Intermediate infrared passive Q-switched solid laser based on Er < 3 + > and Dy < 3 + > doped crystal

Abstract

The invention belongs to the technical field of mid-infrared solid laser, and particularly relates to a mid-infrared passive Q-switched solid laser based on Er < 3 + > and Dy < 3 + > doped crystals. A semiconductor laser or a xenon lamp is used as a pumping source, an Er < 3 + >-doped crystal is used as a laser gain medium, and a Dy < 3 + >-doped crystal is used as a saturable absorber. The pumping source pumps the Er < 3 + >-doped crystal in the resonant cavity to realize the emission of mid-infrared 2.6-3 [mu] m laser, and further modulates the 2.6-3 [mu] m laser by using the saturated absorption characteristic of the Dy < 3 + >-doped crystal to the laser of the wave band, thereby directly realizing the passive Q-switched laser output with high peak power and ns-level pulse width. According to the invention, the development bottleneck that high peak power and compact miniaturization cannot be considered at present can be broken through, and the application requirements in the fields of national defense safety, advanced manufacturing, medical treatment, scientific research and the like can be further met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mid-infrared laser, in particular to a mid-infrared Er-doped 3+ solid-state laser based on passive Q-switching. BACKGROUND

[0002] The mid-infrared laser in the 2.7-3 μm band is located in a region with strong water absorption and a band with concentrated thermal radiation energy, and has important applications in the fields of infrared countermeasures, atmospheric environment monitoring, infrared remote sensing, laser processing, laser medical treatment and nonlinear optics. In particular, the nanosecond (ns) level 2.7-3 μm short pulse laser obtained through Q-switching laser technology has the characteristics of high peak power and short pulse duration. It can be directly used in the fields of infrared countermeasures, laser processing, advanced manufacturing, etc.; it can be used as a laser scalpel in laser surgery, and has the advantages of small thermal damage and fast healing speed; it can also be used as an excellent pump source for mid-long wave lasers, and through pumping Fe:ZnSe crystals, 3.77-5.05 μm band laser can be efficiently output, and through pumping nonlinear crystals (such as optical parametric oscillation technology, OPO), 3-19 μm mid-long wave infrared laser can be output. Therefore, the mid-infrared 2.7-3 μm solid-state laser has important application prospects in the fields of national defense security, advanced manufacturing, medical treatment, scientific research, etc.

[0003] At present, the 2.7-3 μm band ns-level laser is mainly obtained by combining an erbium-doped mid-infrared laser crystal with laser Q-switching technology. According to different working modes, the laser Q-switching technology is mainly divided into active Q-switching (electro-optic Q-switching and acousto-optic Q-switching) and passive Q-switching. Compared with the passive Q-switching, the active Q-switching realizes Q-switching through a Q-switching crystal combined with a corresponding driving power supply, and can obtain Q-switched laser output with larger energy and higher peak power, but the experimental device is relatively complex, which is not conducive to the miniaturization and industrial application of the laser. The passive Q-switching realizes Q-switching through a saturable absorber, and has the advantages of simplicity, compactness and low cost, but is limited by the low damage threshold of the saturable absorber in this band, and has relatively low single-pulse energy and peak power. Therefore, at present, there is still a lack of ns-level mid-infrared solid-state laser that can have both large energy (high peak power) and compact miniaturization. SUMMARY

[0004] In order to overcome the defects in the prior art, the present application proposes a kind of Er-doped 3+ crystal as laser gain medium, Dy-doped 3+A new mid-infrared solid-state laser uses a crystal material as a saturated absorber to directly achieve passive Q-switched laser output. This laser combines the high damage threshold of the crystal material, enabling high-energy (high peak power) laser output, with the compact size advantages of passive Q-switching. This invention overcomes the current development bottleneck of achieving both high peak power and compactness, meeting the national and public needs for high peak power, nanosecond-level pulse width, and portability.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions: a method based on Er-doped 3+ and Dy 3+ Mid-infrared passively Q-switched solid-state laser based on crystal, using semiconductor laser or xenon lamp as pump source, Er-doped 3+ Crystal is used as laser gain medium, doped with Dy 3+ The crystal acts as a saturated absorber; the pump source pumps the Er-doped 3+ crystal, produces mid-infrared 2.6~3μm laser output, and utilizes Dy doped 3+ The crystal's saturation absorption characteristics of the laser in this band further modulate the 2.6-3μm laser, directly achieving passive Q-switched laser output with high peak power and ns-level pulse width.

[0006] As an Er-doped 3+ and Dy 3+ Further improvements to crystal-based mid-infrared passively Q-switched solid-state lasers:

[0007] Preferably, the Er-doped 3+ Crystal refers to Er 3+ Oxide, fluoride, sulfide or selenide crystals doped alone or with other ions, where Er 3+ The doping concentration of the ions is 1 to 50 at.%.

[0008] Preferably, the Dy-doped 3+ Crystal refers to Dy 3+ Oxide, fluoride, sulfide or selenide crystals doped alone or with other ions, where Dy 3+ The doping concentration of the ions is 0.1 to 5 at.%.

[0009] Preferably, Er-doped 3+ and Dy-doped 3+ The matrix crystals of the crystals are the same or different.

[0010] Preferably, the Er-doped 3+ and Dy 3+ The shape of the crystal is one or a combination of two or more of square plate, block, disc, cylinder, lath or optical fiber.

[0011] Preferably, the Er-doped 3+ and Dy 3+ The crystal is a two-piece separated crystal element.

[0012] Preferably, the Er-doped 3+ and Dy 3+ The crystal is a two-piece separated crystal element. 3+ and Dy 3+ The crystal is a two-piece separated crystal element.

[0013] Preferably, the bonded crystal element is bonded at one end of the Er-doped 3+ laser crystal with the Dy-doped 3+ crystal, and the laser crystal and the saturable absorber are combined into one crystal element, further realizing the miniaturization of the laser.

[0014] Preferably, under the condition of semiconductor laser end-pumping, the resonant cavity is composed of a front cavity mirror and a rear cavity mirror, the front cavity mirror has a reflectivity of ≥99.5% in the 2.6-3.0 μm wave band and a transmittance of ≥95% in the 960-980 nm wave band, and the rear cavity mirror has a partial transmittance in the 2.6-3.0 μm wave band, with a transmittance of 0.5-10%.

[0015] Preferably, under the condition of semiconductor laser or xenon lamp side-pumping, the resonant cavity is composed of a front cavity mirror and a rear cavity mirror, the front cavity mirror has a reflectivity of ≥99.5% in the 2.6-3.0 μm wave band, and the rear cavity mirror has a partial transmittance in the 2.6-3.0 μm wave band, with a transmittance of 1-50%.

[0016] The beneficial effects of the present application compared with the prior art are:

[0017] (1) The Er-doped 3+ and Dy 3+ crystal-based mid-infrared passively Q-switched solid-state laser, taking a semiconductor laser or a xenon lamp as a pumping source, the Er-doped 3+ crystal material as a laser gain medium, and the Dy-doped 3+ crystal as a saturable absorber, utilizes the saturable absorption of Dy 3+ to the 2.6-3.0 μm wave band to regulate the loss of the laser resonant cavity, directly realizing the Q-switched laser output with a pulse width of ns level. The present application can break through the development bottleneck that high peak power and compact miniaturization cannot be considered together, and is conducive to further meeting the application needs in the fields of national defense safety, advanced manufacturing, medical treatment, scientific research, etc.

[0018] (2) The laser of the present application adopts the Dy-doped 3+ crystal with a high damage threshold.Crystal materials are used as saturated absorbers to realize passive Q-switched laser operation in the mid-infrared band. They have the high damage threshold of crystal materials and can obtain large energy (high peak power) laser output. They also have the compact and miniaturized advantages of passive Q-switching. This will be a very promising mid-infrared ns laser implementation solution.

[0019] (3) The laser of the present invention can be thermally bonded to Er-doped 3+ and Dy-doped 3+ The crystal is processed into a composite crystal element, thereby achieving laser oscillation and passive Q-switching in one crystal element, realizing "self-Q-switched" laser operation, which is conducive to further miniaturization of the laser. In addition, this method can reduce the number of crystal interfaces in the cavity, thereby reducing the light loss caused by the reflection of the laser gain medium and the saturated absorber during laser operation, and improving the laser output power and efficiency. At the same time, it can also be used in Er-doped 3+ The other end face of the laser crystal is bonded to an undoped matrix crystal as a heat sink, which further improves the heat dissipation capacity of the laser gain medium, reduces the adverse effects caused by thermal effects, and thus improves laser performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 In Example 1, a semiconductor laser is used as the pump source, and Er-doped 3+ The crystal is used as the laser gain medium and Dy-doped 3+ Diagram of the laser experimental setup, which uses a crystal as a saturated absorber to achieve 2.6-3.0μm mid-infrared passively Q-switched laser output.

[0021] Figure 2 The pulse width output characteristic spectrum of passively Q-switched laser output is achieved using the experimental device of Example 1.

[0022] Figure 3 In Example 2, a semiconductor laser is used as the pump source, and Er-doped 3+ The crystal is used as the laser gain medium and Dy-doped 3+ Diagram of the laser experimental setup in which the crystal acts as a saturated absorber to achieve 2.6-3.0μm passively Q-switched laser output.

[0023] Figure 4 In Example 3, a semiconductor laser is used as the pump source, and Er-doped 3+ The crystal is used as the laser gain medium and Dy-doped 3+ Diagram of the laser experimental setup, which uses a crystal as a saturated absorber to achieve 2.6-3.0μm mid-infrared passively Q-switched laser output.

[0024] Figure 5For example 4, a semiconductor laser is used as the pump source, and the Er-doped 3+ crystal is pumped by the side surface. 3+ The composite crystal element is used as the laser gain medium, and the Dy-doped

[0025] Figure 6 For example 5, a xenon lamp is used as the pump source, and the Er-doped 3+ crystal is pumped by the side surface. 3+ The laser crystal piece is used as the saturable absorber, and the Dy-doped

[0026] Figure 7 For example 6, a xenon lamp is used as the pump source, and the Er-doped 3+ crystal is pumped by the side surface. 3+ The laser crystal piece is used as the saturable absorber, and the Dy-doped

[0027] The meanings of the marks in the drawings are as follows:

[0028] 1-semiconductor laser end face pump source; 2-coupling system; 3-first front mirror; 4-Er-doped 3+ crystal; 5-Dy-doped 3+ crystal; 6-back mirror; 7-beam splitter; 8-laser power meter; 9-Er 3+ doped crystal material and Dy 3+ doped crystal material bonded composite crystal element; 10-second front mirror; 11-semiconductor laser side pump source; 12-circulating cooling water; 13-laser energy meter; 14-xenon lamp; 15-xenon lamp condensing cavity. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0030] Example 1

[0031] This embodiment provides a kind of based on Er-doped 3+ and Dy 3+ crystal mid-infrared passively Q-switched solid-state laser, by Figure 1 As shown in the specific structure is as follows:

[0032] Pump source 1 is InGaAs semiconductor laser with emission wavelength near 970nm;

[0033] Coupling system 2 is composed of two convex lenses, which focuses the pump light;

[0034] Er-doped 3+ Crystal 4 and Dy-doped 3+ Crystal 5 is two separated crystal elements.

[0035] The Er-doped 3+ Crystal 4 is Er-doped 3+ YAP crystal, as laser gain medium, Er 3+ ion doping concentration is 10at.%, and the shape is square;

[0036] The Dy-doped 3+ Crystal 5 is Dy-doped 3+ YAP crystal, as saturable absorber, Dy 3+ ion doping concentration is 1at.%, and the shape is round.

[0037] The Er-doped 3+ Crystal 4 and Dy-doped 3+ Crystal 5 is a laser element processed after orientation, cutting and polishing. It can be wrapped with indium foil and placed in a copper cooling clamp (copper heat sink), and the copper heat sink is circulated with cooling water to cool the laser element.

[0038] Under the condition of end-pumping semiconductor laser, the resonant cavity is composed of front mirror 3 and back mirror 6. Front mirror 3 has high reflectivity (≥99.5%) in 2.6-3.0μm waveband. Splitter 7 is used as filter to separate pump light and output laser, which has high reflectivity (≥99.5%) in 2.6-3.0μm waveband and high transmissivity (≥95%) in other waveband (especially 960-980nm waveband). Back mirror 6 has partial transmissivity in 2.6-3.0μm waveband.

[0039] The laser output process of the above-mentioned mid-infrared passively Q-switched solid laser is as follows:

[0040] Pump light emitted by pump source 1 is focused by coupling system 2, and then enters the end face of Er-doped 3+ crystal 4 in the resonant cavity after passing through front mirror 3, and 2.6-3.0μm laser oscillation is generated in the resonant cavity, and then the oscillation laser passes through Dy-doped 3+ crystal 5 in the same resonant cavity, and the 2.6-3.0μm mid-infrared passively Q-switched laser output is realized by using the saturable absorption characteristics of the crystal in this waveband, and the output laser is filtered by splitter 7 to remove pump light, and then the power is measured by laser power meter 8.

[0041] Depend on Figure 2 As shown, the experimental device of Example 1 was used to achieve mid-infrared passive Q-switched laser output, and the pulse waveform is shown in the figure. A 973nm semiconductor laser was used as the pump source, and a 2×2×8mm end-pumped 3 The 10at% Er, 0.1at% Pr: YAP crystal was used, and the 1at% Dy: YAP crystal with a size of D25×0.5mm was used as the saturated absorber to obtain a Q-switched laser output with an average power of 52mW, a pulse width of 190ns, and a peak power of 1.07W.

[0042] Example 2

[0043] This embodiment provides a method based on Er-doped 3+ and Dy 3+ Mid-infrared passively Q-switched solid-state laser made of crystal Figure 3 As shown, the specific structure is as follows:

[0044] Pump source 1 is an InGaAs semiconductor laser with an emission wavelength of around 970 nm;

[0045] The coupling system 2 consists of two convex lenses, which focus and converge the pump light;

[0046] The composite crystal element 9 is made of Er-doped 3+ Crystal 4 with Dy doping 3+ Crystal 5 is a bonded crystal element obtained by a thermal bonding process;

[0047] The composite crystal element 9 is Er-doped 3+ Crystal and Dy-doped 3+ The crystal is processed into a crystal element after orientation, cutting, polishing and thermal bonding. 3+ The crystal part is used as the laser gain medium, doped with Dy 3+ The crystal part acts as a saturated absorber and can be wrapped with indium foil and placed in a copper cooling fixture (copper heat sink). Cooling water circulates through the copper heat sink to cool the crystal element.

[0048] Under the condition of semiconductor laser end-face pumping, the resonant cavity is composed of a front cavity mirror 3 and a rear cavity mirror 6. The first front cavity mirror 3 has a high reflectivity (≥99.5%) in the 2.6-3.0μm band. If the transmittance of the first front cavity mirror 3 in the 960-980nm band cannot reach ≥95%. The spectrometer 7 is used as a filter to separate the pump light and the output laser. It has a high reflectivity (≥99.5%) in the 2.6-3.0μm band and a high transmittance (≥95%) in other bands (especially the 960-980nm band). The rear cavity mirror 6 has partial transmittance in the 2.6-3μm band.

[0049] The laser output process of the above-mentioned mid-infrared passively Q-switched solid-state laser is as follows:

[0050] The pump light emitted by the pump source 1 is focused by the coupling system 2, passes through the front cavity mirror 3 and is incident on the end face of the composite crystal element 9 in the resonant cavity. 3+ The crystal part realizes 2.6~3.0μm laser oscillation, and Dy doped 3+ The crystal part realizes passive Q-switching through saturated absorption, and finally realizes "self-Q-switched" laser output. After the output laser is filtered out of the pump light by the spectroscope 7, the power is measured by the laser power meter 8.

[0051] Example 3

[0052] This embodiment provides a method based on Er-doped 3+ and Dy 3+ Mid-infrared passively Q-switched solid-state laser made of crystal material, Figure 4 As shown, the specific structure is as follows:

[0053] The semiconductor laser side pump source 11 is a semiconductor laser side pump source with circulating cooling water 12;

[0054] Laser energy meter 13;

[0055] Er-doped 3+ Crystal 4 serves as the laser gain medium;

[0056] Dy-doped 3+ Crystal 5 acts as a saturated absorber;

[0057] The Er-doped 3+ Crystal 4 and Dy-doped 3+ The crystal 5 is a laser element that has been processed through orientation, cutting, and polishing.

[0058] Under the side pumping condition of the semiconductor laser, the resonant cavity is composed of a second front cavity mirror 10 and a rear cavity mirror 6. The reflectivity of the second front cavity mirror 10 in the 2.6-3.0 μm band is ≥99.5%, and the rear cavity mirror 6 has partial transmittance in the 2.6-3.0 μm band.

[0059] The semiconductor laser side pump source 10 has multiple semiconductor laser palladium bars with an emission wavelength of around 970nm, which can provide extremely high pump power. The circulating cooling water cools the semiconductor laser target bars and laser crystal components at the same time to avoid damage to the instrument and laser components.

[0060] The laser output process of the above-mentioned mid-infrared passively Q-switched solid-state laser is as follows:

[0061] Will be doped with Er 3+The laser gain medium 4 is placed in a semiconductor laser side-pumped source 11 with circulating cooling water 12, and pump light is incident into the Er-doped 3+ laser gain medium 4 from the side, and 2.6-3.0 μm laser radiation is generated in the laser gain medium 4, and laser oscillation is achieved by an optical resonant cavity, and then the oscillation laser is converted into 2.0-2.4 μm laser radiation by the Dy-doped 3+ crystal 5 in the same resonant cavity, and the 2.6-3.0 μm passive Q-switched laser output is achieved by using the saturated absorption characteristics of the crystal 5 in the waveband, and the output energy is measured by using a laser energy meter 13.

[0062] Example 4

[0063] This example provides a kind of based on Er-doped 3+ and Dy-doped 3+ crystal mid-infrared passive Q-switched solid-state laser, as shown in the specific structure as follows: Figure 5

[0064] The semiconductor laser side-pumped source 11 is a semiconductor laser side-pumped source with circulating cooling water 12;

[0065] The laser energy meter 13;

[0066] The composite crystal element 9 is an Er-doped 3+ crystal and a Dy-doped 3+ crystal processed into a crystal element after orientation, cutting, polishing and thermal bonding. Among them, the Er-doped 3+ crystal part acts as a laser gain medium, and the Dy-doped 3+ crystal part acts as a saturable absorber.

[0067] Under the condition of semiconductor laser side-pumping, the resonant cavity is composed of a second front mirror 10 and a rear mirror 6. The second front mirror 10 has a reflectivity ≥99.5% in the 2.6-3.0 μm waveband, and the rear mirror 6 has a partial transmittance in the 2.6-3.0 μm waveband.

[0068] The laser output process of the above-mentioned mid-infrared passive Q-switched solid-state laser is as follows:

[0069] The composite crystal element 9 bonded by the Er-doped 3+ crystal and the Dy-doped 3+ crystal is placed in a semiconductor laser side-pumped source 11 with circulating cooling water 12, and pump light is incident into the composite crystal element 9 from the side, and the Er-doped 3+ part generates 2.6-3.0 μm laser radiation, and the Dy-doped 3+ crystal part achieves passive Q-switching by saturated absorption, and finally realizes "self-Q-switched" laser output, and the output energy is measured by using a laser energy meter 13.

[0070] Example 5​

[0071] The embodiment provides a mid-infrared passive Q-switched solid laser based on Er-doped 3+ and Dy 3+ crystals, as shown in the figure, and the specific structure is as follows: Figure 6

[0072] The xenon lamp 14 is a side-pumping source with circulating cooling water 12;

[0073] The laser energy meter 13;

[0074] The xenon lamp condensing cavity 15;

[0075] The Er-doped 3+ crystal 4 is used as a laser gain medium;

[0076] The Dy-doped 3+ crystal 5 is used as a saturable absorber;

[0077] The Er-doped 3+ crystal 4 and the Dy-doped 3+ crystal 5 are processed into laser elements after orientation, cutting and polishing;

[0078] Under the condition of side-pumping of the xenon lamp 14, the resonant cavity is composed of the second front mirror 10 and the rear mirror 6. The second front mirror 10 has a reflectivity of greater than or equal to 99.5% in the 2.6-3.0 μm wave band, and the rear mirror 6 has a partial transmittance in the 2.6-3.0 μm wave band.

[0079] The laser output process of the above mid-infrared passive Q-switched solid laser is as follows:

[0080] The Er-doped 3+ crystal 4 is placed in the xenon lamp side-pumping source 15 with circulating cooling water 12, the pumping light of the xenon lamp 14 is incident into the Er-doped 3+ crystal 4 from the side and generates 2.6-3.0 μm laser radiation, laser oscillation is realized through the optical resonant cavity, then the oscillation laser passes through the Dy-doped 3+ crystal 5 in the same resonant cavity, the saturable absorption characteristics of the Dy-doped 3+ crystal 5 in the wave band are used to realize 2.6-3.0 μm passive Q-switched laser output, and the laser energy meter 13 is used to measure the output energy.

[0081] Embodiment 6

[0082] The embodiment provides a mid-infrared passive Q-switched solid laser based on Er-doped 3+ and Dy 3+ crystals, as shown in the figure, and the specific structure is as follows: Figure 7

[0083] The xenon lamp 14 is a side-pumping source with circulating cooling water 12;

[0084] laser energy meter 13;

[0085] xenon lamp condensing cavity 15;

[0086] The composite crystal element 9 is Er-doped 3+ crystal and Dy-doped 3+ crystal is processed into a crystal element after being oriented, cut, polished and heat bonded. The Er-doped 3+ crystal part acts as a laser gain medium, and the Dy-doped 3+ crystal part acts as a saturable absorber.

[0087] Under the condition of side-pumping of the xenon lamp 14, the resonant cavity is composed of a second front cavity mirror 10 and a rear cavity mirror 6. The second front cavity mirror 10 has a reflectivity of ≥99.5% in the 2.6-3.0 μm waveband, and the rear cavity mirror 6 has a partial transmittance in the 2.6-3.0 μm waveband.

[0088] The laser output process of the above-mentioned mid-infrared passively Q-switched solid-state laser is as follows:

[0089] The Er-doped 3+ crystal and the Dy-doped 3+ crystal bonded composite crystal element 9 is placed in the xenon lamp condensing cavity 15 with circulating cooling water 12, and the pumping light of the xenon lamp 14 is incident into the composite crystal element 9 from the side, so that the Er-doped 3+ crystal generates 2.6-3.0 μm laser radiation, and the Dy-doped 3+ crystal realizes passive Q-switching through saturable absorption characteristics, and finally obtains "self-Q-switched" laser output, and the output energy is measured by the laser energy meter 13.

[0090] The mid-infrared passively Q-switched solid-state laser based on the Er-doped 3+ and Dy-doped 3+ crystals provided in Embodiments 2-6 is subjected to laser output, and the output results prove that the laser of the present application uses the Dy-doped 3+ crystal as a saturable absorber of Er 3+ laser, and utilizes the saturable absorption of the Dy 3+ crystal in the 2.6-3.0 μm waveband to regulate the loss of the laser resonant cavity, so as to realize the operation of mid-infrared passively Q-switched laser with ns-level pulse width. The laser has both the high damage threshold of crystal material and the compact and small size advantage of passive Q-switching, and further, the Er-doped 3+ and the Dy-doped 3+ crystals can be processed into a composite crystal element through heat bonding, so that the laser oscillation and passive Q-switching are realized in one crystal element, and "self-Q-switched" laser operation is realized, which is beneficial to further realizing the miniaturization of the laser.

[0091] Those skilled in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limiting. Numerous variations and modifications will be apparent to those skilled in the art, without departing from the scope of the present application.

Claims

1. Based on Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that Using semiconductor laser or xenon lamp as pump source, Er-doped 3+ Crystal is used as laser gain medium, doped with Dy 3+ The crystal acts as a saturated absorber; the pump source pumps the Er-doped 3+ crystal, produces mid-infrared 2.6~3μm laser output, and utilizes Dy doped 3+ The crystal's saturation absorption characteristics of the laser in this band further modulate the 2.6-3μm laser, directly achieving passive Q-switched laser output with high peak power and ns-level pulse width.

2. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that The Er-doped 3+ Crystal refers to Er 3+ Oxide, fluoride, sulfide or selenide crystals doped alone or with other ions, where Er 3+ The doping concentration of the ions is 1 to 50 at.%.

3. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that The Dy-doped 3+ Crystal refers to Dy 3+ Oxide, fluoride, sulfide or selenide crystals doped alone or with other ions, where Dy 3+ The doping concentration of the ions is 0.1 to 5 at.%.

4. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that Er-doped 3+ and Dy-doped 3+ The matrix crystals of the crystals are the same or different.

5. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that The Er-doped 3+ and Dy 3+ The shape of the crystal is one or a combination of two or more of square plate, block, disc, cylinder, lath or optical fiber.

6. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that The Er-doped 3+ and Dy 3+ The crystal is composed of two crystal elements.

7. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that The Er-doped 3+ and Dy 3+ The crystal is a bonded crystal element, made of Er-doped 3+ and Dy 3+ The two crystal components are thermally bonded.

8. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that The bonded crystal element refers to an Er-doped 3+ One end of the laser crystal is bonded with Dy 3+ Crystal, combining laser crystal and saturated absorber into a crystal element, further realizing the miniaturization of laser.

9. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that Under the condition of semiconductor laser end pumping, the resonant cavity is composed of a front cavity mirror and a rear cavity mirror. The reflectivity of the front cavity mirror in the 2.6-3.0μm band is ≥99.5%, and the transmittance in the 960-980nm band is ≥95%. The rear cavity mirror has partial transmittance in the 2.6-3μm band, and the transmittance is 0.5-10%.

10. The Er-doped 3+ and Dy 3+ A crystal mid-infrared passively Q-switched solid-state laser, characterized in that Under the condition of side pumping by a semiconductor laser or a xenon lamp, the resonant cavity is composed of a front cavity mirror and a rear cavity mirror. The reflectivity of the front cavity mirror in the 2.6-3.0 μm band is ≥99.5%, and the rear cavity mirror has partial transmittance in the 2.6-3.0 μm band, with a transmittance of 1-50%.

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