A method and device for generating and amplifying gallery mode laser by exciting a series of microcavities with a continuous wave light source

Abstract

The present invention discloses a method and device for generating and amplifying whispering gallery mode lasers by continuously exciting and connecting microcavities with different diameters, which includes a continuous light source, a first transmission optical fiber, several SiO2 film microcavities with different diameters coated with rare earth ions for generating and amplifying whispering gallery mode lasers, couplers with the same number as the microcavities for coupling the continuous wave light source into the microcavities as the excitation source and coupling the generated whispering gallery mode lasers out, and a second transmission optical fiber. The present invention uses the continuous wave light source to provide a wide range of wavelengths, with polarization in any direction, and there is always light that can adapt to the spectral characteristics of the microcavity morphology to be coupled into the microcavity as the excitation source; and by using the characteristics that rare earth ions have rich energy levels and can absorb photons of the excitation source in a wide range of wavelength bands as the excitation source, the two are combined to construct a structure of connecting microcavities with different diameters in series through an optical fiber coupler, generating whispering gallery mode lasers with the same resonance spectrum as each level of microcavity, and the subsequent microcavity amplifies the whispering gallery mode laser with the same wavelength as the previous level.

Description

Technical Field

[0001] The invention belongs to the field of micro lasers, and in particular relates to a method and a device for generating and amplifying gallery mode lasers by exciting a series of micro cavities with a continuous wave light source. Background Art

[0002] With the development of integrated optoelectronic technology, lasers are evolving towards miniaturization and integration. Low-loss dielectric microcavities, including microsphere cavities, microcylindrical cavities, microring cavities, and microdisk cavities, form smooth surfaces under the action of liquid surface tension due to high-temperature melting. When a near-field evanescent wave coupler is used to couple light to the microcavity by grazing incidence, when the wavelength of the light meets the resonance with the microcavity (the integer multiple of the wavelength of the light in the medium is equal to the circumference of the cavity), the light is constrained by the surface of the medium and continuously reflected on the inner surface, forming a light field distribution around the large circle of the microcavity. This light field distribution is called gallery mode (WGM) resonance, and the wavelength arrangement that meets the gallery mode resonance is called the morphology resonance spectrum. Since the WGM is only distributed in a very small area of ​​the large circle of the microcavity and has a very small mode volume, when a certain optical power is coupled into the surface of the microcavity, the WGM has an extremely high power density. Extremely high power density is the basis of nonlinear optical phenomena and the prerequisite for low-threshold lasers. Therefore, this microcavity with a smooth, low-loss surface can maintain a high quality factor (high Q value) and is often used as a microresonator for rare-earth-doped photoinduced stimulated emission or dielectric nonlinear phenomenon-scattered lasers. This type of laser is often called gallery mode (WGM) laser.

[0003] This low threshold and narrow linewidth gallery mode microcavity laser has been demonstrated in silica, phosphate and tellurite glasses. These microcavities are doped with different rare earth dopant ions, such as neodymium (Nd), erbium (Er), thulium (Tm), holmium (Ho), etc., and are pumped with different laser light sources to form microcavity lasers from visible light to near and mid-infrared, such as patent CN201810239383-a cascade-pumped microcavity laser; CN112290363A is a method for making a low-cost whispering gallery microcavity laser based on erbium-doped microspheres.

[0004] Studies have shown that the output power of this type of microcavity laser is relatively low. Usually, microcavity lasers are stimulated to emit WGM resonances and stimulated radiation by pump light close to the absorption wavelength of the laser active material. This method provides the maximum excitation efficiency, but requires that the optical frequency of the external laser source must match the optical resonance frequency of the pump WGM. Therefore, in gallery mode microcavity lasers, a single-frequency laser source with narrow linewidth and tunable frequency is usually used as the excitation light source, but the wavelength of the pump light output by this pump source needs to be adjusted in real time due to the vibration or the inherent resonance wavelength of the microcavity changes with temperature, so that the pump wavelength matches the inherent wavelength of the microcavity and enters the microsphere with the maximum coupling efficiency, which makes the gallery mode microcavity laser in practical application unadaptable. To solve the above problems, we propose to use a continuous wave light source as the excitation light source, such as amplified spontaneous emission (ASE) or light-emitting diode (LED) light source as a pump laser. Among them, the ASE light source is a highly stable, high-power, broadband light source. It can reduce the coherent noise of the system, the phase noise caused by the fiber Rayleigh dispersion, and the phase shift caused by the optical Kerr effect. The ASE source of rare earth-doped optical fiber has the advantages of stable output spectrum, small environmental impact, and easy coupling with single-mode optical fiber sensing system. By using the combined structure of serially connected rare earth-doped microcavities of different diameters and optical fiber couplers, the wide spectrum and multi-polarization states of the high-power ASE light source can be fully utilized, and microcavities of different diameters can be provided as excitation sources at the same time. It also fully utilizes the rich energy levels of rare earth ions and can absorb multi-wavelength photons as the pump source of outer electrons to efficiently generate and amplify gallery mode lasers. It overcomes the shortcomings of currently using single-frequency lasers as pump light. This single-frequency laser pump source is easily affected by ambient temperature and vibration, causing detuning of the excitation light and the microcavity. The continuous light excitation source always has a wavelength that resonates with the microsphere cavity due to its wide spectrum range, and is not affected by ambient temperature and vibration, and can provide an excitation source for multiple microspheres of different diameters connected in series. Summary of the invention

[0005] The purpose of the present invention is to provide a continuous wave light source to excite the rare earth ion doped SiO 2 Method and device for generating and amplifying gallery mode laser in microcavity,

[0006] The solution adopted by the present invention to solve the technical problem is: a device for generating and amplifying gallery mode laser by exciting a cascaded microcavity with a continuous wave light source, comprising a continuous light source for providing pump light, a first transmission optical fiber for transmitting the excitation light, and a plurality of SiO2 doped with rare earth ions with different diameters for generating and amplifying laser. 2A membrane microcavity, a coupler with the same number as the microcavity for coupling a continuous light source into the microcavity to form a gallery mode and to generate laser coupling output, and a second optical fiber for transmitting laser; one end of the first transmission optical fiber is connected to a continuous wavelength light source as a pump source, and the other end is connected to the head end of the coupler, each of the couplers is tangentially coupled to the large circle cross-section of the microcavity in a one-to-one correspondence, and each coupler is connected head to tail; one end of the second transmission optical fiber is connected to the tail end of the last coupler, and the other end is connected to the output port of the gallery mode laser generated and amplified.

[0007] Furthermore, the coated microcavity is made by coating a functional film on the microcavity using a sol-gel method, the thickness of the functional film is between 0.5 μm and 2 μm, the diameter of the microcavity is between 10 μm and 5000 μm, and can be a microsphere, a microcolumn, a microdisk, a microcore ring microcavity, or a microring; the diameters of the serially connected microcavities are different; the microcavity is made of SiO 2 Microdisk or SiO 2 The optical fiber is heated and melted at high temperature to form a smooth microcavity under the action of liquid surface tension. The high temperature heating source can be an alcohol lamp flame, methane gas flame, hydrogen flame or CO 2 Lasers, etc.; the front-connected microcavity generates lasers, and the rear-connected microcavity can generate new wavelength lasers or amplify the wavelength lasers that resonate with the front microcavity. The generated lasers are related to the doped rare earth ions and the wavelength of the pump source, such as the 1550nm band of the communication wavelength and the 2μm band used for laser procedures and human eye safety.

[0008] Furthermore, the continuous wave light source is a light emitting diode (LED), or an amplified spontaneous emission source (ASE), or other light sources that output continuous wavelengths, and the wavelength may be 900-1100 nm, or 1500-1600 nm.

[0009] Furthermore, the optical fiber coupler is a bi-conical optical fiber or a half-cut optical fiber that is polished in half. The first transmission optical fiber and the second transmission optical fiber are both standard communication quartz optical fiber, plastic optical fiber or nylon optical fiber. The continuous light source, the first transmission optical fiber, the coupler, the second transmission optical fiber and the output port for generating and amplifying the gallery mode laser are all connected through an optical fiber connector, which refers to a passive device that connects optical fibers.

[0010] Furthermore, the doped rare earth ion may be erbium (Er 3+ ), Thulium (Tm 3+ ), Neodymium (Nb 3+ ), Ytterbium (Yb 3+ )Holmium(Ho 3 + ), praseodymium 3+ ) or a combination thereof. Rare earth ion doped SiO is plated outside the microcavity 2The functional film is made by sol-gel method, and the thickness of the functional film is between 0.5 μm and 2 μm;

[0011] The method of doping rare earth ions in the sol of the sol-gel method is a universal method, and the rare earth ions are added through nitrates or chlorides.

[0012] Furthermore, the method for preparing the rare earth ion doped sol comprises the following steps:

[0013] Step S1: according to the volume fraction ratio of 39.9% ethyl orthosilicate, 39.9% anhydrous ethanol, 19.2% deionized water, and 1% dimethylformamide, a total volume of V (5-50) ml of the above solvent with a purity of 99.9% is measured and placed in a beaker;

[0014] Step S2: Add a calculated amount of nitrate or chloride hydrate (so that the rare earth ion content of the film is 2 to 6 wt.%) into a beaker, put in a magnetic vibrator, seal the beaker and place it on a magnetic stirrer;

[0015] Step S3: Turn on the magnetic stirrer and stir at room temperature for 3 to 5 hours;

[0016] Step S4: Turn off the magnetic stirrer, let the beaker stand for 5 to 15 hours to form a sol, and store it in an environment of 25°C.

[0017] Furthermore, the microcavity is coated by a sol-gel method, and the method comprises the following steps:

[0018] Step P1: immerse the microcavity in gel for 1-3 minutes, take it out and air dry it for 3-8 minutes, heat the microcavity attached with the air-dried gel with a discharge arc or laser to melt the gel, cool it naturally to form a dense functional film, and observe the coated microcavity under a microscope to measure and record the diameter;

[0019] Step P2: Repeat step P1 until the thickness of the functional film is between 0.5 μm and 2 μm.

[0020] Furthermore, the excitation light source has a wavelength that can be absorbed by the rare earth ions in the microcavity coating layer and is a light source that emits continuous wavelengths, such as LED, ASE, and SLED light sources, for exciting the rare earth ions in the outer layer of the microcavity to generate gallery mode lasers.

[0021] Furthermore, the wavelength and intensity of the generated and amplified gallery mode laser are detected by a spectrum analyzer, an optical power meter or an optical wavelength meter.

[0022] The present invention also provides a method for generating and amplifying gallery mode laser by the device as described above, wherein SiO2 is coated with rare earth ion doped 2The membrane microcavity is in tangential contact with the coupler, forming a structure in which microcavities of different diameters are connected in series through an optical fiber coupler. The continuous wave light source is turned on, and the light emitted by the continuous wave light source is transmitted as the excitation light to the first-stage coupler of the series-connected microcavity through the first transmission optical fiber. The excitation light is coupled into the first-stage SiO2 doped with rare earth ions as an evanescent wave. 2 In the membrane microcavity, stimulated radiation generates the gallery mode laser of the first microcavity; the remaining excitation light and the gallery mode laser of the first microcavity are selectively entered into the second rare earth ion-doped SiO2 through the second coupler. 2 The gallery mode laser of the second microcavity is generated in the membrane microcavity, and the gallery mode laser of the same wavelength as the gallery mode laser of the second microcavity is amplified by the first microcavity. The three or more microcavities connected in series are the same as this. The continuous light source excites the microcavity of this level to produce the gallery mode laser, amplifies the gallery mode laser of the same wavelength as the previous microcavity connected in series, and finally outputs the gallery mode laser of each wavelength through the second transmission optical fiber. The microcavities of each level of the present invention can generate gallery mode lasers, and at the same time, the lower microcavity amplifies the laser generated by the upper microcavity that can resonate with the gallery mode laser of this level, and the non-resonant wavelength passes almost losslessly, making full use of the energy of the ASE light source and the characteristics of rare earth ions absorbing photons with a wider wavelength band, so as to generate and amplify gallery mode lasers with high efficiency.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) Easy to generate and amplify gallery mode lasers. The present invention uses a coated microcavity to obtain a quality factor and power density far exceeding that of a Fabry-Perot microcavity or a photonic crystal microcavity, which is conducive to realizing the stimulated emission process and obtaining gallery mode lasers.

[0025] (2) The excitation light source is a low-cost LED or ASE light source, and the excitation light source can be efficiently utilized. The present invention fully utilizes the energy of the continuous light source by serially connecting rare earth ion-doped microcavities and amplifies the gallery mode laser with high efficiency.

[0026] (3) By using the structure of serially connected rare earth doped microcavities of different diameters and fiber couplers, the wide spectrum and multi-polarization states of the high-power ASE light source can be fully utilized. Microcavities of different diameters can be provided as excitation sources at the same time. The rare earth ions with rich energy levels and the ability to absorb multi-wavelength photons can be used as pump sources for outer electrons to efficiently generate and amplify gallery mode lasers. This overcomes the shortcomings of currently using single-frequency lasers as pump light. This single-frequency laser pump source is easily affected by ambient temperature and vibration, causing detuning of the excitation light. The continuous light excitation source always has a wavelength that resonates with the microsphere cavity due to its wide spectrum range, and is not affected by ambient temperature and vibration. It can also provide an excitation source for multiple serially connected microspheres of different diameters.

[0027] (4) Low cost. The continuous wave light source, the first transmission optical fiber, the second transmission optical fiber, etc. used in the present invention are all commonly used and technically reliable products, which can greatly reduce the cost of the gallery mode laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described below in conjunction with the accompanying drawings;

[0029] Figure 1 A schematic diagram of a continuous light source exciting a serial connection of microcavities with different diameters to generate and amplify a gallery mode laser device according to the present invention;

[0030] Figure 2 Schematic diagram of the continuous light source excitation cascaded microcavities of different diameters to generate and amplify the gallery mode laser device of Example 1;

[0031] Figure 3 This is the energy absorption spectrum diagram of the ASE light source of Example 1 of the present invention;

[0032] Figure 4 This is a schematic diagram of 2μm gallery mode laser output according to Example 1 of the present invention;

[0033] In the figure: TDSM means Tm doped 3+ Silica microspheres;

[0034] Figure 3 Middle: Transmission spectra of ASE light source when TDSM1, TDSM2 and TDSM1 + TDSM2 are coupled respectively;

[0035] Figure 4 Middle: Laser spectra near 2 μm generated by ASE-pumped TDSM, (a) Laser spectra of TDSM1 and TDSM2 acting alone, (b) Laser spectra of TDSM1 and TDSM2 cascaded. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] like Figure 2 As shown, the 1550nm band ASE continuous light source in this embodiment excites the thulium-doped SiO 2 The device for generating and amplifying 2μm gallery mode laser by microspheres comprises a 1550nm band ASE continuous light source for providing excitation light, a first transmission optical fiber for transmitting the excitation light, two thulium ion-doped SiO2 lasers for generating and amplifying 2μm lasers, and a 1550nm band ASE continuous light source for providing excitation light, a first transmission optical fiber for transmitting the excitation light, and two thulium ion-doped SiO2 lasers for generating and amplifying 2μm lasers. 2 The invention relates to a membrane microsphere, a coupler having the same number as the microspheres for coupling a 1550nm band continuous light source into the microspheres to form a gallery mode and coupling out the generated 2μm laser, and a second optical fiber for transmitting the 2μm laser; one end of the first transmission optical fiber is connected to the 1550nm band continuous light source, and the other end is connected to the head end of the first coupler, and each coupler is respectively connected to the thulium-doped SiO2 The microspheres are tangentially coupled one by one at the equator, and each coupler is connected end to end. One end of the second transmission optical fiber is connected to the tail end of the second coupler, and the other end is a 2μm laser output port.

[0039] In this embodiment, the coated microsphere cavity is made by coating the microsphere cavity with a functional film using a sol-gel method, the thickness of the functional film is between 0.5 μm and 2 μm, and the microsphere cavity is made by melting a single-taper optical fiber, with a diameter between 160 μm and 165 μm.

[0040] In this embodiment, the single-taper optical fiber is produced by heating a short section of standard single-mode optical fiber with a hydrogen flame and then stretching it.

[0041] In this embodiment, the 1550nm CW light source is an amplified spontaneous emission light source (ASE light source) for exciting thulium ions in the microspheres to generate 2μm stimulated emission lasers, and the coupler is a bi-conical optical fiber.

[0042] In this embodiment, the sol-gel method is a thulium ion (Tm 3+ ) doping method, thulium ions are added through thulium nitrate. Although the research and development of various types of gallery mode microcavity lasers are rapid, most of the pump light sources so far use single-wavelength lasers of tunable lasers, which has some problems. First, when the pump laser is coupled into the microsphere, heat is generated, and the refractive index changes due to the thermo-optical effect, resulting in a change in the inherent resonant wavelength, which requires wavelength tuning; secondly, when environmental vibration causes stress changes in the input optical fiber, resulting in a change in the polarization state of the input light and detuning, the wavelength also needs to be tuned, that is, the laser needs a stable environment when working and cannot be vibrated; third, tunable lasers are expensive. The present invention, based on the broadband and omnidirectional polarization characteristics of the ASE light source, provides excitation light that adapts to the environment and changes in the inherent resonant frequency of the microcavity, and uses cascaded microspheres to fully utilize the energy of the excitation light to generate and amplify 2μm lasers.

[0043] In this embodiment, Tm 3+ The doped sol, the processing method thereof comprises the following steps:

[0044] Step S1: according to the volume fraction ratio of 39.9% ethyl orthosilicate, 39.9% anhydrous ethanol, 19.2% deionized water, and 1% dimethylformamide, a total volume of 5 ml of the above solvent with a purity of 99.9% is measured and placed in a beaker;

[0045] Step S2: Add a calculated amount of thulium nitrate hexahydrate into a beaker (to make the Tm of the film 3+ 4 wt.%), and put in a magnetic vibrator, seal the beaker and place it on a magnetic stirrer;

[0046] Step S3: Turn on the magnetic stirrer and stir at room temperature for 4 hours;

[0047] Step S4: Turn off the magnetic stirrer, let the beaker stand for 12 hours to form a sol, and store it in an environment of 25°C.

[0048] In this embodiment, the microsphere cavity is coated by gel method, and the processing method includes the following steps:

[0049] Step P1: Electrode discharge arc burning microspheres: Place the tip of a single-cone optical fiber in the middle of the line connecting the discharge electrode tips, set a specific discharge intensity and discharge time, discharge and melt the tip of the single-cone optical fiber, and cool it naturally to form a microsphere cavity. Place the microsphere cavity under a microscope to observe and measure and record the diameter;

[0050] Step P2: Repeat step P1 until the microsphere cavity diameter is between 160 μm and 165 μm;

[0051] Step P3: immerse the microsphere cavity in gel for 3 minutes, take it out and dry it for 5 minutes, place the microsphere cavity attached with the dried gel at the connection line of the discharge electrode tip, set a specific discharge intensity and discharge time, heat the gel, and naturally cool it into a dense functional film, observe the coated microsphere cavity under a microscope and measure and record the diameter;

[0052] Step P4: Repeat step P3 until the functional film thickness is between 0.5μm-2μm

[0053] Thulium ions have a rich energy level structure and a broad absorption spectrum to excite electrons to upper energy levels. 3+ When the coated microsphere cavity is doped, strong stimulated radiation light will be generated. The first transmission optical fiber and the second transmission optical fiber are selected from ordinary communication single-mode quartz optical fibers with a diameter of 125 μm, and the raw material of the bi-conical optical fiber is also selected from ordinary communication single-mode quartz optical fibers with a diameter of 125 μm.

[0054] The 2μm laser intensity obtained by the two-series microsphere cavity coupling system is enhanced by 12.9 times and 2.7 times respectively compared with the 2μm laser intensity obtained by the two microsphere cavities coupled separately, and the sum of the 2μm laser intensities obtained by the two microsphere cavities coupled separately is also enhanced by 2.2 times.

[0055] In this embodiment, the first transmission optical fiber and the second transmission optical fiber are both standard communication quartz optical fiber, plastic optical fiber or nylon optical fiber.

[0056] In this embodiment, the wavelength and intensity of the generated 2 μm laser are detected by a spectrum analyzer (YOKOGAWA-AQ6375B, wavelength range is 1200 ~ 2400 nm).

[0057] The method of generating and amplifying 2 μm gallery mode laser by the device of this embodiment is to place two SiO2 coated with thulium ions. 2 The membrane microsphere is coupled with two couplers to form a cascade microsphere. The 1550nm band ASE continuous light source is turned on. The light emitted by the 1550nm band ASE continuous light source is transmitted to the first-stage coupler of the cascade microsphere through the first transmission optical fiber as the excitation light. The excitation light is coupled into the first-stage SiO2 doped with thulium ions through the evanescent wave. 2 In the membrane microsphere, stimulated radiation generates gallery mode 2μm laser, and the transmitted excitation light and 2μm gallery mode laser are emitted from the first-stage SiO2 doped with thulium ions. 2 After the membrane microsphere is coupled into the first-stage coupler, it is coupled into the second-stage SiO2 doped with thulium ions through the second-stage coupler. 2 The 2μm gallery mode laser is generated and amplified in the membrane microsphere, and finally outputted through the 2μm gallery mode laser output port of the second transmission optical fiber. The rear-stage microsphere cavity of the present invention can generate 2μm gallery mode laser, and also amplify the 2μm gallery mode laser generated by the front-stage microsphere cavity that can resonate with the microsphere cavity of this stage, and the non-resonant wavelength passes almost losslessly, making full use of the energy of the ASE light source and amplifying the 2μm laser with high efficiency.

[0058] The present invention provides a specific construction structure for generating and amplifying 2μm band (1.85~2.15μm) lasers by connecting microspheres of different diameters in series as follows:

[0059] The excitation light source is an ASE (or LED) light source. The output excitation light is used as pump light and passes through a quartz fiber with a diameter of 125μm (i.e., the first transmission fiber) and then enters the first-stage biconical fiber of the biconical fiber group. The excitation light is coupled into the first-stage coated microsphere cavity through the evanescent wave, and stimulated radiation generates 2μm band laser. After the transmitted excitation light and the 2μm band laser are coupled into the first-stage biconical fiber from the first-stage coated microsphere cavity, they are coupled into the second-stage coated microsphere cavity through the second-stage biconical fiber to generate and amplify the 2μm band laser. They are coupled into the last-stage coated microsphere cavity through the last-stage biconical fiber to generate and amplify the 2μm band laser, and finally output through the second transmission fiber and the 2μm band laser output port. The generated 2μm band laser is output from the last-stage biconical fiber through another quartz fiber with a diameter of 125μm (i.e., the second transmission fiber). In this embodiment, the output end is connected to a spectrum analyzer, and actual measurements show that the cascaded microsphere cavity utilizes the energy of the ASE light source more efficiently and outputs a 2 μm band laser with higher intensity.

[0060] In summary, the method of generating and amplifying 2μm band laser based on the serial connection of thulium-doped microspheres with different diameters coupled to a double-tapered fiber structure has a simple structure, low cost and high reliability. The requirement of serial connection of microsphere cavities with different diameters is that the free spectral range (Δλ) of the morphological resonance characteristic spectrum of microspheres with different diameters FSR =λ 2 / πD) is different. On the one hand, continuous pump light sources such as ASE can be used efficiently. On the other hand, different 2μm band lasers can be generated, and the subsequent microspheres can amplify the lasers of the same wavelength generated by the previous microspheres, thus realizing the function of generating and amplifying 2μm band lasers. If the diameter of each microsphere is the same, its Δλ FSR Similarly, the wavelength of light that resonates with the ASE light source coupled into the front-stage microsphere, the rear-stage microsphere, because it also has the same resonant wavelength as the front microsphere, can hardly get pump energy, and cannot achieve the function of generating multi-wavelength 2μm band lasers and amplifying the laser generated by the front stage. Microspheres of different diameters are combined with continuous wave excitation light sources, which is different from single wavelength lasers as excitation light sources.

[0061] The preferred embodiments listed above further illustrate the objectives, technical solutions and advantages of the present invention in detail. It should be understood that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for generating and amplifying gallery mode laser by exciting a cascaded microcavity with a continuous wave light source, characterized in that: It includes a continuous light source for providing pump light, a first transmission optical fiber for transmitting excitation light, several SiO2 film microcavities with different diameters plated with rare earth ions for generating and amplifying lasers, a number of couplers with the same number as the microcavities for coupling the continuous light source into the microcavity to form a gallery mode and to couple the generated laser output, and a second transmission optical fiber for transmitting lasers; the continuous light source is a light emitting diode, or an amplified spontaneous radiation light source; one end of the first transmission optical fiber is connected to a continuous wavelength light source as a pump source, and the other end is connected to the head end of the first coupler, each coupler is tangentially coupled to the large circle cross section of the microcavity one by one, and each coupler is connected head to tail; one end of the second transmission optical fiber is connected to the tail end of the last coupler, and the other end is connected to the output port of the gallery mode laser generated and amplified; The rare earth ion doped in the plating is erbium (Er 3+ ), Thulium (Tm 3+ ), Neodymium (Nb 3+ ), Ytterbium (Yb 3+ ), holmium (Ho 3+ ), praseodymium 3+ ) or a combination thereof.

2. The device for generating and amplifying gallery mode laser by exciting a continuous wave light source in series with a microcavity according to claim 1, characterized in that: The diameter of the SiO2 film microcavity is between 10 μm and 5000 μm, and the diameters of the serially connected SiO2 film microcavities are different.

3. The device for generating and amplifying gallery mode laser by exciting a continuous wave light source in series with a microcavity according to claim 1, characterized in that: The coupler is a bi-conical optical fiber or a half-split optical fiber with a middle section that is polished.

4. The device for generating and amplifying gallery mode laser by exciting a continuous light source in series with a rare earth ion-doped SiO2 microcavity according to claim 1, characterized in that: The SiO2 membrane microcavity is made of a SiO2 microdisk or a SiO2 optical fiber which is heated and melted at high temperature to form a smooth microsphere under the action of liquid surface tension.

5. The device for generating and amplifying gallery mode laser by exciting a thulium-doped rare earth ion-doped microcavity with a continuous light source according to claim 1, characterized in that: The first transmission optical fiber and the second transmission optical fiber are both standard communication quartz optical fiber, plastic optical fiber or nylon optical fiber. The continuous light source, the first transmission optical fiber, the coupler, the second transmission optical fiber and the output port for generating and amplifying the gallery mode laser are all connected through a connector.

6. A method for generating and amplifying gallery mode laser using the device according to any one of claims 1 to 5, characterized in that: A SiO2 membrane microcavity coated with rare earth ions is brought into tangential contact with a coupler to form a structure in which microcavities of different diameters are connected in series through an optical fiber coupler. A continuous wave light source is turned on, and the light emitted by the continuous wave light source is transmitted as excitation light to the first-stage coupler of the serially connected microcavities through a first transmission optical fiber. The excitation light is coupled into the first-stage SiO2 membrane microcavity coated with rare earth ions in the form of an evanescent wave, and stimulated radiation generates gallery mode laser of the first microcavity. The remaining excitation light and the gallery mode laser of the first-stage microcavity are selectively entered into the second-stage SiO2 membrane microcavity coated with rare earth ions through a second-stage coupler to generate gallery mode laser of the second microcavity and amplify the gallery mode laser of the first microcavity with the same wavelength as the gallery mode laser of the second microcavity. The same is true for more than three serially connected microcavities. The continuous light source excites the microcavity of this stage to generate gallery mode laser, and amplifies the gallery mode laser of the same wavelength as the gallery mode laser of the previous serially connected microcavity. Finally, gallery mode lasers of various wavelengths are output through the second transmission optical fiber.

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