阅读说明：本技术 一种小尺寸面发射近红外激光器及其制备方法 (Small-size surface-emitting near-infrared laser and preparation method thereof ) 是由 庄秀娟 赵贺鹏 潘安练 于 2021-08-10 设计创作，主要内容包括：本发明涉及一种小尺寸面发射近红外激光器及其制备方法。所述激光器包括由底部分布式布拉格反射微腔和顶部分布式布拉格反射微腔构成的分布式布拉格反射微腔；所述底部分布式布拉格反射微腔的顶部为二氧化硅层,该层二氧化硅层布置有单晶铒镱硅酸盐纳米片,底部分布式布拉格反射微腔由厚度为185.5nm的五氧化二钽层和厚度为263.7nm二氧化硅层交替分布9次构成,顶部分布式布拉格反射微腔由厚度为263.7nm二氧化硅层和厚度为185.5nm的五氧化二钽层交替分布8次构成；所述单晶铒镱硅酸盐纳米片也与顶部分布式布拉格反射微腔中的一层二氧化硅层接触。本发明结构设计合理、制备简单可控,便于工业化应用。(The invention relates to a small-size surface-emitting near-infrared laser and a preparation method thereof. The laser comprises a distributed Bragg reflection microcavity consisting of a bottom distributed Bragg reflection microcavity and a top distributed Bragg reflection microcavity; the top of the bottom distributed Bragg reflection microcavity is a silicon dioxide layer, the silicon dioxide layer is provided with single-crystal erbium-ytterbium silicate nano-sheets, the bottom distributed Bragg reflection microcavity is formed by alternately distributing 9 times tantalum pentoxide layers with the thickness of 185.5nm and silicon dioxide layers with the thickness of 263.7nm, and the top distributed Bragg reflection microcavity is formed by alternately distributing 8 times the silicon dioxide layers with the thickness of 263.7nm and the tantalum pentoxide layers with the thickness of 185.5 nm; the single crystal erbium ytterbium silicate nanosheet is also in contact with a layer of silicon dioxide in the top distributed Bragg reflector microcavity. The invention has reasonable structural design, simple and controllable preparation and convenient industrial application.)

1. A small-sized surface-emitting near-infrared laser; it includes distributed Bragg reflection microcavity; the method is characterized in that: the distributed Bragg reflection microcavity comprises a bottom distributed Bragg reflection microcavity and a top distributed Bragg reflection microcavity, the top of the bottom distributed Bragg reflection microcavity is a silicon dioxide layer, the top silicon dioxide layer is provided with a single-crystal erbium-ytterbium silicate nano sheet, the bottom distributed Bragg reflection microcavity comprises a tantalum pentoxide layer with the thickness of 185.5nm and a silicon dioxide layer with the thickness of 263.7nm which are alternately distributed for 9 times, and the top distributed Bragg reflection microcavity comprises a silicon dioxide layer with the thickness of 263.7nm and a tantalum pentoxide layer with the thickness of 185.5nm which are alternately distributed for 8 times; the single crystal erbium ytterbium silicate nanosheet is also in contact with a layer of silicon dioxide in the top distributed Bragg reflector microcavity.

2. A small-sized surface-emitting near-infrared laser according to claim 1, characterized in that: the bottom distributed Bragg reflection microcavity is formed by alternately distributing tantalum pentoxide layers/silicon dioxide layers for 9 times, namely, a substrate is not calculated, the first tantalum pentoxide layer is attached to the substrate, the first silicon dioxide layer is attached to the first tantalum pentoxide layer, the second tantalum pentoxide layer is attached to the first silicon dioxide layer, the second silicon dioxide layer is attached to the second tantalum pentoxide layer … …, and the process is repeated until the ninth tantalum pentoxide layer is attached to the eighth silicon dioxide layer, and the ninth silicon dioxide layer is attached to the ninth tantalum pentoxide layer.

3. A small-sized surface-emitting near-infrared laser according to claim 1, characterized in that: the top distributed Bragg reflector microcavity is formed by alternately distributing silica layers with the thickness of 263.7nm and tantalum pentoxide layers with the thickness of 185.5nm for 8 times, namely the first silica layer in the top distributed Bragg reflector microcavity is in contact with the single-crystal erbium-ytterbium silicate nanosheet, and the first tantalum pentoxide layer in the top distributed Bragg reflector microcavity is attached to the first silica layer in the top distributed Bragg reflector microcavity.

4. A small-sized surface-emitting near-infrared laser according to claim 1, characterized in that: the second silicon oxide layer in the top distributed bragg reflector microcavity is attached to the first tantalum pentoxide layer in the top distributed bragg reflector microcavity.

5. A small-sized surface-emitting near-infrared laser according to claim 1, characterized in that: the second layer of tantalum pentoxide in the top distributed bragg reflector microcavity is attached to the second layer of silicon oxide in the top distributed bragg reflector microcavity, the eighth layer of silicon oxide in the … … top distributed bragg reflector microcavity is attached to the seventh layer of tantalum pentoxide in the top distributed bragg reflector microcavity, and the eighth layer of tantalum pentoxide in the top distributed bragg reflector microcavity is attached to the eighth layer of silicon oxide in the top distributed bragg reflector microcavity.

6. A small-sized surface-emitting near-infrared laser according to claim 1, characterized in that: the laser has a laser threshold as low as 20 muJ/cm 2 and a Q-factor of 1900-2000.

7. A small-sized surface-emitting near-infrared laser according to claim 1, characterized in that: the size of the single-crystal erbium ytterbium silicate nanosheet is 300-900 nm in thickness; the ratio of diameter to thickness is 40-60:1, preferably 48-55: 1.

8. A small-sized surface-emitting near-infrared laser according to claim 1, characterized in that: in the single crystal erbium ytterbium silicate nanosheet, the mass percentage of erbium is 10% -30%, preferably 25%.

9. A method for preparing a small-size surface-emitting near-infrared laser; the method is characterized in that: the preparation method of the distributed Bragg reflection microcavity in the small-size surface-emitting near-infrared laser comprises the following steps:

firstly, depositing a tantalum pentoxide layer with the thickness of 185.5nm on a K9 glass substrate, and alternately depositing 8.5 pairs of silicon dioxide layers with the thickness of 263.7nm and tantalum pentoxide layers with the thickness of 185.5nm to construct a bottom Bragg distributed reflection microcavity; on the top of the bottom distributed Bragg reflection microcavity, silicon dioxide is deposited as a spacing layer to form a sandwich structure around the single-crystal erbium-ytterbium silicate nanosheet material; finally, theSequentially preparing a top distributed Bragg reflection microcavity; both bottom and top distributed bragg reflector microcavities were prepared with a Leybold ARES1110 high vacuum coating system, with 99.99% pure tantalum pentoxide and silicon dioxide used as coating materials; the basic vacuum degree of the film coating chamber is 2 multiplied by 10^-4Pa; when tantalum pentoxide and silicon dioxide were evaporated, 30sccm of high purity argon and 35sccm of high purity oxygen were used as the working gas; during the coating process, the chamber temperature was 230 ℃; the evaporation rates of tantalum pentoxide and silicon dioxide were kept at 0.5nm/s and 1.0nm/s, respectively, and their thicknesses were precisely controlled by a direct optical monitor of the OMS 5000.

10. A method for producing a small-sized surface-emitting near-infrared laser according to claim 9; the method is characterized in that: the single-crystal erbium ytterbium silicate nanosheet is prepared by the following process: the silicon powder in the ceramic boat is placed in the center of a quartz tube, and the quartz tube is inserted into a tube furnace. The silicon substrate is positioned at the position which is 8-9 cm away from the center of the furnace at the downstream and is used for depositing a sample; ErCl₃And YbCl₃Placing the micro-beads in another ceramic boat at a position 1-1.5 cm in front of the substrate; a mixed gas of high-purity argon mixed with 5% hydrogen is introduced into the tube as a carrier gas; after exhausting gas in the quartz tube at a flow rate of 1000-1500sccm for three to five minutes, the flow rate is reduced to 100-150 sccm to grow a sample; the center of the furnace is then heated from room temperature to 1200 ℃ over 30 minutes and held at this temperature for 100 to 150 minutes; then, naturally cooling the furnace to room temperature;

the purity of the silicon powder is more than or equal to 99.99%.

Technical Field

The invention relates to the field of near-infrared communication devices and nanotechnology, in particular to a small-size surface-emitting near-infrared laser and a preparation method thereof.

Background

Integrated photonic devices and systems on chip are core devices for a new generation of computers and information handling systems. The integration of these photonic devices on silicon has become one of the recognized long-term challenges. To date, small-sized key optoelectronic devices such as modulators, detectors, wavelength division multiplexers, and filters have been implemented and even industrialized. The only unsolved problems are active devices such as optical amplifiers and coherent light sources that are energy efficient in the optical communications band. As a source of silicon-based optoelectronic integration, the performance of a silicon-based laser directly affects the overall performance of an optoelectronic integrated circuit. Is the key to realize high-speed, broadband, low-cost and low-power consumption optical interconnection and high-speed broadband information. However, since silicon has low luminous efficiency due to the indirect bandgap property, it is not suitable as a laser material. Erbium (Er) -based materials have been successfully used in the past decades to fabricate fiber amplifiers and lasers in long-haul optical communications. As an active device, the material has the characteristics of polarization insensitivity, low noise, good temperature stability and large bandwidth. In a typical fabry-perot cavity, when the optical gain of the working medium overcomes the loss in the laser cavity, laser oscillation is generated, i.e. the threshold condition of the lasing action is low refractive index and end face reflectivity for erbium silicate materials in the near infrared range, resulting in very high transmission loss and serious insufficiency of the optical feedback of the laser cavity. This is the main reason reported several years ago to hinder the realization of lasers by erbium silicate nanowires.

Disclosure of Invention

The invention provides a small-size surface-emitting near-infrared laser and a preparation method thereof, aiming at effectively solving various problems of an on-chip integrated near-infrared communication band laser device in the prior art.

In the present invention, a highly optical-feedback microcavity is optimally designed to use dielectric distributed bragg reflector (distributed bragg reflector microcavity) mirrors to enhance the cavity reflectivity. By combining the optimization of the material of the single crystal erbium-ytterbium silicate nanosheet, a compact silicon-based Vertical Cavity Surface Emitting Laser (VCSEL) is realized in the near-infrared communication band. The laser has a laser threshold value as low as 20 external communication band implementation and a Q factor of 1900-2000. It provides a path for sub-micron coherent light sources in the NIR communications band.

The invention relates to a small-size surface-emitting near-infrared laser; it includes distributed Bragg reflection microcavity; the distributed Bragg reflection microcavity comprises a bottom distributed Bragg reflection microcavity and a top distributed Bragg reflection microcavity, the top of the bottom distributed Bragg reflection microcavity is a silicon dioxide layer, the silicon dioxide layer is provided with a single-crystal erbium-ytterbium silicate nano sheet, the bottom distributed Bragg reflection microcavity comprises a tantalum pentoxide layer with the thickness of 185.5nm and a silicon dioxide layer with the thickness of 263.7nm which are alternately distributed for 9 times, and the top distributed Bragg reflection microcavity comprises a silicon dioxide layer with the thickness of 263.7nm and a tantalum pentoxide layer with the thickness of 185.5nm which are alternately distributed for 8 times; the single crystal erbium ytterbium silicate nanosheet is also in contact with a layer of silicon dioxide in the top distributed Bragg reflector microcavity.

In the invention, the bottom distributed Bragg reflection microcavity is formed by alternately distributing tantalum pentoxide layers/silicon dioxide layers for 9 times, namely a substrate is not calculated, the first tantalum pentoxide layer is attached to the substrate, the first silicon dioxide layer is attached to the first tantalum pentoxide layer, the second tantalum pentoxide layer is attached to the first silicon dioxide layer, the second silicon dioxide layer is attached to the second tantalum pentoxide layer … …, and the like until the ninth tantalum pentoxide layer is attached to the eighth silicon dioxide layer, and the ninth silicon dioxide layer is attached to the ninth tantalum pentoxide layer.

In the invention, the top distributed Bragg reflector microcavity is formed by alternately distributing silica layers with the thickness of 263.7nm and tantalum pentoxide layers with the thickness of 185.5nm for 8 times, namely, a first silica layer in the top distributed Bragg reflector microcavity is contacted with the single-crystal erbium ytterbium silicate nano-sheet, a first tantalum pentoxide layer in the top distributed Bragg reflector microcavity is attached to the first silica layer in the top distributed Bragg reflector microcavity,

the second silicon oxide layer in the top distributed bragg reflector microcavity is attached to the first tantalum pentoxide layer in the top distributed bragg reflector microcavity,

the second layer of tantalum pentoxide in the top distributed bragg reflector microcavity is attached to the second layer of silicon oxide in the top distributed bragg reflector microcavity, the eighth layer of silicon oxide in the … … top distributed bragg reflector microcavity is attached to the seventh layer of tantalum pentoxide in the top distributed bragg reflector microcavity, and the eighth layer of tantalum pentoxide in the top distributed bragg reflector microcavity is attached to the eighth layer of silicon oxide in the top distributed bragg reflector microcavity.

The invention relates to a small-size surface-emitting near-infrared laser; the laser has a laser threshold as low as 20 muJ/cm 2 and a Q-factor of 1900-2000.

The invention relates to a small-size surface-emitting near-infrared laser; the size of the single-crystal erbium ytterbium silicate nanosheet is 300-900 nm in thickness; the ratio of diameter to thickness is 40-60:1, preferably 48-55: 1.

The invention relates to a small-size surface-emitting near-infrared laser; in the single crystal erbium ytterbium silicate nanosheet, the mass percentage of erbium is 10% -30%, preferably 25%.

The invention relates to a small-size surface-emitting near-infrared laser; the preparation method of the distributed Bragg reflection microcavity comprises the following steps:

first, a thick layer was deposited on a K9 glass substrateA tantalum pentoxide layer of 185.5nm thickness on which a bottom distributed Bragg reflector microcavity was constructed by alternately depositing 8.5 pairs of layers of 263.7nm thick silicon dioxide and 185.5nm thick tantalum pentoxide; on the top of the bottom distributed Bragg reflection microcavity, silicon dioxide is deposited as a spacing layer to form a sandwich structure around the single-crystal erbium-ytterbium silicate nanosheet material; finally, the top distributed bragg reflector microcavity (i.e., 8 pairs of tantalum pentoxide and silicon dioxide layers) was prepared in sequence. Both bottom and top distributed bragg reflector microcavities were prepared with a Leybold ARES1110 high vacuum coating system, with 99.99% pure tantalum pentoxide and silicon dioxide used as coating materials; the basic vacuum degree of the film coating chamber is 2 multiplied by 10^-4Pa; when tantalum pentoxide and silicon dioxide were evaporated, 30sccm of high purity argon (99.999% purity) and 35sccm of high purity oxygen (99.999% purity) were used as the working gas; during the coating process, the chamber temperature was 230 ℃; the evaporation rates of tantalum pentoxide and silicon dioxide were kept at 0.5nm/s and 1.0nm/s, respectively, and their thicknesses were precisely controlled by a direct optical monitor of the OMS 5000.

The invention relates to a small-size surface-emitting near-infrared laser; the single-crystal erbium ytterbium silicate nanosheet is prepared by the following process: the silicon powder in the ceramic boat is placed in the center of a quartz tube, and the quartz tube is inserted into a tube furnace. The silicon substrate is positioned at the position which is 8-9 cm away from the center of the furnace at the downstream and is used for depositing a sample; ErCl₃And YbCl₃Microbeads (Alfa Aesar, 99.99% pure) were placed in another ceramic boat 1-1.5 cm in front of the substrate; a mixed gas of high-purity argon mixed with 5% hydrogen is introduced into the tube as a carrier gas; after exhausting gas in the quartz tube at a flow rate of 1000-1500sccm for three to five minutes, the flow rate is reduced to 100-150 sccm to grow a sample; the center of the furnace is then heated from room temperature to 1200 ℃ over 30 minutes and held at this temperature for 100 to 150 minutes; after that, the furnace was naturally cooled to room temperature.

The purity of the silicon powder is more than or equal to 99.99%.

Preferably, the silicon powder is produced or supplied by Alfa Aesar corporation.

When the method is applied, a self-made high-precision transfer table is used for transferring the single-crystal erbium ytterbium silicate nanosheet. A clean glass slide is used for transferring, a 1cm square polydimethylsiloxane adhesive film is bonded on the glass slide, and the glass slide is placed under a microscope at a position where a sample needs to be transferred and is tightly pressed for 2 minutes, so that the sample (the single crystal erbium ytterbium silicate nanosheet) is separated from the bottom and is bonded on the polydimethylsiloxane adhesive film. And then placing the polydimethylsiloxane with the sample (the single-crystal erbium ytterbium silicate nanosheet) on the prepared lower half-way microcavity, and pressing the part where the sample needs to be placed for 2 minutes, so that the sample is separated from the polydimethylsiloxane adhesive film and is bonded on the microcavity.

Other erbium and ytterbium sources may be used in the present invention, but the parameters need to be adjusted appropriately.

Principles and advantages

The invention firstly uses a chemical vapor deposition method to prepare the single crystal erbium ytterbium silicate nano-sheet (undoped material).

The invention uses the distributed Bragg reflector microcavity combined with erbium ytterbium silicate to realize the near infrared communication band laser, and realizes that the laser has the wavelength as low as 20 mu J/cm²And a Q factor of 1900 to 2000.

The invention can realize the micro-nano laser of the near-infrared communication wave band and well pave the way for on-chip integration. The blank of the near-infrared communication waveband silicon-based laser is made up.

Drawings

FIG. 1 is a schematic diagram of a sample microcavity preparation and transfer method

FIG. 2 shows the X-ray diffraction spectrum test and standard card comparison of the single-crystal erbium-ytterbium silicate nanosheets obtained in example 1.

FIG. 3 is a transmission electron microscope test of the single crystal erbium-ytterbium silicate nanosheets obtained in example 1.

The microcavity preparation and transfer method of the present invention can be seen in FIG. 1.

From FIG. 2 it can be seen that the samples were analysed using an X-ray diffractometer, compared to a standard card to a sample of the formula (Er/Yb)₃Si₂O₈Cl, sample formula (Er/Yb)₃(SiO₄)₂Cl。

From fig. 3 it can be seen that the detailed elemental characterization was done using transmission electron microscopy and from the lattice diffractogram it can be seen that the lattice spacing of the single crystal samples produced was 0.64 nm.

Detailed Description

Example 1

This example uses chemical vapor deposition to grow single crystal erbium-ytterbium silicate nanoplates, see fig. 1. The silicon powder (Alfa Aesar, purity 99.99%) in the ceramic boat was placed in the center of a quartz tube, which was inserted into a tube furnace. The silicon substrate is located at a position 8-9 cm away from the center of the furnace at the downstream and is used for depositing a sample. ErCl₃And YbCl₃Microbeads (Alfa Aesar, 99.99% pure) were placed in another ceramic boat 1cm in front of the substrate. A mixed gas of high purity argon mixed with 5% hydrogen was introduced into the tube as a carrier gas. After exhausting in the quartz tube at a flow rate of 1000sccm for three minutes, the flow rate was reduced to 120sccm to grow the sample. The center of the furnace was then heated from room temperature to 1200 ℃ over 30 minutes and held at this temperature for 120 minutes. After that, the furnace was naturally cooled to room temperature.

This example uses a self-made high precision transfer table, see fig. 1, using a clean glass slide to which a 1cm square piece of polydimethylsiloxane film is adhered, which is placed under a microscope at the location where the sample is to be transferred and pressed for 2 minutes to detach the sample from the substrate and adhere to the polydimethylsiloxane film. And then placing the polydimethylsiloxane with the sample on the prepared lower half micro-cavity, and pressing the part where the sample needs to be placed for 2 minutes so as to separate the sample from the polydimethylsiloxane adhesive film and adhere the polydimethylsiloxane adhesive film on the micro-cavity.

The microcavity fabrication method of this example is shown in FIG. 1. The central wavelength of the distributed bragg reflector microcavity is designed to be 1550nm and is fabricated as follows. First, a tantalum pentoxide layer of 185.5nm thickness was deposited on a K9 glass substrate, on which a bottom bragg reflective microcavity was constructed by alternately depositing 8.5 pairs of a silicon dioxide layer of 263.7nm thickness and a tantalum pentoxide layer of 185.5nm thickness. On top of the bottom distributed Bragg reflector microcavity, silica was deposited as a spacer layer to surround the erbium ytterbium silicate nanosheet materialForming a sandwich structure. Finally, the top distributed bragg reflector microcavity (8 pairs of tantalum pentoxide and silicon dioxide layers) was prepared in sequence. Both the bottom and top distributed bragg reflector microcavities were prepared with a Leybold ARES1110 high vacuum coating system, in which 99.99% pure tantalum pentoxide and silicon dioxide were used as the coating material. The basic vacuum degree of the film coating chamber is 2 multiplied by 10^-4Pa. When tantalum pentoxide and silicon dioxide were evaporated, 30sccm of high purity argon (99.999% purity) and 35sccm of high purity oxygen (99.999% purity) were used as the working gas. During the coating process, the chamber temperature was 230 ℃. The evaporation rates of tantalum pentoxide and silicon dioxide were kept at 0.5nm/s and 1.0nm/s, respectively, and their thicknesses were precisely controlled by a direct optical monitor of the OMS 5000.

The resulting laser has a low to 20 muJ/cm²And a Q factor of 1900 to 2000.

Example 2

Other conditions were the same as in example 1, a mixed gas of 5% hydrogen mixed with high purity argon was introduced into the tube as a carrier gas, and the sample size was about several tens μm at a flow rate of 100-120sccm, which was suitable for the next design.

Comparative example 1

The other conditions were the same as in example 1 except that: when the distance from the silicon substrate to the center of the furnace is less than 8cm, the sample is difficult to deposit and form.

Comparative example 2

The other conditions were the same as in example 1 except that: when the distance between the silicon substrate and the center of the furnace is more than 9cm and less than 10cm, the size of the sample is smaller, generally in a square of several micrometers, and is far less than dozens of micrometers when the distance is 8-9 cm.

Comparative example 3

The other conditions were the same as in example 1 except that: when the silicon substrate is located more than 10cm from the center of the furnace, the sample is difficult to form.

Comparative example 4

The other conditions were the same as in example 1, except that the ErCl was used₃And YbCl₃When the distance from the silicon substrate is more than 2cm, erbium and ytterbium are difficult to be generatedTo be fused into a sample with ErCl₃And YbCl₃Is present on the silicon substrate.

Comparative example 5

The other conditions were the same as in example 1, except that the ErCl was used₃And YbCl₃ErCl due to temperature deficiency when the distance from the silicon substrate is less than 1cm₃And YbCl₃Will not change and can not be volatilized to participate in the subsequent reaction.

Comparative example 5

The other conditions were the same as in example 1 except that: a mixed gas of high purity argon mixed with 5% hydrogen was introduced into the tube as a carrier gas, and when the flow rate was set to less than 100sccm (e.g., 95sccm), the sample size was less than 10 μm, which was insufficient for supporting the next design.

Comparative example 6

The other conditions were the same as in example 1 except that: a mixed gas of high purity argon mixed with 5% hydrogen was introduced into the tube as a carrier gas, and it was difficult to grow and shape the sample at a flow rate of 150 sccm.

Comparative example 7

The other conditions were the same as in example 1 except that: after exhausting in the quartz tube at a flow rate of 1000sccm for three minutes, the flow rate was reduced to 120sccm to grow the sample. The center of the furnace was then heated from room temperature to 1000 ℃ over 30 minutes and held at this temperature for 120 minutes. Then, naturally cooling the furnace to room temperature; silicon source and ErCl₃And YbCl₃The source will be insufficiently volatile to produce a sample.

Comparative example 8

The other conditions were the same as in example 1 except that: after exhausting in the quartz tube at a flow rate of 1000sccm for three minutes, the flow rate was reduced to 120sccm to grow the sample. The center of the furnace was then heated from room temperature to 1250 ℃ over 30 minutes and held at this temperature for 120 minutes. Then, naturally cooling the furnace to room temperature; the temperature exceeds the highest bearing temperature of the used tube furnace, so that instrument damage is caused, and the generated sample cannot be collected.

Comparative example 9

The other conditions were the same as in example 1 except that: after exhausting in the quartz tube at a flow rate of 1000sccm for three minutes, the flow rate was reduced to 120sccm to grow the sample. The center of the furnace was then heated from room temperature to 1200 ℃ over 30 minutes and held at this temperature for 100 minutes. After that, the furnace was naturally cooled to room temperature. When the time is 100 minutes, the sample size is 10 μm or less, which is not suitable for the next design.

Comparative example 10

The other conditions were the same as in example 1 except that: after exhausting in the quartz tube at a flow rate of 1000sccm for three minutes, the flow rate was reduced to 120sccm to grow the sample. The center of the furnace was then heated from room temperature to 1200 ℃ over 30 minutes and held at this temperature for 100 minutes. After that, the furnace was naturally cooled to room temperature. At 150 minutes, the sample size will be heavily packed and unsuitable for further design.

Comparative example 11

The other conditions were the same as in example 1 except that: for example 1, the thickness of tantalum pentoxide and silicon dioxide is varied to shift the center of luminescence, so alternating 8.5 pairs of 263.7nm thick silicon dioxide layers and 185.5nm thick tantalum pentoxide layers were used to construct the bottom dbr microcavity.

Comparative example 12

The other conditions were the same as in example 1 except that: for the erbium ytterbium silicate sample in the distributed Bragg reflector microcavity of example 1, when the thickness is 800nm, the final laser has a light-emitting center at 1400nm and is difficult to form laser.