阅读说明：本技术 一种封装微腔基于模式展宽机制的物质相变检测方法 (Material phase change detection method of packaged microcavity based on mode broadening mechanism ) 是由 杨大全 段冰 王爱强 纪越峰 于 2019-11-29 设计创作，主要内容包括：本发明实施例提供了一种封装微腔基于模式展宽机制的物质相变检测方法,包括：将载玻片放置在单模光纤锥和微泡腔的下方并在单模光纤锥和微泡腔的耦合处滴加胶水,用激光照射单模光纤锥的一端,从单模光纤锥的另一端导出,调节单模光纤锥与微泡腔的位置,当位置达到预设的光学性能条件时停止调节,在载玻片与微泡腔的接触处滴加胶水,胶水固化得到封装微腔,将待测物质注入封装微腔,将封装微腔置于加热板上并加热,采用模式展宽机制监测待测物质的相变过程。本发明在封装时使用自然固化胶水,可以调节微泡腔和单模光纤锥的位置以找到光学性能较好的模式,解决了由于回音壁光学微腔与耦合器件组成的耦合系统不稳定而带来的灵敏度下降的问题。(The embodiment of the invention provides a substance phase change detection method of a packaged microcavity based on a mode broadening mechanism, which comprises the following steps: placing a glass slide below a single-mode optical fiber cone and a micro-bubble cavity, dripping glue at the coupling position of the single-mode optical fiber cone and the micro-bubble cavity, irradiating one end of the single-mode optical fiber cone with laser, leading out from the other end of the single-mode optical fiber cone, adjusting the positions of the single-mode optical fiber cone and the micro-bubble cavity, stopping adjustment when the position reaches a preset optical performance condition, dripping glue at the contact position of the glass slide and the micro-bubble cavity, solidifying the glue to obtain a packaged micro-cavity, injecting a substance to be detected into the packaged micro-cavity, placing the packaged micro-cavity on a heating plate and heating, and monitoring the phase change process of the substance to. The invention uses natural curing glue during packaging, can adjust the positions of the micro-bubble cavity and the single-mode fiber taper to find a mode with better optical performance, and solves the problem of sensitivity reduction caused by instability of a coupling system formed by the echo wall optical micro-cavity and the coupling device.)

1. A method for detecting substance phase change of a packaged microcavity based on a mode broadening mechanism is characterized by comprising the following steps:

placing a glass slide below a single-mode optical fiber cone and a micro-bubble cavity, and dripping glue at the coupling position of the single-mode optical fiber cone and the micro-bubble cavity, wherein the micro-bubble cavity is provided with a micro-flow channel;

irradiating one end of the single-mode optical fiber cone by using laser, so that the laser is conducted into the micro-cavity through one end of the single-mode optical fiber cone and is led out from the other end of the single-mode optical fiber cone;

adjusting the relative position between the single-mode optical fiber cone and the micro-bubble cavity, and stopping adjusting when the relative position between the single-mode optical fiber cone and the micro-bubble cavity reaches a preset optical performance condition;

dripping glue at the contact position of the glass slide and the micro-bubble cavity until the glue covers the micro-bubble cavity and does not cover the two ends of the single-mode optical fiber cone, and stopping dripping the glue;

obtaining a packaging micro-cavity after the glue is cured;

injecting a substance to be detected into the packaging micro-cavity through the micro-flow channel;

placing the packaging micro-cavity filled with the substance to be detected on a heating plate, and heating the packaging micro-cavity;

and monitoring the phase change process of the substance to be detected in the packaging micro-cavity by adopting a mode broadening mechanism.

2. The method according to claim 1, wherein the single-mode fiber taper is made of silica and has a diameter of 1-3 μm, and the single-mode fiber taper is used for coupling light into the micro-bubble cavity.

3. The method of claim 1, wherein the micro-cavities are made of silicon dioxide, have a diameter of 60 to 300 μm, a wall thickness of 1 to 5 μm, and a Q value of not less than 10⁶。

4. The method of claim 1, wherein the chamber of the micro-lumen has an ellipsoidal hollow structure.

5. The method of claim 1, wherein the glass slide is made of silicon dioxide and has a refractive index of 1.45.

6. The method of claim 1, wherein the predetermined optical performance condition is: the Q value of the micro-cavity is not less than 10⁶。

7. The method of claim 1, wherein the glue has a refractive index of 1.33.

8. The method of claim 1, wherein the step of heating the encapsulated microcavity comprises:

and taking the temperature rise amplitude of 0.2 ℃/min as a stepping unit, and heating the packaging micro-cavity.

9. The method of claim 1, wherein the single mode fiber taper is in the shape of a tapered strip, and wherein the diameter of the ends of the taper is greater than the diameter of the middle section of the taper.

Technical Field

The invention relates to the technical field of sensors, in particular to a substance phase change detection method of a packaged microcavity based on a mode broadening mechanism.

Background

Optical microcavities stand out in numerous sensor technologies due to their ultra-high sensitivity. The optical microcavity with the whispering gallery mode with the ultrahigh quality factor and the tiny mode volume can effectively enhance the interaction between light and a detected substance and remarkably improve the detection sensitivity, wherein the whispering gallery mode is a mode in which continuous total reflection occurs when the detection light propagates along the inner wall of the microcavity.

When the echo wall optical microcavity sensor detects a substance based on a mode broadening mechanism, a coupling device is needed to assist in coupling a light field in the echo wall optical microcavity with the substance to be detected, wherein the mode broadening mechanism is based on the principle that sensing is performed by using the change of the line width of an echo wall mode, and the coupling device can adopt an optical fiber cone. In the prior art, the echo wall optical microcavity and the coupling device are generally placed on a 3D nano translation stage, and the preferred relative positions of the echo wall optical microcavity and the coupling device are found by monitoring a mode transmission diagram on an oscilloscope to complete coupling, when the Q value of one echo wall mode of the echo wall microcavity exceeds 10⁶The relative position of the echo wall optical micro-cavity and the coupling device is a better relative position, and the 3D nano translation stage is a device for adjusting the relative position of the echo wall optical micro-cavity and the coupling device at a nano level.

In the prior art, the positions of the echo wall optical microcavity and the coupling device are easy to change, and the change of the positions can cause the mode of the echo wall optical microcavity to change, so that extra mode broadening is brought, however, the extra mode broadening is not caused by the change of a substance to be detected, so that the detection error of the echo wall optical microcavity sensor based on a mode broadening mechanism can be increased, and the detection sensitivity of the echo wall optical microcavity sensor is reduced.

Disclosure of Invention

The embodiment of the invention aims to provide a substance phase change detection method of a packaged microcavity based on a mode broadening mechanism, which is used for solving the problem that the sensitivity of a echo wall optical microcavity sensor is reduced after the echo wall optical microcavity and a coupling device are completely packaged in the prior art. The specific technical scheme is as follows:

placing a glass slide below a single-mode optical fiber cone and a micro-bubble cavity, and dripping glue at the coupling position of the single-mode optical fiber cone and the micro-bubble cavity, wherein the micro-bubble cavity is provided with a micro-flow channel;

irradiating one end of the single-mode optical fiber cone by using laser, so that the laser is conducted into the micro-cavity through one end of the single-mode optical fiber cone and is led out from the other end of the single-mode optical fiber cone;

adjusting the relative position between the single-mode optical fiber cone and the micro-bubble cavity, and stopping adjusting when the relative position between the single-mode optical fiber cone and the micro-bubble cavity reaches a preset optical performance condition;

dripping glue at the contact position of the glass slide and the micro-bubble cavity until the glue covers the micro-bubble cavity and does not cover the two ends of the single-mode optical fiber cone, and stopping dripping the glue;

obtaining a packaging micro-cavity after the glue is cured;

injecting a substance to be detected into the packaging micro-cavity through the micro-flow channel;

placing the packaging micro-cavity filled with the substance to be detected on a heating plate, and heating the packaging micro-cavity;

and monitoring the phase change process of the substance to be detected in the packaging micro-cavity by adopting a mode broadening mechanism.

Optionally, the single-mode fiber taper is made of silicon dioxide, the diameter of the single-mode fiber taper is 1-3 μm, and the single-mode fiber taper is used for coupling light into the micro-bubble cavity.

Optionally, the micro-cavity is made of silicon dioxide, the diameter is 60-300 μm, the wall thickness is 1-5 μm, and the Q value is not less than 10⁶。

Optionally, the cavity of the micro-cavity is of an ellipsoidal hollow structure.

Optionally, the glass slide is made of silicon dioxide, and the refractive index of the glass slide is 1.45.

Optionally, the preset optical performance condition is as follows: the Q value of the micro-cavity is not less than 10⁶。

Optionally, the refractive index of the glue is 1.33.

Optionally, the process of heating the encapsulated micro-cavity includes:

and taking the temperature rise amplitude of 0.2 ℃/min as a stepping unit, and heating the packaging micro-cavity.

Optionally, the single-mode fiber taper is in the shape of a tapered strip, and the diameters of the two ends of the single-mode fiber taper are larger than the diameter of the middle part of the single-mode fiber taper.

The embodiment of the invention has the following beneficial effects:

according to the substance phase change detection method based on the mode broadening mechanism of the packaged microcavity, glue is used for packaging the single-mode optical fiber cone, the micro-bubble cavity and the glass slide into the packaged microcavity, then a substance to be detected is injected into a micro-flow channel of the micro-bubble cavity, the packaged microcavity is placed on a heating plate for heating, and the phase change process of the substance to be detected is monitored by the broadening condition of the optical mode line width. Because the naturally cured glue is used during packaging, in the glue curing process, the relative positions of the micro-bubble cavity and the single-mode fiber cone can be continuously adjusted to find a mode with better optical performance until the glue is completely cured to keep the coupling position of the single-mode fiber cone and the micro-bubble cavity unchanged, and finally the problem of sensitivity reduction caused by instability of a coupling system formed by the echo wall optical micro-cavity and the coupling device is solved.

Of course, not all of the advantages described above need to be achieved at the same time in the practice of any one product or method of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a packaged microcavity structure according to an embodiment of the present invention;

FIG. 2 is a schematic transmission spectrum of the packaged microcavity without injecting the substance to be tested according to the embodiment of the present invention;

FIG. 3 is a Lorentz fit graph of a high Q-factor mode in a mode transmission spectrum when no substance to be tested is injected into the package microcavity according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating wavelength shift and line width broadening when no substance to be tested is injected into the micro-cavity of the package according to an embodiment of the present invention;

fig. 5 is a graph showing wavelength shift and line width broadening with temperature variation when the packaged microcavity injects a substance to be measured according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the embodiment of the present invention provides a packaged microcavity composed of a single-mode fiber taper 1, a micro-bubble cavity 2, glue 3 and a glass slide 4.

The embodiment of the invention provides a substance phase change detection method of a packaged microcavity based on a mode broadening mechanism, which comprises the following steps:

and placing the glass slide 4 below the single-mode optical fiber cone 1 and the micro-bubble cavity 2, and dripping glue at the coupling part of the single-mode optical fiber cone 1 and the micro-bubble cavity 2.

In the embodiment of the invention, the glue 3 is a natural curing glue, and the refractive index of the glue 3 is 1.33. Put single mode fiber cone 1 and microbubble chamber 2 on two nanometer translation platforms, the nanometer translation platform is the device of nanometer level's regulation single mode fiber cone 1 and microbubble chamber 2 relative position, places slide 4 in the below of single mode fiber cone 1 and microbubble chamber 2 to place single mode fiber cone 1 on the surface of microbubble chamber 2, at the coupling department dropwise add glue of single mode fiber cone 1 and microbubble chamber 2. The single-mode optical fiber cone 1 is a coupling device and is used for efficiently coupling the probe light into the micro-bubble cavity 2 and exciting a whispering gallery mode in the cavity, the micro-bubble cavity 2 is a whispering gallery mode optical micro-cavity, when the light is transmitted along the inner wall of the boundary of the micro-bubble cavity, continuous total reflection can be generated, the light is localized on the annular surface of the micro-bubble cavity, and then the whispering gallery mode is generated.

One end of the single-mode optical fiber cone 1 is irradiated by laser, so that the laser is conducted into the micro-bubble cavity 2 through one end of the single-mode optical fiber cone 1 and is led out from the other end of the single-mode optical fiber cone 1.

In the embodiment of the invention, the phase change process of the substance to be detected can be detected by a tunable laser, a polarizer, a photoelectric detector, a data acquisition card, an oscilloscope and a signal generator. Outputting a signal to a laser by a signal generator for frequency sweeping, transmitting detection laser with the wavelength of about 780nm by the laser through a polarizer, enabling the detection laser to enter from one end of a single-mode optical fiber cone 1 and be coupled into a micro-bubble cavity, then transmitting the detection laser from the other end of the single-mode optical fiber cone 1 to a photoelectric detector, converting an optical signal into an electric signal by the photoelectric detector, and finally transmitting the electric signal to a data acquisition card and an oscilloscope, wherein a graph displayed by the oscilloscope is a mode transmission spectrogram of the detection laser, and when the detection laser meets the requirement of 2 pi n, the detection laser_effR＝mλ_mWhen the formula is adopted, a stable whispering gallery mode is generated, wherein n is the formula_effIs the effective index of the mode, R is the microcavity radius, m is the number of angular quanta, λ_mIs the resonance wavelength, the abscissa of the mode transmission spectrum displayed in the oscilloscope is time, and the ordinate is the transmission intensity of the mode.

And adjusting the relative position between the single-mode optical fiber cone 1 and the micro-bubble cavity 2, and stopping adjusting when the relative position between the single-mode optical fiber cone 1 and the micro-bubble cavity 2 reaches a preset optical performance condition.

In the embodiment of the invention, after glue is dripped at the coupling part of the single-mode optical fiber cone 1 and the micro-bubble cavity 2, the relative position of the single-mode optical fiber cone 1 and the micro-bubble cavity 2 can be adjusted, and the adjusting time can be 60 minutes. During the adjustment of the positionMonitoring a transmission spectrogram displayed by an oscilloscope in real time, stopping adjustment when the relative position of the single-mode fiber cone 1 and the micro-bubble cavity 2 reaches a preset optical performance condition, wherein the preset optical performance condition can be that the time length of one mode in the transmission spectrogram displayed by the oscilloscope is lower than 45 mu s, and when the time length of one mode is lower than 45 mu s, the quality factor of the mode can be obtained by calculation to exceed 10⁶The figure of merit is used to represent the ability of the microbubble cavity 2 to confine the laser photons. It should be noted that the glue according to the embodiment of the present invention may be an existing naturally cured glue, and the glue may have a low refractive index, for example, the refractive index is 1.33, and as long as the glue satisfies the above conditions, the glue may be applied to the embodiment of the present invention, and the chemical composition of the glue is not specifically limited in the embodiment of the present invention.

And (3) dripping glue at the contact part of the glass slide 4 and the micro-bubble cavity 2 until the glue 3 covers the micro-bubble cavity 2 and does not cover the two ends of the single-mode optical fiber cone 1, and stopping dripping the glue.

In the embodiment of the invention, the relative position of the micro-bubble cavity 2 and the single-mode optical fiber cone 1 can be adjusted to reach a better optical mode, glue is continuously dripped, the glass slide 4 is used as a substrate of the packaging type microcavity, and the micro-bubble cavity 2 and the single-mode optical fiber cone 1 are packaged on the substrate, so that the packaging microcavity can move at will, the use is more convenient, two ends of the single-mode optical fiber cone 1 are used for transmitting signals, and the glue 3 does not cover two ends of the single-mode optical fiber cone 1.

And curing the glue to obtain the encapsulated micro-cavity.

In the embodiment of the present invention, the curing time of the glue 3 may be 23.5 hours to 24.5 hours, preferably 24 hours, because the inventors found that when the curing time is controlled to be 24 hours, not only the good stability of the encapsulation microcavity can be ensured, but also the encapsulation time is not too long. And (5) after the glue is dripped for 3, curing the glue 3 after 24 hours to obtain the packaging micro-cavity.

And placing the packaging micro-cavity filled with the substance to be detected on a heating plate, and heating the packaging micro-cavity.

In the embodiment of the present invention, the substance to be detected may be a gas or a liquid, because the gas or the liquid may be injected into the microfluidic channel of the microbubble cavity 2 more conveniently, for example, hydrogel may be selected as the substance to be detected, and the hydrogel is injected into the microfluidic channel of the microbubble cavity 2, and since the phase change process of the substance to be detected needs to be monitored in real time, the temperature at which the substance to be detected starts to be heated may be lower than the temperature at which the substance to be detected undergoes phase change.

And monitoring the phase change process of the substance to be detected in the packaging micro-cavity by adopting a mode broadening mechanism.

In the embodiment of the invention, the phase state of the substance to be detected can be changed along with the gradual rise of the temperature, when the temperature rises to the gel temperature of the hydrogel, the hydrogel starts to gel, the scattering of light is enhanced, the line width of the resonance mode starts to widen, the resonance mode can be observed to start to widen through data acquired by the data acquisition card in real time, the red shift is started, and when the mode is observed to be widened and the acquisition range of the data acquisition card is not deviated, the heating is stopped, and the monitoring is finished.

As an optional implementation manner of the embodiment of the present invention, the single-mode fiber taper is made of silicon dioxide, the diameter of the single-mode fiber taper is 1 to 3 μm, and the single-mode fiber taper 1 is used for coupling light into the micro-bubble cavity 2.

In the embodiment of the invention, the single-mode optical fiber cone 1 is a coupling device and is used for efficiently coupling laser into the micro-bubble cavity 2 and exciting a whispering gallery mode in the cavity, so that a substance to be detected and an evanescent field of the micro-bubble cavity 2 can better interact, the evanescent field is an optical field formed by leaking part of the optical field in the micro-bubble cavity 2 to a region near the ellipsoidal cavity, the material for preparing the single-mode optical fiber cone 1 is silicon dioxide, and the diameter of the single-mode optical fiber cone 1 is 1-3 mu m.

As an optional implementation manner of the embodiment of the invention, the material of the micro-cavity 2 is silicon dioxide, the diameter is 60 to 300 μm, the wall thickness is 1 to 5 μm, and the Q value is not less than 10⁶。

In the embodiment of the invention, the sensitivity of the micro-bubble cavity 2 mainly depends on the wall thickness, but the wall thickness is related to the diameter, and the larger the diameter of the micro-bubble cavity 2 is, the thinner the wall thickness is, so that when the diameter of the micro-bubble cavity 2 is 60-300 μm, the wall thickness is 1-5 μm, the micro-bubble cavity 2 can have higher sensitivity, and the size of the micro-bubble cavity 2 can be slowly increased by adopting a multi-heating and pressurizing mode, so as to adjust the wall thickness of the micro-bubble cavity 2.

As an optional implementation manner of the embodiment of the present invention, the cavity of the micro-cavity 2 has an ellipsoidal hollow structure.

In the embodiment of the present invention, the cavity of the micro-bubble cavity 2 has a rotationally symmetric geometry, so that the laser can propagate in the cavity by continuous total reflection along the inner wall of the cavity. The micro-bubble cavity 2 after encapsulation reserves a natural micro-flow channel, substances to be detected can be injected into the micro-flow channel and enter the cavity of the micro-bubble cavity 2 through the micro-flow channel, namely the micro-bubble cavity 2 after encapsulation can also enable the substances to be detected to well interact with detection laser, other echo wall micro-cavities do not have the micro-flow channel, the substances to be detected interact by contacting the surfaces of the micro-bubble cavity, if the micro-cavities are encapsulated by glue, the micro-cavities are isolated from the surrounding environment by the glue, and the evanescent fields of the substances to be detected and the optical micro-cavities cannot well interact.

In an alternative embodiment of the present invention, the material of the slide glass 4 is silicon dioxide, and the refractive index of the slide glass 4 is 1.45.

In the embodiment of the invention, the glass slide 4 is used as a substrate for packaging the microcavity, the micro-bubble cavity 2 and the single-mode fiber taper 1 are packaged on the substrate, so that the packaging microcavity can move at will, the use is more convenient, the silicon dioxide has better thermal conductivity, the temperature can be quickly conducted to a substance to be detected when the heating plate is heated, other heat conducting materials can also be used as the substrate, and in an exemplary way, polydimethylsiloxane can also be selected as the substrate, and the glass slide 4 is selected as a common laboratory material, so that the glass slide is easy to obtain and has lower cost.

As an optional implementation manner of the embodiment of the present invention, the preset optical performance condition is: q value of the micro-cavity 2 is not less than 10⁶。

In the embodiment of the invention, the Q value is the quality factor of the micro-bubble cavity, the quality factor is used for expressing the constraint capacity of the micro-bubble cavity 2 on detecting laser photons, and the higher the Q value is, the more the micro-bubble cavity 2 canMore photons are bound to act with the substance to be measured in the chamber, so that the sensitivity of the micro-bubble cavity 2 is higher, and the Q value from the relative position of the single-mode optical fiber cone 1 and the micro-bubble cavity 2 to the micro-bubble cavity 2 is adjusted to 10⁶And stopping the process, then continuously dripping glue, fixing the relative positions of the single-mode fiber cone 1 and the micro-bubble cavity 2, and keeping the Q value of the micro-bubble cavity 2 at a higher value all the time, so that the sensitivity of the packaged micro-cavity for detecting the phase change process of the substance to be detected based on a mode broadening mechanism is higher.

As an optional implementation manner of the embodiment of the present invention, the refractive index of the glue 3 is 1.33.

The glue 3 is MY-133-MC polymer and is a naturally cured polymer with low refractive index, and the coupling position of the micro-cavity 2 and the single-mode optical fiber cone 1 can be adjusted in real time in the curing process of the glue 3 so as to achieve a better optical mode.

As an optional implementation manner of the embodiment of the present invention, the process of heating the encapsulated micro-cavity includes:

and taking the temperature rise amplitude of 0.2 ℃/min as a stepping unit to heat the packaging micro-cavity.

In the embodiment of the invention, the mode in the oscilloscope begins to widen with the rise of the temperature, the mode widening can be changed continuously when the temperature is just raised to one temperature, the temperature is continuously raised to the next temperature by 0.2 ℃ after the mode widening tends to be stable, the time for the mode widening to be stable can be 1 minute, and the process that at least one mode generates wavelength deviation and linewidth widening can be completely observed by taking the temperature rise amplitude of 0.2 ℃/min as a stepping unit.

As an optional implementation manner of the embodiment of the present invention, the single-mode optical fiber taper 1 has a tapered strip shape, and diameters of two ends of the single-mode optical fiber taper 1 are larger than a diameter of a middle portion of the single-mode optical fiber taper.

In the embodiment of the invention, the adopted single-mode optical fiber cone 1 is a tapered optical fiber, the cladding of the single-mode optical fiber is stripped, the cladding is wiped by alcohol, then the single-mode optical fiber cone is prepared by adopting a hot-drawing method, and the diameter of the fiber core of the single-mode optical fiber is gradually thinned along the axial direction of the optical fiber to form the single-mode optical fiber cone 1. The single-mode optical fiber cone 1 has lower transmission loss and higher coupling efficiency than a cylindrical optical fiber due to the specific structure.