CN111766659A - A kind of controllable preparation device and method of nano-fiber - Google Patents

Abstract

The invention discloses a controllable preparation device for nano-fiber, which can realize the preparation of nano-fiber at the position where the micro-fiber to be processed is to be pulled. A bare fiber adapter connecting one end of the micron fiber to be processed with the output end of the pulsed laser; a micron sheet placed at the position where the micron fiber is to be pulled and capable of forming a near-field effect therewith. By adjusting and fixing the relative positions of the micro-sheet and the micro-fiber, nano-fibers with different gradient distributions can be prepared, and the number of pulses and single-pulse energy of the outgoing laser can be controlled, and the precise control of the diameter of the nano-fiber can be realized. The operation is simple and easy to operate. The drawing process can be monitored in real time at the nanoscale.

Description

A kind of controllable preparation device and method of nano-fiber

technical field

The invention relates to the field of nano-fiber preparation, in particular to a controllable preparation and method of a nano-fiber, which can realize precise regulation of the diameter and gradient of the nano-fiber, and has important applications in the fields of micro-nano photonics devices, micro-nano optical sensing and the like prospect.

Background technique

The interaction of light and matter is a subject that has been widely studied in recent years, especially the study of the interaction between single photons and single atoms. Because the resonant absorption cross-sectional area of a single atom is ^on the order of ~λ2, where λ is the wavelength of the absorbed light, this interaction is usually weak. A number of methods have been used to enhance the interaction of light with atoms, one by increasing the atomic density and the other by enhancing the light field for more efficient and stronger interactions.

Micro-nano fiber refers to an optical fiber with a diameter in the order of micrometers to nanometers. It has a small size and a strong binding ability to the light field, so as to achieve high power density and has a wide range of applications in many aspects, such as Precision spectroscopy, optical coupling devices, quantum storage and optical manipulation, etc.

The efficient preparation of repeatable nanofibers is the key to its practical application. At present, nanofibers are usually prepared by fusion drawing method. The fusion drawing method refers to the use of heating equipment to locally heat the optical fiber. When the optical fiber is in a molten state, a pulling force is applied to both ends of the optical fiber, and the optical fiber will become thinner in the axial direction, and finally at one end form nanofibers. The preparation method has the advantages of good directionality, simple preparation process and low production cost, but has the following problems: 1. The fusion-drawing method uses semi-manual drawing of nano-fibers, which requires operators to repeatedly try to prepare ideal nano-fibers, such as The inconsistency of the tightness of the undrawn fiber fixation and the inconsistent temperature position of the undrawn fiber at the heating source will affect the quality of the nanofiber, and the repeatability is not high; 2. During the drawing process, the heating temperature, drawing speed, Uncontrollable factors such as ambient temperature and ambient airflow will affect the drawing effect; 3. Nano-fibers prepared from standard fibers usually need to be stretched at least 40 cm. At this time, long-distance fibers with micro-nano diameters are affected by slight ambient airflow fluctuations , the airflow impact in the heating area is prone to breakage. A slight deviation in the diameter and surface morphology of the nanofiber will lead to fluctuations in the sensitivity of the sensing device, which will have a certain impact on the acceptance and calibration of the sensing device, and restrict the further development of optical devices based on micro-nanofiber.

Therefore, researching a controllable nanofiber preparation device and method has certain value and significance for improving the development of nanofibers in the field of micro-nano photonic devices.

SUMMARY OF THE INVENTION

Aiming at the problems of poor repeatability and difficult control of precision in the preparation process of the nano-fiber in the prior art, the present invention proposes a controllable preparation device and method for the nano-fiber, which can improve the low repeatability in the preparation process of the nano-fiber in the prior art , and easily broken due to the influence of the external environment, and finally a nanofiber whose diameter and gradient can be precisely controlled are drawn.

To achieve the above object, the technical scheme adopted by the present invention is:

A controllable preparation device for nano-fiber, which can realize the preparation of nano-fiber at the position where the micro-fiber to be processed is to be pulled, including:

Pulsed lasers that provide laser light;

a support table, on which the micron fiber to be processed is suspended and positioned;

A bare fiber adapter connecting one end of the micron fiber to be processed with the output end of the pulsed laser;

A micron sheet placed at the position where the micron optical fiber is to be pulled and capable of forming a near-field effect therewith.

The controllable preparation device for nano-fiber of the present invention mainly includes a micro-chip and a pulsed laser. The micro-chip is placed on the micro-fiber to be processed, and the laser light emitted by the pulsed laser is coupled to the micro-fiber, and the position to be pulled is the micro-chip and the micro-fiber. By controlling the contact position of the micron fiber, by controlling the parameters of the pulsed laser and the micron fiber, the controllable preparation of nanofibers with different diameters and tapers can be realized.

In the present invention, the number of pulses of the pulsed laser can be actively controlled, and nanofibers with different diameters can be prepared by controlling the number of pulses of the outgoing laser. By controlling the diameter of the micro-fiber, the taper of the nano-fiber can be adjusted, and the adjustment accuracy can reach 0.7°.

In the present invention, the micron optical fiber is further preferably an optical fiber with a diameter in the range of 1-20 microns. For microfibers with larger diameters (generally 6 microns to 20 microns in diameter), along the direction of the laser output, the microfibers on one side of the microplate will be subjected to a certain tensile force, resulting in the microfibers on both sides of the microplate. The difference in diameter enables the preparation of gradient fibers.

For micron fibers with smaller diameters (generally 5 microns or less in diameter), due to the strong evanescent field of the optical fibers, the heating is more obvious. Uniform heating to realize the preparation of uniform nanofibers.

Preferably, it also includes an optical fiber clamp for suspending and positioning the micron optical fiber to be processed on the support table.

Preferably, it also includes:

Electron gun, emitting electron beam to scan the position to be pulled;

The detector receives the reflected electron beam information and monitors the position to be pulled in real time.

Preferably, an electron beam microscope is included for real-time monitoring of the position to be pulled. The drawing process of the nanofiber was monitored in real time by the electron beam of the scanning electron microscope and the detector. The electron gun of the electron microscope is used to emit an electron beam to scan the position to be pulled; the detector of the electron microscope is used to receive the information of the reflected electron beam, and the position to be pulled is monitored in real time.

Preferably, the microflakes include metal microflakes and semiconductor microflakes with properties of absorbing laser light.

Preferably, the pulsed laser can be a broad-spectrum light source, including a supercontinuum laser, or a single-wavelength light source, including a nanosecond pulsed laser and a picosecond pulsed laser; the micron fiber includes a single-mode fiber, a multi-mode fiber . The number of pulses of the pulsed laser can be actively adjusted.

Preferably, it also includes a controller for controlling the working parameters of the pulsed laser. The controller of the pulsed laser can be a computer, a control chip or a control circuit board, etc., mainly to control the number of pulsed lasers of the pulsed laser and the energy of a single pulse, thereby realizing the control of the stretching size and stretching accuracy.

Preferably, the present invention provides a controllable preparation device for realizing nano-fiber, including a micro-fiber, a pair of fiber clamps, a micro-chip and a pulsed laser, a bare fiber adapter, a support table, an electron gun and a detector. Both ends of the micro-fiber are fixed on the fiber clamp, the fiber clamp is placed on the support table, so that the micro-fiber is in a suspended state, and the micro-chip is placed on the micro-fiber, and the laser emitted by the pulsed laser is coupled to the micro-fiber through a bare fiber adapter. The position to be pulled is the position where the micron sheet is in contact with the micron fiber. By adjusting and fixing the relative positions of the micron sheet and the micron fiber, nanofibers with different diameter gradient distributions can be prepared, and the number of pulses of the outgoing laser can be controlled. With nanofibers of different diameters, the real-time process of stretching can be monitored in real time by electron beams and detectors.

The direction of the micron fiber is the same as the stretching direction of the fiber.

Preferably, one side of the support table is a boss structure, and one side is a concave platform structure, the boss structure and the concave platform structure are connected to form an integral Z-shaped stepped structure, and the optical fiber clamp is arranged on the boss platform. The two groups on the structure are used to fix the two ends of the micron fiber respectively. After the positioning is completed, the micron fibers are suspended at the concave platform structure.

In the process of processing, the part where the microchips are not provided has a strong support force, which provides sufficient support force for the position to be pulled during the process. At the same time, the microflakes are adhered to the micron fibers by van der Waals force, which further enhances the stability of the microflakes. And after the laser is turned on, the force between the two is further enhanced due to the partial melting on the contact surface.

The present invention does not have strict requirements on the specific size of the microflakes, which are generally several micrometers to hundreds of micrometers. For example, it is generally 5 to 500 microns. When choosing the size of the microchip, it must first be able to be stably supported by the microfiber. At the same time, it needs to be selected according to the processing gradient requirements. The specific size of microchips to be selected also needs to be selected according to the actual gradient requirements to be processed, processing accuracy requirements, and so on. When a certain size of microchip is selected, several pre-experiments can be carried out for the microchip to determine the corresponding tensile size obtained by applying a pulsed laser of a certain intensity. After many experiments, it can be quickly determined. The size of the microflakes, the number of applied laser pulses, and the quantitative relationship between the pulse intensity and the fiber stretched size can be automatically controlled during subsequent processing. Of course, for supercontinuum lasers, the quantitative relationship between laser application time, laser intensity and fiber stretch size can also be determined through multiple implementations, and automatic control can be realized during subsequent processing.

A controllable preparation method of a nano-fiber, comprising: using the device described in any of the above technical solutions to prepare:

(1) Fix one end of the micron fiber to be processed with the output end of the pulsed laser through a bare fiber adapter;

(2) The micron fiber to be processed is suspended and positioned on the support table;

(3) Lay the micron sheet on the to-be-pulled position of the micron fiber to be processed;

(4) Turn on the pulsed laser, and make nanofibers of target size by controlling the laser parameters;

The order of step (1) and step (2) can be reversed or performed simultaneously.

Preferably, the micro-fiber to be processed is a micro-fiber array. By adopting the technical solution, nano-stretching processing of multiple micron optical fibers to be pulled can be realized.

The invention can clamp the micrometer fiber array by a pair of optical fiber clamps, the fiber clamp is placed on the support table, the micrometer fiber is in a suspended state, the micrometer sheet is placed on the micrometer fiber, the pulse laser is passed through one end of the micrometer fiber, and then the micrometer fiber is passed through the bare fiber. The fiber adapter couples the laser light in the pulsed laser to the micrometer fiber. By adjusting and fixing the relative position of the micrometer sheet and the micrometer fiber, nanofibers with different gradient distributions can be prepared. Nanofibers with different diameters are obtained, and finally nanofibers with controllable diameter and gradient are obtained. During the whole drawing process, electron beam imaging and detectors are used to monitor the nanoscale drawing process in real time, and the drawing precision can be improved. up to 1 nanometer; by controlling the diameter of the micron fiber, the taper of the nanofiber can be adjusted, and the adjustment accuracy can reach 0.7°.

Preferably, after processing one of the to-be-pulled positions, remove the remaining micron flakes at this position, take a new micron flake, and process the other to-be-pulled positions of the micron fiber according to steps (3) and (4) to prepare Nanofibers with multiple nanofiber structures. By adopting the technical solution, the processing of nano-fibers at different positions on the same micro-fiber can be realized.

The method of removing the residual microflakes generally selects a chemical solution removal method.

Compared with the prior art, the present invention has the advantages of:

(1) The present invention prepares the nano-fiber on the basis of the micro-fiber, avoids the problem that the length of the nano-fiber directly prepared based on the fusion drawing method is too long and leads to breakage, and greatly improves the preparation efficiency and success rate of the nano-fiber. In addition, the method effectively reduces the problem that the performance of the nanofiber-based device is affected by the external environment (such as airflow, vibration, etc.).

(2) The present invention can realize precise control of the diameter of the nano-fiber through the number of pulses of the pulsed laser, and the control precision can reach 1 nanometer.

(3) The present invention can realize the precise regulation of the nano-fiber gradient by controlling the diameters of the micro-sheet and the micro-fiber, and the control precision can reach 0.7°.

(4) The nanofiber drawing system involved in the present invention can be performed in a vacuum, and the diameter and taper of the nanofiber can be monitored in real time by using an electron microscope.

Description of drawings

FIG. 1 is a perspective view of the structure of the preparation device of the present invention.

2 is a schematic structural diagram of the diameter-controllable nano-fiber prepared by the present invention, (a) a micro-fiber; (b) a diameter-controllable nano-fiber; (c) a taper-controllable nano-fiber.

3 is an integrated perspective view of the structure of the preparation device and the electron microscope system of the present invention.

In the figure: 1-first fiber fixture, 2-second fiber fixture, 3-micron fiber, 4-micron sheet, 5-pulse laser, 6-bare fiber adapter, 7-support table, 8-electron gun, 9-detection device;

Figure 4 is a drawing of the gradient nanofiber; in this device, the diameter of the microfiber is 7.28 microns, the lateral size of the micron sheet is 31.48 microns, and the longitudinal size is 30.38 microns, the device stretching time is 30 seconds, the laser The repetition rate is 100 kHz, the number of pulsed lasers is 3 million, the single pulse energy is 4 microjoules, the single pulse width is 4 nanoseconds, and the stretching precision of the uniform nanofiber is 0.8667 nanometers.

Figure 5 is a drawing of a uniform nanofiber; in this device, the diameter of the microfiber is 3.24 microns, the lateral size of the micron sheet is 29.94 microns, and the longitudinal size is 23.11 microns, and the drawing time of the device is 22 seconds. The repetition rate of the laser is 100 kHz, the number of pulsed lasers is 2.2 million, the single pulse energy is 4 microjoules, the single pulse width is 4 nanoseconds, and the stretching accuracy of the gradient nanofiber is 0.6955 degrees.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments, but the embodiments of the present invention are not limited thereto.

A controllable preparation device and method for nano-optical fibers, comprising an optical fiber fixture, a microchip and a pulsed laser, a bare optical fiber adapter, a support table, an electron gun and a detector. Both ends of the micro-fiber to be processed are fixed on the fiber fixture, and the fiber fixture is placed on the support table, so that the micro-fiber is in a suspended state, and the micro-chip is placed on the micro-fiber. The laser emitted by the pulsed laser is coupled to the On the micron fiber, the position to be pulled is the position where the micron sheet and the micron fiber are in contact. By adjusting and fixing the relative positions of the micron sheet and the micron fiber, nanofibers with different diameter gradient distributions can be prepared, and the number of pulses of the outgoing laser can be controlled. Nanofibers with different diameters are prepared, and the real-time process of stretching can be monitored in real time by electron beams and detectors.

Wherein, the direction of the micron fiber is the same as the stretching direction of the fiber.

Wherein, the micron optical fibers include single-mode optical fibers and multi-mode optical fibers.

Wherein, the micro flakes include metal micro flakes and semiconductor micro flakes.

Wherein, the number of pulses of the pulsed laser can be actively adjusted.

Wherein, the pulsed laser is a broad-spectrum laser or a single-wavelength laser.

Among them, the electron gun and detector are the electron gun and detector in the electron beam microscope.

As shown in Figure 1, a controllable preparation device for nano-optical fibers, a pair of optical fiber fixtures are respectively a first optical fiber fixture 1 and a second optical fiber fixture 2, a micrometer sheet 4 is placed on the micrometer fiber 3, and both ends of the micrometer fiber 3 They are respectively fixed on the first fiber fixture 1 and the second fiber fixture 2, the fiber fixture is placed on the support table 9, so that the micrometer fiber is in a suspended state, and the pulsed laser 5 couples the emitted laser into the micrometer fiber 1 through the bare fiber adapter 6 , can be used in conjunction with a controller (such as a signal generator) to control the working parameters of the pulsed laser (pulse emission frequency, number of pulses, pulse intensity, etc.) Precise regulation of diameter and gradient.

As shown in FIG. 3 , the device of the present invention can be placed in an electron microscope system to form an integrated structure, and the electrons emitted by the electron gun 8 of the electron microscope system are used to image the sample, and the detector 9 is used to detect, so as to obtain an image of the sample. Real-time monitoring of the nanofiber fabrication process is realized.

A method for controllable preparation of nano-fiber, the method steps are as follows:

(1) Fix one end of the micron fiber to be processed with the output end of the pulsed laser through a bare fiber adapter;

(2) and suspend the micron fiber to be processed on the support table;

(3) Lay the micron sheet on the to-be-pulled position of the micron fiber to be processed;

(4) Turn on the pulsed laser, and make nano-fibers with different diameters by controlling the laser parameters;

The order of step (1) and step (2) can be reversed or performed simultaneously.

The processing principle of the present invention is as follows: in the integrated system composed of micron optical fibers and micron sheets, due to the strong evanescent field effect of the micron optical fibers, a part of the light energy can be coupled from the waveguide mode into the evanescent field of the external environment, and the evanescent field of the external environment can be coupled. The field interacts with the microchip to form a near-field enhancement effect, and the instantaneous localized optical field is converted into a thermal field. The integrated system forms a temperature gradient at both ends of the microchip due to the near-field effect, thereby forming an axial direction along the microfiber. Gradient force, realizes the drawing effect on micron fibers. In this system, the magnitude of the gradient force can be controlled by the single pulse energy of the pulsed laser. In turn, nanofiber fabrication in the sub-nanometer precision range is realized.

The micro-fiber to be processed may be a micro-fiber array. By adopting the technical solution, nano-stretching processing of multiple micron optical fibers to be pulled can be realized.

After processing one of the to-be-pulled positions, remove the remaining micron flakes at this position, take a new micron flake, and process the other to-be-pulled positions of the micron fiber according to steps (3) and (4). A nanofiber with a nanofiber structure.

2 is a schematic structural diagram of the diameter-controllable nano-fiber prepared by the method of the present invention, (a) micro-fiber; (b) diameter-controllable nano-fiber; (c) taper-controllable nano-fiber. Wherein (a) is the micro-fiber to be processed, (b) is the nano-fiber processed by using the micro-fiber with a diameter of 2-4 microns, (c) is the micro-fiber processed by using the micro-fiber with a diameter of 6-10 microns ;Using the device and method of the present invention, by adjusting and fixing the relative positions of the micron sheet and the micron fiber, nanofibers with different gradient distributions can be prepared, and by controlling the number of pulsed lasers and the energy of a single pulse, it can be made into different diameters. Nano-fiber, nano-fiber with controllable diameter and gradient is obtained after final preparation. During the whole drawing process, electron beam imaging and detector are used to monitor the nano-scale drawing process in real time, and the drawing precision can reach 1 nanometer; By controlling the diameter of the micro-fiber, the taper of the nano-fiber can be adjusted, and the adjustment accuracy can reach 0.7°.

Figure 4 is a drawing of the gradient nanofiber; in this device, the diameter of the microfiber is 7.28 microns, the lateral size of the micron sheet is 31.48 microns, and the longitudinal size is 30.38 microns, the device stretching time is 30 seconds, the laser The repetition rate is 100kHz, the number of pulsed lasers is 3000k, the single pulse energy is 4 microjoules, the single pulse width is 4 nanoseconds, and the stretching precision of the uniform nanofiber is 0.8667 nanometers.

Figure 5 is a drawing of a uniform nanofiber; in this device, the diameter of the microfiber is 3.24 microns, the lateral size of the micron sheet is 29.94 microns, and the longitudinal size is 23.11 microns, and the drawing time of the device is 22 seconds. The repetition rate of the laser is 100 kHz, the number of pulsed lasers is 2200k, the single pulse energy is 4 microjoules, the single pulse width is 4 nanoseconds, and the stretching accuracy of the gradient nanofiber is 0.6955 degrees.

Claims (10)

1. A controllable preparation facilities of nanometer optic fibre, characterized by that, can realize waiting to process the preparation of micrometer optic fibre and waiting to draw the position nanometer optic fibre, include:

a pulsed laser providing laser light;

the micron optical fiber to be processed is suspended and positioned on the supporting table;

the bare optical fiber adapter is used for connecting one end of the micro optical fiber to be processed with the output end of the pulse laser;

and the micrometer sheet is arranged at the position to be pulled of the micrometer optical fiber and can form a near field effect with the micrometer optical fiber.

2. The apparatus for controllably preparing a nanofiber as claimed in claim 1, further comprising a fiber clamp for positioning the microfiber to be processed on the supporting stage in a floating manner.

3. The apparatus for controllably producing a nanofiber as claimed in claim 1, further comprising:

the electron gun emits an electron beam to scan the position to be pulled;

and the detector receives the transmission electron beam information and monitors the position to be pulled in real time.

4. The apparatus for controllably producing a nanofiber as claimed in claim 1, comprising an electron beam microscope for monitoring the position to be drawn in real time.

5. The apparatus for controllably producing a nanofiber as claimed in claim 1, wherein the micro-slab comprises a metal micro-slab and a semiconductor micro-slab having a laser absorption property.

6. The apparatus for controllably producing a nanofiber as claimed in claim 1, wherein the pulse laser is a broad spectrum light source or a single wavelength light source; the wide-spectrum light source comprises a super-continuous laser, and the single-wavelength light source comprises a nanosecond pulse laser and a picosecond pulse laser; the micron optical fiber comprises a single mode optical fiber and a multimode optical fiber.

7. The apparatus for controllably producing a nanofiber as claimed in claim 1, further comprising a controller for controlling an operating parameter of the pulse laser.

8. A controllable preparation method of a nano optical fiber is characterized by comprising the following steps: use of the apparatus of any one of claims 1 to 7:

(1) one end of a micro-fiber to be processed is fixed with the output end of a pulse laser through a bare fiber adapter;

(2) suspending and positioning the micron optical fiber to be processed on the support table;

(3) putting the micron sheet at the position to be pulled of the micron optical fiber to be processed;

(4) starting a pulse laser, and manufacturing a nano optical fiber with a target size by controlling laser parameters;

the order of the step (1) and the step (2) can be exchanged or carried out simultaneously.

9. The controllable preparation method of the nano optical fiber according to claim 8, wherein the micro optical fiber to be processed is a micro optical fiber array.

10. The controllable preparation method of the nano-optical fiber according to claim 8, wherein after one of the positions to be drawn is processed, the residual micro-sheet at the position is removed, a new micro-sheet is taken, and the other positions to be drawn of the micro-optical fiber are processed according to the steps (3) and (4), so as to prepare the nano-optical fiber with a plurality of nano-optical fiber structures.

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