AU2020101133A4

AU2020101133A4 - A coaxial dual-annular three-core optical fiber cellular laser with strectching function

Info

Publication number: AU2020101133A4
Application number: AU2020101133A
Authority: AU
Inventors: Libo Yuan; Tingting YUAN; Xiaotong Zhang
Original assignee: Guilin University of Electronic Technology
Current assignee: Guilin University of Electronic Technology
Priority date: 2020-06-25
Filing date: 2020-06-25
Publication date: 2020-07-30
Anticipated expiration: 2028-06-25

Abstract

The present invention provides a coaxial dual-annular three-core optical fiber cellular laser system with stretching function. The "fiber-cell" laser comprises of the following four parts: (1) A coaxial dual-annular three-core optical fiber with a new structure, where the fiber end is polished into a rotationally symmetrical multi-angle cone-frustum-shape to prepare fiber optical tweezers; (2) A microspherical optical resonant cavity with a gain medium for optical amplification function; (3) A light source that can provide trapping photodynamic for cells and a gain medium excitation light source; (4) A cell output laser detection spectrograph. The output spectrum of the optical resonant cavity of the cell inside the cell is very sensitive to slight changes of the environmental physical parameters inside the cell such as the cell fluid, so it can be measured by the amplified laser signal output by the multi-core cone fiber. 115 DRAWINGS -00 00 [04 CIO FIG.1I

Description

DRAWINGS

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DESCRIPTION TITLE OF INVENTION

A coaxial dual-annular three-core optical fiber cellular laser with stretching function

TECHNICAL FIELD

[0001] The present invention relates to a coaxial dual-annular three-core optical fiber cellular

laser system with stretching function, which can be used for cells trapping, cells laser spectrum

measurement and self-assembly of cellular lasers, particularly suitable for the technical field of

single cell manipulation, measurement and analysis.

BACKGROUND ART

[0002] In 1960, physicist T.H. Maiman and others successfully created the world's first ruby

crystal laser. In 1961, A. Jia Wen and others successfully developed a helium-neon laser, and in

1962, R.N. Hall and others developed gallium arsenide semiconductor laser. The birth of the

laser marks people's ability to regulate the emission direction, phase, frequency, and polarization

of multiple photons, so that people's understanding and application of light have reached a higher

level. Lasers show unprecedented application value in the direction of miniaturization and

interdisciplinary, so the field of optical fluid lasers came into being. Optical fluid is a new

multidisciplinary research field formed by combining the unique advantages of optics and fluids.

The concept was proposed by the California Institute of Technology in 2003. The biological

body has a natural liquid environment. Sensory detection and imaging have very broad application prospects.

[0003] The cellular laser is a special optofluidic laser (Research Progress and Application of

Cellular lasers. Article in Laser & Optoelectronics Progress 55(12):120001), which can simulate

the liquid environment in which organisms live in vitro or directly in vivo , and under the

excitation of external energy to achieve the laser output of the cell. Compared with the current

fluorescent signal detection methods commonly used in various fields of biomedicine, the use of

laser signal detection has its own unique advantages. First, the laser signal is the spontaneous

radiation of stimulated radiation different from the fluorescent signal. The signal of the resonant

cavity will have good directivity after amplification and feedback; secondly, when the excitation

source laser signal is higher than the threshold, the signal energy output by the working particles

is much higher than the fluorescence signal, so the resolution and sensitivity of the laser signal

detection will also be higher than fluorescence detection, and the line width of the laser signal

output spectrum is extremely narrow compared with the fluorescence spectrum of the

luminescent material, which is conducive to timely response during the sample detection

process. The gain media commonly used in cellular lasers are generally fluorescent materials,

such as fluorescent proteins (Gather, M. C., & Yun, S. H. (2011). Single cell biological lasers.

Nature Photonics, 5(7), 406-410), fluorescent dyes (X. Zhang, et.al. Bio-switchable optofluidic

lasers based on DNA Holliday junctions. Lab on a Chip, 01 Oct 2012, 12(19):3673-3675),

fluorescein, quantum dots, vitamins, and fluorescence energy resonance transfer, etc., organically

integrate the gain medium with the cell, and the gain signal emitted after absorbing excitation

energy is continuously oscillated and feedback amplified by the optical resonant cavity, when the

gain is greater than the total loss in the cavity, a laser output is formed.

[0004] In June, 2001, Gather et.al. of Harvard University allowed human fetal kidney cells to

emit laser signals (Gather, M. C., & Yun, S. H. (2011). Single cell biological lasers. Nature

Photonics, 5(7), 406-410). The excitation light of the device need to pass the focus of the

imaging amplifying systems which reduces the light spot to the size of a single cell, and uses two

high-reflection mirrors to bond a Fabry-Perot cavity with a space slightly larger than the cell size to limit the cells in the position of the excitation light. The device is bulky, and the direction and position of the spatial excitation light are not easy to adjust for single cells, and the cells can only be trapped by means of external space limitations. In 2015, Humar et.al. of Harvard Medical School developed a variety of cellular lasers based on whispering-wall mode microcavities (Humar, M.; Yun, S. H. Intracellular microlasers, Nature Photonics, 2015, 9:572-576), which proved to be achievable in natural cells. Laser output, which artificially inserts a regular circular lipid droplet into the cell as the echo wall mode. The output signal is coupled to the spectral detector through a multimode fiber with a core diameter of 200m, but the device is large and the fiber used to receive the signal is thicker and since it does not have micro-operational functions such as precisely trapping the cells, which makes the operation of the excitation beam irradiating the cells less precise. The slight displacement of the cells in the liquid will cause the excitation beam to not be accurately coupled into the fat drops, which makes the gain signal unable to be continuously enhanced, and also increases the difficulty of the experiment.

[0005] Regarding the trapping and stretching of cells due to optically induced surface forces, common approaches to cell stretching are that individual suspended cells can be deformed by optically induced surface forces through optical stretchers combined with microfluidic delivery, through two beams of spatial light oriented in opposite directions so that cells within the microfluidic channels can be trapped and deformed by the divergent laser beam (Guck, J., et.al. The optical stretcher: a novel laser tool to micromanipulate cells, Biophysical Journal, 2011, 81:767-784). Other methods include, through the connection of red blood cells to two protein coated silicon dioxide pellets, one of the pellets is fixed to a glass plate and the other pellet is trapped by the optical tweezers, where the pellet moves with the movement of the optical tweezers during the movement of the optical trap, and this achieves the effect of stretching the red blood cells (Lim. C. T., et.al., Large deformation of living cells using laser traps, Acta Materialia, 2004, V52, 7:1837-1845). In addition, there are also direct adhesions to cells using glass or metal tips, and the viscosity of the cells is measured by the stretching and bending of the distance between the two tips, this can also stretch the cells. (Desprat, N.., et.al., Creep Function of a Single Living Cell, Biophysical Journal, 2005, 88: 2224-2233). These methods all contain devices in two opposing directions, including optically powered and mechanically powered, to perform contact or non-contact stretching operations on both sides of the cells, in which due to light sources and other reasons, other devices such as microfluidic channels will also be required to ensure that the stretched cells can always be in an easy-to-survive environment, and can only be operated by passing spatial light through the microfluidic channels. The proposed cellular laser based on a new fiber structure integrates the functions of cells trapping, stretching, exciting and receiving, largely reduces the number and size of the required devices, reduces the experimental steps, and reduces the experimental difficulty.

[0006] The invention patent with patent number CN201510295509.8 proposes a tunable liquid

cellular laser. In this patent, two optical fiber tweezers are required to trap the cells at the same

time, and use the method of using one optical fiber to output and another optical fiber to receive

to collect signal lights; the invention patent with patent number CN201510267391.8 proposes a

droplet whispering wall mode laser and its fabrication method. In this patent, the input light

needs to be coupled into the ring core by means of melting tapering of the single-mode optical

fiber and the ring core fiber. The droplet also needs to contact the micro-nano fiber to transmit

the signal light. The invention patent with the patent number CN201510271055.0 proposes a

multi-wavelength droplet laser. In this patent, since multiple droplets need to be excited and

detected, the same as the previous patent, each droplet needs contact with a micro-nano fiber and

output, this method undoubtedly increases the difficulty of the device. As we all know, the size

of the micro-nano fiber is only a few microns, which is easily affected by the external

environment, and it is difficult to keep the surface of the fiber clean for a long time. The linear

arrangement of the droplets means that multiple micro-nano fibers are required for linear

distribution. Due to the small size of the droplets, this also places extremely high requirements

on the experimental operation. The invention patent with the patent number 201810169543.4

proposes a living single cell multifunctional spectrograph based on coaxial dual-waveguide

optical fiber. The cell micro-optical "hand" mentioned in this patent is similar to the principle of

optical fiber trapping cells used in this patent, also uses ring cores to trap, but the device

structure and the function of the central core are different. The present invention not only

enriches the structure of the optical fiber, but also adds a variety of new functions of the optical

fiber, and at the same time changes the processing structure of the optical fiber end of the optical fiber tweezers, thereby changing the position of field of light for trapping of the cells. Comparing to side-throw coupling, the coupling method of the emitted light and the ring cores have been improved, making the experiment more operable. Compared with the above invention patents, the present invention proposes a coaxial dual-annular three-core optical fiber cellular laser system with stretching function. The new structure of the optical fiber includes one central core and two coaxial ring cores of different core distributions, which can integrates multiple functions such as cells trapping, cells attitude stretching, gain medium exciting and optical signals receiving in the same optical fiber, and the optical field of optical fiber tweezers for cells is optimized. This invention will provide a more reliable scientific basis for the analysis detection of living single cells and for revealing the essential laws of life activities.

[0007] The present invention presents, in the above context, a coaxial dual-annular three-core

optical fiber cellular laser system with stretching function. On the one hand, it is capable of

transmitting different optical wavelengths through the ring cores, thus completing the trapping of

cells, the distribution of the operational optical fields and the excitation of cellular lasers, thus

possessing the characteristics of optical field control and excitation. On the other hand, through

regulating the trapped light intensity to adjust the optical trap distribution intensity, and the

degrees of stretching of the microsphere can be controlled so that the excitation light path can be

precisely docked with the resonating microsphere. The device uses a new coaxial dual-annular

three-core optical fiber, it has a characteristics of highly integrated multiple optical paths, a small

size and bendable flexibility, providing an important multifunctional tool for the exploration and

study of life science problems in living single cells similar to microsphere, the present invention

is a new type of laser under the trend of interdisciplinary fusion, so it has a very important

significance and value.

SUMMARY OF INVENTION

[0008] The purpose of the present invention is to provide a coaxial dual-annular three-core optical fiber cellular laser system with stretching function that can be used for single cell trapping and cellular laser spectroscopy measurements.

[0009] A coaxial dual-annular three-core optical fiber cellular laser system with stretching function, the "fiber-cell" laser comprises of the following four parts: (1) A coaxial dual-annular three-core optical fiber with a new structure, where the fiber end is polished into a rotationally symmetrical multi-angle cone-frustum-shape to prepare fiber optical tweezers; (2) A microspherical optical resonant cavity with a gain medium for optical amplification function, can be distributed in the sphere, outside the sphere or on the surface of the sphere; (3) A light source that can provide trapping photodynamic for cells with a wavelength of 980nm, and a gain medium excitation light source with a wavelength of 460-670nm; (4) A cell output laser detection spectrograph. In the laser system: the trapping beam is extracted from the trapping light source 2 by a standard single-mode optical fiber 6, divided into two paths of light via a 1x2 coupler 3, respectively passing through attenuators 4-2 and 4-3 and the coaxial dual-annular three-core optical fiber fan in/out device 8, then into the two ring cores 9-1 and 9-2 of the coaxial dual-annular three-core optical fiber 9. The excitation light beam is extracted from the excitation light source 1 by the standard single-mode optical fiber 6, enters the coaxial dual-annular three core optical fiber fan in/out device 8 through the attenuator 4-1 and circulator 5, and then enters the central core 9-3 of the coaxial dual-annular three-core optical fiber 9.

[0010] The sample pool filled with liquid with cells is stabilized on the stage 11, and the fiber optical tweezers 10 are immersed in the sample pool, which is used to achieve the trapping and manipulation of the cell by a coaxial dual-annular three-core optical fiber probe, and the precise displacement operation process is carried out through the real-time imaging by the imaging module composed of a imaging amplifying system 12, an imaging system (CCD) 13 and a computer 14. At the same time, the detected cellular laser signal is received by the spectrograph 7 via a triple-end circulator 5. The cells in the liquid are trapped by thefiber optical tweezers 10 with a rotationally symmetrical cone-frustum-shaped fiber end, through the joint manipulation of the trapping forces of the fiber optical tweezers' cone-shaped ring cores 9-1 and 9-2, achieving position adjustment and the stretching of the attitude of the cells, making the excitation light emitted by the central core 9-3 and the resonant cell precisely dock, which satisfies the conditions of providing an excitation light source to the cell resonant cavity and outputting the resonance enhanced fluorescence signal to be detected, thereby self-assembling into a new type of "fiber-cell" laser. In the "fiber-cell" laser system structure, the two cone-shaped annular waveguides play a role in the photodynamic trapping and stretching of the cells, and the central core waveguide provides an excitation light to the trapped cells. This enables emitted excitation late to couple with the stretched microspheres in the cells, thereby achieving resonant excitation of the microspheres and the output of laser signals, completing the sensing and measurement of small changes in the refractive index of the cytosol inside the cells and other parameters, as shown in FIG. 1.

[0011] The coaxial dual-annular three-core optical fiber 9 of the invention has one central core

waveguide 9-3 and two coaxial ring cores waveguides 9-1 and 9-2, and the distance between the

two ring cores is related to the diameters of the ring cores. In which the two ring cores

waveguides are used to transmit the trapped beam and precisely control and adjust the cells'

attitude the other and the central core is used to transmit the excitation beam. FIG. 2 shows the

structure and refractive index distribution of a coaxial dual-annular three-core optical fiber, as

well as the type of light passing through the waveguide in each fiber core.

[0012] The trapping beam is injected into the two ring cores 9-1 and 9-2 of the coaxial dual

annular three-core optical fiber 9 through a coupler 3 and attenuators 4-2 and 4-3. The beam is

used for the trapping of cells by using thefiber end of the coaxial dual-annular three-core optical

fiber to prepare a rotationally symmetrical reflective cone table structure by precisely polishing.

This acts as the optical fiber optical tweezers 10, for refractive convergence of the transmitted

light beam in the ring cores to form an optical trapping force. The trapped beam transmitted

within the the ring cores of the coaxial dual-annular three-core optical fiber can also reflect and

focus via the frustum structure, achieving a deeper trapping potential well for trapping cells. To

achieve stable trapping and excitation of cells, optical fiber optical tweezers can be fabricated by fiber end polishing techniques, such as a rotationally symmetric multi-angle cone-frustum structure, as shown in FIG. 4. In order to satisfy the refractive convergence, the cone base angle a <arcsin (n/n) a should satisfy: , where n is the refractive index of the liquid environment in which the cell is located, n2is the refractive index of the ring cores. In order to increase the distance between the focuses so that the cells can be stretched more widely, this can be achieved by the method of optimizing the rotationally symmetrical cone-frustum structure. Process the faceted cone-frustum structure (FIG. 3(a)) into a multi-angle cone-frustum structure (FIG. 3(b)). Through the change of the facet structure, this can further increase the distance between the two focal points which increases the range of manipulation of cells.

[0013] The optical gradient force of cells carried out by using the processed optical fiber optical tweezers of a multi-angle cone-frustum structure (as shown in FIG. 4), every waveguide can regulate optical intensity through its own independent attenuators. This not only traps the cells, but also is able to achieve the stretching manipulation of the cells at the Z radial direction of position (X, Y, Z). The process of this manipulation can obtain rough feedback of the effects of the adjustments by observing the microscope CCD imaging. When the position of the cell near the two focal points of the beam becomes stressed and the cell as a whole is stretched and deformed, the optical power of each beam can be further varied according to the deformation. The forces on the trapped cells are shown in FIG. 5, and the focus of the trapped beam in the ring cores corresponds to the bottom of the gradient force. Fi to F 4 on the XY plane is at equilibrium, which balances with the F 5 and F6 of the ring cores to complete the stable stretching of the cells.

[0014] The excitation beam is injected into the central core 9-3 of the coaxial dual-annular three core optical fiber 9 via the attenuator 4-1, the circulator 5, and the coaxial dual-annular three core optical fiber fan in/out device 8. The excitation beam transmitted within the central core of the coaxial dual-annular three-core optical fiber is able to achieve the excitation of the trapped cell's laser via this frustum structure end face. The method is: after the cells are trapped by the beam emitted by the ring cores, the microsphere is stretched into a microellipsoid shape by an unevenly distributed optical trap force, which is modulated by the adjustment of the two optical focal points' energy. When the excitation light is excited, the microellipsoid can act as an optical Fabry-Perot microcavity, where the excited laser signal is limited to be in the micro-nanometer level resonator cavity. It can also be understood that the two ends of the long axis of the microellipsoid correspond to the two parallel-placed high-reflective mirrors. Light signals are transmitted back and forth between the mirrors, and light propagating near the axis is reflected back and forth to form a standing wave, which is amplified by the feedback light to form a laser then output the cavity. But due to that generally in the experiment, the two parallel-placed mirrors are not absolutely stable, and is extremely sensitive to the small vibrations from the surrounding environment or other external conditions, if the resonant cavity has a small angle deflection, then after many reflections the light signal, which is transmitted back and forth in the resonant cavity, can easily overflow out of the cavity. Hence, a low-threshold laser such as a cellular laser requires a relatively stable Fabry-Perot microcavity. The microellipsoid is manipulated by a centrally symmetrical structured light field distribution, so it is stretched into a regular ellipsoidal shape, and the stability conditions can be theoretically calculated by means of an ABCD matrix.

M=A B C D (1)

The stability condition to be met is:

_< A+D -1< < <1(2) (2 )

[0015] In the resonant cavity of the Fabry-Perot cavity based cellular laser, the light has to pass twice through the mirror and the cell, respectively, and its incident light transmission matrix Mi in the cavity is

1lL-2R 1 1 2RL M =j ncel -no ne [t0 1 )no -ncell no (3) Rno no - Rn,,y n,,,, The reflected light transmission matrix M 2 is

1 0 ]-1 0 ] M2F1 0 2R 1 0] L-2R] M2 n s en"L 0 1 ij1 o'-nell n° 0 1 Rno no - Rncei neell

In the above equation, R is the stability conditions for the cell radius to calculate resonant cavity,

ncel is the effective refractive index of the substances in the cell, and no is the refractive index of

the cell's external environment. The cellular laser outputs a weak laser signal with a lower

threshold than conventional lasers, which is in line with future applications in biomedicine. So

the threshold is an important parameter for cellular lasers. The gain provided by a regular unit

length of fluorescent material is

g(z)= N W(z)<r -+o+ -o-a (5)

Where Nis the molecular concentration of the fluorescent material, r is the fluorescence lifetime,

c is the speed of light propagation in vacuum, and 9ss is the absorption cross-section

corresponding to the laser wavelength. Among them

B=- E(A n (6)

W(z)= J(z)O (7) ho Where n is the refractive index of the laser medium, J(z) is the varying function of the pumping

intensity in the Z-axis direction, 50 is the absorption cross-section corresponding to the

pumping wavelength, hv is the photon energy, E() is the linear function of spontaneous

radiation, and

fE(2)d2=# (8) 0

Where # is the quantum yield. The signal light intensity of one round-trip in the cavity can be

measured by dI -= I(z)g(z) (9) dz When the threshold is reached, the light intensity of one round-trip within the cavity is equal to

the initial light intensity, and this method is used to calculate the threshold of the cellular laser,

but in experiments the threshold is often determined by the fitting curve of the measured data.

FIG. 6 is a schematic diagram of the working principle of the Fabry-Perot resonant cavity microspheres, which limits the light field in such a way that the light intensity in the cavity is very high, and this can effectively improve the pumping efficiency, thus greatly reducing the laser threshold, and can largely meet the needs of applications in cell biology.

[0016] The coaxial dual-annular three-core optical fiber fan in/out device 8 can be understood as

a device capable of splitting the emitting beam into a plurality of different splitting branches that

can be coupled into each of the fiber cores of the coaxial dual-annular three-core optical fiber,

wherein each of the splitting branches can in turn be individually controlled by the attenuator 4.

[0017] The schematic diagram of the working principle of a coaxial dual-annular three-core

optical fiber cellular laser system with stretching function is shown in FIG. 1. In order to meet

the needs of various sensing measurements, the present invention can replace the microsphere

with a single biological cell so that a cellular laser based on a coaxial dual-annular three-core

optical fiber can be achieved.

[0018] The invention has at least the following distinct advantages.

[0019] (1) A cellular laser is proposed. Compared to other single cell plasma lasers that have

been proposed, the proposed laser of this invention has the characteristics of non-invasive and

the achievement of real-time laser spectral detection.

[0020] (2) The present invention combines single cell trapping techniques, stretching function

and a cellular laser to apply to the same coaxial dual-annular three-core optical fiber. It can

provide a wealth of information on cell structure and chemical composition. Thus, the present

invention enables the analysis of single cells in a comprehensive and multifunctional manner.

[0021] (3) The proposed optical fiber probe integrates a plurality of operational functions within

a single fiber, and the optical fiber probe has the characteristics of high integration and

operational flexibility, and this enables quick analysis of living single cells.

BRIEF DESCRIPTION OF DRAWINGS

[0022] FIG. 1 is a schematic diagram of a coaxial dual-annular three-core optical fiber cellular

laser system device with stretching function.

[0023] FIG. 2 is a schematic diagram of the structure and refractive index distribution of a

coaxial dual-annular three-core optical fiber, and the types of light passing through the

waveguide in each fiber core.

[0024] FIG. 3 shows a shape optimization scheme of an optical fiber cone-frustum: (a) pre

optimized optical fiber cone-frustum; (b) post-optimized optical fiber cone-frustum.

[0025] FIG. 4 is a schematic diagram of a rotationally symmetrical multi-angle cone-frustum

structure of a coaxial dual-annular three-core optical fiber end.

[0026]FIG. 5 is a schematic diagram of the microspheres receiving forces when the two light

beams emitted from the coaxial dual-annular three-core optical fiber is combining a lightfield.

[0027] FIG. 6 is a schematic diagram of the atlas of the laser signal received according to the

Fabry-Perot resonant microcavity working principle.

[0028] FIG. 7 is a schematic diagram of the working principle of a coaxial dual-annular three core fiber cellular laser system with stretching function.

DESCRIPTION OF EMBODIMENTS

[0029] As we know, cell biology remains an important discipline in the life sciences field, underpinning the development of biotechnology foundation. Although cells have been discovered for over 300 years, humans currently do not have a complete and clear understanding of the working mechanisms by which the cell works at an overall level. Cell biology is the study of the basic laws of cellular life activity from the different structural levels of the cell. The use of modern scientific and technological achievements, methods, and concepts, at the cellular level to reveal the information inside the cell, is one of the important ways to acquire cell biological information.

[0030] Living single cell technology is at the forefront of current biological technology and can provide scientists with much new biological information. Not only can the conclusions of past classical methods be tested, but many new patterns can be discovered. For example, the single cell technique first allows scientists to test whether there really is an indicator of cellular mean, which means that the reliability of the multicellularity research methodology of the past can be tested, and how accurate this traditional research technique is. In addition, single cell assays can be very informative, sometimes unanticipated, or information that was previously obscured by statistical results. Not only can single cell studies compensate for the previously obscured and omitted important information as a result from population sampling of cells, but they also enable "histological" results of the research to be more objective and comprehensive. Also, it is possible to discover new phenomena and patterns that have not yet been discovered in life sciences research, thus, it is of particular importance for research in the life sciences.

[0031] For decades, researchers have focused on the analysis of cell populations. An important

premise for conducting such studies is that the individual cells that are thought to make up these

cell populations (e.g., normal tissue cells and tumor cells) are more or less homogeneous or

identical, the results obtained are the average of these cell populations' characteristics. In recent

years, single cell analysis techniques have received increasing attention as the phenomenon of

cellular heterogeneity has been revealed. However, single cell analysis faces many problems.

The most challenging one is the difficulty in meeting the demand for sensitivity, whether it is for

a single specific macromolecule or to conduct molecular analysis at the histological level, all of

which suffer from the difficulty with small amounts of single cell extracts that are difficult, if not

impossible, to analyze.

[0032] Due to limitations in sensitivity and sample volume, the usual life science research is

focused on large numbers of cells. However, there is significant microscopic inhomogeneity

(heterogeneity) between different individuals of the same cell species, and experimental results

based on a large number of cells hardly reflect the patterns of life activity at the single cell level.

Therefore, analysis based on living single cells will be able to reveal the nature and laws of life

activities at a deeper level, and provide a more reliable scientific basis for investigating the

causes, development and treatment of major diseases.

[0033] A coaxial dual-annular three-core optical fiber cellular laser system with stretching

function is used as an example to illustrate the invention in detail.

[0034] Embodiment 1: measurement of the laser of a single living cell:

[0035] FIG. 1 is a schematic diagram of a coaxial dual-annular three-core optical fiber cellular

laser system device with stretching function, in the laser system: the trapping beam is extracted

from the trapping light source 2 by a standard single-mode optical fiber 6, divided into two paths of light via a 1x2 coupler 3, respectively passing through attenuators 4-2 and 4-3 and the coaxial dual-annular three-core optical fiber fan in/out device 8, then into the two ring cores 9-1 and 9-2 of the coaxial dual-annular three-core optical fiber 9. The excitation light beam is extracted from the excitation light source 1 by the standard single-mode optical fiber 6, enters the coaxial dual annular three-core optical fiber fan in/out device 8 through the attenuator 4-1 and circulator 5, and then enters the central core 9-3 of the coaxial dual-annular three-core optical fiber 9. The sample pool filled with liquid with cells is stabilized on the stage 11, and the fiber optical tweezers 10 are immersed in the sample pool, which is used to achieve the trapping and manipulation of the cell by a coaxial dual-annular three-core optical fiber probe, and the precise displacement operation process is carried out through the real-time imaging by the imaging module composed of a imaging amplifying system 12, a CCD 13 and a computer 14. At the same time, the detected cellular laser signal is received by the spectrograph 7 via a triple-end circulator

5. The cells in the liquid are trapped by thefiber optical tweezers 10 with a rotationally

symmetrical cone-frustum-shaped fiber end, through the joint manipulation of the trapping

forces of the cone-shaped ring cores 9-1 and 9-2 of thefiber optical tweezers, achieving position

adjustment and the stretching of the attitude of the cells, making the excitation light emitted by

the central core 9-3 and the resonant cell precisely dock, which satisfies the conditions of

providing an excitation light source to the cell resonant cavity and outputting the resonance

enhanced fluorescence signal to be detected, thereby self-assembling into a new type of "fiber

cell" laser. In the "fiber-cell" laser system structure, the two cone-shaped annular waveguides

play a role in the photodynamic trapping and stretching of the cells, and the central core

waveguide provides an excitation light to the trapped cells. This enables emitted excitation late

to couple with the stretched microspheres in the cells, thereby achieving resonant excitation of

the microspheres and the output of laser signals, completing the sensing and measurement of

small changes in the refractive index of the cytosol inside the cells and other parameters.

[0036] As shown in FIG. 7, the cell used here is the HEK293 Human Embryonic Kidney Cells

, which are commonly used in biology to perform transfected mammalian cells. The cell

diameter is 13.8[tm, which is organically integrated from the gain medium: green fluorescent

protein molecules into cells. When the system is operating, the wavelength of the trapping beam

17 is 980nm, the wavelength of the excitation beam 18 is 480nm, and the two light beams are admitted into the two coaxial dual-ring cores 9-1 and 9-2 and the central core 9-3 of the coaxial dual-annular three-core optical fiber 9, respectively. The two ring cores light beams admitted by the 980nm trapping light achieve optical reflection at the cone-frustum, and converges to form an optical trap at a distance from the end face of the fiber, to precisely manipulate and regulate the cell attitude of the trapped cells through respectively adjusting the light intensity in the ring cores. The 480nm excitation light 18 is admitted into the central core 9-3, when the position adjusted by the cell satisfies the oscillation conditions of the excitation light emitted by the gain medium microellipsoid 16 in the cell 15 and the central core waveguide 9-3, the laser signal generated by the excitation of the gain medium is continuously amplified by the microsphere resonant cavity, when the gain is greater than the total loss of the cavity, a laser output is formed, the laser signal 19 is received through the return of the central core 9-3 where the excitation beam is located at and then transmitted to the circulator 5; finally the feedback path is completed by the spectrograph 7 to obtain the cellular laser spectrogram.

Claims

1. A coaxial dual-annular three-core optical fiber cellular laser system with stretching

function, the "fiber-cell" laser comprises of the following four parts: (1) A coaxial dual-annular

three-core optical fiber with a new structure, where the fiber end is polished into a rotationally

symmetrical multi-angle cone-frustum-shape to prepare fiber optical tweezers; (2) A

microspherical optical resonant cavity with a gain medium for optical amplification function, can

be distributed in the sphere, outside the sphere or on the surface of the sphere; (3) A light source

that can provide trapping photodynamic for cells and a gain medium excitation light source; (4)

A cell output laser detection spectrograph. In the laser system: the trapping beam is extracted

from the trapping light source 2 by a standard single-mode optical fiber 6, divided into two paths

of light via a 1x2 coupler 3, respectively passing through attenuators 4-2 and 4-3 and the coaxial

dual-annular three-core optical fiber fan in/out device 8, then into the two ring cores 9-1 and 9-2

of the coaxial dual-annular three-core optical fiber 9. The excitation light beam is extracted from

the excitation light source 1 by the standard single-mode optical fiber 6, enters the coaxial dual

annular three-core optical fiber fan in/out device 8 through the attenuator 4-1 and circulator 5,

and then enters the central core 9-3 of the coaxial dual-annular three-core optical fiber 9. The

sample pool filled with liquid with cells is stabilized on the stage 11, and the fiber optical

tweezers 10 are immersed in the sample pool, which is used to achieve the trapping and

manipulation of the cell by a coaxial dual-annular three-core optical fiber probe, and the precise

displacement operation process is carried out through the real-time imaging by the imaging

module composed of a imaging amplifying system 12, an imaging system (CCD) 13 and a

computer 14. At the same time, the detected cellular laser signal is received by the spectrograph

7 via a triple-end circulator 5. The cells in the liquid are trapped by the fiber optical tweezers 10

with a rotationally symmetrical cone-frustum-shaped fiber end, through the joint manipulation of

the trapping forces of the fiber optical tweezers' cone-shaped ring cores 9-1 and 9-2, achieving

position adjustment and the stretching of the attitude of the cells, making the excitation light

emitted by the central core 9-3 and the resonant cell precisely dock, which satisfies the

conditions of providing an excitation light source to the cell resonant cavity and outputting the

resonance enhanced fluorescence signal to be detected, thereby self-assembling into a new type of "fiber-cell" laser. In the "fiber-cell" laser system structure, the two cone-shaped annular waveguides play a role in the photodynamic trapping and stretching of the cells, and the central core waveguide provides an excitation light to the trapped cells. This enables emitted excitation late to couple with the stretched microspheres in the cells, thereby achieving resonant excitation of the microspheres and the output of laser signals, completing the sensing and measurement of small changes in the refractive index of the cytosol inside the cells and other parameters.

2. A coaxial dual-annular three-core optical fiber cellular laser with stretching function

according to claim 1, the coaxial dual-annular three-core optical fiber involved in the system is

characterized in that the fiber has one central core and two coaxial-distributed ring cores, the

distance between the two ring cores is related to the diameter of the ring cores.

3. A coaxial dual-annular three-core optical fiber cellular laser system with stretching

function according to claim 1, the microspherical optical resonant cavity in the system, characterized in that the microsphere may be some kind of spherical single cell, some kind of

biological particle present in the cell, or a regular elastic spherical particle placed in the cell. The

resonator has a centrally symmetrical geometry, is elastic, deformable by force, and contains a

gain medium.

4. A coaxial dual-annular three-core optical fiber cellular laser system with stretching

function according to claim 1, the two ring cores in the system form two focuses to form two

optical traps, and the microsphere is stretched by the force, changing from spherical to

ellipsoidal.

5. A new type "fiber-cell" lasers self-assembled method, characterized by.

(1) Use two cone-shaped annular waveguides to statically trap the cells;

(2) Stretch the microsphere by the light-trapping forces emitted by the two ring cores and remains in equilibrium, deforms from spherical to ellipsoidal to form a Fabry-Perot microcavity.; (3) Accurately couple the microsphere with the excitation light emitted from the central core waveguide, based on the principle of Fabry-Perot, to achieve the output of the resonant excitation and laser signal of the microsphere.