CN103941040A - Device and method for detecting acceleration on basis of back scattered light of nano particle detection - Google Patents

Abstract

The invention discloses a device and method for detecting acceleration on the basis of back scattered light of nano particle detection. The device comprises a reflective mirror, a light reducing plate, a beam splitter, a light filer, a first focusing lens, first nano particles, second nano particles, grinding taper optical fibers, a rigid connecting rod, a second focusing lens, pinholes, a separating light detector, a laser, a collimating lens, a light intensity modulator, a DSP processor and a micro circulation channel. The device and method for detecting the acceleration on the basis of the back scattered light of the nano particle detection are based on highly sensitive nanoscale displacement measurement, the structure can obtain extremely high measurement resolution of the acceleration and is only restricted by the absolute value of restoring force of light pressure, and meanwhile, a loop-locked control circuit can extend a dynamic measurement range greatly. According to the device and method for detecting the acceleration on the basis of the back scattered light of the nano particle detection, the acceleration of nanoscale displacement is measured without physical contact, the device is not sensitive to other kinds of acting force not in the acceleration direction, and the device and method for detecting the acceleration on the basis of the back scattered light of the nano particle detection have the advantages of being low in noise, high in sensitivity and capable of carrying out high precision identification and analysis, and having feedback functions.

Description

The device and method of the rear orientation light sense acceleration of surveying based on nanoparticle

Technical field

The present invention relates to the detection method that a kind of nanometer displacement accelerates, relate in particular to a kind of device and method of the nanometer displacement acceleration detection based on the detection of nanoparticle rear orientation light and optical pressure adjusting feedback system.

Background technology

Newton second law of motion has illustrated that the acting force that the size of object acceleration is subject to object is directly proportional, and follows the quality of object to be inversely proportional to, and the direction of acceleration is identical with the direction of bonding force, by power, just can realize the measurement of acceleration.Current high precision acceleration transducer is realized the contactless support to sensing quality by technology such as electrostatic suspension technology or magnetic levitation mostly.

By the known light beam of quantum theory, be that a group has again the photon stream of momentum with light velocity motion, existing quality.When light beam, at dielectric surface, refraction and reflex time occurs, the speed of photon and direction change, thereby cause the variation of its momentum vector, are also that light beam exists the effect of power to particulate, are called optical radiation and press, and the minimum particulate yardstick of optical radiation pressure effect is in micron dimension.Along with the widespread use that optical radiation is pressed, nowadays also occurred utilizing laser capture technology to realize the noncontact of sensing quality has been supported, these technology have greatly reduced the measuring error that traditional contact supports accelerometer.The method that common laser capture technology realizes acceleration analysis is that optical fiber light trap acceleration is measured, its utilizes from many and with optical fiber direct, picks out the Gaussian beam of penetrating and produce radiation pressure at particle surface, realize the hovering of particle, and with photoelectric image detector, the skew of particle is observed, thereby realize the measurement to the adjusting of optical pressure and acceleration.The shortcoming of this measurement mechanism is, utilization picks out the Gaussian beam of penetrating and as light tweezer, particle is caught from optical fiber direct, the beam waist diameter of Gaussian beam is similar to the mode field diameter of optical fiber, so be restricted can not be too small for its particle size that can catch, and the power of catching is not strong.And adopt photoelectric image detector to measure the skew of particle, and can only detect the movement of particle micron dimension, be the principal element that limits this acceleration detection method precision.

To optical fiber exit end grinding core, can convert the Gaussian beam of script outgoing to accurate bessel beam, the full width at half maximum of this light beam is than the little magnitude of Gaussian beam, and energy is more concentrated, so can catch less particle, produce stronger radiation pressure, sensitivity and the investigative range surveyed are all increased greatly.

Unmarked (as fluorescence labeling, golden nanometer particle etc.) direct-detection aspect, dropping in the world in recent years ample resources surveys this problem to nanoparticle yardstick and studies, representative achievement has the direct optical detection method based on nanoparticle elastic scattering being proposed by Rochester Univ. optics institute, the method is the amplitude of the scattered light based on interferometry electromagnetic field, the combination of Flow Control passage and optical interference is received in utilization, and build two adjacent, identical Michelson optical interference circuit, when detecting nano particle by optical interference circuit, nanoparticle scattered light is to the two interference optical field amplitudes signal that makes a difference, its amplitude is associated with the size of nanoparticle, show that nanoparticle can be recorded by its scattered optical field.

Summary of the invention

The object of the invention is to for the deficiencies in the prior art, a kind of device and method of the rear orientation light sense acceleration of surveying based on nanoparticle is provided.

The object of the invention is by realizing with lower device: a kind of device of the rear orientation light sense acceleration of surveying based on nanoparticle, comprising: reflective mirror, light damping plate, beam splitter, optical filter, the first condenser lens, the first nanoparticle, the second microparticles, grinding core optical fiber, rigid connecting rod, the second condenser lens, pin hole, separated light detector, laser instrument, collimation lens, light intensity modulator, dsp processor, microchannel; Wherein, one end of rigid connecting rod is fixedly connected with the first nanoparticle, the other end, through after the second microparticles, is rigidly connected in the fixedly turning point of microchannel bottom, and the first nanoparticle and the second microparticles can be used as an integral body around this fixedly turning point rotation; When rigid connecting rod is vertical, two grinding core optical fiber of the second microparticles and its both sides are on same level line, and two grinding core optical fiber respectively connect a light intensity modulator; Separated light detector is all connected with dsp processor with two light intensity modulators; The laser that laser instrument sends enters beam splitter after being collimated by collimation lens; A part is reflected by beam splitter, through light damping plate decay, reflective mirror, reflects, again after light damping plate decay, by beam splitter transmission, forms reference light; Another part is focused into a hot spot by optical filter by the first condenser lens by beam splitter transmission, the first nanoparticle is in this hot spot, the rear orientation light of the first nanoparticle is reflected by beam splitter after the first condenser lens collection and optical filter optical filtering, interfere with reference light, after being focused on by the second condenser lens, through pin hole, by separated light detector, received; Separated light detector is converted into electric signal by the light signal of collection and is sent to dsp processor; Dsp processor is adjusted the light intensity of two grinding core optical fiber outputs by two light intensity modulators, realize the adjustment of the second microparticles position, thereby realizes the adjustment to the first nanoparticle position.

A method of applying the rear orientation light sense acceleration of surveying based on nanoparticle of said apparatus, comprises the following steps:

Step 1: it is in zero environment that device is placed on to acceleration, regulate the second microparticles and the first nanoparticle integral body in center, two duplicate grinding core optical fiber and the second microparticles center are in the same horizontal line, after the equal light intensity of grinding core optical fiber incident, the second microparticles is subject to the optical pressure effect of balance, and rigidly connected the first nanoparticle is also stable at center with it;

Step 2: the optical wavelength that laser instrument penetrates is different from the light in grinding core optical fiber, is radiated on beam splitter after collimation lens lens; The light beam reflecting is through light damping plate and the former road of reflective mirror is returned and again pass through beam splitter, as the relevant reference beam detecting; The light transmiting is focused on the second microparticles by the first condenser lens after optical filter, its rear orientation light is collected by the first condenser lens, the detected light beam of conduct after beam splitter reflection, after relevant with reference light, by the second condenser lens, collected, after a pin hole elimination high fdrequency component and environment parasitic light, incide on separated light detector; Regulate the position of hot spot on separated light detector, make its hot spot when there is no acceleration be in the center of separated light detector, now the differential signal of separated light detector two halves is zero, and feedback system does not regulate the light intensity of grinding core optical fiber;

Step 3: when device is when grinding core optical fiber direction has acceleration, the second microparticles departs from center, rigid connecting rod be take point of fixity and is driven the deflection thereupon of the second microparticles as axle; Because be measures in nano level displacement, the circular arc displacement of the first nanoparticle can be similar to regards straight line as; And the displacement of the first nanoparticle has also been amplified the displacement of the second microparticles, by the second microparticles, the ratio of distances constant to the distance of point of fixity and the first nanoparticle to the second microparticles determines enlargement factor; Now the hot spot of the backscatter signal of the first nanoparticle on separated light detector departed from center, and offset direction determines by acceleration direction, and side-play amount is determined by acceleration magnitude;

Step 4: extract and process interference data: after the rear orientation light of the first nanoparticle and reference light are interfered, the light intensity branch being irradiated on separated light detector can be expressed as:

$I={\left|E_r\right|}^2+{\left|E_s\right|}^2+2\mathrm{Re}\left\{E_r^{*}{E}_s\right\}$

E in formula _rfor reference light oscillator intensity, E _sfor scattered light oscillator intensity, I is the light intensity of just receiving on detector;

The signal P that separated photo-detector records can be expressed as:

$P=\frac{{\∫}_{A1}\mathrm{Ids}-{\∫}_{A2}\mathrm{Ids}}{{\∫}_{A1}\mathrm{Ids}+{\∫}_{A2}\mathrm{Ids}}$

Wherein A1 and A2 represent respectively the two halves up and down of detector surface, and ∫ ds represents the area integral that separated light detector is surveyed; In the first nanoparticle, in center, be system acceleration while being zero, reference light and rear orientation light are adjusted to the center of separated light detector, so differential signal P (t) is zero; When the first nanoparticle is not system acceleration when non-vanishing in center, detectable signal P (t) is expressed as by interference term:

$P\left(t\right)=2\mathrm{Re}\{({\∫}_{A1}{E}_r^{*}{E}_s\mathrm{ds}-{\∫}_{A2}{E}_r^{*}{E}_s\mathrm{ds})/{\∫}_{A1+A2}{\left|E_r\right|}^2\mathrm{ds}\}$

Because much bigger with reference to beam intensity ratio scattered light intensity in this device, can ignore the scattered light strong point in molecule | E _s| ²; In like manner, the reference light strong point only retaining in denominator | E _r| ², and ignore all E _s;

Step 5: carry out feedback regulation and obtain acceleration: the differential signal S (t) obtaining according to separated light detector; dsp processor starts to regulate the light intensity difference of two grinding core optical fiber; direction at the extraneous acceleration of opposing applies larger optical pressure to the second microparticles; the second microparticles is recentered, and the differential signal S (t) that criterion is the acquisition of separated light detector is zero.Now, the optical pressure acting force being applied on the second microparticles by the direction of measuring acceleration and grinding core optical fiber is contrary, and size, by the poor decision of optical pressure of two grinding core optical fiber, provides by dsp processor; Acceleration calculation process is as follows:

a＝K ₁K ₂I(1+R)/c

Wherein, a is institute's measuring acceleration, and I is the luminous energy that the unit interval impinges perpendicularly on unit area, and R is surperficial energy reflectivity, and c is the light velocity in vacuum, K ₁be a coefficient, K ₂for another coefficient.

A kind of device of the rear orientation light sense acceleration of surveying based on nanoparticle, comprise: the first laser diode, the second laser diode, wavelength-division multiplex wave multiplexer, isolator, power bifurcated device, circulator, collimating apparatus, division dual wavelength catoptron, large-numerical aperture lens, attenuator, the first Wave decomposing multiplexer, the second Wave decomposing multiplexer, the first coupling mechanism, the second coupling mechanism, the first photodiode, the second photodiode, amplifier, analog-digital converter, dsp chip, the first nanoparticle, the second microparticles, grinding core optical fiber, rigid connecting rod, light intensity modulator, microchannel, wherein, the first laser diode is all connected with wavelength-division multiplex wave multiplexer with the second laser diode, wavelength-division multiplex wave multiplexer, isolator and power bifurcated device are connected successively, the output terminal of power bifurcated device connects respectively circulator and attenuator, Second Wave division multiplexer is connected with circulator, circulator connects collimating apparatus, and collimating apparatus is connected with microchannel successively with division dual wavelength catoptron, large-numerical aperture lens, attenuator is connected with first wave division multiplexer, one side of the first coupling mechanism connects respectively the shortwave output terminal of first wave division multiplexer and the input end of the first photodiode, opposite side connects the output terminal of the second Wave decomposing multiplexer, one side of the second coupling mechanism connects respectively the long wave output terminal of the first Wave decomposing multiplexer and the input end of the second photodiode, opposite side connects the output terminal of the second Wave decomposing multiplexer, the output terminal of the output terminal of the first photodiode and the second photodiode is all connected with amplifier, amplifier is connected with dsp chip by analog-digital converter, dsp chip is connected with two light intensity controls respectively.

A method of applying the rear orientation light sense acceleration of surveying based on nanoparticle of said apparatus, comprises the following steps:

Step 1: the first laser diode that two wavelength difference are 10-20nm, the second laser diode are as light source, two wavelength light beams that two light sources sent by wavelength-division multiplex wave multiplexer are incorporated in an optical fiber, by isolator, prevent that echo from affecting its stability to DFB/DBR laser diode, the light that separates 90-99% power by power bifurcated device is to collimating device collimation, obtain dual wavelength collimated light beam, as surveying light; Light two wavelength light after attenuator, the first Wave decomposing multiplexer of residue 1-10% power are separated, as with reference to light;

Step 2: dual wavelength collimated light beam is by dividing the light beam that respectively reflects a wavelength about catoptron, afterwards by two half cone-shaped light beams of large-numerical aperture lens focus in microchannel, produce rear orientation light, this rear orientation light is by after circulator, the second Wave decomposing multiplexer, by the first coupling mechanism, the second coupling mechanism, is input to respectively two independently in optical interference circuit;

Step 3: the first photodiode is collected the signal of short wavelength's rear orientation light, is incident in the detection light signal that in the first nanoparticle, keep right in position; The second photodiode is collected the signal of long wavelength's rear orientation light, is incident in the detection light signal that in the first nanoparticle, position keeps left; Two photodiodes receive that signal is after amplifier, analog-digital converter, by dsp chip analyzing and processing data;

Step 4: extract and process interference data: after the rear orientation light of the first nanoparticle and reference light are interfered, the light intensity of two kinds of wavelength is that the signal that two photodiodes detect all can be expressed as:

$I={\left|E_r\right|}^2+{\left|E_s\right|}^2+2\mathrm{Re}\left\{E_r^{*}{E}_s\right\}$

E in formula _rfor reference light oscillator intensity, E _sfor scattered light oscillator intensity, I is the light intensity of just receiving on detector;

Differential signal after being exaggerated can be expressed as:

$S\left(t\right)=\mathrm{\α}(I_{\⋐}-I_{\⊃})$

Wherein with represent that respectively light is surveyed on the left side and light is surveyed on the right, α represents amplification coefficient.In the first nanoparticle, in center, be system acceleration while being zero, the rear orientation light equal and opposite in direction that two wavelength record, so differential signal S (t) is zero; When the first nanoparticle is not that system acceleration is when non-vanishing in center, the rear orientation light size that two wavelength record is unequal, that bundle rear orientation light near the first nanoparticle offset direction is larger, and the differential signal S (t) detecting is non-vanishing;

Step 5: carry out feedback regulation and obtain acceleration: according to the differential signal S (t) obtaining, dsp chip starts to regulate the light intensity difference of two grinding core optical fiber by light intensity modulator, direction at the extraneous acceleration of opposing applies larger optical pressure to the second microparticles, the second microparticles is recentered, and it is zero that criterion is differential signal S (t); Now, the optical pressure acting force being applied on the second microparticles by the direction of measuring acceleration and grinding core optical fiber is contrary, and size, by the poor decision of optical pressure of two grinding core optical fiber, provides by dsp chip; Acceleration calculation process is as follows:

a＝K ₁K ₂I(1+R)/c

Wherein, a is institute's measuring acceleration, and I is the luminous energy that the unit interval impinges perpendicularly on unit area, and R is surperficial energy reflectivity, and c is the light velocity in vacuum, K ₁be a coefficient, K ₂for another coefficient.

The invention has the beneficial effects as follows:

1, the present invention has the feature of low noise, high sensitivity, high precision identification and analysis, automatic feedback regulating power.

2, the present invention measures the acceleration of nanometer scale displacement under the condition of physical contact not having, and to non-insensitive by other acting forces in measuring acceleration direction.

3, the present invention is based on highly sensitive nano-grade displacement and measure, make this structure can obtain high acceleration analysis resolving power, and be only confined to the absolute value of optical pressure restoring force, the control loop of while closed loop is extended dynamic measurement range significantly.

Accompanying drawing explanation

Fig. 1 the present invention is based on the rear orientation light sense acceleration scheme light path schematic diagram that nanoparticle is surveyed;

Fig. 2 the present invention is based on the rear orientation light sense acceleration scheme device schematic diagram that nanoparticle is surveyed;

Fig. 3 is the relation curve of total scattering light intensity and nanoparticle radius size;

Fig. 4 is the scattered light intensity of nanoparticle and the polar plot of angle;

Fig. 5 is the relative position figure of incident light, microscopic scatterers, scattered light;

Fig. 6 is dsp processor 16 workflow diagrams;

Fig. 7 is the side view of rigid connecting rod 9;

Fig. 8 the present invention is based on the rear orientation light sense acceleration optical fiber connection scheme light path schematic diagram that nanoparticle is surveyed;

In figure, reflective mirror 1, light damping plate 2, beam splitter 3, optical filter 4, the first condenser lens 5, the first nanoparticle 6, the second microparticles 7, grinding core optical fiber 8, rigid connecting rod 9, the second condenser lens 10, pin hole 11, separated light detector 12, laser instrument 13, collimation lens 14, light intensity modulator 15, dsp processor 16, microchannel 17, the first laser diode 18, the second laser diode 19, wavelength-division multiplex wave multiplexer 20, isolator 21, power bifurcated device 22, circulator 23, collimating apparatus 24, division dual wavelength catoptron 25, large-numerical aperture lens 26, attenuator 27, the first Wave decomposing multiplexer 28, the second Wave decomposing multiplexer 29, the first coupling mechanism 30, the second coupling mechanism 31, the first photodiode 32, the second photodiode 33, amplifier 34, analog-digital converter 35, dsp chip 36, the first nanoparticle 6, the second microparticles 7, grinding core optical fiber 8, rigid connecting rod 9, light intensity modulator 15, microchannel 17.

Embodiment

Principle of work of the present invention is as follows:

1,, because nanoparticle is more much smaller than optical wavelength size, the back scattering light field of sending can use Rayleigh scattering formula to calculate.For uniform dielectric, the scattered field oscillator intensity E of Rayleigh scattering _scan be expressed in matrix as

$\left(\begin{array}{c}{E}_{\mathrm{PS}}\\ E_{\⊥S}\end{array}\right)=\frac{e^{\mathrm{ik}(r-z)}}{-\mathrm{ikr}}\left(\begin{array}{cc}{S}_2& 0\\ 0& S_1\end{array}\right)\left(\begin{array}{c}{E}_{\mathrm{Pi}}\\ E_{\⊥i}\end{array}\right)$

$S_1=-\frac{{\mathrm{ik}}^3}{2\mathrm{\π}}(m-1)\mathrm{\υf}(\mathrm{\θ},\mathrm{\φ})$

$S_2=-\frac{{\mathrm{ik}}^3}{2\mathrm{\π}}(m-1)\mathrm{\υf}(\mathrm{\θ},\mathrm{\φ})\cos \mathrm{\θ}$

Wherein, E _{|| s}and E _{⊥ s}be respectively parallel component and the vertical component of scattered optical field oscillator intensity; E is the nature truth of a matter; I is the imaginary unit in plural number; Wave vector k=2 π N/ λ, N is surrounding medium refractive index, λ is lambda1-wavelength; R is scattered light vector; Z is incident light vector; E _{|| i}and E _{⊥ i}be respectively parallel component and the vertical component of incident field oscillator intensity; S ₁, S ₂for matrix coefficient; M is relative index of refraction, i.e. the ratio of scattering particle refractive index and surrounding medium refractive index N; υ is particle volume; F (θ, φ) is the function relevant with scattering particle characteristic, and the implication that θ, φ represent as shown in Figure 5.

2,, for uniform ball particles, the function relevant with scattering particle characteristic can be expressed as

$f\left(\mathrm{\θ}\right)=\frac{3}{u^3}(\sin u-u\cos u),u=2x\sin \frac{\mathrm{\θ}}{2}$

Wherein θ is the angle of r and z, as shown in Figure 5; X=ka=2 π Na/ λ, a is particle radii, N is surrounding medium refractive index.

By formula, progressively after substitution, the parallel and vertical scattered optical field of the nanometer ball particles of trying to achieve is respectively:

$\mathrm{Es}1=\frac{e^{\mathrm{ik}(r-z)}}{-\mathrm{ik}\·r}\·(-\frac{{\mathrm{ik}}^3}{2\mathrm{\π}}\·\frac{(m-1)\·4}{3}\·\frac{\mathrm{\π}\·a^3\·3}{{(2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))}^3}\·\cos \mathrm{\θ}\·(\sin (2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))-(2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))\·\cos (2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))))\·\mathrm{Ei}1$

$\mathrm{Es}2=\frac{e^{\mathrm{ik}(r-z)}}{-\mathrm{ik}\·r}\·(-\frac{{\mathrm{ik}}^3}{2\mathrm{\π}}\·\frac{(m-1)\·4}{3}\·\frac{\mathrm{\π}\·a^3\·3}{{(2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))}^3}\·(\sin (2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))-(2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))\·\cos (2k\·a\·\sin \left(\frac{\mathrm{\θ}}{2}\right))))\·\mathrm{Ei}2$

Total scattering light intensity I=E _s ²=E _s1 ²+ E _s2 ², as shown in Figure 3, the upcurve before peak value shows to meet finely much smaller than nanoparticle and the Rayleigh scattering formula of wavelength dimension the result obtaining by the relation of software emulation total scattering light intensity and particle size.

As shown in Figure 4, the rear orientation light of nanoparticle is stronger, is easy to measure.

From Fig. 3 and Fig. 4, on separated light detector, can record hot spot, hot spot produces along with the nano-grade displacement of nanoparticle to move and also can measure.Based on above-mentioned principle, the present invention can detect the micro-displacement variation that nanoparticle causes.

The invention provides a kind of device of the rear orientation light sense acceleration of surveying based on nanoparticle, as depicted in figs. 1 and 2, this device comprises: reflective mirror 1, light damping plate 2, beam splitter 3, optical filter 4, the first condenser lens 5, the first nanoparticle 6, the second microparticles 7, grinding core optical fiber 8, rigid connecting rod 9, the second condenser lens 10, pin hole 11, separated light detector 12, laser instrument 13, collimation lens 14, light intensity modulator 15, dsp processor 16, microchannel 17.

Wherein, one end of rigid connecting rod 9 is fixedly connected with the first nanoparticle 6, the other end, through after the second microparticles 7, is rigidly connected in the fixedly turning point of microchannel 17 bottoms, and the first nanoparticle 6 and the second microparticles 7 can be used as an integral body around this fixedly turning point rotation.When rigid connecting rod 9 is vertical, the second microparticles 7 is with two grinding core optical fiber 8 of its both sides on same level line, and two grinding core optical fiber 8 respectively connect a light intensity modulator 15.Separated light detector 12 is all connected with dsp processor 16 with two light intensity modulators 15.

The laser that laser instrument 13 sends enters beam splitter 3 after being collimated by collimation lens 14; A part is reflected by beam splitter 3, through light damping plate 2 decay, reflective mirror 1, reflects, again after light damping plate 2 decay, by beam splitter 3 transmissions, forms reference light.Another part is focused into a hot spot by optical filter 4 by the first condenser lens 5 by beam splitter 3 transmissions, the first nanoparticle 6 is in this hot spot, the rear orientation light of the first nanoparticle 6 is reflected by beam splitter 3 after the first condenser lens 5 collections and optical filter 4 optical filterings, interfere with reference light, after being focused on by the second condenser lens 10, through pin hole 11, by separated light detector 12, received.Separated light detector 12 is converted into electric signal by the light signal of collection and is sent to dsp processor 16.Dsp processor 16 is adjusted the light intensity of two grinding core optical fiber, 8 outputs by two light intensity modulators 15, realize the adjustment of the second microparticles 7 positions, thereby realizes the adjustment to the first nanoparticle 6 positions.

Above-mentioned laser instrument 13 and grinding core optical fiber 8 adopt the light of different wave lengths.The above-mentioned intensity modulation to grinding core optical fiber 8 adopts the feedback system being comprised of separated light detector 12, dsp processor 16, light intensity modulator 15 automatically to complete.The rigid connecting rod 9 of above-mentioned fixedly turning point is fixed on particulate the plane being determined by grinding core optical fiber 8 and position sensing laser, make it can not in the direction perpendicular to this plane, have any component motion, its side view as shown in Figure 7, because the thrust of light is very little, the material of three-legged structure is to consist of nano-filaments.The aperture of above-mentioned pin hole 11 is 1 to 5 micron, and this pin hole is positioned at the focus place of the second condenser lens 10.

The workflow of above-mentioned dsp processor 16 as shown in Figure 6, can sketch and be by principle of work:

1, extract and process interference data: after the rear orientation light of the first nanoparticle 6 and reference light are interfered, the light intensity branch being irradiated on separated light detector 12 can be expressed as

$I={\left|E_r\right|}^2+{\left|E_s\right|}^2+2\mathrm{Re}\left\{E_r^{*}{E}_s\right\}$

E in formula _rfor reference light oscillator intensity, E _sfor scattered light oscillator intensity, I is the light intensity of just receiving on detector.

Separated photo-detector is surveyed the 12 signal P that obtain and can be expressed as

$P=\frac{{\∫}_{A1}\mathrm{Ids}-{\∫}_{A2}\mathrm{Ids}}{{\∫}_{A1}\mathrm{Ids}+{\∫}_{A2}\mathrm{Ids}}$

Wherein A1 and A2 represent respectively the two halves up and down of detector surface, as shown in Figure 1; ∫ ds represents separated light detector to survey 12 area integral.In the first nanoparticle 6, be system acceleration while being zero in center, reference light and rear orientation light are adjusted to separated light detector 12 center, so differential signal P (t) is zero.When the first nanoparticle 6 is not system acceleration when non-vanishing in center, detectable signal P (t) is expressed as by interference term

$P\left(t\right)=2\mathrm{Re}\{({\∫}_{A1}{E}_r^{*}{E}_s\mathrm{ds}-{\∫}_{A2}{E}_r^{*}{E}_s\mathrm{ds})/{\∫}_{A1+A2}{\left|E_r\right|}^2\mathrm{ds}\}$

Because much bigger with reference to beam intensity ratio scattered light intensity in this device, can ignore the scattered light strong point in molecule | E _s| ².In like manner, the reference light strong point only retaining in denominator | E _r| ², and ignore all E _s.

2, carry out feedback regulation and obtain acceleration: the differential signal S (t) obtaining according to separated light detector 12, dsp processor 16 starts to regulate the light intensity difference of two grinding core optical fiber 8, direction at the extraneous acceleration of opposing applies larger optical pressure to the second microparticles 7, the second microparticles 7 is recentered, and the differential signal S (t) that criterion is 12 acquisitions of separated light detector is zero.Now, the optical pressure acting force being applied on the second microparticles 7 by the direction of measuring acceleration and grinding core optical fiber 8 is contrary, and size, by the poor decision of optical pressure of two grinding core optical fiber 8, provides by dsp processor 16.Acceleration calculation process is as follows:

a＝K ₁K ₂I(1+R)/c

Wherein, a is institute's measuring acceleration, and I is the luminous energy that the unit interval impinges perpendicularly on unit area, and R is surperficial energy reflectivity, and c is the light velocity in vacuum, K ₁be a coefficient, K ₂for another coefficient.

The method that the present invention is based on the rear orientation light sense acceleration of nanoparticle detection, comprises the following steps:

Step 1: it is in zero environment that device is placed on to acceleration, regulate the second microparticles 7 and the first nanoparticle 6 integral body in center, two duplicate grinding core optical fiber 8 and the second microparticles 7 centers are in the same horizontal line, after the equal light intensity of grinding core optical fiber 8 incidents, the second microparticles 7 is subject to the optical pressure effect of balance, and rigidly connected the first nanoparticle 6 is also stable at center with it.

Step 2: the optical wavelength that laser instrument 13 penetrates is different from the light in grinding core optical fiber 8, is radiated on beam splitter 3 after collimation lens 14 lens.The light beam reflecting is through light damping plate 2 and the former road of reflective mirror 1 is returned and again pass through beam splitter 3, as the relevant reference beam detecting; The light transmiting is focused on the second microparticles 7 by the first condenser lens 5 after optical filter 4, its rear orientation light is collected by the first condenser lens 5, the detected light beam of conduct after beam splitter 3 reflections, after relevant with reference light, by the second condenser lens 10, collected, after pin hole 11 elimination high fdrequency components and environment parasitic light, incide on separated light detector 12.Regulate the position of hot spot on separated light detector 12, make its hot spot when there is no acceleration be in the center of separated light detector 12, now the differential signal of separated light detector 12 two halves is zero, and feedback system does not regulate the light intensity of grinding core optical fiber 8.

Step 3: when device is when grinding core optical fiber 8 directions have acceleration, the second microparticles 7 departs from center, rigid connecting rod 9 be take point of fixity and is driven the second microparticles 7 deflection thereupon as axle.Because be measures in nano level displacement, the circular arc displacement of the first nanoparticle 6 can be similar to regards straight line as.And the displacement of the first nanoparticle 6 has also been amplified the displacement of the second microparticles 7, enlargement factor is determined to the distance of point of fixity and the ratio of distances constant of the first nanoparticle 6 to second microparticles 7 by the second microparticles 7.Now the hot spot of the backscatter signal of the first nanoparticle 6 on separated light detector 12 departed from center, and offset direction determines by acceleration direction, and side-play amount is determined by acceleration magnitude.

Step 4: extract and process interference data: after the rear orientation light of the first nanoparticle 6 and reference light are interfered, the light intensity branch being irradiated on separated light detector 12 can be expressed as

$I={\left|E_r\right|}^2+{\left|E_s\right|}^2+2\mathrm{Re}\left\{E_r^{*}{E}_s\right\}$

E in formula _rfor reference light oscillator intensity, E _sfor scattered light oscillator intensity, I is the light intensity of just receiving on detector.

Separated photo-detector is surveyed the 12 signal P that obtain and can be expressed as

$P=\frac{{\∫}_{A1}\mathrm{Ids}-{\∫}_{A2}\mathrm{Ids}}{{\∫}_{A1}\mathrm{Ids}+{\∫}_{A2}\mathrm{Ids}}$

Wherein A1 and A2 represent respectively the two halves up and down of detector surface, as shown in Figure 1; ∫ ds represents separated light detector to survey 12 area integral.In the first nanoparticle 6, be system acceleration while being zero in center, reference light and rear orientation light are adjusted to separated light detector 12 center, so differential signal P (t) is zero.When the first nanoparticle 6 is not system acceleration when non-vanishing in center, detectable signal P (t) is expressed as by interference term

$P\left(t\right)=2\mathrm{Re}\{({\∫}_{A1}{E}_r^{*}{E}_s\mathrm{ds}-{\∫}_{A2}{E}_r^{*}{E}_s\mathrm{ds})/{\∫}_{A1+A2}{\left|E_r\right|}^2\mathrm{ds}\}$

Because much bigger with reference to beam intensity ratio scattered light intensity in this device, can ignore the scattered light strong point in molecule | E _s| ².In like manner, the reference light strong point only retaining in denominator | E _r| ², and ignore all E _s.

Step 5: carry out feedback regulation and obtain acceleration: the differential signal S (t) obtaining according to separated light detector 12, dsp processor 16 starts to regulate the light intensity difference of two grinding core optical fiber 8, direction at the extraneous acceleration of opposing applies larger optical pressure to the second microparticles 7, the second microparticles 7 is recentered, and the differential signal S (t) that criterion is 12 acquisitions of separated light detector is zero.Now, the optical pressure acting force being applied on the second microparticles 7 by the direction of measuring acceleration and grinding core optical fiber 8 is contrary, and size, by the poor decision of optical pressure of two grinding core optical fiber 8, provides by dsp processor 16.Acceleration calculation process is as follows:

a＝K ₁K ₂I(1+R)/c

Wherein, a is institute's measuring acceleration, and I is the luminous energy that the unit interval impinges perpendicularly on unit area, and R is surperficial energy reflectivity, and c is the light velocity in vacuum, K ₁be a coefficient, K ₂for another coefficient.

In addition, except realizing this method by space optics device, can also realize by optical fiber splicing device, as shown in Figure 8, this device comprises: the first laser diode 18, the second laser diode 19, wavelength-division multiplex wave multiplexer 20, isolator 21, power bifurcated device 22, circulator 23, collimating apparatus 24, division dual wavelength catoptron 25, large-numerical aperture lens 26, attenuator 27, the first Wave decomposing multiplexer 28, the second Wave decomposing multiplexer 29, the first coupling mechanism 30, the second coupling mechanism 31, the first photodiode 32, the second photodiode 33, amplifier 34, analog-digital converter 35, dsp chip 36, the first nanoparticle 6, the second microparticles 7, grinding core optical fiber 8, rigid connecting rod 9, light intensity modulator 15, microchannel 17.

Wherein, the first laser diode 18 is all connected with wavelength-division multiplex wave multiplexer 20 with the second laser diode 19, wavelength-division multiplex wave multiplexer 20, isolator 21 and power bifurcated device 22 are connected successively, the output terminal of power bifurcated device 22 connects respectively circulator 23 and attenuator 27, Second Wave division multiplexer 29 is connected with circulator 23, circulator 23 connects collimating apparatus 24, and collimating apparatus 24 is connected with microchannel 17 successively with division dual wavelength catoptron 25, large-numerical aperture lens 26, attenuator 27 is connected with first wave division multiplexer 28, one side of the first coupling mechanism 30 connects respectively the shortwave output terminal of first wave division multiplexer 28 and the input end of the first photodiode 32, opposite side connects the output terminal of the second Wave decomposing multiplexer 29, one side of the second coupling mechanism 31 connects respectively the long wave output terminal of the first Wave decomposing multiplexer 28 and the input end of the second photodiode 33, opposite side connects the output terminal of the second Wave decomposing multiplexer 29, the output terminal of the output terminal of the first photodiode 32 and the second photodiode 33 is all connected with amplifier 34, amplifier 34 is connected with dsp chip 36 by analog-digital converter 35, dsp chip 36 is connected with two light intensity controls 15 respectively.

Above-mentioned the first laser diode 18 and the second laser diode 19 can be DFB laser diode or DBR laser diode.The numerical aperture of above-mentioned large-numerical aperture lens 26 is greater than 0.65.Structure in above-mentioned microchannel 17 is identical with a kind of front method.

For said apparatus, the present invention realizes the method for the rear orientation light sense acceleration of surveying based on nanoparticle, comprises the following steps:

Step 1: the first laser diode 18 that two wavelength difference are 10-20nm, the second laser diode 19 are as light source, two wavelength light beams that two light sources sent by wavelength-division multiplex wave multiplexer 20 are incorporated in an optical fiber, by isolator 21, prevent that echo from affecting its stability to DFB/DBR laser diode, by power bifurcated device 22, separated the light of 90-99% power to collimating apparatus 24 collimations, obtain dual wavelength collimated light beam, as surveying light.Light two wavelength light after attenuator 27, the first Wave decomposing multiplexer 28 of residue 1-10% power are separated, as with reference to light.

Step 2: dual wavelength collimated light beam is by the light beam that divides catoptron 25 left and right and respectively reflect a wavelength, by large-numerical aperture lens 26, focus on two half cone-shaped light beams in microchannel 17 afterwards, produce rear orientation light, this rear orientation light is by after circulator 23, the second Wave decomposing multiplexer 29, by the first coupling mechanism 30, the second coupling mechanism 31, is input to respectively two independently in optical interference circuit.

Step 3: the first photodiode 32 is collected the signal of short wavelength's rear orientation light, is incident in the detection light signal that in the first nanoparticle 6, keep right in position; The second photodiode 33 is collected the signal of long wavelength's rear orientation light, is incident in the detection light signal that in the first nanoparticle 6, position keeps left.Two photodiodes receive that signal is after amplifier 34, analog-digital converter 35, by dsp chip 36 analyzing and processing data.

Step 4: extract and process interference data: after the rear orientation light of the first nanoparticle 6 and reference light are interfered, the light intensity of two kinds of wavelength is that the signal that two photodiodes detect all can be expressed as

$I={\left|E_r\right|}^2+{\left|E_s\right|}^2+2\mathrm{Re}\left\{E_r^{*}{E}_s\right\}$

E in formula _rfor reference light oscillator intensity, E _sfor scattered light oscillator intensity, I is the light intensity of just receiving on detector.

Differential signal after being exaggerated can be expressed as

$S\left(t\right)=\mathrm{\α}(I_{\⋐}-I_{\⊃})$

Wherein with represent that respectively light is surveyed on the left side and light is surveyed on the right, α represents amplification coefficient.In the first nanoparticle 6, be system acceleration while being zero in center, the rear orientation light equal and opposite in direction that two wavelength record, so differential signal S (t) is zero.When the first nanoparticle 6 is not that system acceleration is when non-vanishing in center, the rear orientation light size that two wavelength record is unequal, that bundle rear orientation light near the first nanoparticle 6 offset directions is larger, and the differential signal S (t) detecting is non-vanishing.

Step 5: carry out feedback regulation and obtain acceleration: according to the differential signal S (t) obtaining, dsp chip 36 starts to regulate the light intensity difference of two grinding core optical fiber 8 by light intensity modulator 15, direction at the extraneous acceleration of opposing applies larger optical pressure to the second microparticles 7, the second microparticles 7 is recentered, and it is zero that criterion is differential signal S (t).Now, the optical pressure acting force being applied on the second microparticles 7 by the direction of measuring acceleration and grinding core optical fiber 8 is contrary, and size, by the poor decision of optical pressure of two grinding core optical fiber 8, provides by dsp chip 36.Acceleration calculation process is as follows:

a＝K ₁K ₂I(1+R)/c

Wherein, a is institute's measuring acceleration, and I is the luminous energy that the unit interval impinges perpendicularly on unit area, and R is surperficial energy reflectivity, and c is the light velocity in vacuum, K ₁be a coefficient, K ₂for another coefficient.

Claims (4)

1. the device of a rear orientation light sense acceleration of surveying based on nanoparticle, it is characterized in that, this device comprises: reflective mirror (1), light damping plate (2), beam splitter (3), optical filter (4), the first condenser lens (5), the first nanoparticle (6), the second microparticles (7), grinding core optical fiber (8), rigid connecting rod (9), the second condenser lens (10), pin hole (11), separated light detector (12), laser instrument (13), collimation lens (14), light intensity modulator (15), dsp processor (16), microchannel (17), wherein, one end of rigid connecting rod (9) is fixedly connected with the first nanoparticle (6), the other end is through after the second microparticles (7), be rigidly connected in the fixedly turning point of microchannel (17) bottom, the first nanoparticle (6) can be used as an integral body around this fixedly turning point rotation with the second microparticles (7), when rigid connecting rod (9) is vertical, the second microparticles (7) is with two grinding core optical fiber (8) of its both sides on same level line, and two grinding core optical fiber (8) respectively connect a light intensity modulator (15), separated light detector (12) is all connected with dsp processor (16) with two light intensity modulators (15), the laser that laser instrument (13) sends enters beam splitter (3) after being collimated by collimation lens (14), a part, by beam splitter (3) reflection, reflects, again after light damping plate (2) decay, by beam splitter (3) transmission, forms reference light through light damping plate (2) decay, reflective mirror (1), another part is focused into a hot spot by optical filter (4) by the first condenser lens (5) by beam splitter (3) transmission, the first nanoparticle (6) is in this hot spot, the rear orientation light of the first nanoparticle (6) is reflected by beam splitter (3) after the first condenser lens (5) collection and optical filter (4) optical filtering, interfere with reference light, after being focused on by the second condenser lens (10), through pin hole (11), by separated light detector (12), received, separated light detector (12) is converted into electric signal by the light signal of collection and is sent to dsp processor (16), dsp processor (16) is adjusted the light intensity of two grinding core optical fiber (8) output by two light intensity modulators (15), realize the adjustment of the second microparticles (7) position, thereby realizes the adjustment to the first nanoparticle (6) position.

2. application rights requires a method for the rear orientation light sense acceleration of surveying based on nanoparticle of device described in 1, it is characterized in that, the method comprises the following steps:

Step 1: it is in zero environment that device is placed on to acceleration, regulate the second microparticles (7) and the first nanoparticle (6) whole in center, two duplicate grinding core optical fiber (8) and the second microparticles (7) center are in the same horizontal line, after the equal light intensity of grinding core optical fiber (8) incident, the second microparticles (7) is subject to the optical pressure effect of balance, and rigidly connected the first nanoparticle (6) is also stable at center with it;

Step 2: the optical wavelength that laser instrument (13) penetrates is different from the light in grinding core optical fiber (8), is radiated on beam splitter (3) after collimation lens (14) lens; The light beam reflecting is through light damping plate (2) and the former road of reflective mirror (1) is returned and again pass through beam splitter (3), as the relevant reference beam detecting; The light transmiting is focused on the second microparticles (7) by the first condenser lens (5) after optical filter (4), its rear orientation light is collected by the first condenser lens (5), the detected light beam of conduct after beam splitter (3) reflection, after relevant with reference light, by the second condenser lens (10), collected, after a pin hole (11) elimination high fdrequency component and environment parasitic light, incide on separated light detector (12); Regulate the position of hot spot on separated light detector (12), make its hot spot when there is no acceleration be in the center of separated light detector (12), now the differential signal of separated light detector (12) two halves is zero, and feedback system does not regulate the light intensity of grinding core optical fiber (8);

Step 3: when device is when grinding core optical fiber (8) direction has acceleration, the second microparticles (7) departs from center, rigid connecting rod (9) be take point of fixity and is driven the second microparticles (7) deflection thereupon as axle; Because be measures in nano level displacement, the circular arc displacement of the first nanoparticle (6) can be similar to regards straight line as; And the displacement of the first nanoparticle (6) has also been amplified the displacement of the second microparticles (7), by the second microparticles (7), the ratio of distances constant to the distance of point of fixity and the first nanoparticle (6) to the second microparticles (7) determines enlargement factor; Now the hot spot of the backscatter signal of the first nanoparticle (6) on separated light detector (12) departed from center, and offset direction determines by acceleration direction, and side-play amount is determined by acceleration magnitude;

Step 4: extract and process interference data: after the rear orientation light of the first nanoparticle (6) and reference light are interfered, the light intensity branch being irradiated on separated light detector (12) can be expressed as:

$I={\left|E_r\right|}^2+{\left|E_s\right|}^2+2\mathrm{Re}\left\{E_r^{*}{E}_s\right\}$

E in formula _rfor reference light oscillator intensity, E _sfor scattered light oscillator intensity, I is the light intensity of just receiving on detector;

The signal P that separated photo-detector survey (12) obtains can be expressed as:

$P=\frac{{\∫}_{A1}\mathrm{Ids}-{\∫}_{A2}\mathrm{Ids}}{{\∫}_{A1}\mathrm{Ids}+{\∫}_{A2}\mathrm{Ids}}$

Wherein A1 and A2 represent respectively the two halves up and down of detector surface, and ∫ ds represents separated light detector to survey the area integral of (12); In the first nanoparticle (6), be system acceleration while being zero in center, reference light and rear orientation light are adjusted to the center of separated light detector (12), so differential signal P (t) is zero; When the first nanoparticle (6) is not system acceleration when non-vanishing in center, detectable signal P (t) is expressed as by interference term:

$P\left(t\right)=2\mathrm{Re}\{({\∫}_{A1}{E}_r^{*}{E}_s\mathrm{ds}-{\∫}_{A2}{E}_r^{*}{E}_s\mathrm{ds})/{\∫}_{A1+A2}{\left|E_r\right|}^2\mathrm{ds}\};$

Step 5: carry out feedback regulation and obtain acceleration: the differential signal S (t) obtaining according to separated light detector (12), dsp processor (16) starts to regulate the light intensity difference of two grinding core optical fiber (8), direction at the extraneous acceleration of opposing applies larger optical pressure to the second microparticles (7), the second microparticles (7) is recentered, and the differential signal S (t) that criterion is separated light detector (12) acquisition is zero.Now, contrary with the optical pressure acting force that grinding core optical fiber (8) is applied on the second microparticles (7) by the direction of measuring acceleration, size, by the poor decision of optical pressure of two grinding core optical fiber (8), provides by dsp processor (16); Acceleration calculation process is as follows:

a＝K ₁K ₂I(1+R)/c

Wherein, a is institute's measuring acceleration, and I is the luminous energy that the unit interval impinges perpendicularly on unit area, and R is surperficial energy reflectivity, and c is the light velocity in vacuum, K ₁be a coefficient, K ₂for another coefficient.

3. the device of a rear orientation light sense acceleration of surveying based on nanoparticle, it is characterized in that, this device comprises: the first laser diode (18), the second laser diode (19), wavelength-division multiplex wave multiplexer (20), isolator (21), power bifurcated device (22), circulator (23), collimating apparatus (24), division dual wavelength catoptron (25), large-numerical aperture lens (26), attenuator (27), the first Wave decomposing multiplexer (28), the second Wave decomposing multiplexer (29), the first coupling mechanism (30), the second coupling mechanism (31), the first photodiode (32), the second photodiode (33), amplifier (34), analog-digital converter (35), dsp chip (36), the first nanoparticle (6), the second microparticles (7), grinding core optical fiber (8), rigid connecting rod (9), light intensity modulator (15), microchannel (17), wherein, the first laser diode (18) is all connected with wavelength-division multiplex wave multiplexer (20) with the second laser diode (19), wavelength-division multiplex wave multiplexer (20), isolator (21) is connected successively with power bifurcated device (22), the output terminal of power bifurcated device (22) connects respectively circulator (23) and attenuator (27), Second Wave division multiplexer (29) is connected with circulator (23), circulator (23) connects collimating apparatus (24), collimating apparatus (24) and division dual wavelength catoptron (25), large-numerical aperture lens (26) are connected successively with microchannel (17), attenuator (27) is connected with first wave division multiplexer (28), one side of the first coupling mechanism (30) connects respectively the shortwave output terminal of first wave division multiplexer (28) and the input end of the first photodiode (32), opposite side connects the output terminal of the second Wave decomposing multiplexer (29), one side of the second coupling mechanism (31) connects respectively the long wave output terminal of the first Wave decomposing multiplexer (28) and the input end of the second photodiode (33), opposite side connects the output terminal of the second Wave decomposing multiplexer (29), the output terminal of the output terminal of the first photodiode (32) and the second photodiode (33) is all connected with amplifier (34), amplifier (34) is connected with dsp chip (36) by analog-digital converter (35), dsp chip (36) is connected with two light intensity controls (15) respectively.

4. application rights requires a method for the rear orientation light sense acceleration of surveying based on nanoparticle of device described in 3, it is characterized in that, the method comprises the following steps:

Step 1: the first laser diode (18) that two wavelength difference are 10-20nm, the second laser diode (19) are as light source, two wavelength light beams that two light sources sent by wavelength-division multiplex wave multiplexer (20) are incorporated in an optical fiber, by isolator (21), prevent that echo from affecting its stability to DFB/DBR laser diode, light to the collimating apparatus (24) that is separated 90-99% power by power bifurcated device (22) collimates, obtain dual wavelength collimated light beam, as surveying light; Light two wavelength light after attenuator (27), the first Wave decomposing multiplexer (28) of residue 1-10% power are separated, as with reference to light;

Step 2: dual wavelength collimated light beam is by dividing the light beam that respectively reflects a wavelength about catoptron (25), by large-numerical aperture lens (26), focus on two half cone-shaped light beams in microchannel (17) afterwards, produce rear orientation light, this rear orientation light is by after circulator (23), the second Wave decomposing multiplexer (29), by the first coupling mechanism (30), the second coupling mechanism (31), is input to respectively two independently in optical interference circuit;

Step 3: the first photodiode (32) is collected the signal of short wavelength's rear orientation light, is incident in the detection light signal of keeping right in the upper position of the first nanoparticle (6); The second photodiode (33) is collected the signal of long wavelength's rear orientation light, is incident in the detection light signal that the upper position of the first nanoparticle (6) keeps left; Two photodiodes receive that signal is after amplifier (34), analog-digital converter (35), by dsp chip (36) analyzing and processing data;

Step 4: extract and process interference data: after the rear orientation light of the first nanoparticle (6) and reference light are interfered, the light intensity of two kinds of wavelength is that the signal that two photodiodes detect all can be expressed as:

$I={\left|E_r\right|}^2+{\left|E_s\right|}^2+2\mathrm{Re}\left\{E_r^{*}{E}_s\right\}$

E in formula _rfor reference light oscillator intensity, E _sfor scattered light oscillator intensity, I is the light intensity of just receiving on detector;

Differential signal after being exaggerated can be expressed as:

$S\left(t\right)=\mathrm{\α}(I_{\⋐}-I_{\⊃})$

Wherein with represent that respectively light is surveyed on the left side and light is surveyed on the right, α represents amplification coefficient.In the first nanoparticle (6), be system acceleration while being zero in center, the rear orientation light equal and opposite in direction that two wavelength record, so differential signal S (t) is zero; When the first nanoparticle (6) is not that system acceleration is when non-vanishing in center, the rear orientation light size that two wavelength record is unequal, that bundle rear orientation light near the first nanoparticle (6) offset direction is larger, and the differential signal S (t) detecting is non-vanishing;

Step 5: carry out feedback regulation and obtain acceleration: according to the differential signal S (t) obtaining, dsp chip (36) starts to regulate the light intensity difference of two grinding core optical fiber (8) by light intensity modulator (15), direction at the extraneous acceleration of opposing applies larger optical pressure to the second microparticles (7), the second microparticles (7) is recentered, and it is zero that criterion is differential signal S (t); Now, contrary with the optical pressure acting force that grinding core optical fiber (8) is applied on the second microparticles (7) by the direction of measuring acceleration, size, by the poor decision of optical pressure of two grinding core optical fiber (8), provides by dsp chip (36); Acceleration calculation process is as follows:

a＝K ₁K ₂I(1+R)/c

Wherein, a is institute's measuring acceleration, and I is the luminous energy that the unit interval impinges perpendicularly on unit area, and R is surperficial energy reflectivity, and c is the light velocity in vacuum, K ₁be a coefficient, K ₂for another coefficient.