CN117624427A

CN117624427A - Laser gain medium, preparation method thereof and yellow-green laser

Info

Publication number: CN117624427A
Application number: CN202410100894.5A
Authority: CN
Inventors: 王巍; 张四维; 贾中青; 翟瑞占; 朱天瑜; 刘民哲; 赵坤; 孙丽媛; 张明山; 田晓琳; 吴永静; 刘梦霖
Original assignee: Laser Institute of Shandong Academy of Science
Current assignee: Laser Institute of Shandong Academy of Science
Priority date: 2024-01-25
Filing date: 2024-01-25
Publication date: 2024-03-01
Anticipated expiration: 2044-01-25
Also published as: CN117624427B

Abstract

The application relates to the technical field of lasers and provides a laser gain medium, a preparation method thereof and a yellow-green laser, wherein the method comprises the steps of dissolving perylene orange in one of ethanol, acetone or methanol to obtain perylene orange solution; mixing an initiator with methyl methacrylate to obtain a first mixed solution; mixing the perylene orange solution with the first mixed solution to obtain a second mixed solution; injecting the second mixed solution into a quartz container; the quartz container is of a prismatic structure with an opening, the number of the side walls of the prismatic structure is n, and each side wall is provided with a blue light LED lamp strip; and controlling n blue light LED lamp strips to irradiate the second mixed solution for a preset time to obtain the laser gain medium. The preparation method can produce a solidified laser gain medium with a larger volume in a shorter time, maintains the high-gain characteristic of the laser dye, is simple, has low preparation cost, can prepare the laser gain medium with a large volume, and effectively reduces the production cost.

Description

Laser gain medium, preparation method thereof and yellow-green laser

Technical Field

The application relates to the technical field of lasers, in particular to a laser gain medium, a preparation method thereof and a yellow-green laser.

Background

Yellow-green light is widely applied to a plurality of fields such as medicine, chemistry, communication, biology, glass color-Einstein condensation, display technology and the like, and the preparation of a laser gain medium for outputting the yellow-green light is also particularly important.

A laser gain medium refers to a material system that achieves population inversion and generates stimulated radiation amplification of light, for which purpose the laser gain medium needs to have a suitable energy level structure and transition characteristics.

Existing methods of preparing laser gain media include thermal polymerization methods and laser methods. In the thermal polymerization method, it is necessary to continuously heat to a specific temperature and hold for a certain period of time to allow the reaction to proceed smoothly, resulting in higher production costs and low production efficiency. In the laser method, although reaction heating is not required, there are still technical problems of low output power and poor output beam quality.

Therefore, there is a need for a method for preparing gain media that is low cost, high yield, and meets the requirements of lasers.

Disclosure of Invention

The application provides a laser gain medium, a preparation method thereof and a yellow-green laser, so as to solve the technical problems that the gain medium preparation method is high in cost and low in yield, and the prepared gain medium cannot meet the laser requirements.

The preparation method of the laser gain medium provided in the first aspect of the application comprises the following steps: dissolving perylene orange in one of ethanol, acetone or methanol to obtain perylene orange solution; mixing an initiator with methyl methacrylate to obtain a first mixed solution; mixing the perylene orange solution with the first mixed solution to obtain a second mixed solution; injecting the second mixed solution into a quartz container; the quartz container is of a prismatic structure with an opening, the number of the side walls of the prismatic structure is n, each side wall is provided with a blue light LED lamp strip, and n is greater than or equal to 5; and controlling n blue light LED lamp strips to irradiate the second mixed solution for a preset time to obtain the laser gain medium.

In some possible implementations, the molar ratio of perylene orange to ethanol is 1:1.53, the molar ratio of perylene orange to acetone is 1:1.26, and the molar ratio of perylene orange to methanol is 1:2.25; the mass ratio of the initiator to the methyl methacrylate is 2:98; the volume ratio of the perylene orange solution to the first mixed solution is 9:100.

in some possible implementations, the initiator is 2-hydroxy-2-methylpropionacetone.

In some possible implementations, in the blue LED light bar, the wavelength of the LED light beads is less than or equal to 455nm, and the optical power is 1.5W; the preset time is more than or equal to 5min and less than or equal to 15min.

The laser gain medium provided in the second aspect of the application is prepared by the preparation method of the laser gain medium provided in the first aspect, and the gain medium comprises a polished surface.

The yellow-green laser provided in the second aspect of the present application includes: the laser gain medium of the second aspect; a pump light source configured to generate pump light; a first mirror disposed on an optical path of the pump light and configured to reflect the pump light; the beam expander is arranged at one side of the first reflector, which is far away from the pump light source, and is configured to expand the pump light; wherein the beam expansion multiple of the beam expander is 5; the cylindrical mirror is arranged on one side of the beam expander, far away from the reflecting mirror, and is configured to focus the pump light after beam expansion; the laser gain medium is arranged on one side of the cylindrical mirror far away from the beam expander and is configured to convert the focused pump light into yellow-green light; the second reflecting mirror is arranged on one side of the gain medium and is parallel to the cylindrical mirror; wherein the second mirror is configured to reflect yellow-green light; and an output mirror disposed at the other side of the gain medium, the second reflecting mirror and the output mirror being disposed at both sides of the gain medium, respectively, wherein the output mirror is configured to output yellow-green light.

In some possible implementations, the laser gain medium is a cuboid structure with dimensions of 2mm x 10mm; the wall surface of the laser gain medium facing the cylindrical mirror is a side wall surface, the side wall surface is a polished surface, and the end wall surfaces at two ends of the laser gain medium are polished surfaces.

In some possible implementations, the focal point of the focused pump light output by the cylindrical mirror is located inside the gain medium, and the distance between the focal point and the surface of the gain medium, which is close to one side of the cylindrical mirror, is 1.5mm; wherein the focal length of the cylindrical mirror is 150mm.

In some possible implementations, the wavelength of the pump light is 532nm or 515nm; the pumping light source is a nanosecond light source, the pulse width is 8ns, and the repetition frequency is 100kHz; or the pumping light source is a picosecond light source, the pulse width is 20ps, and the repetition frequency is 1MHz; or the pumping light source is a femtosecond light source, the pulse width is 350fs, and the repetition frequency is 1MHz.

In some possible implementations, the coating parameters of the first mirror and the second mirror are: 565-585nm, the reflectivity is more than 99.5%; the coating parameters of the output mirror are as follows: 565-585nm, the transmittance is: 39% -41%.

In the preparation method of the laser gain medium, the laser gain medium and the yellow-green light laser, the preparation method of the laser gain medium comprises the steps of dissolving perylene orange in one of ethanol, acetone or methanol to obtain perylene orange solution; mixing an initiator with methyl methacrylate to obtain a first mixed solution; mixing the perylene orange solution with the first mixed solution to obtain a second mixed solution; injecting the second mixed solution into a quartz container; the quartz container is of a columnar structure with an opening, the number of the side walls of the columnar structure is n, each side wall of the n side walls is provided with a blue light LED lamp strip, and n is greater than or equal to 5; and controlling n blue light LED lamp strips to irradiate the second mixed solution for a preset time to obtain the laser gain medium. In the preparation method, after the perylene orange is cured by a photopolymerization method, a larger volume of cured laser gain medium can be produced in a shorter time. Can directly receive pumping and output laser without using dye pump to do circulation cooling, and maintains the high gain characteristic of laser dye. In addition, the method has simple working procedures in the manufacturing process, can prepare large-volume laser gain media, and effectively reduces the production cost.

Drawings

In order to more clearly illustrate the technical solutions of the present application, the drawings that are needed in the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a schematic flow chart of a method for preparing a gain medium according to an embodiment of the present application;

FIG. 2 is a schematic view of a quartz container according to an embodiment of the present application;

FIG. 3 is an ASE spectrum of perylene orange 240:PMMA provided in the examples of the present application;

fig. 4 is a schematic structural diagram of a yellow-green laser according to an embodiment of the present application.

The graphic indicia:

a 100-quartz vessel; 11-quartz structure; a 12-aluminum alloy bracket; 13-LED lamp strips;

200-yellow-green laser, 21-pump light source; 22-a first mirror; 23-beam expander; 24-cylindrical mirror; 25-a laser gain medium; 26-a second mirror; 27-output mirror.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. It will be apparent that the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments of the present application, other embodiments that may be obtained by a person of ordinary skill in the art without making any inventive effort are within the scope of the present application.

Hereinafter, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

Furthermore, in this application, the terms "upper," "lower," "inner," "outer," and the like are defined relative to the orientation in which components are schematically depicted in the drawings, and it should be understood that these directional terms are relative terms, which are used for descriptive and clarity relative, and which may vary accordingly depending on the orientation in which components are depicted in the drawings.

In order to facilitate the technical solution of the application, some concepts related to the present application will be described below first.

Laser dye: in dye lasers, excitation of an excitation light source produces a dye that tunes the laser. Dye lasers use different laser dyes to generate laser light of different wavelengths for spectroscopy and atmospheric pollution monitoring, isotope separation, specific photochemical reactions, color holography, disease diagnosis and treatment, and the like.

Perylene orange 240: BASF Lumogen F Orange 240A laser dye is used in the fields of copying operations, electricity, etc. Can be used as fluorescent pigment.

MMA: methyl methacrylate, formula C ₅ H ₈ O ₂ The resin is colorless liquid, is slightly soluble in water, is soluble in most organic solvents such as ethanol and the like, is mainly used as a monomer of organic glass, and is also used for manufacturing other resins, plastics, paint, adhesives, lubricants, impregnating compounds of wood and cork, paper polishing agents and the like.

PMMA: polymethyl Methacrylate polymethyl methacrylate is a high molecular polymer, also called acrylic or organic glass, has the advantages of high transparency, low price, easy machining and the like, and is a glass substitute material which is commonly used.

HMPP: photo initiator 1173,2-hydroxy-2-methyl propiophenone (initiator 1173), photoinitiator.

Amplified spontaneous emission spectrum (Absorption Spectroscopy Emission, ASE): the dye is excited to generate ASE light beam, and the excitation wavelength and gain spectrum of the material can be known by measuring the spectrum of the ASE light beam.

Yellow-green light is widely applied to a plurality of fields such as medicine, chemistry, communication, biology, vitreo-Einstein condensation and display technology, and is particularly applied to scenes such as cancer phototherapy, retina treatment, visible light communication, optogenetics, laser display and the like. At present, the yellow-green light has great demands in the fields of sodium star guiding, optogenetics, temperature and wind measuring laser radar, silicon chip processing, laser display, space target detection and identification and the like.

The preparation of the laser gain medium for outputting yellow-green light is also particularly important. A laser gain medium refers to a material system that achieves population inversion and generates stimulated radiation amplification of light, for which purpose the laser gain medium needs to have a suitable energy level structure and transition characteristics.

Existing methods of preparing laser gain media include thermal polymerization methods and laser methods.

The thermal polymerization method is to add a thermal initiator into a mixed solution of dye, solvent thereof and polymer, and uniformly heat the mixed solution to realize polymerization reaction. Thermal polymerization protocol: the perylene orange is dissolved in organic solvents such as ethanol, acetone or methanol, and is uniformly mixed with MMA and a thermal polymerization initiator. The ratio of MMA to benzoyl peroxide (Benzoyl peroxide Benzoyl superoxide, BPO) as a thermal polymerization initiator in the thermal polymerization mixed solution was 1ml MMA and 3mg of the thermal polymerization initiator was dispensed, and the reaction temperature at 60℃was maintained for 80 minutes, followed by heating at 100℃for 60 minutes to conduct thermal polymerization.

Such thermal polymerization not only has a long reaction time, but also causes a large production cost and a low yield due to a continuous heating environment.

The laser method comprises a yellow-green light implementation method and a yellow-green light laser main stream implementation method.

In the yellow-green light implementation method, the damage threshold of the end face of the crystal is limited, so that the output power is not high.

In the mainstream implementation method of the yellow-green light laser, the dysprosium Dy crystal or the optical fiber doped laser can realize the output of the yellow-green light laser without additional conversion in a single resonant cavity, but the method has small yield and high cost.

In order to solve the above technical problems, embodiments of the present application provide a method for preparing a laser gain medium. The method can produce a solidified laser gain medium with a larger volume in a shorter time, maintains the high gain characteristic of the laser dye, is simple, has low preparation cost, can prepare the laser gain medium with a large volume, and effectively reduces the production cost.

Fig. 1 is a schematic flow chart of a method for preparing a laser gain medium according to an embodiment of the present application.

Referring to fig. 1, the laser gain medium provided in the embodiment of the present application may be implemented by the following steps S100 to S500.

Step S100: and dissolving the perylene orange in one of ethanol, acetone or methanol to obtain perylene orange solution.

In step S100, one solvent of ethanol, acetone or methanol is selected.

Wherein, the molar ratio of the perylene orange to the ethanol is 1:1.53, the molar ratio of the perylene orange to the acetone is 1:1.26, and the molar ratio of the perylene orange to the methanol is 1:2.25.

Taking ethanol solution as an example, 1mol of perylene orange is dissolved in 1.53mol of ethanol to obtain perylene orange solution.

It is noted that the volume measurement is convenient when the organic solvent such as ethanol is taken, and the volume of the organic solvent such as ethanol is taken as a reaction parameter. The molar parameters are conveniently converted into volume parameters.

In one specific implementation, 0.001mol of perylene orange powder is dissolved in 90 μl of one of ethanol or acetone or methanol. The concentration of the perylene orange solution at this time was 0.011mol/ml. In the implementation, the reaction material with smaller component is mainly used for installing the prepared laser gain medium in a yellow-green laser, so that the laser gain medium with smaller volume is prepared according to the requirement. Of course, in other implementations, larger volumes of laser gain medium may be prepared using the molar ratios described above.

The concentration of perylene orange molecules is not too high, the concentration of the perylene orange molecules after curing is high, concentration quenching is easy to occur in the excitation process, and stimulated radiation cannot be generated, so that the concentration of the prepared perylene orange solution is controlled to be 0.011mol/ml, and the perylene orange solution is convenient for a laser gain medium obtained later to be better applied to a laser.

In particular, perylene orange is a powdered material. In some possible implementations, to promote rapid and more complete dissolution of the perylene orange powder in an organic solvent of ethanol, acetone or methanol, heating may be performed during the dissolution process, and the heating temperature may be 50-60 ℃.

Step S200: the initiator is mixed with methyl methacrylate to obtain a first mixed solution.

In step S200, an initiator and Methyl Methacrylate (MMA) may be mixed at a mass ratio of 2:98 to obtain a first mixed solution.

In one particular implementation, the initiator may be 2-hydroxy-2-methylpropionacetone (HMPP).

Step S300: and mixing the perylene orange solution with the first mixed solution to obtain a second mixed solution. Wherein the volume ratio of the perylene orange solution to the first mixed solution is 9:100.

Specifically, 1ml of the first mixed solution was mixed with 90. Mu.l of perylene orange solution until complete mixing, to obtain a second mixed solution. The second mixed solution is in the form of a liquid of the laser gain medium, and needs to be solidified in a subsequent step, so that the solid laser gain medium is obtained.

Step S400: the second mixed solution was injected into the quartz vessel.

The quartz container is of a prismatic structure with an opening, the number of the side walls of the prismatic structure is n, and each side wall is provided with a blue light LED lamp strip 13, wherein n is greater than or equal to 5.

Fig. 2 is a schematic structural view of a quartz container according to an embodiment of the present application.

Referring to fig. 2, in step S400, the second mixed solution is poured into the quartz container 100 to be solidified, the quartz container 100 is a column structure having one end closed and the other end having an opening structure, and the second mixed solution may be poured into the quartz container 100 through the opening.

The description is given with n being 5, and the quartz vessel 100 is a regular pentagonal prism.

Specifically, the inner wall of the pentagonal prism is a quartz structure 11, and a layer of aluminum alloy bracket 12 is attached to the outer side of the quartz structure 11, so that the blue light LED light bar 13 can be conveniently installed. The aluminum alloy bracket 12 is provided with a mounting groove, wherein each side wall is correspondingly provided with a mounting groove, the blue LED lamp strip 13 is arranged in the mounting groove, and the quartz container 100 is of a transparent structure, so that light emitted by the blue LED lamp strip 13 in the mounting groove can penetrate through the quartz container 100 to irradiate a second mixed solution in the quartz container 100.

It is noted that in other embodiments, the quartz container 100 may also be a hexagonal prism structure, an eight-prism structure, or the like. The shape of the quartz container 100 can be adjusted according to the size and the characteristics of the laser gain medium required by the laser, and the quartz container 100 is set to have a side wall structure with n being more than or equal to 5, mainly considering the uniformity of the irradiation of the LED lamp beads to the second mixed solution, thereby ensuring the characteristics of the laser gain medium.

Step S500: and controlling n blue LED lamp strips 13 to irradiate the second mixed solution for preset time to obtain the laser gain medium.

Taking n as an example, 5 blue LED light bars 13 are controlled to irradiate the second mixed solution for a preset time. In the irradiation process, the LED lamp beads are kept to output the maximum light power, the preset time is more than or equal to 5min and less than or equal to 15min, and compared with thermal polymerization, the reaction time is greatly shortened.

Because the curing speed of the ultraviolet LED is faster, ultraviolet light can break the chemical bond of perylene orange molecules easily, and the energy transfer can not be completed, so that the dye is finally disabled. Meanwhile, the longer wavelength of the curing light is selected to delay the curing time, so that the wavelength needs to be controlled, and a light source with shorter wavelength and lower destructive power is selected as the curing light. Specifically, the wavelength of the LED lamp beads in each blue LED lamp strip 13 is less than or equal to 455nm, and the optical power is 1.5W.

In a specific implementation, the preset time may be 10 minutes.

After the solidification is completed, the solid laser gain medium can be taken out from the quartz container 100, and the obtained solid laser gain medium is perylene orange 240:PMMA.

According to the preparation method of the laser gain medium, after the second mixed solution is solidified through the photopolymerization method, the solidified laser gain medium with a larger volume can be produced in a shorter time. The laser dye can be directly pumped and output under the condition of not using a dye pump for circulating cooling, and the high-gain characteristic of the laser dye is maintained. In addition, the method has simple working procedures in the manufacturing process, can prepare large-volume laser gain media, and effectively reduces the production cost.

Corresponding to the preparation method of the laser gain medium, the application also provides an embodiment of the laser gain medium, and the laser gain medium is prepared by the preparation method of the laser gain medium provided by the embodiment, so that the method has all the beneficial technical effects in the embodiment.

Specifically, the laser gain medium provided in the embodiments of the present application includes a polished surface. The purpose of the polishing process of the laser gain medium is to subsequently assemble it into a laser for better injection of pump light and to reduce losses of laser oscillation.

FIG. 3 is an ASE spectrum of perylene orange 240:PMMA as provided in the examples of the present application.

Referring to fig. 3, it can be seen that after the solid laser gain medium prepared by the method provided in the embodiment of the present application is subjected to a short pulse pump light with a certain power, the highest peak of the ASE spectrum is located at 573.1nm, and the luminous intensity can reach about 8000. It can be seen that the luminous intensity gradually increases to a maximum value in the course of increasing the wavelength from 555nm to 573.1nm, and gradually decreases in the course of increasing the wavelength from 573.1nm to 590 nm.

The application also provides an embodiment of a yellow-green laser.

Fig. 4 is a schematic structural diagram of a yellow-green laser 200 according to an embodiment of the present disclosure.

Referring to fig. 4, the yellow-green laser includes a laser gain medium 25, a pump light source 21, a first mirror 22, a beam expander 23, a cylindrical mirror 24, a second mirror 26, and an output mirror 27.

The pump light source 21 is used to generate pump light.

Specifically, the light source of the pump light may be one of a nanosecond light source, a picosecond light source, or a femtosecond light source. Since the laser gain medium 25 needs short pulse pump light, and avoids fluorescence quenching caused by the tri-linear effect generated by long pump light time, the embodiment of the application provides the 8ns, 20ps and 350fs full width at half maximum pulse pump light source 21 to output the pump light. Meanwhile, the laser gain medium 25 is easily damaged as compared with the pump light of the ultraviolet wavelength, so the wavelength of the pump light may be 532nm or 515nm.

In one specific implementation, the pump light source 21 may be a nanosecond light source, with a pulse width of 8ns, and a repetition rate of 100kHz.

In one specific implementation, the pump light source 21 may be a picosecond light source, with a pulse width of 20ps and a repetition rate of 1MHz.

In one specific implementation, the pump light source 21 may be a femtosecond light source, the pulse width may be 350fs, and the repetition frequency is 1MHz.

The first reflecting mirror 22 is disposed on the optical path of the pump light for reflecting the pump light.

Specifically, the first reflecting mirror 22 may be disposed obliquely, and the angle of inclination of the first reflecting mirror 22 is 45 °. Thus, the angle between the incident light of the first mirror 22 and the light reflected therefrom is 90 °.

A beam expander 23 disposed at a side of the first reflector 22 away from the pump light source 21, for expanding the pump light; the beam expansion factor of the beam expander 23 is 5. Specifically, the diameter of the light after beam expansion is five times the diameter of the light before beam expansion.

And a cylindrical mirror 24 disposed at a side of the beam expander 23 remote from the first reflecting mirror 22 for focusing the pump light. The focal point of the focused pump light output by the cylindrical mirror 24 is located in the laser gain medium 25, and the distance between the focal point and the surface of the laser gain medium 25, which is close to one side of the cylindrical mirror 24, is 1.5mm; wherein the focal length of the cylindrical mirror 24 is 150mm.

Thus, the laser beam emitted from the pump light source 21 passes through the 5-fold beam expander 23 and then is focused by the cylindrical mirror 24 with a focal length of 150mm, and the focal point J is located at 1.5mm of the laser gain medium 25, that is, the distance L from the focal point J to the surface of the laser gain medium 25 on the side close to the cylindrical mirror 24 is 1.5mm.

In order to ensure the output power of the yellow-green laser 200, the mode volume in the laser gain medium 25 needs to be ensured. The pump light is focused and injected into the laser gain medium 25, the area between the incident pump light and the focal point J is the area where the pump light with high power density is gained, the gain in this area is the highest, under the action of the resonant cavity, the area of the laser gain medium 25 is the laser mode area, and the area of the laser mode area needs to be ensured to ensure that the output pump light has a certain power, so the focal point J is controlled at 1.5mm of the laser gain medium 25, and a certain output power is ensured.

The laser gain medium 25 is disposed on a side of the cylindrical mirror 24 away from the beam expander 23, and is used for converting the focused pump light into yellow-green light.

Wherein the laser gain medium 25 is prepared by the preparation method provided in the above embodiment.

Specifically, the laser gain medium 25 may have a rectangular parallelepiped structure, and may have dimensions of 2mm×2mm×10mm. The purpose of the small volume of laser gain medium 25 is to facilitate heat dissipation. The wall of the laser gain medium 25 facing the cylindrical mirror 24 is a side wall, that is, a wall having dimensions of 2mm×10mm is a side wall. In order to facilitate injection of the pump light, the wall surface of 2×10mm may be polished to become a polished surface. Meanwhile, in order to reduce the oscillation loss of the pump light, the end wall of the laser gain medium 25 is also provided as a polished surface, that is, a wall surface having a size of 2mm×2mm is also provided as a polished surface.

In one possible implementation, after the laser gain medium 25 is obtained by using the method for preparing the laser gain medium 25 provided in the above embodiment, the laser gain medium 25 may be cut into a cuboid structure with dimensions of 2mm×2mm×10mm by using a cutter, and the wall surface of the laser gain medium 25 may be polished by using sand paper. Of course, in other possible implementations, the laser gain medium 25 may be polished in other manners, and the polishing limitation is not specifically limited in the embodiments of the present application.

A second reflecting mirror 26 disposed on one side of the gain medium, the second reflecting mirror 26 being disposed parallel to the cylindrical mirror 24; wherein the second mirror 26 is configured to reflect yellow-green light.

With continued reference to fig. 4, the laser gain medium 25 has a length direction that is the same as the light-emitting direction of the yellow-green light.

After the pump light is incident on the laser gain medium 25, two paths of yellow-green light are generated, one path of yellow-green light is directly transmitted to the output mirror 27 along the direction a and is emitted, and the other path of yellow-green light is transmitted to the second reflecting mirror 26 along the direction B and is reflected by the second reflecting mirror 26 and is transmitted to the output mirror 27 along the direction a. Wherein the direction B is the opposite direction A. The second mirror 26 is provided mainly for reflecting a part of the return light, avoiding the loss of yellow-green light.

Specifically, since the peak position of the gain spectrum is shifted due to the slight difference of the concentration of the laser gain medium 25, the coating parameters of the first mirror 22 and the second mirror 26 may be 565-585nm, and the reflectivity is greater than 99.5%.

In one specific implementation, the coating parameters of the first mirror 22 are 567nm, and the reflectivity is 99.8%; the second mirror 26 has a coating parameter of 567nm and a reflectivity of 99.8%.

The output mirror 27 is arranged on the other side of the laser gain medium 25, the second reflecting mirror 26 and the output mirror 27 are respectively arranged on two sides of the laser gain medium 25, wherein the output mirror 27 is used for outputting yellow-green light, and the coating parameters of the output mirror 27 are as follows: 565-585nm, the transmittance is: 39% -41%.

In one specific implementation, the output mirror 27 may have a coating parameter of 565nm and a transmittance of 39%.

The laser gain medium 25 in the yellow-green laser 200 provided by the embodiment of the present application is prepared by adopting the method provided by the embodiment, which has the beneficial technical effects in the embodiment, and meanwhile, the yellow-green laser 200 can perform side pumping, so that the design difficulty of a resonant film system structure is avoided, and the yellow-green laser can be directly output.

It is noted that other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the application pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope of the application being indicated by the following claims.

It is to be understood that the present application is not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. A method of preparing a laser gain medium, comprising:

dissolving perylene orange in one of ethanol, acetone or methanol to obtain perylene orange solution;

mixing an initiator with methyl methacrylate to obtain a first mixed solution;

mixing the perylene orange solution with the first mixed solution to obtain a second mixed solution;

injecting the second mixed solution into a quartz container; the quartz container is of a prismatic structure with an opening, the number of the side walls of the prismatic structure is n, each side wall is provided with a blue light LED lamp strip, and n is greater than or equal to 5;

and controlling n blue light LED lamp strips to irradiate the second mixed solution for preset time to obtain a laser gain medium.

2. The method of manufacturing a laser gain medium according to claim 1, wherein,

the molar ratio of the perylene orange to the ethanol is 1:1.53, the molar ratio of the perylene orange to the acetone is 1:1.26, and the molar ratio of the perylene orange to the methanol is 1:2.25;

the mass ratio of the initiator to the methyl methacrylate is 2:98;

the volume ratio of the perylene orange solution to the first mixed solution is 9:100.

3. The method of manufacturing a laser gain medium according to claim 2, wherein,

the initiator is 2-hydroxy-2-methyl propiophenone.

4. The method of manufacturing a laser gain medium according to claim 1, wherein,

in the blue light LED lamp strip, the wavelength of the LED lamp beads is less than or equal to 455nm, the light power is 1.5W, the preset time is greater than or equal to 5min and less than or equal to 15min.

5. A laser gain medium, characterized in that the laser gain medium is prepared by the preparation method of any one of claims 1-4,

the laser gain medium includes a polished surface.

6. A yellow-green laser, comprising:

the laser gain medium of claim 5;

a pump light source configured to generate pump light;

a first reflecting mirror provided on an optical path of the pump light and configured to reflect the pump light;

the beam expander is arranged at one side of the first reflector, which is far away from the pumping light source, and is configured to expand the pumping light; wherein the beam expansion multiple of the beam expander is 5;

the cylindrical mirror is arranged on one side of the beam expander, far away from the reflecting mirror, and is configured to focus the pump light after beam expansion;

the laser gain medium is arranged on one side of the cylindrical mirror far away from the beam expander and is configured to convert the focused pump light into yellow-green light;

the second reflecting mirror is arranged on one side of the laser gain medium and is parallel to the cylindrical mirror; wherein the second mirror is configured to reflect the yellow-green light;

and the output mirror is arranged on the other side of the laser gain medium, and the second reflecting mirror and the output mirror are respectively arranged on two sides of the laser gain medium, wherein the output mirror is configured to output the yellow-green light.

7. The yellow-green laser of claim 6, wherein,

the laser gain medium is of a cuboid structure, and the size is 2mm multiplied by 10mm; the wall surface of the laser gain medium facing the cylindrical mirror is a side wall surface, the side wall surface is a polished surface, and the end wall surfaces at two ends of the laser gain medium are polished surfaces.

8. The yellow-green laser of claim 6, wherein,

the focal point of the focused pump light output by the cylindrical mirror is positioned in the laser gain medium, and the distance between the focal point and the surface of the laser gain medium, which is close to one side of the cylindrical mirror, is 1.5mm; wherein, the focal length of cylindrical mirror is 150mm.

9. The yellow-green laser of claim 6, wherein,

the wavelength of the pump light is 532nm or 515nm;

the pumping light source is a nanosecond light source, the pulse width is 8ns, and the repetition frequency is 100kHz; or (b)

The pumping light source is a picosecond light source, the pulse width is 20ps, and the repetition frequency is 1MHz; or (b)

The pumping light source is a femtosecond light source, the pulse width is 350fs, and the repetition frequency is 1MHz.

10. The yellow-green laser of claim 6, wherein,

the coating parameters of the first reflecting mirror and the second reflecting mirror are as follows: 565-585nm, the reflectivity is more than 99.5%;

the coating parameters of the output mirror are as follows: 565-585nm, the transmittance is: 39% -41%.