AU2020102853A4

AU2020102853A4 - A particle transport device based on a three-core optical fiber

Info

Publication number: AU2020102853A4
Application number: AU2020102853A
Authority: AU
Inventors: Jun Yang; Shitai Yang; Tingting YUAN; Yonggui YUAN; Xiaotong Zhang
Original assignee: Harbin Engineering University
Current assignee: Harbin Engineering University
Priority date: 2020-10-19
Filing date: 2020-10-19
Publication date: 2020-12-17
Anticipated expiration: 2028-10-19

Abstract

The present invention provides a particle transport device based on a three-core optical fiber. The particle transport device is primarily composed of three parts: (1) a three-waveguide optical fiber having a cross-section in a straight line, one side of the end of the optical fiber being polished to a bevel, then prepared to form an optical fiber operating probe; (2) including a light source that can provide photodynamic power for particle transport, and (3) a splitter that can independently input light to a three-waveguide optical fiber. The polished end of the optical fiber can form a crossed beam, and the transport route of the particles can be planned by adjusting the power value of each beam of light. The invention can be used for single-cell transport, drug-targeted transport, and can be widely used in single-cell analysis, biological therapy, cell sensing, and other technical fields. 4/4 -- The motion path FIG.7 12 13 FIG. 8

Description

4/4

-- The motion path

FIG.7

12

13

FIG. 8

DESCRIPTION TITLE OF INVENTION

A particle transport device based on a three-core optical fiber

TECHNICAL FIELD

[0001] The invention provides a particle transport device based on a three-core optical fiber

(TCF), this can be used for single-cell transport, drug-targeted transport, especially suitable for

single-cell analysis, biological therapy, cell sensing and other technical fields.

BACKGROUND ART

[0002] The emergence of nanotechnology provides a new approach for the diagnosis and

treatment of disease (Expert Opinion on Biological Therapy, Nanotechnology and medicine,

2003, 3, 655-663), such as the DNA- and RNA-based therapeutics, that have been proven to treat

the cancer cell by delivering the RNA molecular (Ther. Deliv, Research Spotlight: Delivery of

therapeutic RNA molecules to cancer cells by bacteria, 2011, 2, 441-449). For the advantage of

the precise treatment and low cost, the drug delivery and nanomedicine has drawn researchers'

interests for solving cancer therapy (Adv Drug Deliv, Targeted delivery of low molecular drugs

using chitosan and its derivatives, 2010, 62, 28-41), cell response (Biomed. Opt. Express,

Method of targeted delivery of laser beam to isolated retinal rods by fiber optics, 2011, 2, 2926

2933), and cell metabolism (Nanoscale, Trapping and delivery of Escherichia coli in a

microfluidic channel using an optical nanofiber, 2013, 5, 6720-6724). In biological experiments, optical technology plays an important role, such as Raman spectra discrimination of cell (J.

Invest. Dermatol, Discriminating Basal Cell Carcinoma from its Surrounding Tissue by Raman

Spectroscopy, 2002, 119, 64-69) in which light plays the role of signal detection or cell

manipulation, in which light plays a controlling role. Particularly the cell manipulation by light is

widely available in biology and medicine (Chinese Optics Letters, Optical-fiber-based powerful

tools for living cell manipulation, 2019, 17, 090603). All the achievement of the optical trapping

was benefited by Ashkin, who first demonstrated the optical manipulation of a single cell in 1987

(Nature, Optical trapping and manipulation of single cells using infrared laser beams, 1987, 330,

769-771). The radiation pressure of a focused laser beam generates two kinds of forces, a

scattering force, and a gradient force. The scattering force in the direction of the incident light

beam can push the particle along the direction of light propagation. Meanwhile, the gradient

force which is in the direction of the intensity gradient of the light beam that can trap the particle

to the focus of the beam (Review of Scientific Instruments, Optical trapping, 2004, 75, 2787

2809). With this basic knowledge of optical forces, a variety of optical manipulations have been

demonstrated. Among the various optical manipulations, optical transport, which refers to the

optical pushing and pulling along the optical axis, is useful in the application of optical conveyor

(Phys. Rev. Lett., Optical conveyors: a class of active tractor beams, 2012,109,163903), drug

delivery (Opt. Express, Optical vortices generated by a PANDA ring resonator for drug trapping

and delivery applications, 2011, 2, 159-168) and cell surgery (Applied Physics Letters, Laser

induced fusion of human embryonic stem cells with optical tweezers, 2013, 103, 033701).

However, most optical manipulation instrument needs complicated optical path design, special

structure optical beam, and bulky microscope. The optical fiber, by contrast, possessing the

advantages of simple structure, low cost, and easy to integrate, has become the substitution of

most optical devices. Consequently, the optical fiber is widely applied to optical manipulations

by many researchers. In the early days, two opposed single mode optical fiber were used to hold

and manipulate small particles. In spite of this method is effective, it cannot flexibly manipulate

particle in 3-dimensions. For this reason, researchers have developed optical tweezers by a single

optical fiber. In order to generate sufficient force to manipulate particles at the front end of the

fiber, the fiber tip needs to be processed into a spherical or wedge surface. In this patent, we

proposed a compact optical fiber manipulation probe for particle transport along a specific path

based on a TCF. The fabrication shape and method of the fiber end is proposed, and the experiments about the trajectory delivery of the particle is demonstrated.

[0003] With the above background, the invention proposes a multi-beam combined organelle mobile device based on a TCF, which can be used for single-cell transport and drug-targeted transport. The emitted beam of this device forms a cross optical field, and different tracks for particle transport can be formed by adjusting the optical power, enabling the track transport of particle with one single optical fiber. The device uses a linear TCF with a high degree of integration of multiple optical paths, and is compact and flexible, providing an important tool for exploring scientific questions about the properties of single-cells and for the study of cell targeted therapy.

SUMARRY OF INVENTION

[0004] The invention has the object to provide a particle transport device based on a three waveguide optical fiber, which can be used for single-cell transport and drug-targeted transport.

[0005] A particle track transport device based on a linear TCF, the particle transport device is primarily composed of three parts: (1) a linear TCF, one side of the end of the optical fiber being polished to a bevel, then prepared to form an optical fiber operating probe; (2) including a multi path light source that can provide photodynamic power for particle operation at a wavelength of 980nm, and (3) a splitter that can independently input light signals to the splitter of the TCF. In the transport system, the light beam is led by a standard single-mode fiber (SMF) 5 from the multi-path light source 1 into three paths, the light paths pass through the 1 x 2 couplers 3-1, 3-2 and 3-3, respectively, to each divide into two light paths. One of the two paths of each passes through the multi-core optical fiber splitter 2 then enters the side core 6-1, the center core 6-2, and the side core 6-3 of the TCF 6, while the other path of each is accepted by the optical power meters 4-1, 4-2 and 4-3.

[0006] The sample cell contains the particle solution and is stabilized on the stage 8, in which the

fiber operating probe 7 is immersed, and the transport of particle is achieved by the TCF probe.

The precise displacement operation process is imaged in real time by an imaging module

consisting of a microscopic objective 9, a charged coupled device (CCD) 10, and a monitor 11.

At the same time, the optical power value of each fiber core in the TCF can be detected by

optical power meters 4-1, 4-2, and 4-3, respectively, and the adjustment of the power intensity of

the emitted light from the TCF can be realized by adjusting the power of the multi-path light

source 1 to realize the construction of the particle transport track. In the above system structure

of the particle transport device, each core waveguide of the TCF provides an optical radiation

thrust on the particle in the optical field, and by the action of the optical thrust, the particle can

move along the beam, and at the point where the beams intersect, the particle will continue to

move along the high-power-beam, as shown in FIG. 1.

[0007] The TCF 6 employed in the present invention is equipped with a center core waveguide

6-2 and two equally spaced side cores 6-1 and 6-3, the distance of the two side cores from the

center core determines the orbital range over which the particle can move. The beam emitted

from one of the side cores intersects the beam emitted from the other two fiber cores, as shown

in FIG. 2 for the structure of a linear TCF, and FIG. 3 for the refractive index (RI) distribution of

the TCF.

[0008] The multi-path light source emits three paths of light through three SMFs that transmits to

three couplers 3-1, 3-2 and 3-3, which are divided into two paths. One of which is received by

the three optical power meters 4-1, 4-2 and 4-3 as a power detection optical path, and the other

one is transmitted through the ordinary single-core optical fiber 5 to the multi-core fiber

connector 2, and finally to the three cores of the TCF 6. The last three beams of light are output

from the fiber operating probe 7 acting on the particle. In order to achieve multiple trajectories of

motion, it is necessary for the emitting beams to generate a crossover, and afiber operating

probe can be fabricated by the fiber-end polishing technique, such as a single-sided wedge-face

structure, as shown in FIG. 4.

[0009] In order to satisfy the beam refraction convergence, the grinding angle 0 of the wedge

surface needs to satisfy 0 < arcsin(nI/n 2), ni is the RI of the liquid environment in which the

particle is located, and n2 is the RI of the fiber core. The grinding angle will have an effect on the

distance D from the intersection point of the beam to the end face of the fiber, and at a certain

fiber core spacing, the relationship between the distance D and the grinding angle 0 is shown in

FIG. 5. The angle of the grinding can be selected optimally according to the application

requirements.

[0010] The light emitted from the fiber core on the grinding side of the polished optical fiber

operating probe crosses the light emitted from the other two fiber cores, and the particle can

move along the beams. When passing the intersection of the two beams, the particle will change

the direction of motion according to the strength of the beam power. As shown in FIG. 6, the

particle starts moving from beam I and moves along beam III at the intersection point, and when

the particle moves to the second intersection point, the particle continues to move along beam II.

[0011] By modulating the power in each fiber core, five tracks of motion can be formed, as

shown in FIG. 7, and the particle can change the direction of motion at the position where the

beams intersect.

[0012] The invention has at least the following distinct advantages:

[0013] (1) A particulate transport device based on a TCF is proposed. Compared with other

particle transport systems, the proposed device has the features that the track of the particle

motion is adjustable and the velocity of the particle motion can be controlled.

[0014] (2) The present invention integrates the track generating device for particle transport in the same optical fiber, which has the characteristics of high integration and flexible operation, and can realize the directional transport of particles, as well as facilitate the analysis of the particle characteristics.

BRIEF DESCRIPTION OF DRAWINGS

[0015] FIG. 1 is a schematic diagram of a particle transport device based on the TCF

[0016]FIG. 2 is a schematic diagram of the structure of a TCF.

[0017]FIG. 3 is a schematic diagram of the RI distribution of the TCF.

[0018]FIG. 4 is a schematic diagram of the ground bevel of the optical fiber operating probe tip.

[0019]FIG. 5 is the relationship between the grinding angle and the distance of the intersection point of the center beam from the end face of the optical fiber.

[0020]FIG. 6 is a schematic diagram of particle changing tracks while transporting along the track.

[0021] FIG. 7 is a schematic diagram of the tracks that can be generated by a TCF particle transport device.

DESCRIPTION OF EMBODIMENTS

[0022] The experimental setup was constructed simply by a multiple-channel 980 nm

wavelength laser source, a multi-core fiber fan-in and fan-out device (homemade), a 3

dimensional micro stage for adjusting the position of the three-core fiber probe, and a

microscope connecting with the monitor screen for observing the motion of the particles. Among

these devices, the fan-in and fan-out (FIFO) device plays an important role in adjusting the

optical power in each fiber core of the TCF. The FIFO is made by our laboratory, and the

fabrication process includes the following main steps. The first step is to inset seven dual

cladding optical fibers into a seven-hole capillary with a diameter of 1 mm. The hole spacing in

the capillary is proportional to the spacing of the fiber core. Then the capillary with the fiber

inserted is heated and tapered to the fiber size by a hydrogen-oxygen flame. At last, the tapered

capillary is cut at the taper waist. As a result, the FIFO with a seven-core fiber at one end and

seven dual-cladding optical fibers at the other end is made. One end of the FIFO can be

connected to single mode fiber and the other end can be connected to a multi-core fiber of

matching size.

[0023] In our experiment, the TCF is connected with the multi-core end of the FIFO. The cores

of the TCF are linearly distributed. One core is in the center of the optical fiber, and the other

two cores are located beside the central core with the same spacing. In addition, the RIs of the

cores are the same. Since the two ends of the FIFO are respectively connected to the light source

and the TCF, the power in each core of the TCF can be adjusted separately. Therefore, this

feature provides convenience for TCF to manipulate particle.

[0024] The cores of the TCF are linearly arranged in the cladding, which generate parallel output

beams. However, in order to generate a cross optical field, the end of the TCF needs to be

micromachined. A simple method is to grind off a corner of the fiber end. So, the fiber end

grinding method is used to process the fiber end of the TCF. The fiber is fixed in an optical fiber fixture, and the fiber end is in contact with the rotating grinding disk. In order to determine the grinding angle and the grinding position, microscopes were placed at the front and on the side of the fiber, respectively. Then, the fiber end can be observed to find the fiber core position and the side of the fiber can be observed to determine the grinding angle. Therefore, only one side of the TCF can be grinded to produce crossed light beams.

[0025] Using the TCF particle transport device as an example to give a specific description of the invention.

[0026] Embodiment: realize the movement along the track of a particle

[0027] FIG. 1 is a schematic diagram of a particle track transport device based on a linear TCF, it consists of a multi-path output light source 1, a multi-core optical fiber splitter 2, three 1 x 2 couplers 3-1,3-2, 3-2, three optical power meters 4-1, 4-2, 4-3, an SMF 5, a TCF 6, fiber operating probe 7, a stage 8, a microscopic objective 9, a CCD 10, and a monitor 11. In the system, one light beam of the TCF operating probe is led by the SMF 5 from the multi-path light source 1, then it passes through the 1 x 2 couplers 3 and divides into two light paths. One of which passes through the multi-core optical fiber splitter 2 then enters one of the cores of the TCF 6. The sample cell contains the particle sample solution and is stabilized on the stage 8, in which the fiber operating probe 7 is immersed, and the particle transport is achieved by the TCF probe. The precise displacement operation process is imaged in real time by an imaging module consisting of the microscopic objective 9, the CCD 10, and the monitor 11.

[0028] The particle chosen here is a yeast cell, which is manipulated by a one-side-wedged TCF probe 7, which uses the three light beams formed by the three fiber cores 6-1, 6-2 and 6-3 of the fiber probe and the micro-manipulation region with two intersection points to jointly manipulate, and achieve the control of particle motion track. For ease of calculations, we use water as the environmental medium. The FIs of the core and cladding are ni = 1.462 and n2 = 1.457, respectively, and the refractive index of water na = 1.33. The grinding angle a is less than 240, as calculated from the critical angle. The TCF used in this case has a grinding angle of 20°. The intersection points of the light beams are shown in FIG. 6, with the side core light beam and the light beams of the other two cores intersecting at points A and B, respectively. The center core of the optical fiber is set as the z-axis, with the x-axis located on the plane where the beam is located and is perpendicular to the z-axis. Every fiber core has the same optical power, which are set to be 20mW in the simulation calculation. When a particle encounters the beams, the particle is subjected to gradient forces (perpendicular to the direction of propagation of the beams) and scattering forces (along the direction of propagation of the beams), and the total force on the particle can be added on to the forces generated by the beams as calculated by ray tracing. When the particle is on one light beam, the scattering forces of the beam will drive the movement of the particle, at the beam intersections, the particle will continue to move along the light beam of a large scattering force. By adjusting the power of the beams can achieve particles along the different tracks of the transport function, tracks that can be achieved are shown in FIG. 7.

Claims

1. A particle track transport device based on a linear three-core optical fiber (TCF), the

particle transport device is primarily composed of three parts: (1) a linear TCF, one side of the

end of the optical fiber being polished to a bevel, then prepared to form an optical fiber operating

probe; (2) including a multi-path light source that can provide photodynamic power for particle

operation at a wavelength of 980nm, and (3) a splitter that can independently input light to the

TCF. In the transport system, the light beam is led by a standard single-mode fiber (SMF) 5 from

the multi-path light source 1 into three paths, the light paths pass through the 1 x 2 couplers 3-1,

3-2 and 3-3, respectively, to each divide into two light paths. One of the two paths of each passes

through the multi-core optical fiber splitter 2 then enters the side core 6-1, the center core 6-2,

and the side core 6-3 of the TCF 6, while the other path of each is accepted by the optical power

meters 4-1, 4-2 and 4-3. The sample cell contains the particle solution and is stabilized on the

stage 8, in which the fiber operating probe 7 is immersed, and the transport of particle is

achieved by the TCF probe. The precise displacement operation process is imaged in real time

by an imaging module consisting of a microscopic objective 9, a charged coupled device (CCD)

, and a monitor 11. At the same time, the optical power value of each fiber core in the TCF can

be detected by optical power meters 4-1, 4-2, and 4-3, respectively, and the adjustment of the

power intensity of the emitted light from the TCF can be realized by adjusting the power of the

multi-path light source 1 to realize the construction of the particle transport track.

2. A particle track transport device based on a linear TCF according to claim 1, the TCF

related to the invention has the characteristics of: the optical fiber has one center core and two

cores on the same line with the same distance.

3. A particle track transport device based on a linear TCF according to claim 1, the proposed

multi-path light source used in the system to provide particle operation photodynamic power at a

wavelength of 980 nm is characterized by having three optical output channels and the optical power of each output channel is independently adjustable.

4. A particle track transport device based on a linear TCF according to claim 1, the splitter

involved for independently inputting an optical signal to the TCF is characterized by having

three SMFs as the input and one TCF as the output.

5. A particle track transport device based on a linear TCF according to claim 1, the particle

in the system can be a spherical or ellipsoidal single-cell, or a spherical or ellipsoidal polymeric

microparticle.