A device and method for assembling a micro-nano lighting lamp using an optical fiber

Abstract

The application discloses a kind of micro-nano lighting lamp assembly devices based on optical fiber, it is related to micro-nano optics and photonic integrated field.The device includes lithium niobate chip, the tapered waist of superfine optical fiber is formed by optical fiber drawing workstation preparation and laser focusing light path.Wherein, laser focusing light path is used to focus laser to lithium niobate chip, make it generate spatial electric field by photoelectric effect;The spatial electric field and the evanescent field of superfine optical fiber side jointly form optical gradient force, for polystyrene microsphere high-precision assembly on superfine optical fiber surface;The light of superfine optical fiber introduction is coupled into microsphere interior and is scattered output by multiple times, to form bright and stable micro-nano illumination light source.The application compact structure, small volume, assembly is convenient and size controllable, with high sensitivity and high reliability of laser auxiliary control, applicable to the construction and integrated application of photonic integrated chip micro light source.

Description

Technical Field

[0001] This invention relates to the fields of micro-nano photonics, micro-nano manipulation and integrated optics, specifically to the assembly of an ultrafine fiber micro-nano illumination structure based on evanescent field gradient force and the photovoltaic effect of lithium niobate. Background Technology

[0002] With the rapid development of micro-nano photonics and integrated optical chips, miniature, integrated, and in-situ fabricable micro-nano light sources are becoming increasingly important in fields such as chip sensing, bio-imaging, near-field optics, and on-chip optical interconnects. Traditional micro-nano light sources rely on complex processes such as photolithography, deposition, and etching, which result in high costs and difficulties in achieving dynamic assembly and flexible control.

[0003] High-efficiency light emission can be achieved by using microsphere resonant cavities coupled with optical fibers, but there are technical challenges to the high-precision and stable assembly of polystyrene and other microspheres on the surface of optical fibers; mechanical operation is prone to damage to devices and it is difficult to achieve micro-nano scale precision; traditional optical tweezers are bulky and not easy to integrate into chips, and the control method is also easily affected by environmental interference.

[0004] Lithium niobate materials can generate a spatial electric field under illumination due to the photovoltaic effect, exerting an electric field binding effect on microspheres; the evanescent field on the surface of ultrafine optical fibers can generate optical gradient forces for non-contact trapping. However, there is no mature technology that uses the synergy of spatial electric field and evanescent field to assemble microspheres on the surface of optical fibers and construct micro / nano lighting lamps in situ, which limits the development of on-chip integrated micro light sources. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a device and method for assembling micro-nano lighting lamps using optical fibers, which solves the problems of complex processes, low microsphere assembly precision, limited control methods, and difficulty in compatibility with chips in traditional micro-nano light sources.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: an apparatus and method for assembling micro / nano lighting lamps using optical fibers, comprising a laser focusing optical path, an optical fiber drawing stage, a tapered ultra-fine optical fiber, a lithium niobate chip, and a micro-manipulation platform; the ultra-fine optical fiber is prepared by the drawing stage and has a smoothly transitioned tapered waist, and is laid on the lithium niobate chip; the laser focusing optical path is used to irradiate the lithium niobate chip and the tapered region of the ultra-fine optical fiber with a focused laser beam, thereby generating a photovoltaic space electric field on the lithium niobate chip and exciting an evanescent field on the surface of the ultra-fine optical fiber, forming a photoelectric synergistic potential field, realizing the precise capture, movement, and stable assembly of polystyrene microspheres in solution, with the microspheres fixed at a designated position on the tapered waist of the ultra-fine optical fiber; the ultra-fine optical fiber is used to guide the lighting light and couple it into the microspheres, forming an outward high-brightness and highly directional micro / nano lighting output through multiple scattering and resonance.

[0009] Preferably, the ultrafine optical fiber is a standard single-mode optical fiber drawn at high temperature, with a waist diameter ranging from micrometers to submicrometers and a smooth transition in the tapered region, in order to achieve efficient waveguide and generate a stable evanescent field.

[0010] Preferably, the polystyrene microspheres have a controllable particle size, and the photo-electric synergistic potential field is used to achieve the fixed-point adsorption and orderly arrangement of one or more microspheres at the waist of the cone, with adjustable spacing.

[0011] Furthermore, by adjusting the output power and focusing position of the laser and the diameter of the tapered waist of the ultrafine fiber, the intensity of the spatial electric field and the magnitude of the optical gradient force can be precisely controlled, thereby achieving controllable adjustment of the number, position, and spacing of the microspheres.

[0012] Furthermore, the device is small in size and easy to integrate. The assembly process is non-mechanical and damage-free, and the resulting micro-nano lighting structure has controllable size, high stability and reliability.

[0013] (III) Beneficial Effects

[0014] This invention provides an apparatus and method for assembling micro-nano lighting lamps using optical fibers, which has the following beneficial effects:

[0015] This device and method for assembling micro-nano lighting lamps using optical fibers achieves several advantages. First, the evanescent field light gradient force and the photovoltaic space electric field work together to achieve high trapping force, high positioning accuracy, and strong anti-interference capability, enabling stable assembly of microspheres on optical fibers. Second, using ultra-fine optical fibers as the carrier and light guide structure eliminates the need for complex photolithography, allowing for in-situ assembly onto chips. This results in a simple structure that is easy to integrate. Furthermore, the microsphere particle size, assembly position, and illumination wavelength are adjustable, resulting in micro-nano lighting lamps that are small in size, high in brightness, and stable in performance. In addition, the entire process is laser-assisted, non-contact, non-destructive, and highly sensitive, making it suitable for applications such as chip-level micro-nano light sources, biosensing, and near-field imaging. This has significant value for the development of integrated photonic devices. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention;

[0017] Figure 2 A schematic diagram illustrating the working principle of microspheres coupled with light emission to form a micro / nano lighting lamp;

[0018] Figure 3 This is a schematic diagram of the assembly process of the tapered waist of an ultra-thin optical fiber with a single microsphere.

[0019] Figure 4 A schematic diagram of the assembly structure of the tapered waist of an ultra-fine optical fiber and individual microspheres of different sizes;

[0020] Figure 5 A schematic diagram of the assembly process of the tapered waist of an ultra-fine optical fiber and multiple microspheres arranged in parallel and connected in series.

[0021] Figure 6 This is a schematic diagram of different assembly structures of the tapered waist of an ultra-fine optical fiber and multiple microspheres. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments.

[0023] This invention discloses an apparatus and method for assembling micro-nano lighting lamps using optical fibers. The apparatus includes: a laser 1, an electronic shutter 2, an aperture 3, a laser reflector 4, a focusing objective lens 5, a tapered optical fiber 6, a filter 7, a CCD camera 8, a background light source 9, a microsphere 10, a lithium niobate chip 11, and a fiber laser 12.

[0024] As a preferred technical solution of the present invention:

[0025] Example 1

[0026] An apparatus for assembling micro / nano lighting lamps using optical fibers, comprising:

[0027] The system comprises a continuous-wave laser, a focusing optical path system, an optical fiber drawing stage, a single-mode ultrafine optical fiber, a lithium niobate wafer, a three-dimensional micromanipulation platform, and a microfluidic cell. The ultrafine optical fiber, approximately 1 cm in length, with a waist diameter of about 1 μm and a taper length of about 3 mm, is drawn from standard single-mode fiber using an oxyhydrogen flame at high temperature. The fiber has a smooth transition and spans the surface of the lithium niobate wafer. The entire assembly is placed in the microfluidic cell, through which a suspension of polystyrene microspheres is introduced. The laser, with a wavelength of 473 nm, is focused onto the taper waist of the ultrafine optical fiber, resulting in a spot diameter of approximately 2 μm.

[0028] Example 2

[0029] A method for assembling micro / nano lighting using optical fibers comprises the following steps: Fiber drawing: The coating layer of a single-mode optical fiber is stripped, and a tapered ultra-thin optical fiber is drawn using a fiber drawing stage to ensure low loss and a strong evanescent field; Device mounting: The ultra-thin optical fiber is fixed onto a lithium niobate chip, placed in a microfluidic pool, mounted on a three-dimensional micromanipulation platform, and the optical path is adjusted for focusing; Microsphere assembly: A suitable concentration of polystyrene microsphere suspension is injected, with microspheres having a diameter of 2-8 μm. The laser is turned on, and the lithium niobate is excited by light to generate a photovoltaic electric field. The ultra-thin optical fiber guides the light, generating an evanescent field and an optical gradient force. Under the action of these two fields, the microspheres are rapidly captured and stably adsorbed at the waist of the fiber tapered shape; Micro / nano lighting: 638 nm red light is introduced through the input end of the ultra-thin optical fiber. The light field couples into the microsphere, where multiple scattering and resonance occur, forming a bright red micro / nano lighting lamp with uniform light output and good stability, suitable for use as an on-chip micro-light source. By adjusting the laser power, the electric field strength and the magnitude of the optical gradient force can be changed, enabling the linear assembly of single or multiple microspheres, thereby controlling the size and brightness of the illumination spot.

[0030] The working principle of this device is to assemble micro-nano lighting lamps using optical fibers. In use, the user uses an optical fiber drawing stage to draw single-mode optical fibers into micron to submicron tapered ultra-thin optical fibers. The tapered region is smooth, with low transmission loss and strong evanescent field. Using ultra-thin optical fibers as the carrier and light guide structure, complex photolithography is not required, and the fibers can be assembled in situ onto the chip. The structure is simple and easy to integrate. A solution containing polystyrene microspheres is introduced, and the laser is turned on. Lithium niobate generates a spatial electric field, and the evanescent field of the optical fiber generates an optical gradient force. The two fields work together to capture and assemble the microspheres on the surface of the optical fiber. The illumination light is introduced into the optical fiber, and the light is coupled into the microspheres and scattered multiple times to achieve stable micro-nano lighting output.

Claims

1. A device for assembling micro / nano lighting lamps using optical fibers, comprising a laser focusing optical path module, an optical fiber drawing stage, an ultra-fine optical fiber, a lithium niobate chip, and a micro-manipulation platform, characterized in that: The ultra-fine optical fiber, fabricated by the optical fiber drawing stage and having a tapered waist structure, is laid on the lithium niobate chip. The laser focusing optical path is used to output a focused laser beam and act on the lithium niobate chip and the ultra-fine optical fiber region. Under laser irradiation, the lithium niobate chip generates a spatial electric field through the photovoltaic effect, which, together with the evanescent field on the side of the ultra-fine optical fiber, generates an optical gradient force to achieve the fixed-point capture and assembly of polystyrene microspheres on the surface of the ultra-fine optical fiber. The light transmitted inside the ultra-fine optical fiber is coupled to the interior of the microspheres and forms a micro-nano illumination source through multiple scattering.

2. The device for assembling micro / nano lighting lamps using optical fibers according to claim 1, characterized in that: The ultra-fine optical fiber is a single-mode optical fiber drawn at high temperature, with a waist diameter ranging from micrometers to submicrometers and a smooth transition in the tapered region. It is used for efficient wave guiding and excitation of evanescent fields.

3. The device for assembling micro / nano lighting lamps using optical fibers according to claim 1, characterized in that: The polystyrene microspheres have a controllable particle size. By utilizing the synergistic effect of the optical gradient force and the spatial electric field, one or more microspheres can be stably adsorbed and arranged at a designated position on the ultrafine optical fiber.

4. The device for assembling micro / nano lighting lamps using optical fibers according to claim 1, characterized in that: The assembly and light emission process of the device includes: fixing the ultrafine optical fiber to the surface of the lithium niobate chip in a solution environment and placing it on the micro-manipulation platform; adjusting the focusing optical path of the laser to irradiate the tapered region of the ultrafine optical fiber; achieving precise capture and assembly of the microsphere on the surface of the ultrafine optical fiber under the synergistic effect of the optical gradient force generated by the spatial electric field and the evanescent field; introducing illumination light into the ultrafine optical fiber, so that the light field couples into the microsphere, and forming a micro-nano illumination source that radiates outward after multiple scattering and resonance.

5. The apparatus for assembling micro / nano lighting lamps using optical fibers according to claim 1, characterized in that: By adjusting the output power and focusing position of the laser and the waist diameter of the ultra-fine fiber, the spatial electric field and the optical gradient force can be precisely controlled, thereby enabling the assembly position and quantity of the microspheres to be controllable.

6. The apparatus for assembling micro / nano lighting lamps using optical fibers according to claim 1, characterized in that: By selecting polystyrene microspheres of different sizes and illumination light of different wavelengths, the brightness, spot size, and emission wavelength of the micro-nano illumination source can be adjusted.

7. The apparatus for assembling micro / nano lighting lamps using optical fibers according to claim 1, characterized in that: The assembly and illumination process relies on contactless and non-destructive laser-assisted manipulation, which is suitable for in-situ fabrication and integration of micro-nano light sources for photonic integrated chips.

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