阅读说明：本技术 一种铥离子掺杂的近红外微球激光器的制备方法 (Preparation method of thulium ion doped near-infrared microsphere laser ) 是由 王鹏飞 王鑫 余吉波 赵海燕 于 2019-09-26 设计创作，主要内容包括：本发明属于集成光学领域,具体涉及可以在近红外泵浦源泵浦下,实现1.88微米的荧光以及激光发射的一种铥离子掺杂的近红外微球激光器的制备方法。本发明包括以下步骤：将各种玻璃原料按照摩尔百分比为：70SiO<Sub>2</Sub>-15KF-15ZnF<Sub>2</Sub>的比例称量好,放在玛瑙研钵中充分搅拌10分钟；然后将混合料装入铂金坩埚中,置于1550℃高温炉内保温20min；将溶体玻璃倒在预热过的铜板上,压制成前驱体玻璃样品；将样品置于退火炉中进行退火处理,以消除玻璃中的应力,3h后冷却至室温；用CO<Sub>2</Sub>激光器加热玻璃纤维,制备成微球激光器。在808nm激光泵浦下,在微球中输出1.88微米的激光。本发明可以在近红外泵浦源泵浦下,实现1.88微米的荧光以及激光发射。在集成光学领域有重要应用。(The invention belongs to the field of integrated optics, and particularly relates to a preparation method of a thulium ion doped near-infrared microsphere laser, which can realize 1.88 micron fluorescence and laser emission under the pumping of a near-infrared pumping source. The invention comprises the following steps: the method comprises the following steps of (1) mixing various glass raw materials in percentage by mole: 70SiO 2 ‑15KF‑15ZnF 2 The components are weighed in proportion and are placed in an agate mortar to be fully stirred for 10 minutes; then the mixture is put into a platinum crucible and is placed in a high-temperature furnace at 1550 ℃ for heat preservation for 20 min; pouring the molten glass on a preheated copper plate, and pressing to obtain precursor glassA sample; placing the sample in an annealing furnace for annealing treatment to eliminate stress in the glass, and cooling to room temperature after 3 hours; with CO 2 The glass fiber is heated by the laser to prepare the microsphere laser. Under the pump of 808nm laser, 1.88 micron laser is output in the microsphere. The invention can realize the fluorescence and laser emission of 1.88 microns under the pumping of a near infrared pump source. Has important application in the field of integrated optics.)

1. A preparation method of a thulium ion doped near-infrared microsphere laser is characterized by comprising the following steps:

step 1: the method comprises the following steps of (1) mixing various glass raw materials in percentage by mole: 70SiO₂-15KF-15ZnF₂The components are weighed in proportion and are placed in an agate mortar to be fully stirred for 10 minutes;

step 2: then the mixture is put into a platinum crucible and is placed in a high-temperature furnace at 1550 ℃ for heat preservation for 20 min;

and step 3: pouring the molten glass on a preheated copper plate, and pressing to form a precursor glass sample;

and 4, step 4: placing the sample in an annealing furnace for annealing treatment to eliminate stress in the glass, and cooling to room temperature after 3 hours;

and 5: with CO₂Heating the glass fiber by a laser to prepare a microsphere laser;

step 6: under the pump of 808nm laser, 1.88 micron laser is output in the microsphere.

Technical Field

The invention belongs to the field of integrated optics, and particularly relates to a preparation method of a thulium ion doped near-infrared microsphere laser, which can realize 1.88 micron fluorescence and laser emission under the pumping of a near-infrared pumping source.

Background

An optical microcavity refers to a laser resonator with dimensions on the order of the wavelength of light. In the aspect of microsphere cavity theory, as early as the beginning of the 20 th century, Mi et al established the basic theory that planar electromagnetic waves are uniformly scattered, namely Mie scattering theory, and deduced the expressions of scattering coefficient, absorption coefficient and extinction coefficient of microspheres. The 1964 Purcell research found that the increase of the mode density of the vacuum field when the optical micro-cavity resonates causes the probability of spontaneous radiation of the atoms in the cavity to far exceed the value of free space. The experimental research of the optical microcavity is gradually developed along with the related theory of the microsphere cavity and the development of various microsphere preparation processes. Although Richtmeyer has observed a high quality cavity factor mode in spherical objects in 1939, the microsphere resonant cavity studies were in a standstill due to the lack of correspondingly good dielectric materials and practical and effective coupling means at that time. Garrett et al, berl telephone laboratories, usa, up to 1961, demonstrated for the first time that microspherical resonators could be used as laser resonators and operated at liquid hydrogen temperatures at Sm3+ of 1-2 microns in diameter: pulsed laser generation and oscillation of microsphere Whispering Gallery Mode (WGM) fluorescence emission were observed in CaF2 crystal microspheres. Benner et al reported in 1980 the phenomenon of structural resonance of fluorescence of microspheres containing fluorescent substances. Thereafter, optical microcavity cameras of various host materials were reported.

The optical glass microspheres with the diameters ranging from several micrometers to hundreds of micrometers can form a natural optical microcavity, and a whispering gallery mode photon resonance mode exists in the glass microspheres with high dielectric constants, so that the glass microsphere cavity has an extremely high quality factor and an extremely small mode volume. In recent years it has been in the nonlinear optics of low threshold microsphere lasers. The cavity quantum electrodynamics effect and the quantum optics field attract wide attention. As is well known, optical glasses are widely classified into, for example, quartz glass, silicate glass, phosphate glass, borate glass, tellurite glass, fluoride glass, and chalcogenide glass, among others, according to the glass system. The glass properties (e.g. refractive index, transmission range, coefficient of expansion, mechanical strength) of different systems vary widely. Glass microspheres for optical microsphere cavities were first of the concern to researchers at the end of the last century. The cavity quantum electrokinetic effect of neodymium-doped glass microspheres with the diameter of 120 microns is researched by Lubao dragon and the like in 1994.

The heterogeneity of the microsphere cavity derives from its unique whispering gallery light field pattern: the light waves coupled into the microspheres are continuously totally reflected on the surfaces of the microsphere cavities, constrained near the equatorial plane and detour along a great circle. When the detour light waves meet certain phase matching conditions, the detour light waves can be mutually overlapped and enhanced. While the optical field outside the sphere is near field, i.e. evanescent wave confined to the surface of the sphere. The micro-sphere is a non-propagating wave, the amplitude of a light field is exponentially reduced in the radial direction, so that a WGM mode with the average energy flow from the interior of the sphere to the exterior of the sphere is confined in a small volume and a long rocket is contained without any loss, the energy can be confined in the small volume for a long time, and the micro-sphere in the whispering gallery mode has an extremely high quality factor and an extremely small mode volume.

The WGM mode of the microsphere cavity can be expressed by three variables of n, m and l, which respectively represent a mirror modulus, an azimuth modulus and an azimuth modulus. Among all modes of the microsphere cavity, the fundamental mode is the most important mode. In this mode, the light energy coupled into the microsphere cavity is confined to a large circle tangential to the coupling tapered fiber, which is the highest degree of photon degeneracy in the case of the WGM, so that the mode can achieve the lowest mode volume, and thus higher energy density.

Although the research on glass microspheres and microsphere lasers has been in the past 20 years, the basic research and application of glass microspheres are still in the beginning stage, and many defects and problems to be solved are present, which are shown in the following: 1. the rare earth ions related to the active glass microspheres currently only comprise four rare earth ions of Nd3+, Er3+, Yb3+ and Tm3+, and doping of other rare earth ions is not related. 2. Between the laser threshold of the microsphere and the parameters of the diameter, the doping ion, the doping concentration and the like of the microsphereAn association change rule relationship is not established yet. 3. Reported quality factors for multicomponent glass microsphere cavities are generally 10⁴-10⁵And the Q value of the quartz glass microsphere cavity is about 10⁸From theoretical limit 10¹⁰There is a great gap. How to reduce material loss, prepare glass microspheres with perfect structures and efficiently excite WGM specific optical modes so as to obtain stable optical microcavity resonance spectra and have extremely high Q values becomes the key point of future research. 4. The coupling and integration technology of the glass microsphere and the traditional optical communication devices such as optical fibers, waveguides and the like is also a key problem whether the glass microsphere laser can be commercially applied in the fields of optical communication and sensing in the future. At present, the demand for communication capacity is rapidly increased, and the miniaturization trend of optical devices is increasingly obvious, the glass microspheres have wide development prospects in the fields of low-threshold laser emission, integrated optics, nonlinear optical fibers, sensing, quantum communication and the like by virtue of extremely high quality factors and extremely small mode volume characteristics. At present, the overall research level of the glass microspheres is still in a theoretical and experimental stage, but with continuous improvement and perfection of related preparation processes, coupling and integration technologies and the like, the glass microspheres are bound to be used in the future.

Disclosure of Invention

The invention aims to provide a preparation method of a thulium ion doped near-infrared microsphere laser.

The purpose of the invention is realized as follows:

a preparation method of a thulium ion doped near-infrared microsphere laser comprises the following steps:

step 1: the method comprises the following steps of (1) mixing various glass raw materials in percentage by mole: 70SiO₂-15KF-15ZnF₂The components are weighed in proportion and are placed in an agate mortar to be fully stirred for 10 minutes;

step 2: then the mixture is put into a platinum crucible and is placed in a high-temperature furnace at 1550 ℃ for heat preservation for 20 min;

and step 3: pouring the molten glass on a preheated copper plate, and pressing to form a precursor glass sample;

and 4, step 4: placing the sample in an annealing furnace for annealing treatment to eliminate stress in the glass, and cooling to room temperature after 3 hours;

and 5: with CO₂The glass fiber is heated by the laser to prepare the microsphere laser.

Step 6: under the pump of 808nm laser, 1.88 micron laser is output in the microsphere.

The invention has the beneficial effects that: fluorescence and laser emission of 1.88 microns can be achieved under the pumping of a near infrared pump source. Has important application in the field of integrated optics.

Drawings

FIG. 1 is a photograph of a microsphere laser under a microscope;

FIG. 2 is a laser emission spectrum of a microsphere laser in the near infrared band;

fig. 3 is the laser emission spectrum of a microsphere laser pumped with a laser having a wavelength of 808 nm.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

The invention aims to realize near-infrared emission by selecting a proper glass matrix and proper rare earth ions; the glass material is prepared into a microsphere laser, and the output of 1.88 micron laser is realized. The invention provides a preparation method of a neodymium ion doped near-infrared microsphere laser. The method comprises the preparation of a bulk glass sample and the preparation of a microsphere laser. The prepared glass and the microsphere laser have the same components: (mol%) 70SiO2-15KF-15ZnF2. under 808nm laser excitation, a strong 1.88 micron fluorescence emission was generated in the glass sample, while in the microsphere laser we detected a 1.88 micron single mode laser emission.

The preparation of the sample comprises the following steps:

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

(2) then putting the mixture into a platinum crucible, and placing the platinum crucible in a 1500 ℃ high-temperature furnace for heat preservation for 30 min;

(3) pouring the molten glass on a preheated copper plate, and pressing to form a precursor glass sample;

(4) placing the sample in an annealing furnace for annealing treatment to eliminate stress in the glass, and cooling to room temperature after 3 hours;

(5) the glass fiber was heated with a CO2 laser to produce a microsphere laser.

(6) Under the pump of 808nm laser, the output of 1.88 micron laser is realized in the microsphere.

The invention relates to a novel Nd³⁺An ion-doped fluorosilicate glass microsphere laser. Fluorescence and laser emission of 1.88 microns can be achieved under the pumping of a near infrared pump source. Has important application in the field of integrated optics.

The invention comprises the following contents:

1. preparing a glass material: the method comprises the following steps of (1) mixing various glass raw materials in percentage by mole: 70SiO2-15KF-15ZnF2 is weighed in proportion and placed in an agate mortar to be fully stirred for 10 minutes, so that the raw materials are fully mixed. Then put into a platinum crucible, covered, and insulated in a high temperature furnace at 1550 ℃ for 20 minutes, and then poured onto a preheated copper plate to be pressed into a block-shaped glass sample.

2. Preparing a microsphere laser: the glass with the components is drawn into glass fiber, and then the glass fiber is heated by a CO2 laser to be melted and condensed into glass microspheres. And then the pump light source is coupled into the microsphere through the tapered fiber, so that the output of the 1.88 micron microsphere laser is realized.