L3, the third laser gain medium G3 and the second 45° reflecting mirror M2 are horizontally arranged in sequence.

[0066] It is understandable that the optical components arranged along the horizontal direction simplify the arrangement of the optical path, facilitate the adjustment and optimization of the optical path, and thus indirectly improve the amplification effect of the laser.

[0067] The working principle of the technical solution of this utility model is as follows:

[0068] A picosecond seed light source is used to generate pulsed light with stable average power, namely seed light S1. The beam passes through the first half-wave plate, which adjusts its polarization to a horizontal direction to improve the efficiency of seed light S1's transmission through the polarization beam splitter. After passing through the polarization beam splitter P1, seed light S1 enters the Faraday rotator F1, rotating its polarization 45° clockwise. The beam then passes through the second half-wave plate, rotating its polarization 45° counterclockwise, restoring horizontal polarization. The beam then passes through the first focusing lens L1 and is focused into the first laser gain medium G1. During the first amplification process, seed light S1 is reflected by the dichroic mirror DM into the first laser gain medium G1. Under the action of the first pump light PL1, the first laser gain medium G1 provides initial gain for seed light S1, effectively amplifying its power. The double-pass amplified beam is then polarized by the polarization beam splitter P1, achieving high-power laser output.

[0069] During the second amplification process, the light coming out of the polarization beam splitter P1 passes through the second focusing lens L2 and is focused into the second laser gain medium G2; under the action of the second pump light PL2, the light beam is amplified for the second time.

[0070] During the third amplification process, the light beam coming out of the second laser gain medium G2 passes through the third focusing lens L3 and is focused into the third laser gain medium; under the action of the third pump light PL3, the third amplification of the light beam is achieved.

[0071] Furthermore, the amplified light beam is reflected by the second 45° reflector M2 and the third 45° reflector M3 and enters the acousto-optic Q switch. The acousto-optic Q switch controls the diffraction of the laser beam to realize the switching and final output of the laser.

[0072] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser amplification device, characterized in that: include A first half-wave plate and a polarization beam splitter are sequentially arranged horizontally and spaced apart from each other, wherein the first half-wave plate is used to receive the seed light and can adjust the polarization direction of the seed light to be horizontal; and the polarization beam splitter transmits the seed light; and a Faraday rotator, a second half-wave plate, a first laser gain medium, and a dichroic mirror, which are sequentially arranged along the transmission direction of the polarization beam splitter; the Faraday rotator is incident on the seed light in the forward direction and is capable of rotating the polarization direction of the seed light by 45°; the second half-wave plate rotates the polarization direction of the seed light again by -45° to restore the polarization direction of the seed light to be horizontal; the first laser gain medium is used to amplify the energy of the seed light; the dichroic mirror is used to receive and transmit the first pump light, and reflect the seed light in the incident direction of the seed light, so that the seed light passes through the first laser gain medium again; Among them, after amplification, the seed light passes through the second half-wave plate to rotate the polarization direction of the seed light by -45° again; the Faraday rotator injects the seed light in the opposite direction and rotates the polarization direction of the seed light by -45°, so that the polarization direction of the seed light is adjusted to vertical; the polarization beam splitter reflects the seed light to reflect the amplified seed light with a vertical polarization direction.

2. The laser amplification device according to claim 1, wherein: A first focusing lens is further arranged between the second half-wave plate and the first laser gain medium; The first focusing lens is used to focus the seed beam onto the first laser gain medium.

3. The laser amplification device according to claim 1, wherein: It also includes a first 45° reflecting mirror and a second laser gain medium that are horizontally spaced in sequence; The first 45° reflector is used to reflect the seed light reflected by the polarization beam splitter and transmit the second pump light incident in the horizontal direction; The second laser gain medium receives the seed light and the second pump light in the same direction, so as to secondary amplify the seed light.

4. The laser amplification device according to claim 3, wherein: The invention also includes horizontally arranging a third laser gain medium and a second 45° reflecting mirror in sequence; The second 45° reflector is used to reflect the seed light and transmit the third pump light incident in the horizontal direction; The second laser gain medium receives the seed light and the third pump light emitted by the laser gain medium in reverse order to amplify the seed light three times.

5. The laser amplification device according to claim 4, wherein: Also included are a third 45° reflector and an acoustic-optical Q switch, which are spaced apart; The third 45° reflector is used to reflect the seed light that is sequentially amplified by the third laser gain medium and reflected by the second 45° reflector, and the acousto-optic Q switch is used to modulate the amplified seed light.

6. The laser amplification device according to claim 4, wherein: A second focusing lens is further provided between the polarization beam splitter and the first 45° reflecting mirror, and the second focusing lens is used to focus the seed beam onto the second laser gain medium; A third focusing lens is further provided between the second laser gain medium and the third laser gain medium. The third focusing lens is used to focus the seed beam onto the third laser gain medium.

7. The laser amplification device according to claim 6, wherein: The first 45° reflecting mirror, the second laser gain medium, the third focusing lens, the third laser gain medium and the second 45° reflecting mirror are arranged horizontally in sequence.

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