CN104868351A - Method for adjusting resonant frequency of echo wall mode microcavity - Google Patents
Method for adjusting resonant frequency of echo wall mode microcavity Download PDFInfo
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- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 29
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Abstract
The invention provides a method for adjusting resonant frequency of an echo wall mode microcavity. The method comprises the following steps of providing the echo wall mode microcavity, testing resonant wavelength of the echo wall mode microcavity, selecting a mode of the echo wall mode microcavity, determining target wavelength, and performing hot reflux treatment on the echo wall mode microcavity with a hot reflux device to adjust the resonant frequency of the echo wall mode microcavity, wherein the hot reflux device comprises a laser device which emits laser to irradiate the echo wall mode microcavity. A hot reflux treatment process comprises the concrete steps of fixing the hot reflux time and gradually increase output power of the laser device or fixing the output power of the laser device and gradually increase the hot reflux time, and observing the change of the resonant wavelength of the echo wall mode microcavity until an absolute value of a difference value of the target wavelength and the resonant wavelength of the echo wall mode microcavity is less than line width of the mode of the echo wall mode microcavity.
Description
Technical Field
The invention belongs to the field of micro-nano optical devices, and particularly relates to a method for adjusting resonant frequency of a whispering gallery mode microcavity by low-power thermal reflux.
Background
Whispering gallery mode microcavity is one of the most important and most deeply studied high quality optical microcavities. In a whispering gallery mode optical microcavity, light is continuously transmitted within the microcavity by total reflection. Whispering gallery mode microcavity typically contains microsphere cavity (microdisperse), microdisk cavity (microdisk), micro-core annular microcavity (microtrioid), etc. The whispering gallery mode microcavity surface is very smooth, and the material used (usually silica) has little absorption of light, so the lifetime of photons is very long, and the quality factor Q is very high (up to 10)8Above). In addition, the mode volume (effective volume of optical field distribution) of this type of microcavity is also very small, and the intensity of the optical field in the cavity is greater at the same incident power. Based on the above advantages, whispering gallery mode optical microcavities have many very important and wide-ranging applications.
The resonance frequency is one of the very important parameters of an optical microcavity. The method is one of important research subjects in the field of micro-nano photonic devices by simply and effectively regulating and controlling the method. Referring to fig. 1, fig. 1 is a schematic diagram illustrating the shift of the resonant frequency in an optical microcavity, and it can be seen from the diagram that after the resonant frequency of the optical microcavity is adjusted, the whole lorentz line can be shifted to the right, which represents the increase of the resonant wavelength (decrease of the resonant frequency).
The existing means for regulating and controlling the resonant frequency of the whispering gallery mode microcavity is mainly temperature regulation. However, temperature regulation has several drawbacks: firstly, when the heating temperature is too high and the temperature difference between the microcavity and the surrounding environment is too large, the whole system becomes very unstable, and the change of the environment may generate great disturbance to the resonant frequency of the microcavity, thereby seriously influencing and restricting the practical application of the microcavity; secondly, the regulation of a single micro-cavity is difficult to realize, and the temperature of a nearby sample is usually influenced when a temperature regulation method is used for regulating and controlling a target cavity, so that corresponding parameters are changed, and a negative effect is generated; finally, the experimental apparatus is complex, temperature adjustment often requires the use of complex processing techniques or the addition of a large number of additional control instruments, is difficult to integrate, and is very unfavorable for application in daily production and life. Therefore, there is a need to find a simple and effective method to tune the resonance frequency of whispering gallery mode microcavity.
Disclosure of Invention
In view of the above, it is necessary to provide a method for adjusting resonant frequency of whispering gallery mode microcavity, which can overcome the disadvantages of the conventional temperature adjustment.
A method of tuning the resonant frequency of a whispering gallery mode microcavity by low power thermal reflow, comprising the steps of: s1: providing a whispering gallery mode microcavity, testing the resonance wavelength of the whispering gallery mode microcavity, and selecting the mode of the whispering gallery mode microcavity; s2: determining a target wavelength; and S3: the resonance frequency of the whispering gallery mode microcavity is adjusted by performing thermal reflow processing on the whispering gallery mode microcavity by adopting a thermal reflow device, the thermal reflow device comprises a laser, the laser emitted by the laser irradiates on the whispering gallery mode microcavity, and the thermal reflow processing process specifically comprises the following steps: fixing the time of thermal reflow and simultaneously increasing the output power of the laser step by step, or fixing the output power of the laser and simultaneously increasing the time of thermal reflow step by step; and observing the change of the resonant wavelength of the whispering gallery mode microcavity until the absolute value of the difference between the target wavelength and the resonant wavelength of the whispering gallery mode microcavity is smaller than the mode line width of the whispering gallery mode microcavity.
Compared with the prior art, the method for adjusting the resonant frequency of the whispering gallery mode microcavity by low-power thermal reflux has the following advantages: firstly, the resonance wavelength is adjusted by changing the geometric shape of the whispering gallery mode microcavity, the temperature of the microcavity is kept to be basically the same as the outside temperature in practical application, the influence of the surrounding environment on the microcavity is greatly reduced, the disturbance resistance is strong, and the whole system is very stable; secondly, by adopting a thermal reflux method, laser can be focused on a single target microcavity through a lens, and the single target microcavity is adjusted without influencing other microcavities; thirdly, the method fully utilizes the thermal reflux process in the preparation process of the whispering gallery mode microcavity to adjust the resonance frequency of the microcavity, and the required equipment is simple without additional control devices.
Drawings
FIG. 1 is a schematic diagram of the frequency shift of an optical microcavity resonance.
Fig. 2 is a schematic perspective view of a micro-core annular microcavity provided in an embodiment of the present invention.
Fig. 3 is a schematic diagram of a process for fabricating a micro-core annular microcavity according to an embodiment of the present invention.
FIG. 4 is a schematic diagram of a micro-core annular microcavity and an optical fiber coupling according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of connection between optical paths and circuits when the micro-core ring microcavity resonance wavelength is tested according to an embodiment of the present invention.
Fig. 6 is a schematic diagram of a thermal reflow process in the micro-core circular ring micro-cavity provided in the embodiment of the invention.
Fig. 7 is a graph showing the change of the microcavity resonance wavelength of the micro-core ring when the output power of the carbon dioxide laser is gradually increased with a fixed thermal reflow time according to the embodiment of the present invention.
Fig. 8 is a graph of the change of the microcavity resonance wavelength of the micro-core ring when the output power of the fixed carbon dioxide laser provided by the embodiment of the invention is in the red-shifted region to increase the thermal reflux time.
Fig. 9 is a graph of the change of the microcavity resonance wavelength of the micro-core ring when the output power of the fixed carbon dioxide laser provided by the embodiment of the invention is in the blue-shifted region to increase the thermal reflux time.
Description of the main elements
| Silicon wafer | 1 |
| Silicon dioxide layer | 2 |
| Photoresist | 3 |
| Micro-disk cavity | 4 |
| Micro-core ring micro-cavity | 5 |
| Signal generator | 6，11 |
| Tunable laser | 7 |
| Oscilloscope | 8 |
| Polarization controller | 9 |
| Photoelectric detector | 10 |
| Controller | 12 |
| Laser device | 13 |
| Lens and lens assembly | 14 |
The following detailed description will further illustrate the invention in conjunction with the above-described figures.
Detailed Description
The method for adjusting the resonant frequency of the whispering gallery mode microcavity provided by the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
The invention provides a method for adjusting resonant frequency of a whispering gallery mode microcavity, which comprises the following steps:
s1: providing a whispering gallery mode microcavity, testing the resonance wavelength of the whispering gallery mode microcavity, and selecting the mode of the whispering gallery mode microcavity;
s2: determining a target wavelength; and
s3: the resonance frequency of the whispering gallery mode microcavity is adjusted by performing thermal reflow processing on the whispering gallery mode microcavity by adopting a thermal reflow device, the thermal reflow device comprises a laser, the laser emitted by the laser irradiates on the whispering gallery mode microcavity, and the thermal reflow processing process specifically comprises the following steps: fixing the time of thermal reflow and simultaneously increasing the output power of the laser step by step, or fixing the output power of the laser and simultaneously increasing the time of thermal reflow step by step; and observing the change of the resonant wavelength of the whispering gallery mode microcavity until the absolute value of the difference between the target wavelength and the resonant wavelength of the whispering gallery mode microcavity is smaller than the mode line width of the whispering gallery mode microcavity.
In step S1, preferably, the whispering gallery mode microcavity is a micro-core annular microcavity, a microsphere cavity, or a micro-disk cavity. When the whispering gallery mode microcavity is a microsphere cavity and a microdisk cavity, the output power of the laser is lower than that of the microcube circular ring microcavity. More preferably, the whispering gallery mode microcavity is a micro-core annular microcavity. Referring to fig. 2, the micro-core ring micro-cavity includes a pillar made of a silicon wafer 1 with a good heat dissipation effect, and the upper portion of the pillar is a solidified fused silica layer 2. In this embodiment, the whispering gallery mode microcavity is a micro-core annular microcavity with a regular shape and a better mode.
Referring to fig. 3, the method for preparing the micro-core annular microcavity includes the following steps:
s11: providing a high-purity silicon wafer 1, wherein the surface of the silicon wafer 1 is plated with a silicon dioxide layer 2 with the thickness of about 2 mu m;
s12: cleaning and drying, and uniformly coating a layer of photoresist 3 on the surface of the silicon dioxide layer 2 far away from the silicon wafer 1;
s13: placing a template with an etching pattern on the surface of the photoresist 3 far away from the silicon dioxide layer 2 in parallel, exposing and developing under an ultraviolet lamp, wherein the photoresist irradiated by ultraviolet rays can be washed away by a developing solution, and the photoresist not irradiated still remains on the silicon wafer 1 to form a required pattern;
s14: washing away residual developing solution, drying, putting into hydrofluoric acid for corrosion, wherein the hydrofluoric acid has the function of reacting with the silicon dioxide layer 2, the silicon dioxide layer 2 covered by the photoresist cannot be corroded, the residual silicon dioxide layer 2 can quickly react and disappear, and the hydrofluoric acid and the photoresist 3 are washed away, so that the pattern formed by the photoresist is converted into the pattern of the silicon dioxide layer 2;
s15: reacting in xenon fluoride, wherein the xenon fluoride reacts with the silicon chip 1 but does not react with the silicon dioxide layer 2, and slowly etching for a long time to obtain a micro-disk cavity 4; and
s16: and carrying out thermal reflux treatment on the microdisk cavity 4 to obtain the microcore annular microcavity 5.
The quality factor (Q) is an important parameter describing the optical microcavity confinement power, and is expressed as:
，
wherein,andrespectively, a center frequency and a center wavelength;andthe line width in frequency and wavelength, i.e. the frequency or wavelength difference corresponding to a height of half the peak or valley, respectively.
The quality factor of the microdisk cavity obtained in step S15 can reach 105. After the high-power thermal reflow treatment, the quality factor of the micro-core annular microcavity obtained in step S16 is greatly improved to a maximum of 108。
It is understood that the micro-core annular microcavity 5 is not limited to be obtained by the preparation method, and can be obtained by any preparation method available in the art.
The mode of the whispering gallery mode microcavity in step S1 is an eigensolution obtained by solving maxwell' S equations, each eigensolution corresponds to a specific spatial distribution, and the eigensolution is composed of four mode numbers、、、To depict.Representative is a TE (transverse electric) mode or a TM (transverse magnetic) mode;is the number of radial modes, which is the maximum number of radial field strengths;is the angular mode number, which can be understood as the number of field intensity maxima in the equatorial plane;is the number of azimuthal modes and is understood to be the number of field intensity maxima at the tangent plane perpendicular to the equatorial plane. Different mode distributions correspond to different resonance frequencies and quality factors. It will be appreciated that in experiments, the number of modes actually observed will be very large, since the shape of whispering gallery mode microcavity cannot be as completely symmetrical as theoretically possible, so the theoretically degenerate microcavity mode will cleave.
In step S1, the mode of the whispering gallery mode microcavity needs to be excited. In this embodiment, the adopted method is to couple the micro-core annular microcavity by using a fiber taper. The advantages of the optical fiber taper coupling are high coupling efficiency and strong adjustability. Referring to fig. 4, when preparing the optical fiber taper, the outer cladding of the optical fiber is removed and cleaned; it is heated in oxyhydrogen flame and stretched in two opposite directions until the thinnest part is about 2 μm. It will be appreciated that the method of exciting the whispering gallery modes can be other than fiber taper coupling.
Referring to fig. 5, fig. 5 shows the connection between the optical path and the circuit when the micro-core ring microcavity 5 is tested for resonance wavelength. The test principle is as follows: the signal generator 6 outputs a triangular wave signal, one path of the triangular wave signal is used for frequency modulation for the tunable laser 7, the other path of the triangular wave signal is used for the oscilloscope 8, laser emitted by the tunable laser 7 enters the micro-core annular microcavity 5 through coupling of the optical fiber cone after the polarization state of the laser is adjusted through the polarization controller 9, transmitted light passing through the micro-core annular microcavity 5 is detected by the photoelectric detector 10 and is output to the oscilloscope 8 for waveform observation. In this embodiment, the adjustment range of the tunable laser 7 is 1520nm to 1570nm, and the line width of the laser emitted by the tunable laser 7 is less than 200 KHz.
Referring to fig. 6, in step S3, the thermal reflow apparatus in the thermal reflow process is composed of a signal generator 11, a controller 12, a laser 13 and a lens 14, where the laser 13 is used to output laser light, and in this embodiment, the laser 13 is a carbon dioxide laser and outputs square pulse laser light; the signal generator 11 is used for setting the frequency and duty ratio of the laser; the controller 12 may control the maximum light intensity and time of the pulse; the lens 14 is used for focusing laser on the micro-core ring micro-cavity 5.
In this embodiment, since the center wavelength of the laser output by the carbon dioxide laser is 10.6 μm, the silicon dioxide material of the micro-core ring microcavity 5 has strong absorption in this wavelength band, and the silicon wafer 1 at the bottom of the silicon dioxide layer 2 has less absorption in this wavelength band. Therefore, when a low-power carbon dioxide laser is focused on the micro-core ring microcavity 5, the radius of the micro-core ring microcavity 5There will be slight variations due to the approximate relationThe resonance frequency (resonance wavelength) of the micro-core annular microcavity 5 changes with the change of the radius, and the shape of the bottom pillar material silicon wafer 1 is almost unchanged. It is to be understood that the laser 14 is not limited to the carbon dioxide laser in this embodiment, and other lasers may be substituted according to the molten material in the whispering gallery mode microcavity.
In step S3, before the thermal reflow process is performed, the output power of the laser or the time required for the thermal reflow process can be estimated according to the difference between the resonant wavelength of the whispering gallery mode microcavity and the target wavelength and experimental experience. In the thermal reflow process, the position of the whispering gallery mode microcavity should be the same during each thermal reflow, that is, during each thermal reflow, the position of the laser emitted by the laser 13 focused on the whispering gallery mode microcavity after passing through the lens 14 is the same, so as to ensure that the energy received by the whispering gallery mode microcavity and the output of the laser are in a linear relationship.
When the output power of the laser is increased stepwise at a fixed time of the thermal reflow, the output power is preferably increased gradually from zero. Referring to fig. 7, fig. 7 is a graph showing the change of the resonant wavelength of the micro-core ring microcavity 5 when the thermal reflow time is fixed and the output power of the carbon dioxide laser is gradually increased in this embodiment, and it can be seen from the graph that in this process, the resonant wavelength of the micro-core ring microcavity 5 is first increased (in a red shift region), and when the output power of the carbon dioxide laser is 6W, the resonant wavelength of the micro-core ring microcavity 5 reaches a critical value, the output power of the carbon dioxide laser is continuously increased, and the resonant wavelength of the micro-core ring microcavity 5 starts to decrease (in a blue shift region). The dynamic process of the whole process is as follows: when the output power of the carbon dioxide laser is relatively small (red shift region), the energy received by the micro-core annular microcavity 5 is relatively small, and the silicon dioxide on the surface part of the microcavity is melted to increase the radius. According to the formulaIt is known that an increase in radius results in an increase in the resonant wavelength of the micro-core annular microcavity 5. When the output power of the carbon dioxide laser reaches a certain threshold (blue shift region), the surface tension of the micro-core ring microcavity 5 becomes large enough to force the micro-core ring microcavity 5 to further contract, and meanwhile, part of the silicon dioxide is heated and evaporated to reduce the radius, so that the resonance wavelength of the micro-core ring microcavity 5 is correspondingly reduced. It can also be seen from fig. 7 that the same resonance frequency corresponds to both thermal reflow laser powers. Therefore, when the red shift area does not reach the expected target by using lower laser output power for thermal reflow, the power of the laser can be continuously increased to reach the blue shift area, the expected target is realized, and the success rate is greatly improved.
When the method of fixing the output power of the laser and gradually increasing the time of the thermal reflow is adopted, the moving direction of the resonance wavelength needs to be judged firstly, and the output power of the laser is selected according to the moving direction. The output power of the red-shifted region is selected if the target wavelength is greater than the resonant wavelength of the whispering gallery mode microcavity, and the output power of the blue-shifted region is selected otherwise. In this embodiment, when the target wavelength is longer than the resonance wavelength of the micro-core annular microcavity 5, the selection range of the output power is larger than 0W and smaller than 6W; when the target wavelength is less than the resonance wavelength of the micro-core annular microcavity 5, the selection range of the output power is more than 6W and less than 13W.
Referring to fig. 8, fig. 8 is a graph showing the change of the resonant wavelength of the microcavity 5 with a micro-core ring when the output power of the fixed carbon dioxide laser is in the red-shifted region (4.5W is selected here) to increase the thermal reflow time in this embodiment. It can be seen from the figure that the resonance wavelength increases in this region with increasing thermal reflow time. When the thermal reflow time is short, the resonant wavelength is substantially linearly related to the thermal reflow time, and when the turning point is reached, the increase rate of the resonant wavelength is significantly slowed down. Referring to fig. 9, fig. 9 is a graph showing the change of the resonant wavelength of the microcavity 5 with a small core ring when the output power of the carbon dioxide laser is fixed in the blue-shifted region (11W is selected here) to increase the thermal reflow time. As can be seen from the graph, when the thermal reflow time is short, the resonance wavelength is substantially negatively linearly related to the thermal reflow time, and after the turning point is reached, the rate of change of the resonance wavelength is slowed down. Comparing fig. 8 and 9, it can be seen that the thermal reflow time corresponding to the transition point in the blue-shift region is significantly smaller than the thermal reflow time corresponding to the transition point in the red-shift region, because this process is a melting contraction process in the blue-shift region and a natural melting process in the red-shift region, and therefore the relaxation time of the blue-shift region is shorter than that of the red-shift region.
The first adjustment mode is as follows:
providing a micro-core ring micro-cavity and testing the resonance wavelength of the micro-core ring micro-cavity; setting a target wavelength, wherein the target wavelength is 20 pm longer than the resonance wavelength of the micro-core annular microcavity; the maximum output power of the laser in the thermal reflow process is estimated to be 3-4W according to experimental experience, in the thermal reflow process, the frequency of the square pulse carbon dioxide laser is set to be 1Hz, the duty ratio is set to be 10%, the thermal reflow time of each time is fixed to be 100s, and the output power of the laser is increased from zero and by taking 0.6W as a unit. The quality factor of the micro-core annular microcavity one mode is 1.9 multiplied by 106(the line width of this mode in the 1550nm band is 0.8 pm). Referring to table 1, it can be seen from table 1 that, as the output power of the laser increases, the difference between the target wavelength and the microcavity resonance wavelength gradually decreases, and when the output power of the laser increases to 3.6W, the difference between the target wavelength and the microcavity resonance wavelength is substantially the same, and is 0.4pm, which is much smaller than 0.8pm of the mode line width of the microcavity having the micro-core ring, which can be considered to achieve the predetermined adjustment requirement. The heat reflux power in the process of manufacturing the micro-core ring micro-cavity is generally more than 25W, and the power required by the adjusting method is relatively low and is far lower than the heat reflux power in the process of manufacturing the micro-core ring micro-cavity.
TABLE 1 Table for changing resonant wavelength by fixing thermal reflow time to 100s and increasing laser power
| Thermal reflux power (W) | 0 | 0.6 | 1.2 | 1.8 | 2.4 | 3.0 | 3.6 |
| Difference between target wavelength and resonance wavelength (pm) | 20 | 12.8 | 8.8 | 3.6 | 1.8 | 0.9 | 0.4 |
The second adjustment mode is as follows:
providing a micro-core ring micro-cavity and testing the resonance wavelength of the micro-core ring micro-cavity; setting a target wavelength which is 25pm greater than the resonance wavelength, and estimating the total time of the thermal reflux to be about 60-70 s according to experimental experience. Since the microcavity resonance wavelength should be shifted toward the increasing direction, the laser output power should be in the red shift region, and the laser output power is selected to be 5W. The time of each thermal reflux is increased by 15s, the frequency of the square pulse laser is set to be 1Hz, and the duty ratio is set to be 10%. The quality factor of the micro-core annular microcavity one mode is 1.2 multiplied by 106(the line width of this mode in the 1550nm band is 1.29 pm).
Referring to table 2, it can be seen that, as time increases, the resonant wavelength of the micro-core annular microcavity gradually approaches the target wavelength, and when the thermal reflow time is 60s, the difference between the target wavelength and the resonant wavelength of the micro-core annular microcavity is about-0.34 pm, and the absolute value thereof is smaller than 1.29pm of the line width, which is basically considered to achieve the purpose of effective adjustment.
TABLE 2 fixed laser power 5W and increased thermal reflow time, resonance wavelength shift pattern
| Time of thermal reflux(s) | 0 | 15 | 30 | 45 | 60 |
| Difference between target wavelength and resonance wavelength (pm) | 25 | 13.5 | 9.12 | 7.49 | -0.34 |
The method for adjusting the resonant frequency of the whispering gallery mode microcavity provided by the embodiment of the invention through low-power thermal reflux has the following advantages: firstly, the whispering gallery mode microcavity is irradiated by laser for the first time, so that the geometric shape of the whispering gallery mode microcavity generates tiny change to adjust the resonance wavelength, the temperature of the microcavity is kept to be the same as the external temperature in experiments and practical application, the influence of the surrounding environment on the microcavity is greatly reduced, the disturbance resistance is strong, and the problem of system instability caused by overlarge temperature difference between the microcavity and the external environment during temperature adjustment is avoided; secondly, by adopting a thermal reflux method, the carbon dioxide laser can be focused on a single target microcavity through a lens, and is adjusted aiming at the single target microcavity without influencing other microcavities; thirdly, the method fully utilizes the same thermal reflux process as the preparation process of the whispering gallery mode microcavity to adjust the resonance frequency of the microcavity, and is different from temperature adjustment in that no additional control device is needed, and after the adjustment purpose is achieved, the stability of the resonance frequency can be maintained without an adjusting device, and the method and the required equipment are simple; fourthly, the adjustment precision can reach below 0.005nm (corresponding to 1550nm wave band about 600 MHz), the maximum adjustment range can be above 0.06nm (corresponding to 1550nm wave band about 7.5 GHz), and the method is more suitable for use in actual production and life; fifthly, the power of the laser in the tuning method of the present invention is generally below 13W, which is much lower than the thermal reflow power (about 25W or more) in the microcavity fabrication process.
In addition, other modifications within the spirit of the invention will occur to those skilled in the art, and it is understood that such modifications are included within the scope of the invention as claimed.
Claims (10)
1. A method of adjusting the resonant frequency of a whispering gallery mode microcavity comprising the steps of:
s1: providing a whispering gallery mode microcavity, testing the resonance wavelength of the whispering gallery mode microcavity, and selecting the mode of the whispering gallery mode microcavity;
s2: determining a target wavelength; and
s3: the resonance frequency of the whispering gallery mode microcavity is adjusted by performing thermal reflow processing on the whispering gallery mode microcavity by adopting a thermal reflow device, the thermal reflow device comprises a laser, the laser emitted by the laser irradiates on the whispering gallery mode microcavity, and the thermal reflow processing process specifically comprises the following steps: fixing the time of thermal reflow and simultaneously increasing the output power of the laser step by step, or fixing the output power of the laser and simultaneously increasing the time of thermal reflow step by step; and observing the change of the resonant wavelength of the whispering gallery mode microcavity until the absolute value of the difference between the target wavelength and the resonant wavelength of the whispering gallery mode microcavity is smaller than the mode line width of the whispering gallery mode microcavity.
2. The method of tuning the resonant frequency of a whispering gallery mode microcavity of claim 1, wherein said whispering gallery mode microcavity is a micro-cored toroid microcavity, a microsphere cavity, or a microdisk cavity.
3. The method of adjusting the resonant frequency of a whispering gallery mode microcavity of claim 1, wherein the laser is a carbon dioxide laser.
4. The method of adjusting the resonant frequency of a whispering gallery mode microcavity of claim 1, wherein the laser light emitted from said laser is focused through a lens at the same location on said whispering gallery mode microcavity at each thermal reflow.
5. The method of adjusting the resonant frequency of the whispering gallery mode microcavity as claimed in claim 1, wherein in step S3, the output power is gradually increased from zero by using the method of fixing the time of the thermal reflow while gradually increasing the output power of the laser.
6. The method of tuning the resonant frequency of a whispering gallery mode microcavity of claim 5, wherein the output power is increased in units of 0.6W.
7. The method of adjusting the resonant frequency of the whispering gallery mode microcavity as claimed in claim 1, wherein in step S3, when the method of fixing the output power of the laser while gradually increasing the thermal reflow time is used, the moving direction of the resonant wavelength of the whispering gallery mode microcavity is first determined, the output power of the laser is selected according to the moving direction, and when the target wavelength is longer than the resonant wavelength of the whispering gallery mode microcavity, the output power of the red-shifted region is selected; and when the target wavelength is less than the resonance wavelength of the whispering gallery mode microcavity, selecting the output power of the blue shift region.
8. The method of tuning the resonant frequency of a whispering gallery mode microcavity of claim 7, wherein the selected range of output power is greater than 0W and less than 6W when the target wavelength is greater than the resonant wavelength of the whispering gallery mode microcavity; when the target wavelength is less than the resonant wavelength of the whispering gallery mode microcavity, the selected range of output power is greater than 6W and less than 13W.
9. The method of adjusting the resonant frequency of a whispering gallery mode microcavity of claim 1, wherein the output power of said laser is 13W or less.
10. The method of tuning the resonant frequency of a whispering gallery mode microcavity of claim 1, wherein the tuning accuracy of the method is less than 0.005nm and the tuning range is greater than 0.06 nm.
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Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105731352A (en) * | 2016-03-01 | 2016-07-06 | 南京大学 | On-chip integrated arsenic sulfide microdisk cavity and method for manufacturing same |
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| CN108808433A (en) * | 2017-04-26 | 2018-11-13 | 中国科学院化学研究所 | A kind of Whispering-gallery-mode photonic device and its preparation method and application with pillar support |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040179573A1 (en) * | 2002-10-02 | 2004-09-16 | California Institute Of Technology | Ultra-high Q micro-resonator and method of fabrication |
| US20080203052A1 (en) * | 2007-02-27 | 2008-08-28 | Mani Hossein-Zadeh | Method of fabricating a microresonator |
| US20090097031A1 (en) * | 2007-10-01 | 2009-04-16 | Armani Andrea M | Micro-cavity gas and vapor sensors and detection methods |
| CN102530852A (en) * | 2012-03-06 | 2012-07-04 | 中国科学院上海光学精密机械研究所 | Method for fabricating three-dimensional optical echo wall mode micro-cavity by using femtosecond laser |
| CN102718180A (en) * | 2012-06-28 | 2012-10-10 | 中国科学院苏州纳米技术与纳米仿生研究所 | Concentric ring core nano silicon micro-disk micro-cavity device and preparation method thereof |
| CN104466657A (en) * | 2014-11-07 | 2015-03-25 | 南京大学 | Chip-integrated 2-micrometer wavelength micro laser |
-
2015
- 2015-04-27 CN CN201510204835.3A patent/CN104868351B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040179573A1 (en) * | 2002-10-02 | 2004-09-16 | California Institute Of Technology | Ultra-high Q micro-resonator and method of fabrication |
| US20080203052A1 (en) * | 2007-02-27 | 2008-08-28 | Mani Hossein-Zadeh | Method of fabricating a microresonator |
| US20090097031A1 (en) * | 2007-10-01 | 2009-04-16 | Armani Andrea M | Micro-cavity gas and vapor sensors and detection methods |
| CN102530852A (en) * | 2012-03-06 | 2012-07-04 | 中国科学院上海光学精密机械研究所 | Method for fabricating three-dimensional optical echo wall mode micro-cavity by using femtosecond laser |
| CN102718180A (en) * | 2012-06-28 | 2012-10-10 | 中国科学院苏州纳米技术与纳米仿生研究所 | Concentric ring core nano silicon micro-disk micro-cavity device and preparation method thereof |
| CN104466657A (en) * | 2014-11-07 | 2015-03-25 | 南京大学 | Chip-integrated 2-micrometer wavelength micro laser |
Non-Patent Citations (1)
| Title |
|---|
| D.K.ARMANI等: "Ultra-high-Q toroid microcavity on a chip", 《NATURE》 * |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105731352A (en) * | 2016-03-01 | 2016-07-06 | 南京大学 | On-chip integrated arsenic sulfide microdisk cavity and method for manufacturing same |
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| CN113314933A (en) * | 2021-05-11 | 2021-08-27 | 温州激光与光电子协同创新中心 | Whispering gallery mode microcavity antiresonance laser |
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