CN111983708B - Gravity measurement device and method based on optical trap - Google Patents
Gravity measurement device and method based on optical trap Download PDFInfo
- Publication number
- CN111983708B CN111983708B CN202010790955.7A CN202010790955A CN111983708B CN 111983708 B CN111983708 B CN 111983708B CN 202010790955 A CN202010790955 A CN 202010790955A CN 111983708 B CN111983708 B CN 111983708B
- Authority
- CN
- China
- Prior art keywords
- microspheres
- optical trap
- module
- gravity
- aom
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 60
- 230000005484 gravity Effects 0.000 title claims abstract description 44
- 238000005259 measurement Methods 0.000 title claims abstract description 23
- 238000000034 method Methods 0.000 title claims abstract description 13
- 239000004005 microsphere Substances 0.000 claims abstract description 100
- 238000001514 detection method Methods 0.000 claims abstract description 23
- 230000009471 action Effects 0.000 claims abstract description 10
- 238000001816 cooling Methods 0.000 claims abstract description 8
- 238000012360 testing method Methods 0.000 claims abstract description 5
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 230000007613 environmental effect Effects 0.000 claims description 3
- 239000000725 suspension Substances 0.000 claims description 3
- 238000004891 communication Methods 0.000 claims description 2
- 230000000087 stabilizing effect Effects 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 5
- 230000008901 benefit Effects 0.000 abstract description 4
- 239000002245 particle Substances 0.000 description 6
- 230000008859 change Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01V—GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS
- G01V7/00—Measuring gravitational fields or waves; Gravimetric prospecting or detecting
Landscapes
- Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- Geophysics (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
The invention discloses a gravity measurement device and method based on an optical trap. The device comprises an optical trap capturing module, a vacuum module, a feedback module and a position detection module, wherein the vacuum module is used for realizing that the microspheres are in a high vacuum environment during gravity test; the optical trap capturing module is used for capturing the microspheres in a vacuum environment and cooling the mass center of the microspheres to move, the laser light intensity is adjusted to be zero through an acousto-optic modulator (AOM), so that the optical trap is closed, the microspheres can freely fall under the action of gravity, the AOM is controlled to reopen the optical trap after a short time, the microspheres are captured again, the position detecting module is used for measuring the free falling process of the microspheres, and absolute gravity measurement can be carried out according to the falling process of the microspheres. The above process is repeated to realize continuous measurement of absolute gravity. The invention realizes the free fall of the suspended microspheres by using the optical trap under the high vacuum condition, thereby calibrating the environment absolute gravity and having the advantages of short test time, small device volume and capability of continuously measuring the absolute gravity.
Description
Technical Field
The invention relates to the technical field of optical trap based measurement, in particular to a gravity measurement device and method based on an optical trap.
Background
According to the quantum theory, a light beam is a group of photons which move at the speed of light and have mass and momentum, when the photons are incident on the surface of a medium, refraction and reflection are generated, the speed and the direction of the photons are changed, so that the momentum vector of the photons is changed, the change can be deduced by the law of momentum conservation, when the light beam irradiates on particles, the momentum change of the photons is equal to the momentum change of the particles, so that the light beam has mechanical action on the particles, namely optical radiation pressure, the optical radiation pressure comprises scattering force along the propagation direction of the light beam and gradient force always pointing to the position with larger light intensity, and under the action of the two forces, the light beam can capture the particles in a certain area, so that the particles are stabilized at a certain position, and the area is called an optical trap.
The existing gravity measurement mode mainly utilizes a mode of mechanically releasing a mass block, and realizes measurement of the absolute gravity of the mass block through the free falling motion of the mechanical block, but the measurement mode has the defects of complex reset, large volume, multiple error factors and the like.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides a gravity measurement device and method based on an optical trap.
An optical trap-based gravity measurement device, comprising four modules: the device comprises an optical trap capturing module, a vacuum module, a position detection module and a feedback module;
the optical trap capturing module is used for stabilizing the suspended microspheres, and simultaneously, the opening and closing of the optical trap can be controlled through an acousto-optic modulator (AOM), so that the microspheres can freely fall;
the vacuum module is used for ensuring that the suspension capture of the microspheres is realized under a high vacuum condition and the gravity measurement is carried out, so that the influence of air molecule flow and collision on the detection precision is reduced;
the position detection module is used for realizing the detection of the movement information of the microspheres so as to obtain the landing distance of the microspheres when the microspheres freely land;
the feedback module is used for transmitting the movement information of the microspheres to an upper computer, and simultaneously outputting feedback signals for completing the mass center movement cooling of the microspheres according to the acquired movement information of the microspheres.
The optical trap capturing module comprises a laser, an acousto-optic modulator (AOM), a reflector and a focusing lens, wherein the laser outputs high-intensity laser to suspend the microspheres, the AOM completes the movement and cooling of the mass center of the microspheres by adjusting the light intensity of the laser, controls the optical trap to be closed to enable the microspheres to freely fall, and the focusing lens is used for focusing the laser to construct an optical trap for capturing the microspheres at a focus.
The vacuum module comprises a vacuum cavity and a vacuum pump, the vacuum cavity is used for ensuring that the microspheres are in a high vacuum condition during capture, the vacuum pump is used for adjusting the pressure in the vacuum cavity, and optical windows are arranged on two sides of the vacuum cavity to ensure that captured laser passes through.
The position detection module comprises a light spot displacement detector and a converging lens, the converging lens is used for collecting scattered light of the microspheres, then the scattered light is converged on the light spot position detector, and position information of the microspheres is obtained by analyzing light field distribution on the light spot position detector.
The feedback module comprises a Field Programmable Gate Array (FPGA) and an upper computer PC, wherein the FPGA can acquire microsphere position information and output the microsphere position information to the upper computer to realize communication, and meanwhile, a feedback control algorithm in the FPGA outputs a feedback signal according to a microsphere motion signal to control the AOM to adjust the light intensity, so that the centroid cooling of the microsphere motion is realized.
The microsphere is an optically uniform transparent microsphere with the size of nanometer to millimeter magnitude.
The testing method of the device comprises the following steps:
1) after the optical trap captures the microspheres, the movement information of the microspheres is detected in real time through a position detection module, displacement signals obtained by the detection of the position detection module are input into an FPGA (field programmable gate array), the FPGA transmits the position information to an upper computer, and simultaneously outputs feedback signals by using an internal algorithm, and the feedback signals adjust an AOM (automatic optical module) so as to control the laser intensity to inhibit the mass center movement of the microspheres;
2) when the microspheres need to freely fall, the AOM is controlled through the FPGA to enable the output light intensity to be 0, the optical trap is in a non-working state at the moment, the microspheres freely fall under the action of gravity, after milliseconds, the optical trap is opened again through the AOM, the positions of the initial and final states of the falling of the microspheres are recorded, and the gravity is calculated according to the falling time and the falling distance of the microspheres;
3) after the optical trap is opened again, the microspheres overcome the gravity under the action of the optical trap force and are lifted to the initial capturing position again, at the moment, the movement state of the microspheres is cooled again by the AOM, and then the environmental gravity calibration can be repeatedly carried out in the system.
The invention has the beneficial effects that:
according to the characteristic that the optical trap can suspend microspheres, after the optical trap suspends the microspheres in a high-vacuum environment, the laser intensity is modulated through the AOM, so that the optical trap is closed temporarily, the microspheres can fall freely under the action of gravity during the period, then the optical trap is opened again through the AOM to measure the positions of the microspheres, the falling time and the distance of the microspheres are calculated, and the measurement and calibration of the environment gravity are completed;
the optical trap is opened and closed by using the AOM, so that the gravity measurement can be completed in a very short time, and in addition, after the optical trap is opened to stably capture the microspheres again, the gravity measurement of the microspheres can be realized again by using the process, so that the scheme has the advantage of multiple gravity measurements;
the optical trap is used for measuring gravity under the high vacuum condition, the interference of air molecules of the environment on the microspheres is small, the AOM inhibits the movement speed of the microspheres in the vertical direction before the microspheres land, so that the initial landing speed of the microspheres approaches to zero, and higher gravity measurement precision can be obtained.
The invention has the advantages that the general gravity measuring device does not have: compared with the traditional gravimeter, the working range of the gravity measuring device is only a plurality of millimeters, and the gravity measuring device has the advantage of miniaturization; in addition, the photo-induced suspension microspheres are utilized, the gravity of the microspheres can be measured in a high vacuum environment, and the collision of air molecules in the high vacuum environment is less, so that the method has high sensitivity; after each detection, the optical trap can be used for capturing the microspheres again, so that the repeated measurement of the gravity can be realized.
Drawings
FIG. 1 is a schematic diagram of a gravity measurement device module based on an optical trap.
Fig. 2 is a block diagram of an embodiment of the apparatus of the present invention.
Detailed Description
The invention is further elucidated below with reference to the accompanying drawing.
Referring to fig. 1, the optical trap-based gravity measurement device includes four modules, namely, an optical trap capturing module, a position detecting module, a feedback module, and a vacuum module.
Referring to fig. 2, the optical trap capturing module includes a laser 1, an AOM2, a reflector 3, and a focusing lens 4, the laser can emit high-power laser, and after being modulated by the AOM light intensity and focused by the focusing lens, the laser can be configured into a high-focusing light spot, and a microsphere can be stably captured at the focusing light spot.
Referring to fig. 2, the vacuum module includes a vacuum chamber 10 and a vacuum pump 11, wherein the vacuum chamber is a closed chamber for ensuring that the gravity testing environment is in a vacuum state, and the vacuum pump includes an air pump and a molecular pump for reducing the pressure in the vacuum chamber to a high vacuum condition.
Referring to fig. 2, the position detection module includes a converging lens 6 and a light spot position detector 7, where the converging lens is used to collect a scattered light field after interaction between the microsphere and the light field, and when the position of the microsphere moves, the shape of the light spot projected onto the light spot position detector through the converging lens also changes correspondingly, so as to complete analysis of the position of the microsphere.
Referring to fig. 2, the feedback device comprises an upper computer PC8 and an FPGA9, wherein a position signal in the position detection module is input into the FPGA, the FPGA inputs position information of the microspheres into the upper computer for real-time display, and outputs a control signal for inhibiting the movement speed of the microspheres through a PID algorithm, and the feedback signal regulates the AOM to control the laser intensity, thereby realizing the cooling of the centroid of the movement of the particles.
The method comprises the following specific implementation steps:
1) after the optical trap captures the microspheres, detecting the movement information of the microspheres in real time through a position detection module, inputting displacement signals obtained by the detection of the position detection module into an FPGA (field programmable gate array), outputting signals for inhibiting the movement of the microspheres by using a related algorithm in the FPGA, outputting the signals to an AOM (automatic optical network), and controlling the laser intensity through the AOM so as to inhibit the movement of the mass center of the microspheres;
2) when the microspheres need to freely fall, the AOM is controlled through the FPGA to enable the output light intensity to be 0, the optical trap is in a non-working state at the moment, the microspheres freely fall under the action of gravity, after a short time (several milliseconds), the optical trap is opened again through the AOM, the falling distance of the microspheres is calculated at the moment, and the gravity can be calculated according to the falling time of the microspheres;
3) and after the optical trap is opened again, the microspheres overcome the gravity under the action of the optical trap force, rise to the initial capturing position again, re-cool the motion state of the microspheres by using the AOM, and repeat the process to calibrate the environmental gravity again.
Finally, the above embodiments are merely illustrative and not restrictive, and it should be understood by those skilled in the art that modifications and equivalents may be made to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention, and all such modifications and equivalents are intended to be included in the scope of the claims of the present invention.
Claims (2)
1. The gravity measurement device based on the optical trap is characterized by comprising four modules: the device comprises an optical trap capturing module, a vacuum module, a position detection module and a feedback module;
the optical trap capturing module is used for stabilizing the suspended microspheres, and simultaneously, the opening and closing of the optical trap can be controlled through an acousto-optic modulator (AOM), so that the microspheres can freely fall;
the vacuum module is used for ensuring that the suspension capture of the microspheres is realized under a high vacuum condition and the gravity measurement is carried out, so that the influence of air molecule flow and collision on the detection precision is reduced;
the position detection module is used for realizing the detection of the movement information of the microspheres so as to obtain the landing distance of the microspheres when the microspheres freely land;
the feedback module is used for transmitting the motion information of the microspheres to an upper computer and outputting feedback signals to finish the mass center motion cooling of the microspheres according to the acquired motion information of the microspheres;
the optical trap capturing module comprises a laser, an acousto-optic modulator (AOM), a reflector and a focusing lens, wherein the laser outputs high-intensity laser to suspend the microspheres, the AOM completes the movement and cooling of the mass center of the microspheres by adjusting the light intensity of the laser and controls the optical trap to be closed to enable the microspheres to freely fall, and the focusing lens is used for focusing the laser to construct an optical trap for capturing the microspheres at a focus;
the vacuum module comprises a vacuum cavity and a vacuum pump, the vacuum cavity is used for ensuring that the microspheres are in a high vacuum condition during capture, the vacuum pump is used for adjusting the pressure intensity in the vacuum cavity, and two sides of the vacuum cavity are provided with optical windows to ensure that captured laser passes through;
the position detection module comprises a light spot displacement detector and a converging lens, the converging lens is used for collecting scattered light of the microspheres, then converging the scattered light on the light spot position detector, and obtaining position information of the microspheres by analyzing light field distribution on the light spot position detector;
the feedback module comprises a Field Programmable Gate Array (FPGA) and an upper computer PC, wherein the FPGA can acquire microsphere position information and output the microsphere position information to the upper computer to realize communication, and meanwhile, a feedback control algorithm in the FPGA outputs a feedback signal according to a microsphere motion signal to control the AOM to adjust the light intensity, so that the centroid cooling of the microsphere motion is realized;
the microsphere is an optically uniform transparent microsphere with the size of nanometer to millimeter magnitude.
2. A method for testing a device according to claim 1, comprising the steps of:
1) after the optical trap captures the microspheres, the movement information of the microspheres is detected in real time through a position detection module, displacement signals obtained by the detection of the position detection module are input into an FPGA (field programmable gate array), the FPGA transmits the position information to an upper computer, and simultaneously outputs feedback signals by using an internal algorithm, and the feedback signals adjust an AOM (automatic optical module) so as to control the laser intensity to inhibit the mass center movement of the microspheres;
2) when the microspheres need to freely fall, the AOM is controlled through the FPGA to enable the output light intensity to be 0, the optical trap is in a non-working state at the moment, the microspheres freely fall under the action of gravity, after milliseconds, the optical trap is opened again through the AOM, the positions of the initial and final states of the falling of the microspheres are recorded, and the gravity is calculated according to the falling time and the falling distance of the microspheres;
3) after the optical trap is opened again, the microspheres overcome the gravity under the action of the optical trap force and are lifted to the initial capturing position again, at the moment, the movement state of the microspheres is cooled again by the AOM, and then the environmental gravity calibration can be repeatedly carried out in the system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010790955.7A CN111983708B (en) | 2020-08-07 | 2020-08-07 | Gravity measurement device and method based on optical trap |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010790955.7A CN111983708B (en) | 2020-08-07 | 2020-08-07 | Gravity measurement device and method based on optical trap |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111983708A CN111983708A (en) | 2020-11-24 |
| CN111983708B true CN111983708B (en) | 2021-11-23 |
Family
ID=73445312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010790955.7A Active CN111983708B (en) | 2020-08-07 | 2020-08-07 | Gravity measurement device and method based on optical trap |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111983708B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112485163A (en) * | 2020-11-20 | 2021-03-12 | 浙江大学 | Device and method for feeding back cooling particles in double-beam optical trap |
| CN112802620A (en) * | 2021-01-18 | 2021-05-14 | 郑州轻工业大学 | Method and apparatus for manipulating microparticles |
| CN112925036B (en) * | 2021-03-16 | 2021-12-24 | 哈尔滨工业大学 | Miniaturized absolute gravimeter based on micro-nano chip |
| CN114859076B (en) * | 2022-07-06 | 2022-10-21 | 之江实验室 | Acceleration measurement method and device based on optical suspension multi-microsphere array |
| CN115480514B (en) * | 2022-09-28 | 2024-07-26 | 山东大学 | FPGA-based integrated light intensity feedback and light trap quantification system |
| CN116027444B (en) * | 2023-03-27 | 2023-06-27 | 之江实验室 | Suspension power gravity measurement device and method based on electrostatic regulation and control |
| CN117111163B (en) * | 2023-08-07 | 2024-08-02 | 之江实验室 | Gravity measuring device |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1403617B1 (en) * | 2010-12-29 | 2013-10-31 | Eni Spa | ABSOLUTE GRAVIMETRIC MEASURING DEVICE AT ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPLICATIONS PARTICULARLY FOR THE MONITORING OF HYDROCARBON FIELDS |
| IT1404154B1 (en) * | 2010-12-29 | 2013-11-15 | Eni Spa | PILOT METHOD OF A LASER SYSTEM OF AN ABSOLUTE GRAVIMETRIC MEASUREMENT DEVICE AT ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPILATIONS PARTICULARLY FOR THE MONITORING OF HYDROCARBON FIELDS |
| FR2975218B1 (en) * | 2011-05-10 | 2013-05-17 | Thales Sa | ATOMIC COOLING AND TRAPPING DEVICE |
| GB2547628A (en) * | 2015-12-22 | 2017-08-30 | Scheel Monteiro Tania | An aligned electro-optical hybrid trap spectrometer for cooling and characterising nanoparticles |
| CN105785071B (en) * | 2016-03-07 | 2018-09-07 | 浙江大学 | A kind of high sensitivity ligh trap measuring device and its measurement method |
| CN108645751B (en) * | 2018-05-15 | 2020-05-19 | 浙江大学 | Method and device for measuring dynamic viscosity based on light suspended particles |
| CN109814165B (en) * | 2019-02-25 | 2020-05-19 | 浙江大学 | Light power cooling miniaturized high-precision optical gravimeter |
| CN110595151B (en) * | 2019-09-19 | 2021-06-01 | 之江实验室 | Method and apparatus for forming optical traps and cooling particles using self-focusing optical fibers |
| CN110850498A (en) * | 2019-11-14 | 2020-02-28 | 中国船舶重工集团公司第七0七研究所 | Magneto-optical trap device for gravity measurement |
-
2020
- 2020-08-07 CN CN202010790955.7A patent/CN111983708B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN111983708A (en) | 2020-11-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111983708B (en) | Gravity measurement device and method based on optical trap | |
| CN111551250B (en) | Method and device for measuring light field distribution | |
| CN108426633B (en) | Vibration measurement method and device based on optical trap | |
| CN106520535B (en) | A kind of label-free cell detection device and method based on mating plate illumination | |
| EP3431264A1 (en) | Apparatus for additevely manufacturing three-dimensional objects | |
| US8415613B2 (en) | Method and apparatus for characterizing a sample with two or more optical traps | |
| CN1040796C (en) | Particle analysing equipment | |
| CN102818759B (en) | On-line measurement system and method for shape parameters of wet particles based on light scattering | |
| TWI824890B (en) | Diagnostic apparatuses and euv light source apparatuses | |
| CN111999295B (en) | Method and device for repeatedly capturing microspheres in double-beam optical trap | |
| CN102213669A (en) | Device and method for measuring granularity of dynamic light scattering nano particles of image | |
| CN209086170U (en) | A kind of high reflection mirror beauty defects parameter characterization device | |
| CN1086314A (en) | Particle analysing device | |
| CN105842202A (en) | Multichannel optical element surface particle scattering measuring system and method | |
| CN104833620A (en) | Atmospheric particulate matter concentration monitoring device | |
| CN202693451U (en) | Wet particle shape parameter online measuring system based on light scattering | |
| CN111816344A (en) | Device for simultaneously manipulating low-refractive-index particles in multiple Rayleigh regions and achieving high capture efficiency | |
| CN111947593B (en) | Particle shape and surface roughness detection device and method based on optical trap | |
| CN201984012U (en) | Image dynamic light scattering nano particle size measuring device | |
| CN111623871A (en) | Method and device for measuring laser light field relative intensity distribution by using nano particles | |
| CN109297986B (en) | Laser gyroscope high reflector surface defect parameter characterization device and detection method | |
| CN116929219A (en) | Calibration method for particle displacement conversion factor in optical trap | |
| CN110966930B (en) | Femtosecond laser processing morphological parameter time-resolved differential confocal measurement method and device | |
| CN114659951B (en) | Device for measuring suspension scattering characteristics of micro-nano particles | |
| CN109444047A (en) | A kind of efficient implementation method of unimolecule mechanical test |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |