阅读说明：本技术 基于超低阈值多组分钬离子掺杂玻璃材料的微球腔激光器 (Microsphere cavity laser based on ultralow-threshold multi-component holmium ion doped glass material ) 是由 王鹏飞 余吉波 于 2020-06-08 设计创作，主要内容包括：本发明公开了一种超低阈值的多组分钬离子掺杂的玻璃材料,所述玻璃材料的摩尔组成按化学式表示为：72TeO<Sub>2</Sub>-20ZnO-5Na<Sub>2</Sub>CO<Sub>3</Sub>-2Y<Sub>2</Sub>O<Sub>3</Sub>并掺杂浓度为1 mol%的Ho<Sup>3+</Sup>离子。本发明还提供了一种基于超低阈值的多组分钬离子掺杂的玻璃材料的微球腔激光器的制备方法和控制方法。本发明制备的微球腔表面完美,具有极高的Q值,制作出的激光器阈值极低,耦合效率大幅提高,有效解决了回音壁模式微腔激光器输出功率低和收集能效低的问题,可实现高效率的、低阈值的窄带宽光纤的中红外光纤微腔激光器。(The invention discloses an ultralow-threshold multi-component holmium ion-doped glass material, which comprises the following molar compositions according to a chemical formula: 72TeO 2 ‑20ZnO‑5Na 2 CO 3 ‑2Y 2 O 3 And doping Ho with a concentration of 1mol% 3+ Ions. The invention also provides a preparation method and a control method of the microsphere cavity laser based on the ultralow-threshold multi-component holmium ion doped glass material. The microsphere cavity prepared by the method has perfect surface and extremely high Q value, the prepared laser has extremely low threshold value, the coupling efficiency is greatly improved, the problems of low output power and low collection efficiency of the whispering gallery mode microsphere laser are effectively solved, and the high-efficiency and low-threshold value mid-infrared fiber microsphere laser with narrow bandwidth fibers can be realized.)

1. An ultralow-threshold multicomponent holmium ion-doped glass material, which is characterized in that the molar composition of the glass material is represented by the chemical formula: 72TeO₂-20ZnO-5Na₂CO₃-2Y₂O₃And doping Ho with a concentration of 1mol%³⁺Ions.

2. The ultra-low threshold multicomponent holmium ion-doped glass material of claim 1, wherein the Ho is characterized by^{3 +}Ion by HoF₃The form is doped.

3. A preparation method of a microsphere cavity laser based on an ultralow-threshold multi-component holmium ion-doped glass material is characterized by comprising the following steps:

step 1, according to a chemical formula of 72TeO₂-20ZnO-5Na₂CO₃-2Y₂O₃And doping Ho with a concentration of 1mol%³⁺Calculating the mass ratio of the high-purity raw materials according to the molar composition of ions, weighing, and grinding and stirring to fully mix various raw materials;

step 2, putting the uniformly mixed raw materials into a corundum crucible and heating;

step 3, drawing and cooling the molten glass liquid to prepare a multi-component doped glass optical fiber;

step 4, heating the glass optical fiber by using a carbon dioxide laser to taper the glass optical fiber to obtain a tapered optical fiber;

step 5, adjusting the focusing position of the output light of the carbon dioxide laser, and focusing the light beam to the tail end of the tapered optical fiber to ensure that the tail end of the tapered optical fiber is upwards shrunk and melted into a microsphere;

step 6, preparing a silicon dioxide tapered optical fiber with the diameter of 1.5-3.0 mu m by using a melting tapering method;

and 7, packaging and coupling the microspheres and the silica tapered optical fibers to form the microsphere cavity laser.

4. The method for preparing a microsphere cavity laser based on an ultralow threshold multi-component holmium ion-doped glass material according to claim 3, wherein the grinding and stirring in the step 1 are carried out in a ball mill.

5. The method of claim 3 wherein the Ho in step 1 is selected from the group consisting of a laser of microsphere cavity type based on ultra-low threshold multi-component holmium ion doped glass material³⁺Ion by HoF₃The form is doped.

6. The method for preparing the microsphere cavity laser based on the ultralow-threshold multi-component holmium ion-doped glass material according to claim 3, wherein the heating in the step 2 is specifically: heating the mixture in a high temperature furnace at 800-900 ℃ for 60-120 min.

7. The method for preparing the microsphere cavity laser based on the ultralow-threshold multi-component holmium ion-doped glass material according to claim 3, wherein the step 4 specifically comprises the following steps:

step 4.1, hanging a heavy object at the tail end of the glass optical fiber;

step 4.2, focusing the laser output by the carbon dioxide laser on the glass optical fiber by using a focusing lens;

and 4.3, slowly increasing the power of the carbon dioxide laser, when the glass optical fiber reaches the softening point of the glass optical fiber, slowly dropping the glass optical fiber under the action of a weight, gradually reducing the diameter of the glass optical fiber until the conical diameter of the tail end of the glass optical fiber is smaller than 10 mu m, and stopping heating.

8. The method for preparing a microsphere cavity laser based on an ultralow threshold multi-component holmium ion-doped glass material according to claim 3, wherein the diameter of the microspheres in the step 5 can be changed by controlling the number of times of heating in the step 4.

9. The method for preparing the micro-spherical cavity laser based on the ultralow threshold multi-component holmium ion-doped glass material according to claim 3, wherein the encapsulation coupling in the step 7 is performed by using precise three-dimensional platform control.

10. A control method of a microsphere cavity laser based on an ultralow-threshold multi-component holmium ion-doped glass material is characterized by comprising the following steps:

step 1, injecting 1150nm single-mode pump light into one end of a silica tapered optical fiber through a light path protection device;

step 2, utilizing a precise three-dimensional platform to control the conical optical fiber and the optical fiber with molar composition expressed as 72TeO according to a chemical formula₂-20ZnO-5Na₂CO₃-2Y₂O₃And doping Ho with a concentration of 1mol%³⁺Coupling is realized by microspheres made of ionic glass materials;

step 3, coupling the pump light in the tapered optical fiber to the microsphere to form a whispering gallery mode, and transmitting the whispering gallery mode on the equatorial plane of the microsphere cavity;

and 4, adding a pumping light source, and coupling the inside of the microsphere to the other end of the silica tapered fiber due to the inversion of the particle number on the doped ion energy level to form narrow-bandwidth laser output.

Technical Field

The invention relates to the technical field of near-infrared lasers, in particular to a microsphere cavity laser based on an ultralow-threshold multi-component holmium ion doped glass material.

Background

Background of microspheres: the optical microsphere cavity can bind light into microspheres with small light beam, has high energy density and small mode field volume, and an optical mode capable of being stably transmitted in the microsphere cavity is called a whispering gallery mode. The british scientist lordrrayleigh study that when the sound propagates on a curved hallway corridor of the st paul university, it is found that stealing whispers by two persons located far from himself at the other end of the corridor can be clearly heard, so this mode of sound propagation is called "whisper corridor mode". In fact, there is a similar phenomenon in the echo wall of the beijing Temple. Similar to the reflection of sound waves on a wall surface, when light is incident from a light density to a light sparse medium and the incident angle is large enough, total reflection can also occur on the surfaces of the two media, and then an optical whispering gallery mode also exists at the interface of the curved high refractive index medium. Within the boundaries of the closed cavity, the light can then be trapped all the time to maintain a stable transmission mode inside the cavity. The advantages of high Q value, micro-nano size and the like of the microsphere cavity are utilized, and the method has wide application in the aspects of quantum electrodynamics, quantum mechanics, computers, linear phenomena, sensing, lasers, couplers, filters and the like.

The traditional echo wall optical microcavity comprises a micro-ring cavity, a spherical cavity, a bottle cavity, a disc cavity and a micro-bubble cavity, because the micro-ball cavity is easier to obtain a very high quality factor compared with other resonant cavities, and the manufacturing process is mature, the micro-ball with the scale in the optical wavelength level can be more easily obtained, and the application in the optical fiber laser is more and more extensive.

Since the first generation of glass fiber lasers in the world was invented in 1964, fiber lasers have become increasingly important in the fields of fiber communication, optoelectronics, linear optics, sensing and the like. The fiber laser has the characteristics of low manufacturing cost, relatively easy integrated manufacture, small overall size, tunable output wavelength and the like, is suitable for various complex working environments, has a series of advantages of power and the like, but compared with a solid laser, the output single-mode pulse is still small, so that the threshold value is reduced, and the wavelength tuning range becomes more important. From 2005 to 2010, the sales of fiber lasers has rapidly risen at a rate of 35% per year.

Research on rare earth ion doped lasers has been in history for several decades, but converting luminescent materials to have excellent luminescent properties and good practical properties under rare earth ion doping is still a research focus in the current field of luminescent materials.

Therefore, the technical personnel in the field are dedicated to developing a microsphere cavity laser based on an ultralow-threshold multi-component holmium ion doped glass material, and the problems of low microsphere quality, overhigh pumping threshold and the like in the existing microsphere laser development process are solved.

Disclosure of Invention

In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is how to solve the problems of low microsphere quality, too high pumping threshold, etc. in the process of developing the microsphere laser.

In order to achieve the aim, the invention provides an ultralow-threshold multi-component holmium ion-doped glass material, and the molar composition of the glass material is represented by the chemical formula: 72TeO₂-20ZnO-5Na₂CO₃-2Y₂O₃And doping Ho with a concentration of 1mol%³⁺Ions.

Further, the Ho³⁺Ion by HoF₃The form is doped.

The invention also provides a preparation method of the microsphere cavity laser based on the ultralow-threshold multi-component holmium ion-doped glass material, which comprises the following steps:

step 1, according to a chemical formula of 72TeO₂-20ZnO-5Na₂CO₃-2Y₂O₃And doping Ho with a concentration of 1mol%³⁺Calculating the mass ratio of the high-purity raw materials according to the molar composition of ions, weighing, and grinding and stirring to fully mix various raw materials;

step 2, putting the uniformly mixed raw materials into a corundum crucible and heating;

step 3, drawing and cooling the molten glass liquid to prepare a multi-component doped glass optical fiber;

step 4, heating the glass optical fiber by using a carbon dioxide laser to taper the glass optical fiber to obtain a tapered optical fiber;

step 5, adjusting the focusing position of the output light of the carbon dioxide laser, and focusing the light beam to the tail end of the tapered optical fiber to ensure that the tail end of the tapered optical fiber is upwards shrunk and melted into a microsphere;

step 6, preparing a silicon dioxide tapered optical fiber with the diameter of 1.5-3.0 mu m by using a melting tapering method;

and 7, packaging and coupling the microspheres and the silica tapered optical fibers to form the microsphere cavity laser.

Further, the grinding and stirring in the step 1 are performed in a ball mill.

Further, the Ho in the step 1³⁺Ion by HoF₃The form is doped.

Further, the heating in the step 2 is specifically: heating the mixture in a high temperature furnace at 800-900 ℃ for 60-120 min.

Further, the step 4 specifically includes the following steps:

step 4.1, hanging a heavy object at the tail end of the glass optical fiber;

step 4.2, focusing the laser output by the carbon dioxide laser on the glass optical fiber by using a focusing lens;

and 4.3, slowly increasing the power of the carbon dioxide laser, when the glass optical fiber reaches the softening point of the glass optical fiber, slowly dropping the glass optical fiber under the action of a weight, gradually reducing the diameter of the glass optical fiber until the conical diameter of the tail end of the glass optical fiber is smaller than 10 mu m, and stopping heating.

Further, the diameter of the microspheres in step 5 can be changed by controlling the number of times of heating in step 4.

Further, the package coupling in step 7 is performed by using a precise three-dimensional platform control.

The invention also provides a control method of the microsphere cavity laser based on the ultralow-threshold multi-component holmium ion-doped glass material, which is characterized by comprising the following steps of:

step 1, injecting 1150nm single-mode pump light into one end of a silica tapered optical fiber through a light path protection device;

step 2, utilizing a precise three-dimensional platform to control the conical optical fiber and the optical fiber with molar composition expressed as 72TeO according to a chemical formula₂-20ZnO-5Na₂CO₃-2Y₂O₃And doping Ho with a concentration of 1mol%³⁺Coupling is realized by microspheres made of ionic glass materials;

step 3, coupling the pump light in the tapered optical fiber to the microsphere to form a whispering gallery mode, and transmitting the whispering gallery mode on the equatorial plane of the microsphere cavity;

and 4, adding a pumping light source, and coupling the inside of the microsphere to the other end of the silica tapered fiber due to the inversion of the particle number on the doped ion energy level to form narrow-bandwidth laser output.

The invention has the advantages that:

from CO₂The microsphere cavity prepared by the laser and formed by the surface tension effect has perfect surface and extremely high Q value, the threshold value of the prepared laser is extremely low, and the problem that the microsphere cavity with the diameter of dozens of microns and the high Q value is difficult to prepare is solved.

The pump light of the micro-nano fiber coupled laser is injected and collected to emit laser, so that the coupling efficiency is greatly improved, and the problems of low output power and low collection energy efficiency of the whispering gallery mode microcavity laser are effectively solved.

The threshold values of the selected glass components and the doped ions are extremely low, so that no microcavity laser with the low threshold value is reported so far, and the invention can realize a medium-infrared optical fiber microcavity laser with a high efficiency and a low threshold value and a narrow bandwidth optical fiber.

Drawings

FIG. 1 is an absorption spectrum of a tellurite glass according to a preferred embodiment of the present invention;

FIG. 2 is a photograph of a tellurate microsphere in a preferred embodiment of the present invention;

FIG. 3 is a diagram of the laser output spectrum of a microsphere cavity laser in accordance with a preferred embodiment of the present invention.

Detailed Description

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings for clarity and understanding of technical contents. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

The invention aims to realize a narrow-linewidth microsphere cavity laser based on a multi-component glass material which can stably output laser and has an extremely low threshold value by selecting a proper glass matrix and proper rare earth ions.

The invention relates to a microsphere cavity laser based on an ultralow threshold and high conversion efficiency, which comprises the steps of preparation of matrix glass, doping of ions, preparation of microspheres, coupling and emission of narrow-linewidth laser.

The mol percentage of each raw material of the glass (tellurite glass doped with holmium ions) matrix is 72TeO₂-20ZnO-5Na₂CO₃-2Y₂O₃-1HoF₃. The concentration of the doped holmium ions is 1mol percent. The absorption spectrum of the prepared glass is shown in figure 1.

The preparation process of the microcavity laser comprises the preparation of glass and the preparation of microspheres, and specifically comprises the following steps:

weighing high-purity raw materials according to a certain proportion, and stirring in a ball mill to fully mix the raw materials;

then putting the mixture into a corundum crucible, and heating for 90 min in a high-temperature furnace at 850 ℃;

and drawing and cooling the molten glass liquid to prepare the fiber core of the optical fiber. Tapering the multi-component doped glass fiber by using a carbon dioxide laser, hanging a heavy object at the tail end of the multi-component glass fiber, focusing laser output by the carbon dioxide laser on the multi-component doped glass fiber by using a focusing lens, slowly increasing the power of the carbon dioxide laser, and when the glass fiber reaches the softening point of the glass fiber, the glass fiber slowly drops down due to the action of the weight, the diameter of the fiber is gradually reduced until the conical diameter of the tail end of the doped glass fiber is about 10 mu m, the heating can be stopped, then the focusing position of the output light of the carbon dioxide laser is adjusted, the light beam is focused on the tail end of the tapered optical fiber, the tail end of the tapered glass optical fiber starts to shrink upwards due to the surface tension and melt into a small ball, and the required diameter of the microsphere can be obtained by controlling the heating times (as shown in figure 2). Then a common silica tapered optical fiber with the thickness of about 2 mu m is prepared by utilizing ceramic tapering equipment.

And finally, respectively connecting two ends of the prepared common single-mode optical fiber to an input system of a light source and a collection system of the light source, and controlling the finest cone areas of the multi-component doped microspheres and the silica tapered optical fiber to be close to each other and coupled by using a precise three-dimensional platform, thereby realizing laser output.

The specific principle of obtaining laser output:

the single-mode laser light source outputs 1150nm pump light, the pump light enters the common single-mode silica tapered optical fiber through the light path protection device (preventing reflected light from entering the light source), because the thinnest cone waist of the tapered optical fiber is only a few microns, the optical fiber with the wavelength scale has a strong evanescent field, a precise three-dimensional platform is utilized, the diameter of the tapered optical fiber and the diameter of the microsphere are controlled to realize high-efficiency coupling, the pump light in the tapered optical fiber is coupled into the microsphere to form a whispering gallery mode and is transmitted on the equatorial plane of the microsphere, when Ho ions are excited by the 1150nm pump light, the Ho ions in the ground state⁵I₈（Ho³⁺) Electron transition to excited state⁵I₆Energy level of, in turn, from⁵I₈Energy level transfer to intermediate metastable energy level⁵I₇Energy level, the particles in metastable state are continuously accumulated, when the particle number is higher than that of the ground state, the particle number inversion is formed, the spontaneous radiation is converted into the stimulated radiation, and a 2-micron radiation is radiatedMeter photons (as shown in figure 3).

The high Q value of the microsphere enables 1150nm pump light transmitted in the microsphere to easily excite energy level transition of doped particles to realize particle number inversion.

When the pumping threshold is low, the 1150nm pumping wavelength in the microsphere cannot enable the particle beam to be inverted to form stable laser output, the pumping light source is continuously added, laser output is formed in the microsphere due to the inversion of the particle number on the doped ion energy level, the output laser forms a whispering gallery mode of stable transmission in the microsphere again, and the coupling of the tapered fiber and the microsphere is regulated and controlled through the three-dimensional platform, so that 2080 nm single-mode laser output can be obtained from the spectrometer (as shown in fig. 3).

Compared with the traditional optical fiber laser, the invention provides the glass whispering gallery mode laser which is provided with the high-Q-value multi-component glass microsphere cavity with a perfect surface formed by surface tension and used for injecting pump light and collecting emission laser through the optical fiber cone with high coupling efficiency, and the laser has an extremely low threshold value. The conversion efficiency of the microsphere cavity pump light can be improved by several orders of magnitude, so that low-threshold laser output is possible. Secondly, different from drawing optical fiber, when manufacturing a glass microsphere cavity device, the heating temperature is near the melting temperature of glass, the heating efficiency is high, the heating time is extremely short, the crystallization temperature of the glass can be quickly skipped, and the phenomenon of crystallization of the glass during secondary heating is avoided.