Laser device

Abstract

The invention discloses a laser, and the laser comprises a light-emitting chip, a first dielectric film is disposed on a first side surface of the light-emitting chip, and the light-emitting chip is used for emitting pump light towards a first direction; a third dielectric film is arranged on the third side face, facing the light-emitting chip, of the laser gain medium, a fourth dielectric film is arranged on the fourth side face, deviating from the light-emitting chip, of the laser gain medium, and the laser gain medium is used for receiving the pump light and emitting fundamental frequency light in the first direction under the trigger action of the pump light; wherein the first dielectric film has pump light reflection characteristics, the third dielectric film has pump light anti-reflection and fundamental frequency light reflection characteristics, and the fourth dielectric film has pump light reflection characteristics, so that a first resonant cavity for pump light reciprocating reflection oscillation is formed between the first dielectric film and the fourth dielectric film. According to the laser, the length of the laser gain medium is reduced, and the power density of the pump light in the laser gain medium and the conversion efficiency of the laser are improved.

Description

Technical Field

[0001] The present application relates to the field of laser technology, and in particular to a laser. Background Art

[0002] In recent years, lasers have been widely used in various fields such as military, civilian, biomedicine, industry and scientific research due to their good directionality, coherence and high brightness.

[0003] Currently, end-pumped all-solid-state lasers generally use semiconductor lasers as pump sources. Semiconductor lasers and end-pumped all-solid-state lasers each have an independent laser resonant cavity, and a coupling lens assembly is usually used to couple the pump light emitted by the semiconductor laser into the solid-state laser resonant cavity. The pump light source is then passed through the pumped laser crystal once to trigger the laser output. As a result, the length of the laser crystal cannot be reduced any further, and the conversion efficiency cannot be improved any further. This also limits the reduction of the overall length of the laser resonant cavity and the miniaturization of the laser. Summary of the invention

[0004] The present application provides a laser that can solve the problems in the prior art of reducing the overall length of the laser resonant cavity, limiting the miniaturization of the laser, and causing low laser conversion efficiency.

[0005] To solve the above technical problems, the present application adopts a technical solution: providing a laser, wherein the laser includes: a light-emitting chip, a first dielectric film is provided on a first side surface of the light-emitting chip, and the light-emitting chip is used to emit pump light in a first direction; a laser gain medium is provided in the first direction of the light-emitting chip, a third dielectric film is provided on a third side surface of the laser gain medium facing the light-emitting chip, and a fourth dielectric film is provided on a fourth side surface of the laser gain medium facing away from the light-emitting chip, and the laser gain medium is used to receive pump light and emit fundamental frequency light in the first direction when triggered by the pump light; wherein the first side surface faces away from the laser gain medium, the first dielectric film has pump light reflection characteristics, the third dielectric film has pump light anti-reflection and fundamental frequency light reflection characteristics, and the fourth dielectric film has pump light reflection characteristics, so as to form a first resonant cavity between the first dielectric film and the fourth dielectric film, in which the pump light reciprocates and oscillates.

[0006] The fourth dielectric film also has a partial reflection characteristic of the fundamental frequency light, so as to form a second resonant cavity between the third dielectric film and the fourth dielectric film, in which a part of the fundamental frequency light reciprocates and oscillates, and another part of the fundamental frequency light is transmitted in the first direction.

[0007] Among them, the laser further includes a laser output mirror, which is arranged in the first direction of the laser gain medium. A fifth dielectric film is provided on the fifth side of the laser output mirror facing the laser gain medium. The fifth dielectric film has the characteristic of partially reflecting the fundamental frequency light, so as to form a second resonant cavity in which the fundamental frequency light partially reciprocates and reflects between the third dielectric film and the fifth dielectric film, and another part of the fundamental frequency light is transmitted in the first direction.

[0008] Among them, a sixth dielectric film is provided on the sixth side of the laser output mirror facing away from the laser gain medium. The sixth dielectric film has the characteristic of increasing the transmittance of the fundamental frequency light.

[0009] Among them, the laser further includes a frequency conversion device and a laser output mirror. The frequency converter and the laser output mirror are sequentially arranged in the first direction of the laser gain medium. The frequency conversion device is used to receive the fundamental frequency light sent by the laser gain medium, convert the fundamental frequency light into frequency-converted light, and then emit it to the laser output mirror in the first direction. Among them, a fifth dielectric film is provided on the fifth side of the laser output mirror facing the laser gain medium. The fifth dielectric film has the characteristics of reflecting the fundamental frequency light and increasing the transmittance of the frequency-converted light, so as to form a third resonant cavity in which the fundamental frequency light reciprocates and reflects between the third dielectric film and the fifth dielectric film.

[0010] Among them, the characteristic of partially reflecting the fundamental frequency light is to reflect 30%-99.5% of the fundamental frequency light.

[0011] Among them, the laser further includes a coupling focusing mirror, which is arranged between the light-emitting chip and the laser gain medium, and the center lines of the light-emitting chip, the coupling focusing mirror, and the laser gain medium are located on the same straight line and parallel to the first direction.

[0012] Among them, a second dielectric film is provided on the second side of the light-emitting chip facing the laser gain medium. The second dielectric film has the characteristic of increasing the transmittance of the pump light.

[0013] Among them, the first side is parallel to the fourth side; and / or, the third side is parallel to the fourth side.

[0014] Among them, the first side is in the shape of a first partial spherical surface, and the center of the first partial spherical surface faces the laser gain medium and is located on the same straight line as the center line of the laser gain medium, and the straight line is parallel to the first direction; and / or, the third side is in the shape of a second partial spherical surface, and the center of the second partial spherical surface faces away from the light-emitting chip and is located on the same straight line as the center line of the light-emitting chip; and / or, the fourth side is in the shape of a third partial spherical surface, and the center of the third partial spherical surface faces the light-emitting chip and is located on the same straight line as the center line of the light-emitting chip.

[0015] The beneficial effects of the present application are as follows: different from the prior art, the first side surface of the light-emitting chip in the laser provided by the present application is provided with a first dielectric film, the light-emitting chip is used to emit pump light in a first direction, the laser gain medium is provided in the first direction of the light-emitting chip, a third dielectric film is provided on the third side surface of the laser gain medium facing the light-emitting chip, a fourth dielectric film is provided on the fourth side surface of the laser gain medium facing away from the light-emitting chip, the laser gain medium is used to receive pump light, and is triggered by the pump light to generate fluorescence with a wavelength of fundamental frequency light, and emit the fundamental frequency light in the first direction, wherein the first dielectric film has a pump light reflection characteristic, and the third dielectric film has The fourth dielectric film has pump light reflection characteristics, so that a first resonant cavity in which the pump light reciprocally reflects and oscillates can be formed between the first dielectric film and the fourth dielectric film, and a portion of the first resonant cavity is composited and shared with the laser gain medium, thereby effectively reducing the volume of the laser and improving the stability of the laser. The laser gain medium located in the first resonant cavity converts the reciprocally reflected and oscillating pump light into fundamental frequency light, effectively increasing the power density of the pump light in the laser gain medium, thereby improving the conversion efficiency of the pump light into fundamental frequency light, and effectively reducing the length of the laser gain medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of the first embodiment of the laser of the present application;

[0017] Figure 2 This is a schematic structural diagram of a second embodiment of the laser of the present application;

[0018] Figure 3 This is a schematic structural diagram of a third embodiment of the laser of the present application;

[0019] Figure 4 It is a structural diagram of the fourth embodiment of the laser of the present application. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0021] The terms "first", "second", and "third" in this application are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of this application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined. In the embodiments of this application, all directional indications (such as up, down, left, right, front, back...) are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, then the directional indication also changes accordingly. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0022] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0023] The following describes this application in detail with reference to the drawings and embodiments.

[0024] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the first embodiment of the laser of this application. In this embodiment, the laser 10 specifically includes: a light-emitting chip 11 and a laser gain medium 12.

[0025] Among them, a laser 10 provided in this application specifically uses the light-emitting chip 11 as a pump source to emit pump light toward the laser gain medium 12, and the laser gain medium 12 is excited by the pump light and converted into fundamental frequency light to be used as laser in any reasonable application scenarios such as laser marking, laser ranging, lidar, etc., so as to be able to play an important role in various fields such as military, civilian, biomedical, industrial, and scientific research.

[0026] Specifically, the light-emitting chip 11 has opposite first and second sides. The first side faces away from the laser gain medium 12, and a first dielectric film 111 is provided on the first side. The light-emitting chip 11 is specifically used to generate pump light under electrical excitation and emit pump light in the first direction X.

[0027] It should be noted that the light-emitting chip 11 emits pump light in the form of a Gaussian beam on the side facing the laser gain medium 12. That is, the emission of pump light, fundamental frequency light, or frequency-converted light in the first direction X mentioned in this article refers to the emission in the form of a Gaussian beam, rather than in the form of parallel light. And only the fundamental frequency light within the acceptance angle of the frequency conversion device in the propagation direction can be converted into frequency-converted light. The first direction X can be specifically understood as the extension direction of the center line of the emitted light, which will not be elaborated further below.

[0028] Among them, usually, for the fundamental mode radiation field emitted by the laser resonator, the amplitude distribution of its cross-section follows the Gaussian function, so it is called Gaussian beam.

[0029] Furthermore, the laser gain medium 12 has opposite third and fourth sides. The fourth side faces away from the light-emitting chip 11. The laser gain medium 12 is arranged in the first direction X of the light-emitting chip 11, and specifically can be in contact with the second side of the light-emitting chip 11 or can be spaced apart from the light-emitting chip 11. The laser gain medium 12 is specifically used to receive the pump light emitted by the light-emitting chip 11, and is excited by the pump light to generate fluorescence with a wavelength of fundamental frequency light, so as to emit fundamental frequency light in the first direction X, which is used as the laser in any reasonable application scenarios such as laser marking, laser ranging, and lidar.

[0030] And a third dielectric film 121 is also provided on the third side of the laser gain medium 12 facing the light-emitting chip 11, and a fourth dielectric film 122 is provided on the fourth side of the laser gain medium 12 facing away from the light-emitting chip 11.

[0031] Among them, the first dielectric film 111 has the characteristic of reflecting pump light, the third dielectric film 121 has the characteristics of increasing the transmission of pump light and reflecting fundamental frequency light, and the fourth dielectric film 122 has the characteristic of reflecting pump light.

[0032] It should be noted that the characteristic of reflecting pump light specifically refers to the characteristic of being able to block the transmission of pump light and reflect at least most of the pump light in the opposite direction of the irradiation direction; while the characteristics of increasing the transmission of pump light and reflecting fundamental frequency light refer to the characteristics of simultaneously improving the transmission efficiency of pump light and reflecting at least most of the fundamental frequency light in the opposite direction of the irradiation direction. Therefore, the first dielectric film 111 and the fourth dielectric film 122 can be specifically understood as high-reflection films for pump light, and the third dielectric film 121 can be understood as a high-reflection film for increasing the transmission of pump light and reflecting fundamental frequency light, and specifically can be a multi-layer dielectric film, that is, a multi-layer dielectric film with the two characteristics of increasing the transmission of pump light and reflecting fundamental frequency light obtained by alternately laminating two dielectric films with corresponding different frequency characteristics.

[0033] It can be seen from this that when the light-emitting chip 11 emits pump light towards the laser gain medium 12 along the first direction X, the pump light can pass through the third dielectric film 121 and shoot towards the fourth dielectric film 122, so that the laser gain medium 12 can excite fluorescence with a fundamental frequency wavelength to emit fundamental frequency light towards the first direction X. The pump light will be reflected by the fourth dielectric film 122 and pass through the third dielectric film 121 again towards the opposite direction of the first direction X, so as to shoot towards the first dielectric film 111. After being reflected by the first dielectric film 111, it passes through the third dielectric film 121 towards the first direction X again and shoots towards the fourth dielectric film 122, so as to excite the laser gain medium 12 again to generate fluorescence with a fundamental frequency wavelength and emit fundamental frequency light towards the first direction X. This reciprocating reflection and oscillation continues until the pump light decays, so that a first resonant cavity for the reciprocating reflection and oscillation of the pump light can be formed between the first dielectric film 111 and the fourth dielectric film 122.

[0034] It can be understood that during the propagation and oscillation process of the pump light between the first dielectric film 111 and the fourth dielectric film 122, it passes through the laser gain medium 12 multiple times to excite the laser gain medium 12 to generate fluorescence with a fundamental frequency wavelength and propagate the fundamental frequency light towards the first direction X and its opposite direction. During the propagation and oscillation process between the third dielectric film 111 and the fourth dielectric film 122, it passes through the laser gain medium 12 multiple times, so that it can be amplified by the laser gain medium 12 and partially output through the fourth dielectric film 122.

[0035] In the above solution, by arranging the laser gain medium 12 in the first resonant cavity where the pump light reciprocates and oscillates, that is, by compounding and sharing a part of the first resonant cavity with the laser gain medium 12, the pump light can pass through the laser gain medium 12 repeatedly, and repeatedly stimulate and trigger the laser gain medium 12 to generate fluorescence with a fundamental frequency wavelength and amplify the fundamental frequency light. Thus, through the reciprocating reflection and oscillation of the pump light, the power density of the pump light in the first resonant cavity can be effectively increased to improve the conversion efficiency of converting the pump light into fundamental frequency light, and the length of the laser gain medium 12 can be effectively reduced, and the light-emitting chip 11 and the laser gain medium 12 can be arranged more compactly, so as to effectively reduce the overall volume and length of the laser 10 and improve the stability of the laser 10.

[0036] In one embodiment, the fourth dielectric film 122 on the fourth side surface of the laser gain medium 12 specifically further has the characteristic of partially reflecting the fundamental frequency light, that is, the fourth dielectric film 122 is specifically a film with high reflection for pump light and partial reflection for fundamental frequency light, so as to be able to reflect at least most of the pump light irradiated onto the fourth dielectric film 122, and reflect a part of the fundamental frequency light irradiated onto the fourth dielectric film 122, and allow the other part of the fundamental frequency light to transmit, so that when the laser gain medium 12 emits the fundamental frequency light toward the fourth dielectric film 122 along the first direction X, a part of the fundamental frequency light can be reflected toward the third dielectric film 121 in the opposite direction of the first direction X, and after being reflected by the third dielectric film 121, it irradiates onto the fourth dielectric film 122 again along the first direction X, so as to reciprocally reflect and oscillate between the third dielectric film 121 and the fourth dielectric film 122, and each time the other part of the fundamental frequency light irradiated onto the fourth dielectric film 122 will transmit through the fourth dielectric film 122 and continue to emit along the first direction X, so as to form a partial reciprocating reflection oscillation of the fundamental frequency light between the third dielectric film 121 and the fourth dielectric film 122 along the second reciprocating path b, and another part of the fundamental frequency light transmits toward the first direction X to form a second resonant cavity, so as to be able to effectively increase the emission power of the fundamental frequency light by means of this second resonant cavity.

[0037] It can be understood that this second resonant cavity specifically corresponds to the second reciprocating path b.

[0038] Optionally, this characteristic of partially reflecting the fundamental frequency light can specifically be to reflect 30%-99.5% of the fundamental frequency light, that is, 30%-99.55% of the fundamental frequency light irradiated onto the fourth dielectric film 122 each time will be reflected toward the third dielectric film 121, and the other part of the fundamental frequency light will transmit through the fourth dielectric film 122 to continue to emit along the first direction X.

[0039] In one embodiment, a second dielectric film 112 is specifically further provided on the second side surface of the light-emitting chip 11 facing the laser gain medium 12, and this second dielectric film 112 has the characteristic of increasing the transmittance of the pump light, so as to be able to effectively improve the transmission efficiency of the pump light when the light-emitting chip 11 emits the pump light toward the laser gain medium 12 along the first direction X.

[0040] Optionally, the first side surface of the light-emitting chip 11 and the fourth side surface of the laser gain medium 12 are specifically parallel to each other, so that the first resonant cavity formed by the first dielectric film 111 provided on the first side surface and the fourth dielectric film 122 provided on the fourth side surface can more efficiently form a reciprocating reflection effect on the pump light.

[0041] Optionally, the third side surface of the laser gain medium 12 and its fourth side surface are also correspondingly parallel to each other, so that the second resonant cavity formed by the third dielectric film 121 provided on the third side surface and the fourth dielectric film 122 provided on the fourth side surface can more efficiently form a reciprocating reflection effect on the fundamental frequency light.

[0042] Optionally, the first side surface of the light-emitting chip 11 may specifically be in the shape of a first partial spherical surface, or a lens with a first partial spherical surface is provided on the first side surface of the light-emitting chip 11, and a pump light reflecting film, that is, a first dielectric film, is prepared on the lens. Wherein, the center of the first partial spherical surface faces the laser gain medium 12 and is on the same straight line as the center line of the laser gain medium 12, and this straight line is parallel to the first direction X. When the pump light irradiates the first dielectric film 111 shaped by the first side surface, it can be collimated and focused by the first dielectric film 111 and then reflected to the third side surface of the laser gain medium 12, so as to effectively improve the efficiency of the laser gain medium 12 in converting the pump light that reciprocally reflects and oscillates in the first resonant cavity into fundamental frequency light, and is conducive to obtaining higher conversion efficiency and beam quality.

[0043] Optionally, the third side surface of the laser gain medium 12 is in the shape of a second partial spherical surface, and the center of the second partial spherical surface faces away from the light-emitting chip 11 and is on the same straight line as the center line of the light-emitting chip 11. Similarly, when the pump light irradiates the third dielectric film 121 shaped by the third side surface, it can be collimated and focused by the third dielectric film 121 and then reflected to the first side surface of the light-emitting chip 11, so as to effectively improve the efficiency of the laser gain medium 12 in converting the pump light that reciprocally reflects and oscillates in the first resonant cavity into fundamental frequency light, and is conducive to obtaining higher conversion efficiency and beam quality.

[0044] Optionally, the fourth side surface of the laser gain medium 12 is in the shape of a third partial spherical surface, and the center of the third partial spherical surface faces the light-emitting chip 11 and is on the same straight line as the center line of the light-emitting chip 11. When the fundamental frequency light irradiates the fourth dielectric film 122 shaped by the fourth side surface, it can be collimated and focused by the fourth dielectric film 122 and then reflected to the third side surface of the laser gain medium 12, so as to effectively improve the emission power of the fundamental frequency light that reciprocally reflects and oscillates in the second resonant cavity by the laser gain medium 12, and is conducive to obtaining higher conversion efficiency and beam quality.

[0045] Optionally, the light-emitting chip 11 may specifically be a semiconductor chip with edge emission or vertical surface emission, and the emission wavelength is in the range of 400 nanometers to 1500 nanometers, or any reasonable wavelength such as 1.5 micrometers or 1.3 micrometers. The present application does not limit this.

[0046] Optionally, the laser gain medium 12 may specifically be made of materials such as Pr:YLF (praseodymium-doped yttrium lithium fluoride crystal), Nd:YLF (neodymium-doped yttrium lithium fluoride), Nd:YAG (neodymium-doped yttrium aluminum garnet), Nd:YVO4 (neodymium-doped yttrium vanadate crystal), Nd:GaVO4 (neodymium-doped gadolinium vanadate crystal), Nd:YAP (neodymium-doped yttrium aluminum perovskite crystal), Yb:YAG (ytterbium-doped yttrium aluminum garnet), Tm-doped Ho:YAG (holmium yttrium aluminum garnet), Tm-doped Ho:YLF (holmium-doped yttrium lithium fluoride crystal), Tm:YAG (thulium-doped yttrium aluminum garnet crystal), Tm:YVO4 (thulium-doped yttrium vanadate), Er:YAG (erbium-doped yttrium aluminum garnet crystal) laser crystals or laser ceramics, etc. The present application does not limit this.

[0047] Please refer to Figure 2 , Figure 2 which is a schematic structural diagram of the second embodiment of the laser of the present application. This embodiment is based on the first embodiment of the laser provided by the present application. The laser 20 specifically further includes a laser output mirror 23.

[0048] Among them, the laser output mirror 23 has opposite fifth and sixth sides. The sixth side faces away from the laser output mirror 23, and the laser output mirror 23 is disposed in the first direction X of the laser gain medium 22, and may specifically abut against the fourth side of the laser gain medium 22 or be spaced apart from the laser gain medium 22, for receiving the fundamental frequency light emitted by the laser gain medium 22, and reflecting a part of the fundamental frequency light back to the laser gain medium 22, while allowing the other part to continue to be emitted in the first direction X.

[0049] Specifically, a fifth dielectric film 231 is further provided on the fifth side of the laser output mirror 23 facing the laser gain medium 22. The fifth dielectric film 231 has the characteristic of partially reflecting the fundamental frequency light. At the same time, the fourth dielectric film 222 on the fourth side of the laser gain medium 22 only has the characteristic of transmitting the pump light. Specifically, a second resonant cavity is formed in which the fundamental frequency light partially reciprocally reflects and oscillates along the second round-trip path b between the third dielectric film 221 and the fifth dielectric film 231, and the other part of the fundamental frequency light is transmitted in the first direction X. That is, when the laser gain medium 22 emits the fundamental frequency light to the fourth dielectric film 222, it can pass through the fourth dielectric film 222 and shoot towards the fifth dielectric film 231. After the fifth dielectric film 231 reflects a part of the fundamental frequency light, it reciprocally reflects and oscillates between the third dielectric film 221 and the fifth dielectric film 231 to increase the power of the fundamental frequency light emitted by the laser output mirror 23.

[0050] Optionally, the third side surface of the laser gain medium 22 is parallel to the fifth side surface of the laser output mirror 23, so that the second resonant cavity formed by the third dielectric film 221 provided on the third side surface and the fifth dielectric film 231 provided on the fifth side surface can more efficiently form a reciprocating reflection effect on the fundamental frequency light.

[0051] Optionally, the third side surface of the laser gain medium 22 is in the shape of a second partial spherical surface, and the center of the second partial spherical surface faces away from the light-emitting chip 21 and is on the same straight line as the center line of the light-emitting chip 21; and the fifth side surface of the laser output mirror 23 is in the shape of a fourth partial spherical surface, and the center of the fourth partial spherical surface faces the light-emitting chip 21 and is on the same straight line as the center line of the light-emitting chip 21. When the fundamental frequency light is incident on the third dielectric film 221 shaped by the third side surface and the fifth dielectric film 231 shaped by the fifth side surface, after being collimated and focused by the third dielectric film 221 and the fifth dielectric film 231, it can be repeatedly reflected and oscillated between the third dielectric film 221 and the fifth dielectric film 231, thereby effectively improving the emission power of the fundamental frequency light that will be repeatedly reflected and oscillated in the second resonant cavity by the laser gain medium 22, and being beneficial to obtaining higher conversion efficiency and beam quality.

[0052] In an embodiment, a sixth dielectric film 232 is further provided on the sixth side surface of the laser output mirror 23 facing away from the laser gain medium 22. The sixth dielectric film 232 has the characteristic of increasing the transmittance of the fundamental frequency light, so as to effectively improve the transmission efficiency of the fundamental frequency light when the laser gain medium 22 emits the fundamental frequency light towards the laser output mirror 23 along the first direction X.

[0053] It can be understood that in this embodiment, the light-emitting chip 21, the first dielectric film 211, the second dielectric film 221, the laser gain medium 22, and the third dielectric film 221 are the same as the light-emitting chip 11, the first dielectric film 111, the second dielectric film 112, the laser gain medium 12, and the third dielectric film 121 respectively. For details, please refer to Figure 1 and the relevant text content, which will not be elaborated here.

[0054] Please refer to Figure 3 , Figure 3 is a schematic structural diagram of the third embodiment of the laser of the present application. This embodiment is based on the first embodiment of the laser provided by the present application. The laser 30 specifically further includes a frequency conversion device 34 and a laser output mirror 33.

[0055] Among them, the frequency converter and the laser output mirror 33 are sequentially arranged on the first direction X of the laser gain medium 32, and specifically can be in contact with the laser gain medium 32 or be arranged at intervals along the first direction X.

[0056] The frequency conversion device 34 is specifically used to receive the fundamental frequency light sent by the laser gain medium 32, and convert the fundamental frequency light into frequency conversion light, and then transmit it in the first direction X to the laser output mirror 33, so that the frequency conversion light continues to be transmitted in the first direction X through the laser output mirror 33.

[0057] A fifth dielectric film 331 is provided on the fifth side surface of the laser output mirror 33 facing the laser gain medium 32. The fifth dielectric film 331 specifically has fundamental frequency light reflection and frequency conversion light anti-reflection properties, while the fourth dielectric film 322 has the fundamental frequency light transmission properties. When the laser gain medium 32 transmits fundamental frequency light to the frequency conversion device 34, a portion of the fundamental frequency light can pass through the frequency conversion device 34 and be emitted toward the fifth dielectric film 331. After being reflected by the fifth dielectric film 331, it is emitted toward the third dielectric film 321 on the third side surface of the laser gain medium 32. After being reflected by the third dielectric film 321, it is emitted toward the fifth dielectric film 331 again. Thus, a third resonant cavity is formed between the third dielectric film 321 and the fifth dielectric film 331, where the fundamental frequency light reciprocates and oscillates. This effectively improves the frequency conversion efficiency of the frequency conversion device 34 and the emission power of the frequency conversion light.

[0058] Optionally, the fifth dielectric film 331 may also specifically have the characteristics of high reflection of fundamental frequency light and high transmittance of frequency conversion light, and the sixth dielectric film 332 on the sixth side of the laser output mirror 33 away from the laser gain medium 32 may also specifically have the characteristics of high transmittance of frequency conversion light, so as to effectively improve the transmission efficiency of frequency conversion light.

[0059] In one embodiment, a seventh dielectric film (not shown) and an eighth dielectric film (not shown) are respectively prepared on two opposite side surfaces of the frequency conversion device 34, and the seventh dielectric film and the eighth dielectric film have transmittance-enhancing properties for fundamental frequency light and frequency-converted light, so as to improve the transmission efficiency of fundamental frequency light and frequency-converted light.

[0060] It is worth noting that in different laser application scenarios, lasers of different wavelengths or colors are usually required. This requires frequency conversion of the fundamental frequency light emitted by the laser gain medium 32 to meet the needs of different scenarios. After setting a frequency conversion device 34 between the laser gain medium 32 and the laser output mirror 33, frequency-converted light can be effectively obtained to obtain a wider range of applications; and the application range of the laser 30 can be further expanded by replacing or setting more frequency conversion devices 34.

[0061] It is understood that in this embodiment, the light emitting chip 31, the first dielectric film 311, the second dielectric film 321, the laser gain medium 32, the third dielectric film 321, and the fourth dielectric film 322 are respectively the same as the light emitting chip 11, the first dielectric film 111, the second dielectric film 112, the laser gain medium 12, the third dielectric film 121, and the fourth dielectric film 122. For details, seeFigure 1 And the related text content will not be repeated here.

[0062] See also Figure 4 , Figure 4 This is a schematic structural diagram of the fourth embodiment of the laser of the present application. This embodiment is based on the first embodiment of the laser provided in the present application, and the laser 40 specifically further includes a coupling focusing mirror 45.

[0063] The coupling focusing mirror 45 is disposed between the light emitting chip 41 and the laser gain medium 42 , and specifically can be in contact with the light emitting chip 41 and the laser gain medium 42 , or spaced apart from the light emitting chip 41 and the laser gain medium 42 in the first direction X.

[0064] The center lines of the light-emitting chip 41, the coupling focusing mirror 45, and the laser gain medium 42 are located on the same straight line and are parallel to the first direction X. When the light-emitting chip 41 emits pump light in the first direction X, the coupling focusing mirror 45 can collimate and focus the pump light and then emit it to the laser gain medium 42, thereby facilitating higher conversion efficiency and beam quality.

[0065] In one embodiment, the coupling focusing mirror 45 is provided with a pump light anti-reflection film on both sides facing and away from the light emitting chip 41, so as to effectively improve the transmission efficiency of the pump light when the light emitting chip 41 emits the pump light toward the coupling focusing mirror 45 along the first direction X.

[0066] Optionally, the coupling focusing lens 45 can be any one or more of a fast-axis compression optical fiber, a fast-axis collimating lens, a slow-axis collimating lens, a self-focusing lens, a spherical lens, and an aspheric lens, and this application does not limit this.

[0067] It is understood that in this embodiment, the light emitting chip 41, the first dielectric film 411, the second dielectric film 421, the laser gain medium 42, the third dielectric film 421, and the fourth dielectric film 422 are respectively the same as the light emitting chip 11, the first dielectric film 111, the second dielectric film 112, the laser gain medium 12, the third dielectric film 121, and the fourth dielectric film 122. For details, see Figure 1 And the related text content will not be repeated here.

[0068] The beneficial effects of the present application are as follows: different from the prior art, the first side surface of the light-emitting chip in the laser provided by the present application is provided with a first dielectric film, the light-emitting chip is used to emit pump light in a first direction X, the laser gain medium is provided in the first direction X of the light-emitting chip, a third dielectric film is provided on the third side surface of the laser gain medium facing the light-emitting chip, a fourth dielectric film is provided on the fourth side surface of the laser gain medium facing away from the light-emitting chip, the laser gain medium is used to receive pump light and emit fundamental frequency light in the first direction X when triggered by the pump light, wherein the first dielectric film has pump light reflection characteristics, and the third dielectric film has pump light anti-reflection, The fourth dielectric film has a fundamental frequency light reflection characteristic, and the fourth dielectric film has a pump light reflection characteristic, so that a first resonant cavity in which the pump light reciprocally reflects and oscillates can be formed between the first dielectric film and the fourth dielectric film, and a portion of the first resonant cavity is composited and shared with the laser gain medium, thereby effectively reducing the volume of the laser and improving the stability of the laser. The laser gain medium located in the first resonant cavity converts the reciprocally reflected oscillating pump light into fundamental frequency light, effectively increasing the power density of the pump light in the laser gain medium, thereby improving the conversion efficiency of converting the pump light to fundamental frequency light, and also effectively reducing the length of the laser gain medium.

[0069] The above is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A laser, characterized in that, The laser comprises: a light-emitting chip, wherein a first dielectric film is provided on a first side surface of the light-emitting chip, and the light-emitting chip is configured to emit pump light in a first direction; A laser gain medium is provided in the first direction of the light-emitting chip, a third dielectric film is provided on a third side surface of the laser gain medium facing the light-emitting chip, and a fourth dielectric film is provided on a fourth side surface of the laser gain medium facing away from the light-emitting chip. The laser gain medium is configured to receive the pump light and, triggered by the pump light, emit fundamental frequency light in the first direction. The first side surface faces away from the laser gain medium, the first dielectric film has the pump light reflection characteristic, the third dielectric film has the pump light anti-reflection and fundamental frequency light reflection characteristics, and the fourth dielectric film has the pump light reflection characteristic, so as to form a first resonant cavity between the first and fourth dielectric films in which the pump light reciprocates and oscillates.

2. The laser according to claim 1, characterized in that The fourth dielectric film also has a partial reflection characteristic of the fundamental frequency light, so as to form a second resonant cavity between the third dielectric film and the fourth dielectric film, in which a portion of the fundamental frequency light reciprocates and oscillates, and another portion of the fundamental frequency light is transmitted toward the first direction.

3. The laser according to claim 1, characterized in that The laser further includes a laser output mirror, which is arranged in the first direction of the laser gain medium. A fifth dielectric film is provided on the fifth side of the laser output mirror facing the laser gain medium. The fifth dielectric film has a partial reflection characteristic of the fundamental frequency light, so as to form a second resonant cavity between the third dielectric film and the fifth dielectric film, in which a portion of the fundamental frequency light is reciprocally reflected and oscillated, and another portion of the fundamental frequency light is transmitted toward the first direction.

4. The laser according to claim 3, characterized in that A sixth dielectric film is provided on the sixth side of the laser output mirror away from the laser gain medium, and the sixth dielectric film has a fundamental frequency light anti-transmission property.

5. The laser according to claim 1, characterized in that The laser further includes a frequency conversion device and a laser output mirror, wherein the frequency conversion device and the laser output mirror are sequentially arranged in the first direction of the laser gain medium, and the frequency conversion device is used to receive the fundamental frequency light transmitted by the laser gain medium, and convert the fundamental frequency light into frequency-converted light, and then transmit the light to the laser output mirror in the first direction; A fifth dielectric film is provided on the fifth side of the laser output mirror facing the laser gain medium. The fifth dielectric film has the characteristics of reflecting the fundamental frequency light and increasing the transmittance of the frequency-converted light, so as to form a third resonant cavity between the third dielectric film and the fifth dielectric film in which the fundamental frequency light reciprocates and oscillates.

6. The laser according to any one of claims 2 to 4, characterized in that The fundamental frequency light partial reflection characteristic is to reflect 30%-99.5% of the fundamental frequency light.

7. The laser according to any one of claims 1 to 4, characterized in that The laser further includes a coupling focusing mirror, which is disposed between the light-emitting chip and the laser gain medium, and the center lines of the light-emitting chip, the coupling focusing mirror, and the laser gain medium are located on the same straight line and parallel to the first direction.

8. The laser according to any one of claims 1-4, wherein a second dielectric film is provided on the second side of the light-emitting chip facing the laser gain medium, and the second dielectric film has the property of increasing the transmission of pump light.

9. The laser according to any one of claims 1-4, wherein the first side is parallel to the fourth side; and / or, the third side is parallel to the fourth side.

10. The laser according to any one of claims 1-4, wherein and / or, the third side is in the shape of a second partial spherical surface, and the center of the second partial spherical surface faces away from the light-emitting chip and is located on the same straight line as the center line of the light-emitting chip; and / or, the fourth side is in the shape of a third partial spherical surface, and the center of the third partial spherical surface faces the light-emitting chip and is located on the same straight line as the center line of the light-emitting chip.

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