CN219980045U - Angle separation intracavity pump slat Ho laser - Google Patents

Abstract

The utility model provides an angle separation intracavity pump slat Ho laser, comprising: the device comprises a pump source, a thulium laser resonant cavity, a holmium laser resonant cavity, a thulium doped slat gain medium and a holmium doped slat gain medium; the pump source is used for emitting pump light; the thulium-doped slat gain medium and the holmium-doped slat gain medium are both positioned in the thulium laser resonant cavity; the thulium-doped slab gain medium is used for absorbing pump light and generating thulium laser under the action of thulium laser resonance; the thulium laser is incident into the holmium-doped slab gain medium and generates holmium laser under the action of the holmium laser resonant cavity; the thulium laser travels in a first optical path in the thulium doped slat gain medium and the holmium doped slat gain medium; the holmium laser travels in the holmium doped slab gain medium in a second optical path and exits. The complex energy transfer and serious cooperative conversion loss in the thulium-holmium co-doped laser medium are avoided, the thulium-doped slab gain medium with serious thermal effect in the process of oscillation feedback of holmium laser is avoided, and high-beam quality and high-power Ho laser output are realized.

Description

Angle separation intracavity pump slat Ho laser

Technical Field

The utility model relates to the technical field of solid laser, in particular to an angle separation intracavity pumping lath Ho laser.

Background

A holmium (Ho) laser is a device that can generate 2.1 μm band laser light. Currently, the general implementation method of the solid-state Ho laser includes: a Tm, ho codoped laser sensitized by pumping thulium (Tm) ions through a gallium arsenide aluminum laser semiconductor (LD, wavelength range 750 nm-810 nm); 1.9 mu m laser pumping single doped Ho laser; tm laser cavity resonance Tm/Ho laser of pump Ho laser.

The Tm/Ho bonding laser bonds the Tm-doped gain medium and the Ho-doped gain medium into the same gain medium based on the same-band pumping principle, can efficiently realize Ho laser output under the pumping of the conventional gallium arsenide aluminum LD, and has the advantages of compact structure and convenience.

However, tm, ho co-doped lasers suffer from significant drawbacks: complex energy transfer, serious cooperative conversion loss and the like, and meanwhile, the Tm and Ho co-doped crystal lasers cannot effectively control the thermal effect inside the gain medium, so that the quality of the laser beam is deteriorated.

The 1.9 mu m semiconductor laser or thulium laser is adopted to pump the single doped Ho laser outside the cavity, and the high-beam quality and high-power Ho laser output can be realized, but the structure is complex and the price of the laser is high.

Disclosure of Invention

The utility model provides an angle separation intracavity pump slat Ho laser, which is used for solving the problems of serious conversion loss of Tm and Ho co-doped crystals, poor beam quality, smaller power, complex structure and high price of a 1.9 mu m laser pump single-doped Ho laser in the prior art, realizing high beam quality and high power Ho laser output and reducing cost.

The utility model provides an angle separation intracavity pump slat Ho laser, comprising: the device comprises a pump source, a thulium laser resonant cavity, a holmium laser resonant cavity, a thulium doped slat gain medium and a holmium doped slat gain medium;

the pump source is used for emitting pump light, and the pump light is incident to the thulium doped slat gain medium;

the thulium doped slat gain medium and the holmium doped slat gain medium are both positioned in the thulium laser resonant cavity;

the thulium-doped slat gain medium is used for absorbing pump light and generating thulium laser under the action of the thulium laser resonance;

the thulium laser is incident to the holmium-doped slat gain medium and generates holmium laser under the action of the holmium laser resonant cavity;

the thulium laser travels in the thulium doped slat gain medium and the holmium doped slat gain medium in a first optical path;

the holmium laser travels and exits in the holmium doped slat gain medium in a second optical path;

the thermal management part is connected with the thulium doped slat gain medium and the holmium doped slat gain medium and is used for cooling the thulium doped slat gain medium and the holmium doped slat gain medium.

According to the angle separation intracavity pump slab Ho laser provided by the utility model, the plane formed by the holmium doped slab gain medium along the length direction and the width direction is a large plane; the holmium-doped slab gain medium is characterized in that the two large surfaces of the holmium-doped slab gain medium are provided with thulium and holmium laser reflection layers, and the reflection of thulium and holmium lasers between the large surfaces of the holmium-doped slab gain medium is realized by means of the total internal reflection principle, so that the thulium and holmium lasers travel in the holmium-doped slab gain medium in a Z-shaped optical path.

According to the angle separation intracavity pump slab Ho laser provided by the utility model, the plane formed by the thulium doped slab gain medium along the length direction and the width direction is a large plane; and the thulium-doped slat gain medium is provided with thulium laser reflection layers on two large surfaces, and the thulium-doped slat gain medium is used for reflecting thulium laser to enable the thulium laser to travel in the thulium-doped slat gain medium in a Z-shaped optical path.

According to the angular separation intracavity pump lath Ho laser provided by the utility model, the thulium laser resonant cavity comprises two cavity mirrors, and the two cavity mirrors are plated with thulium laser high-reflection films to form feedback oscillation of thulium laser.

According to the angle separation intracavity pump slat Ho laser provided by the utility model, the holmium laser resonant cavity comprises a front cavity mirror and an output mirror; the front cavity mirror is plated with a holmium laser high-reflection film; the output mirror may partially transmit the holmium laser light.

According to the angle separation intracavity pump slat Ho laser provided by the utility model, the reflectivity of the front cavity mirror to holmium laser is more than 99%; the transmissivity of the output mirror to holmium laser is 5% -30%.

According to the angle separation intracavity pump slab Ho laser provided by the utility model, the planes formed by the thulium doped slab gain medium and the holmium doped slab gain medium along the width direction and the height direction are end surfaces; the end face of the thulium doped slat gain medium is plated with a thulium laser anti-reflection layer, and the end face of the holmium doped slat gain medium is plated with a holmium laser anti-reflection layer.

According to the angle separation intracavity pump slab Ho laser provided by the utility model, the thulium laser enters the holmium doped slab gain medium from a large surface, and the end surface of the holmium doped slab gain medium is plated with the thulium laser high-reflection layer.

According to the pump slab Ho laser in the angle separation cavity, the end face and the large face of the thulium doped slab gain medium form an included angle of 45-60 degrees; and/or the end face of the holmium doped slat gain medium and the large face form an included angle of 45-60 degrees.

According to the angular separation intracavity pump slab Ho laser provided by the utility model, the matrix of the thulium doped slab gain medium is selected from one of YAG crystals, YAG ceramics, luAG crystals, luAG ceramics and LuYAG crystals.

According to the angle separation intracavity pump slab Ho laser provided by the utility model, the matrix of the holmium doped slab gain medium is selected from one of YAG crystals, YAG ceramics, luAG crystals and LuAG ceramics.

According to the angular separation intracavity pump slab Ho laser provided by the utility model, the pump light can be incident from the end face, the side face or the large face of the thulium doped slab gain medium.

According to the pump slab Ho laser in the angle separation cavity, the wavelength of the pump light source is 760-820 nm.

The utility model provides an angle separation intracavity pump lath Ho laser, which also comprises a thermal management part; the thermal management section includes:

the heat sink main body is internally provided with a passage for cooling water to circulate, and the holmium-doped slat gain medium and the thulium-doped slat gain medium are connected to the heat sink main body in a large-surface welding mode;

the water nozzle is arranged on the heat sink main body and communicated with the passage in the heat sink main body, and is used for supplying cooling water to the heat sink main body.

According to the angle separation intracavity pumping slab Ho laser provided by the utility model, the thulium-doped slab gain medium and the holmium-doped slab gain medium are separated, the thulium-doped slab gain medium is utilized to absorb pumping light, oscillation feedback of thulium laser is formed under the action of a thulium laser resonant cavity, the thulium laser is incident and is pumped with the holmium-doped slab gain medium, oscillation of holmium laser is formed under the action of the holmium laser resonant cavity and is output, and compared with the traditional Tm and Ho co-doped crystals, independent oscillation of thulium laser and holmium laser is respectively completed by adopting two resonant cavities with different spatial arrangements, so that complex energy transfer and serious cooperative conversion loss are avoided; meanwhile, as the first optical path and the second optical path are different, thulium-doped slat gain medium with serious thermal effect in the process of oscillation feedback of holmium laser is avoided, compared with the traditional Tm/Ho bonding slat gain medium, the thermal effect in the gain medium can be obviously improved, and thus high-beam quality and high-power Ho laser output are realized; in addition, compared with the traditional 1.9 mu m laser cavity external pumping single-doped holmium laser, the structure is simplified, and the cost is reduced.

Drawings

In order to more clearly illustrate the utility model or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of an angle-splitting intracavity pump slab Ho laser according to one embodiment of the present utility model;

fig. 2 is a schematic structural diagram of a Tm laser thulium laser resonator according to an embodiment of the present utility model;

FIG. 3 is a schematic diagram of an angle-splitting intracavity pump slab Ho laser according to another embodiment of the present utility model;

FIG. 4 is a schematic diagram of a thermal management section according to an embodiment of the present utility model.

Reference numerals:

1. a pump source; 2. a thulium laser resonator; 20. a first cavity mirror; 21. a second cavity mirror; 3. a holmium laser resonator; 30. a front cavity mirror; 31. an output mirror; 4. thulium doped slab gain media; 40. a first end face; 41. a second end face; 5. holmium doped slab gain medium; 50. a third end face; 51. a fourth end face; 6. a first optical path; 7. a second light path; 8. thermal management section: 80. a heat sink body.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present utility model, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that, in the description of the embodiments of the present utility model, terms such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like are used for indicating orientations or positional relationships based on the orientations or positional relationships shown in the drawings, only for convenience in describing the present utility model and simplifying the description, and are not meant to indicate or imply that the device or element to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," "third," and the like, as used herein, are used for descriptive purposes only and are not to be construed as indicating or implying any relative importance.

In order to facilitate understanding of the angular separation intracavity pump slab Ho laser provided by the present utility model, first, an application background thereof will be described, and a solid-state holmium laser is an apparatus for obtaining 2.1um band laser, and a current implementation method of the solid-state holmium laser generally includes: a Tm, ho codoped laser sensitized by pumping thulium (Tm) ions through a gallium arsenide aluminum laser semiconductor (LD, wavelength range 750 nm-810 nm); 1.9 mu m laser pumping single doped Ho laser; tm laser cavity resonance Tm/Ho laser of pump Ho laser.

However, complex energy transfer, serious cooperative conversion loss and the like exist in the Tm and Ho codoped lasers; the bonding crystal can not effectively control the thermal effect inside the gain medium, so that the quality of the laser beam is deteriorated; the 1.9 mu m laser pump single doped Ho laser can realize high beam quality and high power Ho laser output, but has complex structure, low absorption efficiency and high price.

The slab laser has the advantages of small thermal effect, good light beam quality maintenance, good laser polarization degree maintenance and the like by carrying out large-area cooling on the slab gain medium, and is suitable for lasers with larger power. In the slab laser structure, a Zig-zag light path beam enters a certain angle with the large surface of the slab, and the incident beam is totally reflected back and forth and propagates forwards on the upper surface and the lower surface of a medium, and the whole light path is in a Z-shaped structure.

Ideally, the effects of thermal distortion are substantially compensated within the matrix material when the beam is reflected from one surface of the ribbon to the other. As long as the incident angle meets the total reflection requirement, the selectable incident angle is not unique, and no matter which angle is selected for incidence, the problems of gain reduction, thermal deformation and the like caused by deviation from the center of the crystal do not exist, so that the output with high beam quality can be realized.

Based on the above, the utility model provides an angle separation intracavity pump slab Ho laser, which is used for solving the problems of serious conversion loss of Tm and Ho co-doped crystals, poor beam quality, low absorption efficiency, complex structure, limited power and high price of a 1.9 mu m laser pump single doped Ho laser in the prior art, realizing high beam quality and high power Ho laser output, and reducing cost.

The angle-splitting intracavity pump slab Ho laser of the present utility model is described below in connection with fig. 1-4.

Referring to fig. 1 and 2, an angle separation intracavity pump slab Ho laser comprises a pump source 1, a thulium laser resonant cavity 2, a holmium laser resonant cavity 3, a thulium doped slab gain medium 4 and a holmium doped slab gain medium 5; the pump source 1 is used for emitting pump light; the thulium-doped slat gain medium 4 and the holmium-doped slat gain medium 5 are both arranged in the thulium laser resonant cavity 2, pump light is incident to the thulium-doped slat gain medium 4, the thulium-doped slat gain medium 4 absorbs the pump light to form particle number inversion, oscillation feedback of thulium laser is formed under the action of the thulium laser resonant cavity 2, and the thulium laser advances in the thulium-doped slat gain medium 4 and the holmium-doped slat gain medium 5 through the first optical path 6.

After the thulium laser is incident into the holmium-doped slab gain medium 5, under the in-band pumping of the thulium laser, the particle number in the holmium-doped slab gain medium 5 is reversed, and oscillation feedback of the holmium laser is formed under the action of the holmium laser resonant cavity 3, and the holmium laser travels in the holmium-doped slab gain medium 5 in a second optical path 7 different from the first optical path 6 and is output by a cavity mirror of the holmium laser resonant cavity 3.

By separating the thulium-doped slat gain medium 4 from the holmium-doped slat gain medium 5, absorbing pump light by utilizing the thulium-doped slat gain medium 4, forming oscillation feedback of thulium laser under the action of the thulium laser resonant cavity 2, and forming oscillation of holmium laser under the action of the holmium laser resonant cavity 3 and outputting the oscillation by making the thulium laser incident and pumping the holmium-doped slat gain medium 5, compared with the traditional Tm and Ho co-doped crystal, the independent oscillation of the thulium laser and the holmium laser is respectively completed by adopting two resonant cavities with different spatial arrangements, thereby avoiding complex energy transfer and serious cooperative conversion loss; meanwhile, as the first optical path 6 and the second optical path 7 are different, the phenomenon that the holmium laser passes through the thulium doped slat gain medium 4 with serious thermal effect in the process of oscillation feedback is avoided, and compared with the traditional Tm/Ho bonding gain medium, the thermal effect in the gain medium can be obviously improved. Thereby realizing high beam quality and high power Ho laser output. In addition, compared with the traditional 1.9 mu m laser cavity external pumping single-doped holmium laser, the structure is simplified, and the cost is reduced.

Specifically, the pump source 1 comprises a pump laser and a shaping unit, and is used for emitting a pump light spot matched with a thulium laser mode in the thulium laser resonant cavity 2; the pump laser can adopt a high-power semiconductor laser with optical fiber coupling, can also adopt a high-power LD stacked array integrated by LD bars, and the like, and can be specifically selected according to actual requirements.

In this embodiment, the pumping laser adopts the LD array to directly pump, and the pumping light generated by the array is not required to be coupled into the optical fiber through the spatial light path, and then pumped through the optical fiber, so that the structure is more compact, the use is more economical and convenient, and the hundred watt pump power which is difficult to achieve by the optical fiber coupling semiconductor laser can be obtained.

The shaping unit is mainly used for carrying out beam shaping on pump light with preset wavelength, the light inlet end of the shaping unit is connected with the optical path of the pump laser, namely, after the pump light emitted by the pump laser enters the shaping unit, the pump light enters the thulium-doped lath gain medium 4 after being shaped into a required shape by the shaping unit, and the pump light can be well matched with the laser mode volume by the shaping unit, so that the light-light conversion efficiency is improved. According to actual demands, the shaping unit can select various existing optical devices, and can be obtained by combining according to shaping demands.

Specifically, the wavelength of the pump light is 760-820 nm; the shaping unit adopts a cylindrical lens, and a dielectric film with high transmittance to the pump light wavelength is plated on the lens.

The thulium laser resonant cavity 2 comprises two cavity mirrors, and the thulium doped slat gain medium 4 and the holmium doped slat gain medium 5 are positioned between the two cavity mirrors; the two cavity mirrors of the thulium laser resonant cavity 2 are plated with thulium laser high-reflection films, namely the reflectivity of the thulium laser high-reflection films to the wave bands of 1.9-2.0 μm is more than 99%.

The two surfaces formed by the thulium-doped slat gain medium 4 and the holmium-doped slat gain medium 5 along the length direction and the width direction are large surfaces, the two large surfaces of the thulium-doped slat gain medium 4 are plated with thulium laser reflection layers, and the thulium laser is reflected between the large surfaces of the thulium-doped slat gain medium 4 by means of the total internal reflection principle; specifically, the thulium laser reflection layer may be an evanescent wave film, so as to implement total reflection of the thulium laser between large faces of the thulium-doped slab gain medium 4.

The two large surfaces of the holmium-doped slat gain medium 5 are plated with thulium laser and holmium laser reflection layers, and the reflection of thulium and holmium laser between the large surfaces of the holmium-doped slat gain medium 5 is realized by means of the total internal reflection principle; specifically, the thulium and holmium laser reflection layer can adopt an evanescent wave film to realize total reflection of thulium and holmium laser between large surfaces of the holmium-doped slat gain medium 5.

Specifically, the evanescent film is typically a silica material.

After the pump light enters the thulium-doped lath gain medium 4, the thulium-doped lath gain medium 4 absorbs the pump light and forms particle number inversion, and oscillation feedback of thulium laser is formed under the action of the thulium laser resonant cavity 2, so that thulium laser confined in the thulium laser resonant cavity 2 is formed.

Under the large-surface reflection of the thulium-doped slab gain medium 4, the thulium laser travels in the thulium-doped slab gain medium 4 in a Zig-zag optical path and enters the holmium-doped slab gain medium 5 at a first angle. After the thulium laser enters the holmium doped slab gain medium 5, the thulium laser travels in a Zig-zag optical path under the large-surface reflection of the holmium doped slab gain medium 5, so that the first optical path 6 is formed.

The holmium laser resonant cavity 3 comprises two cavity mirrors, namely a front cavity mirror 30 and an output mirror 31; the holmium doped slat gain medium 5 is located between the front cavity mirror 30 and the output mirror 31, wherein a holmium laser high-reflection film layer is plated on the front cavity mirror 30, and the output mirror 31 can partially transmit holmium laser. After the thulium laser enters the holmium-doped slat gain medium 5, the holmium-doped slat gain medium 5 is pumped in a same way, and oscillation of the holmium laser is generated under the reflection of the front cavity mirror 30 and the output mirror 31, and the holmium laser travels in the holmium-doped slat gain medium 5 in a Zig-zag optical path under the large-surface reflection of the holmium-doped slat gain medium 5, so that the second optical path 7 is formed.

After being reflected by the front cavity mirror 30, holmium laser enters the holmium doped slat gain medium 5 at a second angle, the first angle is different from the second angle, so that the first optical path 6 and the second optical path 7 are different, thulium laser oscillates in the thulium laser resonant cavity 2 through the first optical path 6 and is confined in the thulium laser resonant cavity 2, holmium laser oscillates between the front cavity mirror 30 and the output mirror 31 through the second optical path 7 and is output through the output mirror 31, the holmium laser is prevented from passing through the thulium doped slat gain medium 4 with higher thermal effect, the thermal effect in the gain medium can be obviously improved, and high-beam quality and high-power Ho laser output are realized.

It should be noted that, the first angle and the second angle both use the large surface of the holmium doped slab gain medium 5 as the incident surface, and the first angle and the second angle both are incident angles, that is, the included angles between the laser and the normal line of the large surface of the holmium doped slab gain medium 5.

It can be appreciated that the first angle and the second angle can be selected according to actual requirements, but it is required to ensure that the thulium laser and the holmium laser just propagate for an integer number of periods in the holmium doped slab gain medium 5:

L＝N·L _b =2n·t·tgβ, where L is the length of the holmium doped slab gain medium 5; n is the number of cycles; l (L) _b Is the propagation path of the single-period laser; t is the thickness of the holmium doped slab gain medium 5; beta is the angle between the laser beam and the normal of the large surface in the gain medium.

Specifically, the front cavity mirror 30 is coated with a film layer with a reflectivity of 99% or more to holmium laser, and the transmittance of 5% -30% to holmium laser of the output mirror 31.

Specifically, the surfaces formed by the thulium doped slat gain medium 4 and the holmium doped slat gain medium 5 along the width and thickness directions are end surfaces; the thulium-doped lath gain medium 4 is plated with a thulium laser antireflection film layer on the end face, which is beneficial to the transmission of thulium laser; the holmium-doped slab gain medium 5 is plated with a holmium laser antireflection film layer on the end face, which is beneficial to the transmission of holmium laser.

Specifically, the holmium-doped slat gain medium 5 and the thulium-doped slat gain medium 4 are both trapezoid, the end face of the thulium-doped slat gain medium 4 forms an included angle of 45-60 degrees with the large surface, and the end face of the holmium-doped slat gain medium 5 forms an included angle of 45-60 degrees with the large surface, so that the incidence of laser is facilitated.

Referring to fig. 1 and 3, a cavity mirror of the thulium laser resonant cavity 2 close to the thulium doped slab gain medium 4 is a first cavity mirror 20, and a cavity mirror close to the holmium doped slab gain medium 5 is a second cavity mirror 21; the end face of the thulium doped slat gain medium 4, which is close to the first cavity mirror 20, is a first end face 40, and the end face, which is far away from the first cavity mirror 20, is a second end face 41; the end face of the holmium doped slat gain medium 5, which is close to the front cavity mirror 30, is a third end face 50, and the end face, which is close to the output mirror 31, is a fourth end face 51.

In an embodiment of the utility model, referring to fig. 1, a pump source 1 is arranged at the end face of a thulium doped slab gain medium 4; the pump light is shaped into a thin line with a rectangular cross section and uniform light intensity distribution through the shaping unit, the thin line is incident to the end face from the position of the large face of the thulium doped slat gain medium 4, the thin line is reflected to the thulium doped gain medium 4 through the total internal reaction of the end face, thulium laser is generated under the action of the thulium laser resonant cavity 2, and the thulium laser exits from the second end face 41 and is incident to the holmium doped slat gain medium 5 from the third end face 50. The third end surface 50 and the fourth end surface 51 are plated with thulium laser antireflection films, which is beneficial to the transmission of thulium laser.

In another embodiment of the present utility model, referring to fig. 3, the pump light is shaped into a rectangular light spot by the shaping unit, and is incident through a large surface or a side surface of the thulium doped slab gain medium 4, thulium laser is generated under the action of the thulium laser resonant cavity 2, and exits from the second end surface 41 and enters the holmium doped slab gain medium 5 from the third end surface 50, and the incident thulium laser forms a Zig-zag optical path through total reflection of the large surface.

It is understood that the thulium laser resonant cavity 2 and the holmium laser resonant cavity 3 can be any stable cavity structure such as a flat cavity, a flat concave cavity or a concave-convex cavity.

Specifically, the matrix of the thulium doped slat gain medium 4 may be one of YAG crystal, YAG ceramic, luAG crystal, luAG ceramic and LuYAG crystal, and the absorption characteristics of the thulium doped slat gain medium 4 are different according to different selected matrixes, and pump light with different wavebands can be selected according to different selected matrix materials. The matrix of the holmium doped slab gain medium 5 may be one of YAG crystals, YAG ceramics, luAG crystals, and LuAG ceramics.

In the embodiment, the thulium doped lath gain medium 4 is Tm, YAG and the doping concentration is 2%; the Ho-doped lath gain medium is Ho-YAG, and the doping concentration is 0.5%.

Referring to fig. 4, the angle separation intracavity pump slab Ho laser further includes a thermal management section 8 for cooling the holmium doped slab gain medium 5 and the thulium doped slab gain medium 4.

Specifically, the thermal management section 8 includes a heat sink body 80 and a water nozzle; the heat sink body 80 is made of a metal material having good heat conductivity, and has a passage for flowing a cooling liquid therein, and the water nozzle communicates with the passage in the heat sink body 80 for flowing the cooling liquid therein. The holmium doped slat gain medium 5 and the thulium doped slat gain medium 4 are welded on the heat sink body 80 by way of large-surface welding.

By the heat management part 8, the slab gain medium can be cooled in a large area, the heat effect in the slab gain medium is reduced, and the beam quality can be well maintained.

The novel innovation point of the utility model is that: the thulium-doped slat gain medium 4 and the holmium-doped slat gain medium 5 are separated, and independent oscillation of thulium laser and holmium laser is realized through the thulium laser resonant cavity 2 and the holmium laser resonant cavity 3, so that complex energy transfer and serious cooperative conversion loss are avoided; the holmium laser and the thulium laser have different light paths in the holmium-doped slat gain medium 5, so that the holmium laser is prevented from passing through the thulium-doped slat gain medium 4 with serious thermal effect in the process of oscillation feedback, the thermal effect in the gain medium can be obviously improved, and the high-beam quality and high-power Ho laser output can be realized.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims (10)

1. An angle-splitting intracavity pump slab Ho laser comprising: the device comprises a pumping source (1), a thulium laser resonant cavity (2), a holmium laser resonant cavity (3), a thulium-doped slat gain medium (4), a holmium-doped slat gain medium (5) and a thermal management part (8);

the pump source (1) is used for emitting pump light, and the pump light is incident to the thulium doped slat gain medium (4);

the thulium doped slat gain medium (4) and the holmium doped slat gain medium (5) are both positioned in the thulium laser resonant cavity (2);

the thulium-doped slat gain medium (4) is used for absorbing pump light and generating thulium laser under the action of the thulium laser resonance;

the thulium laser is incident to the holmium-doped slat gain medium (5) and generates holmium laser under the action of the holmium laser resonant cavity (3);

the thulium laser travels in a first optical path (6) in the thulium doped slab gain medium (4) and the holmium doped slab gain medium (5);

the holmium laser travels in the holmium doped slat gain medium (5) in a second optical path (7) and exits;

the thermal management part (8) is connected with the thulium doped slat gain medium (4) and the holmium doped slat gain medium (5) and is used for cooling the thulium doped slat gain medium (4) and the holmium doped slat gain medium (5).

2. The angle separation intracavity pump slab Ho laser of claim 1 wherein the plane of the holmium doped slab gain medium (5) formed along the length and width directions is a large plane; the holmium-doped slat gain medium (5) is characterized in that thulium and holmium laser reflection layers are arranged on two large surfaces of the holmium-doped slat gain medium (5), and the reflection of thulium and holmium laser between the large surfaces of the holmium-doped slat gain medium (5) is realized by means of the total internal reflection principle, so that the thulium and holmium laser travel in the holmium-doped slat gain medium (5) in a Z-shaped optical path.

3. The angle-separating intracavity pump slab Ho laser of claim 2 wherein the planes of the thulium doped slab gain medium (4) formed in the length and width directions are large planes; and thulium laser reflection layers are arranged on two large surfaces of the thulium-doped slat gain medium (4) and used for reflecting thulium laser to enable the thulium laser to travel in the thulium-doped slat gain medium (4) in a Z-shaped optical path.

4. An angle-separating intracavity pump slab Ho laser as claimed in claim 3 wherein the thulium laser resonator (2) comprises two mirrors with high reflectivity thulium laser films coated thereon for constituting feedback oscillation of thulium laser.

5. The angle-splitting intracavity pump slab Ho laser of claim 2 wherein the holmium laser resonator (3) includes a front cavity mirror (30) and an output mirror (31); the front cavity mirror (30) is plated with a holmium laser high-reflection film; the output mirror (31) is partially transmissive to the holmium laser light.

6. The angle-splitting intracavity pump slab Ho laser of claim 5 wherein the front facet mirror (30) has a reflectivity of 99% or more for the holmium laser; the transmittance of the output mirror (31) to holmium laser is 5% -30%.

7. The angle separation intracavity pump slab Ho laser according to claim 3, wherein the planes of the thulium doped slab gain medium (4) and the holmium doped slab gain medium (5) formed in the width direction and the height direction are end faces; the end face of the thulium doped slat gain medium (4) is plated with a thulium laser anti-reflection layer, and the end face of the holmium doped slat gain medium (5) is plated with a holmium laser anti-reflection layer.

8. The angle separation intracavity pump slab Ho laser of claim 7 wherein said thulium laser light is incident from an end face of a holmium doped slab gain medium (5), said end face of said holmium doped slab gain medium (5) being coated with a thulium laser anti-reflection layer.

9. The angle separation intracavity pump slab Ho laser of claim 7 wherein the end face of said thulium doped slab gain medium (4) forms an angle of 45 ° to 60 ° with the large face; and/or the end face and the large face of the holmium doped slat gain medium (5) form an included angle of 45-60 degrees.

10. The angle-separating intracavity pump slab Ho laser of any one of claims 1 to 9 wherein the matrix of the holmium doped slab gain medium (5) is selected from one of YAG crystal, YAG ceramic, luAG crystal and LuAG ceramic.