CN113568181B - System and method for directly capturing particles by using optical tweezers under high vacuum condition - Google Patents
System and method for directly capturing particles by using optical tweezers under high vacuum condition Download PDFInfo
- Publication number
- CN113568181B CN113568181B CN202110805978.5A CN202110805978A CN113568181B CN 113568181 B CN113568181 B CN 113568181B CN 202110805978 A CN202110805978 A CN 202110805978A CN 113568181 B CN113568181 B CN 113568181B
- Authority
- CN
- China
- Prior art keywords
- axis
- light
- convex lens
- micro
- optic modulator
- 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
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/28—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising
- G02B27/283—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 for polarising used for beam splitting or combining
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/11—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on acousto-optical elements, e.g. using variable diffraction by sound or like mechanical waves
Abstract
The invention discloses a system and a method for directly capturing particles by using optical tweezers under a high vacuum condition. Comprises a vacuum cavity, micro-nano particles, a supporting device, an optical tweezers device and a detection feedback device; the micro-nano particles are attached to the support device, the support device attached with the micro-nano particles is arranged in the vacuum cavity, and the optical tweezers device is connected with the detection feedback device through an optical path; the optical tweezers device generates trapping light for trapping micro-nano particles in an optical trap trapping region in the vacuum cavity; the detection feedback device generates cooling light for cooling and consuming the mass center movement energy of the micro-nano particles, so that the micro-nano particles are stabilized. The method is used for realizing the stable capture of the micro-nano particles by the system. The invention can directly capture micro-nano particles by using optical tweezers under the high vacuum condition by using a feedback cooling means.
Description
Technical Field
The invention relates to a system and a method for capturing particles by using optical tweezers under a vacuum condition in the technical field of precision measurement, in particular to a system and a method for directly capturing particles by using optical tweezers under a high vacuum condition.
Background
The vacuum optical tweezers are a technical means which can be applied to precision sensing and basic physical exploration. It can be used to measure very weak mechanical quantities including forces, accelerations, moments, etc. It can also be used to explore basic physical problems such as macroscopic quantum effect, non-Newtonian gravitation, Casimilar force, etc. Because the suspended micro-nano particles in the vacuum optical tweezers system are not in mechanical contact with the external environment, the environmental noise can be well isolated, and the high measurement precision is achieved.
In order to achieve the measurement accuracy required by precise measurement and basic physical exploration, measurement needs to be performed under a high vacuum condition, but the conservative trap property of the optical tweezers causes that dissipative force is required in the process of trapping particles, so the prior art means needs to utilize the dissipative force brought by air damping to trap the particles under the condition of atmospheric environment or low vacuum degree, and then reduce the air pressure while keeping the trapping of the particles so as to achieve the high vacuum condition required by measurement. The particles are affected by various noises in the process of vacuum pumping, and easily escape from the optical trap trapping region of the optical tweezers, once escaping, the process of low vacuum trapping and vacuum pumping must be repeated. Such frequent changes of the pressure in the measurement area are based on the fact that precision measurement devices of vacuum optical tweezers systems are moving towards a critical point that must be solved for practical applications. Therefore, there is a need to develop a new capture means capable of directly capturing micro-nano particles under a high vacuum condition, so that the capture process and the measurement process of the vacuum optical tweezers during the application process can be performed under the same air pressure.
However, the existing technical means depends on that the random collision probability of gas molecules and micro-nano particles under low vacuum degree is very high, so that the mass center movement energy of the micro-nano particles is dissipated and can be easily bound by the optical tweezers. The probability of random collision between gas molecules and micro-nano particles under high vacuum is very low, so that the particles cannot be captured under the high vacuum condition by the prior art.
Disclosure of Invention
In order to solve the problems in the background art, the invention provides a system and a method for directly capturing particles by using optical tweezers under a high vacuum condition.
The technical scheme adopted by the invention is as follows:
system for directly capturing particles by optical tweezers under high vacuum condition
The system comprises a vacuum cavity VC, a micro-nano particle MS, a support device LP, an optical tweezers device and a detection feedback device;
the micro-nano particles MS are attached to the support device LP, the support device LP attached with the micro-nano particles MS is arranged in the vacuum cavity VC, and the optical tweezers device is connected with the detection feedback device through a light path; the optical tweezers device generates trapping light for trapping micro-nano particles MS in an optical trap trapping region in the vacuum cavity VC; the detection feedback device generates cooling light for cooling and consuming the mass center motion energy of the micro-nano particle MS, so that the micro-nano particle MS is stabilized.
The optical tweezers device comprises a trapping light source LS, a half-wave plate HWP, a first polarizing beam splitter PBS1, a first mirror M1, a dichroic mirror DM, a first convex lens L1, a second mirror M2, a first beam splitter BS1, a third mirror M3, a second polarizing beam splitter PBS2, and a second convex lens L2;
the capturing light source LS generates capturing light, the capturing light enters the first polarization beam splitter PBS1 to be reflected and transmitted after passing through the half-wave plate HWP, and the p-polarization capturing light transmitted by the first polarization beam splitter PBS1 is incident into the vacuum cavity VC from the left side of the vacuum cavity VC after being reflected by the first reflecting mirror M1 and the dichroic mirror DM in sequence;
the s-polarized captured light reflected by the first polarizing beam splitter PBS1 is incident into the vacuum chamber VC from the right side thereof after being reflected by the second reflecting mirror M2, transmitted by the first beam splitter BS1, reflected by the third reflecting mirror M3 and transmitted by the second polarizing beam splitter PBS2 in sequence;
the first convex lens L1 and the second convex lens L2 are both disposed in the vacuum chamber VC; p-polarization capture light and s-polarization capture light which are incident into the vacuum cavity VC form a light trap capture area in the vacuum cavity VC after being focused by a first convex lens L1 and a second convex lens L2 respectively;
the detection feedback device comprises a fourth reflector M4, a third convex lens L3, a second beam splitter BS2, a third beam splitter BS3, a fourth convex lens L4, a first D-shaped mirror DSM1, a second D-shaped mirror DSM2, a fifth reflector M5, a fifth convex lens L5, a sixth convex lens L6, a sixth reflector M6, a seventh convex lens L7, an eighth convex lens L8, a Z-axis balanced detector BPDZ, an X-axis balanced detector BPDX, a Y-axis balanced detector BPDY, a feedback circuit, a cooling light source CS, a fourth reflector BS4, a fifth reflector BS5, a Z-axis acousto-optic modulator AOMZ, a seventh reflector M7, a ninth convex lens L9, an X-axis acousto-optic modulator MX, an eighth reflector M8, a tenth convex lens L10, a ninth reflector M9, a Y-axis acousto-optic modulator M7, a ninth convex lens M874, a tenth acousto-optic modulator MY and an eleventh reflector 867;
the cooling light source CS generates cooling light, the cooling light is reflected and transmitted by the fourth light splitter BS4, and the Z-axis cooling light reflected by the fourth light splitter BS4 sequentially passes through the Z-axis acousto-optic modulator AOMZ, the seventh reflector M7, the ninth convex lens L9, the dichroic mirror DM of the optical tweezers device and the first convex lens L1 and then acts on the light trap capturing area in the vacuum cavity VC;
the cooling light transmitted by the fourth spectroscope BS4 is reflected and transmitted by the fifth spectroscope BS5, the ninth spectroscope M9 is arranged below the fourth spectroscope BS4, the tenth spectroscope M10 and the eleventh convex lens L11 are arranged up and down and are arranged below the vacuum chamber VC, and the Y-axis cooling light reflected by the fifth spectroscope BS5 sequentially passes through the ninth spectroscope M9, the Y-axis acousto-optic modulator AOMY, the tenth spectroscope M10 and the eleventh convex lens L11 and then acts on the light trap capture area in the vacuum chamber VC;
the X-axis cooling light transmitted by the fifth beam splitter BS5 sequentially passes through the X-axis acousto-optic modulator AOMX, the eighth reflector M8 and the tenth convex lens L10 and then acts on a light trap capturing area in the vacuum cavity VC;
the s-polarized capture light reflected by the first beam splitter BS1 of the optical tweezers device is reflected by the fourth reflector M4 and focused by the third convex lens L3 in sequence and then irradiates one detection end of the Z-axis balance detector BPDZ;
p-polarized captured light in the vacuum cavity VC passes through a light trap capture area, is transmitted by a second convex lens L2 and a second polarizing beam splitter PBS2 in sequence and then enters a second beam splitter BS2 to be reflected and transmitted, the p-polarized captured light reflected by a second beam splitter BS2 is divided into first p-polarized captured light and second p-polarized captured light after passing through a first D-shaped mirror DSM1, the first p-polarized captured light is reflected by a fifth reflector M5 in sequence and transmitted by a sixth convex lens L6 and then irradiates one detection end of the X-axis balanced detector BPDX, and the second p-polarized captured light irradiates the other detection end of the X-axis balanced detector BPDX after being transmitted by a fifth convex lens L5;
the p-polarized captured light transmitted by the second spectroscope BS2 is reflected and transmitted by the third spectroscope BS3, the p-polarized captured light reflected by the third spectroscope BS3 is divided into third p-polarized captured light and fourth p-polarized captured light after passing through the second D-shaped mirror DSM2, the third p-polarized captured light is reflected by the sixth reflector M6 and transmitted by the eighth convex lens L8 in sequence and then irradiates one detection end of the Y-axis balanced detector BPDY, and the fourth p-polarized captured light irradiates the other detection end of the Y-axis balanced detector BPDY after being transmitted by the seventh convex lens L7;
the p-polarized capture light transmitted by the third beam splitter BS3 irradiates the other detection end of the Z-axis balanced detector BPDZ after passing through the fourth convex lens L4;
the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ are respectively connected with the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ through corresponding feedback circuits, the feedback circuits process captured signals collected by the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ to form corresponding feedback signals, and then the feedback signals are output to control terminals of the acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ to achieve feedback regulation, so that the motion of the micro-nano particle MS is restrained.
Carrying out differential detection on two detection ends of the Z-axis balance detector BPDZ to obtain Z-axis motion information of the micro-nano particle MS; the two detection ends of the X-axis balance detector BPDX perform differential detection to obtain X-axis motion information of the micro-nano particle MS; and carrying out differential detection on two detection ends of the Y-axis balance detector BPDY to obtain Y-axis motion information of the micro-nano particles MS.
The straight edge of the first D-shaped mirror DSM1 is perpendicular to the motion direction of the X axis of the micro-nano particle, and the straight edge of the second D-shaped mirror DSM2 is perpendicular to the motion direction of the Y axis of the micro-nano particle.
The vacuum degree in the vacuum cavity VC is high vacuum.
The dichroic mirror DM is an optical element exhibiting different optical properties according to wavelength, and reflects the capture light and transmits the cooling light.
And a light-transmitting optical window for light beam transmission/passing is arranged on the cavity wall of the vacuum cavity VC.
Second, a method for directly capturing particles by using optical tweezers under high vacuum condition
The method comprises the following steps:
1) turning on a capture light source LS;
2) adjusting the half-wave plate HWP so that light intensities of the p-polarized trapped light and the s-polarized trapped light incident to the vacuum chamber VC from the left and right sides thereof are equal;
3) turning on a cooling light source CS;
4) captured signals obtained by detection of the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ are respectively fed back and controlled by corresponding feedback circuits to control the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ so as to control the light intensity of cooling light of the X axis, the Y axis and the Z axis;
5) starting a support starting device LP to enable the micro-nano particles MS to be separated from the support starting device and enter an optical trap capture area of the vacuum cavity VC;
6) observing whether a stable capture signal is observed through an X-axis balance detector BPDX, a Y-axis balance detector BPDY and a Z-axis balance detector BPDZ;
7) if no stable captured signal is observed, adjusting the feedback coefficient of the corresponding feedback circuit, and repeating the steps 4) -6); if a stable capture signal is observed, the micro-nano particle MS is stably captured.
The feedback circuit sequentially performs time differentiation and inverse multiplication on captured signals detected by the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY or the Z-axis acousto-optic modulator AOMZ to obtain feedback signals, and the feedback signals are output to the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY or the Z-axis acousto-optic modulator AOMZ to perform feedback control.
The stable capture signal is specifically represented as a resonance peak with stable intensity at the resonance frequency of the micro-nano particle MS.
The invention has the beneficial effects that:
according to the invention, on one hand, the particles are bound by forming the optical trap trapping region through trapping light under the high vacuum condition, and on the other hand, the mass center motion energy of the micro-nano particles is consumed by cooling light through a feedback cooling mode, so that the particles are directly trapped by using the optical tweezers under the high vacuum condition, and a foundation is laid for the application of the vacuum optical tweezers technology in precision measurement and basic physical exploration.
The general vacuum optical tweezers capture particles release micro-nano particles by using a support device, and after the micro-nano particles enter an optical trap capture area, the micro-nano particles reach an unstable capture state due to the conservative force action of capture light, and at the moment, the micro-nano particles have larger mass center movement energy and are easy to escape from the optical trap capture area. In order to achieve a stable capture state of the micro-nano particles, the energy of the micro-nano particles is dissipated by utilizing the collision between the micro-nano particles and surrounding gas molecules, so that a low-vacuum environment needs to be maintained to achieve a sufficiently high collision probability when the particles are captured. According to the method, the detection feedback device is started before the support device is started to release the micro-nano particles, so that the micro-nano particles are subjected to the action of cooling light once entering the optical trap capturing area. Therefore, even if the collision probability of gas molecules and micro-nano particles is very low under high vacuum, the mass center movement energy of the micro-nano particles can be consumed in time in a feedback cooling mode, so that the micro-nano particles are not easy to escape from a light trap capture area of the optical tweezers. Therefore, the method of the invention enables the process of trapping particles by the vacuum optical tweezers to be carried out under the condition of high vacuum.
Vacuum optical tweezers are generally used for high-precision mechanical quantity measurement after trapping particles, so that a high-vacuum environment is required to reduce environmental interference when performing actual measurement application. The traditional optical tweezers capture means can cause great change of the vacuum degree of the environment, namely, low vacuum is needed during capture, and high vacuum is needed during measurement, which limits the practical application capacity of the vacuum optical tweezers. The method allows the environment where the micro-nano particles are located to be always in a high vacuum state, so that the measurement means of the vacuum optical tweezers can meet the actual application requirements.
Drawings
FIG. 1 is a schematic top view of the system of the present invention;
fig. 2 is a flow chart of the method of the present invention.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the accompanying drawings:
as shown in fig. 1, the system of the present invention comprises a vacuum chamber VC, a micro-nano particle MS, a support device LP, an optical tweezer device and a detection feedback device;
the micro-nano particles MS are attached to the support device LP, the support device LP attached with the micro-nano particles MS is arranged in the vacuum cavity VC, and the optical tweezers device is connected with the detection feedback device through a light path; the optical tweezers device generates trapping light for trapping the micro-nano particles MS in the optical trap trapping region in the vacuum cavity VC; the detection feedback device generates cooling light for cooling and consuming the mass center movement energy of the micro-nano particle MS, so that the micro-nano particle MS is stabilized.
The optical tweezers device comprises a trapping light source LS, a half-wave plate HWP, a first polarizing beam splitter PBS1, a first mirror M1, a dichroic mirror DM, a first convex lens L1, a second mirror M2, a first beam splitter BS1, a third mirror M3, a second polarizing beam splitter PBS2, and a second convex lens L2;
the capturing light source LS generates capturing light, the capturing light enters the first polarization beam splitter PBS1 for reflection and transmission after passing through the half-wave plate HWP, and the p-polarization capturing light transmitted by the first polarization beam splitter PBS1 is incident into the vacuum cavity VC from the left side of the vacuum cavity VC after being reflected by the first reflecting mirror M1 and the dichroic mirror DM in sequence;
the s-polarized captured light reflected by the first polarizing beam splitter PBS1 is incident into the vacuum cavity VC from the right side of the vacuum cavity VC after being reflected by the second reflecting mirror M2, transmitted by the first beam splitter BS1, reflected by the third reflecting mirror M3 and transmitted by the second polarizing beam splitter PBS2 in sequence;
the first convex lens L1 and the second convex lens L2 are both disposed in the vacuum chamber VC; p-polarization capture light and s-polarization capture light which are incident into the vacuum cavity VC form a light trap capture area in the vacuum cavity VC after being focused by a first convex lens L1 and a second convex lens L2 respectively;
the detection feedback device comprises a fourth reflector M4, a third convex lens L3, a second spectroscope BS2, a third spectroscope BS3, a fourth convex lens L4, a first D-shaped mirror DSM1, a second D-shaped mirror DSM2, a fifth reflector M5, a fifth convex lens L5, a sixth convex lens L6, a sixth reflector M6, a seventh convex lens L7, an eighth convex lens L8, a Z-axis balanced detector DBPZ, an X-axis balanced detector BPDX, a Y-axis balanced detector BPDY, a feedback circuit, a cooling light source CS, a fourth reflector BS4, a fifth reflector BS5, a Z-axis acousto-optic modulator AOMZ, a seventh reflector M7, a ninth convex lens L9, an X-axis acousto-optic modulator MX, an eighth reflector 8, a tenth convex lens L10, a ninth reflector M9, a Y-axis modulator M7, a ninth convex lens L695 2, an X-axis acousto-optic modulator MX, an eighth reflector 8, a tenth convex lens L867 and an eleventh reflector 867; the X, Y, Z axes respectively correspond to three motion directions of the micro-nano particles. X, Y, Z the axes are perpendicular to each other. The X-axis represents a direction perpendicular to the optical axis of the capturing light and parallel to the horizontal plane, the Y-axis represents a direction perpendicular to the optical axis of the capturing light and perpendicular to the horizontal plane, and the Z-axis represents a direction parallel to the optical axis of the capturing light.
The cooling light source CS generates cooling light, the cooling light is reflected and transmitted through the fourth light splitter BS4, the Z-axis cooling light reflected by the fourth light splitter BS4 sequentially passes through the Z-axis acousto-optic modulator AOMZ, the seventh light splitter M7, the ninth convex lens L9, the dichroic mirror DM of the optical tweezers device and the first convex lens L1 and then acts on an optical trap capturing area in the vacuum cavity VC, the acting direction is the same as the optical axis direction of the p-polarization capturing light and is used for cooling the Z-axis movement of the micro-nano particle MS;
the cooling light transmitted by the fourth spectroscope BS4 is reflected and transmitted by the fifth spectroscope BS5, the ninth spectroscope M9 is arranged below the fourth spectroscope BS4, the tenth spectroscope M10 and the eleventh convex lens L11 are arranged up and down and are both arranged below the vacuum chamber VC, the Y-axis cooling light reflected by the fifth spectroscope BS5 sequentially passes through the ninth spectroscope M9, the Y-axis acousto-optic modulator AOMY, the tenth spectroscope M10 and the eleventh convex lens L11 and then acts on the light trap capturing area in the vacuum chamber VC, the acting direction is vertical to the optical axis direction of the p-polarized capturing light and vertical to the horizontal plane, and the Y-axis cooling light is used for cooling the micro-nano particle MS;
the X-axis cooling light transmitted by the fifth spectroscope BS5 sequentially passes through the X-axis acousto-optic modulator AOMX, the eighth reflector M8 and the tenth convex lens L10 and then acts on the light trap capture area in the vacuum cavity VC, the acting direction is vertical to the optical axis direction of the p-polarized captured light, and the X-axis cooling light is used for cooling X-axis movement of the micro-nano particle MS in the horizontal plane;
the s-polarized trapping light reflected by the first beam splitter BS1 of the optical tweezers device is reflected by the fourth mirror M4 and focused by the third convex lens L3 in sequence and then irradiates one detection end of the Z-axis balance detector BPDZ;
p-polarized captured light in the vacuum cavity VC passes through a light trap capture area, is transmitted by a second convex lens L2 and a second polarizing beam splitter PBS2 in sequence and then enters a second beam splitter BS2 to be reflected and transmitted, the p-polarized captured light reflected by a second beam splitter BS2 is divided into first p-polarized captured light and second p-polarized captured light after passing through a first D-shaped mirror DSM1, the first p-polarized captured light is reflected by a fifth reflector M5 in sequence and transmitted by a sixth convex lens L6 and then irradiates one detection end of the X-axis balanced detector BPDX, and the second p-polarized captured light irradiates the other detection end of the X-axis balanced detector BPDX after being transmitted by a fifth convex lens L5;
the p-polarized captured light transmitted by the second spectroscope BS2 is reflected and transmitted by the third spectroscope BS3, the p-polarized captured light reflected by the third spectroscope BS3 is divided into third p-polarized captured light and fourth p-polarized captured light after passing through the second D-shaped mirror DSM2, the third p-polarized captured light is reflected by the sixth reflector M6 and transmitted by the eighth convex lens L8 in sequence and then irradiates one detection end of the Y-axis balanced detector BPDY, and the fourth p-polarized captured light irradiates the other detection end of the Y-axis balanced detector BPDY after being transmitted by the seventh convex lens L7;
the p-polarized capture light transmitted by the third beam splitter BS3 irradiates the other detection end of the Z-axis balanced detector BPDZ after passing through the fourth convex lens L4;
the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ are respectively connected with the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ through corresponding feedback circuits, the feedback circuits process captured signals collected by the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ to form corresponding feedback signals, and then the feedback signals are output to control terminals of the acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ to achieve feedback regulation, so that the motion of the micro-nano particle MS is restrained. The feedback circuit differentiates the collected capture signal with respect to time and multiplies the differentiated capture signal by a feedback coefficient to form a feedback signal, and the feedback coefficient can be adjusted. The feedback regulation has the effect similar to that of air damping, namely the damping of the micro-nano particles by the air is that the size is in direct proportion to the motion speed of the micro-nano particles, and the direction is opposite to the motion direction of the micro-nano particles. Therefore, the air damping cooling effect which is lacked when the micro-nano particles are directly captured under the high vacuum condition can be provided by the cooling light under the regulation of the feedback signal.
Carrying out differential detection on two detection ends of a Z-axis balance detector BPDZ to obtain Z-axis motion information of the micro-nano particle MS; carrying out differential detection on two detection ends of the BPDX of the X-axis balance detector to obtain X-axis motion information of the micro-nano particle MS; and carrying out differential detection on two detection ends of the Y-axis balance detector BPDY to obtain Y-axis motion information of the micro-nano particles MS.
The straight side of the first D-shaped mirror DSM1 is perpendicular to the motion direction of the X axis of the micro-nano particle, and the straight side of the second D-shaped mirror DSM2 is perpendicular to the motion direction of the Y axis of the micro-nano particle.
The vacuum degree in the vacuum chamber VC is high vacuum. High vacuum means that the gas pressure is below 1E-3 mbar.
The dichroic mirror DM is an optical element exhibiting different optical properties according to wavelength, and reflects the capture light and transmits the cooling light.
The wall of the vacuum cavity VC is provided with a light-transmitting optical window for light beam transmission/passing.
As shown in fig. 2, the method comprises the steps of:
1) turning on a capture light source LS;
2) adjusting the half-wave plate HWP so that light intensities of the p-polarized trapped light and the s-polarized trapped light incident to the vacuum chamber VC from the left and right sides thereof are equal;
3) turning on a cooling light source CS;
4) captured signals obtained by detection of the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ are respectively fed back and controlled to the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ through corresponding feedback circuits, so that the light intensity of cooling light of the X axis, the Y axis and the Z axis is controlled;
5) starting a support starting device LP to enable the micro-nano particles MS to be separated from the support starting device and enter an optical trap capture area of the vacuum cavity VC;
6) observing whether a stable capture signal is observed through an X-axis balance detector BPDX, a Y-axis balance detector BPDY and a Z-axis balance detector BPDZ;
7) if no stable captured signal is observed, adjusting the feedback coefficient of the corresponding feedback circuit, and repeating the steps 4) -6); if a stable capture signal is observed, the micro-nano particle MS is stably captured.
The feedback circuit differentiates the capture signals detected by the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY or the Z-axis acousto-optic modulator AOMZ in time sequence and multiplies the capture signals by a feedback coefficient to obtain feedback signals, and the feedback signals are output to the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY or the Z-axis acousto-optic modulator AOMZ for feedback control.
The stable capture signal is embodied as that a resonance peak with stable intensity appears at the resonance frequency of the micro-nano particle MS, the resonance frequency of the micro-nano particle MS depends on the rigidity of the optical tweezers and the mass of the micro-nano particle MS, and the rigidity of the optical tweezers is related to the capture light intensity, the focal lengths of the first convex lens L1 and the second convex lens L2 and the beam waist radius after the capture light is converged. So that the micro-nano particles are subjected to the action of cooling light as soon as the micro-nano particles enter the light trap trapping region. Therefore, even if the collision probability of gas molecules and micro-nano particles is very low under high vacuum, the mass center movement energy of the micro-nano particles can be consumed in time in a feedback cooling mode, so that the micro-nano particles are not easy to escape from a light trap capture area of the optical tweezers.
Claims (9)
1. A system for directly trapping particles with optical tweezers under high vacuum conditions, comprising: comprises a vacuum cavity VC, a micro-nano particle MS, a support device LP, an optical tweezers device and a detection feedback device;
the micro-nano particles MS are attached to the support device LP, the support device LP attached with the micro-nano particles MS is arranged in the vacuum cavity VC, and the optical tweezers device is connected with the detection feedback device through a light path; the optical tweezers device generates trapping light for trapping micro-nano particles MS in an optical trap trapping region in the vacuum cavity VC; the detection feedback device generates cooling light for cooling and consuming the mass center movement energy of the micro-nano particle MS, so that the micro-nano particle MS is stabilized;
the optical tweezers device comprises a trapping light source LS, a half-wave plate HWP, a first polarizing beam splitter PBS1, a first mirror M1, a dichroic mirror DM, a first convex lens L1, a second mirror M2, a first beam splitter BS1, a third mirror M3, a second polarizing beam splitter PBS2, and a second convex lens L2;
the capturing light source LS generates capturing light, the capturing light enters the first polarization beam splitter PBS1 for reflection and transmission after passing through the half-wave plate HWP, and the p-polarization capturing light transmitted by the first polarization beam splitter PBS1 is incident into the vacuum cavity VC from the left side of the vacuum cavity VC after being reflected by the first reflecting mirror M1 and the dichroic mirror DM in sequence;
the s-polarized captured light reflected by the first polarizing beam splitter PBS1 is incident into the vacuum cavity VC from the right side of the vacuum cavity VC after being reflected by the second reflecting mirror M2, transmitted by the first beam splitter BS1, reflected by the third reflecting mirror M3 and transmitted by the second polarizing beam splitter PBS2 in sequence;
the first convex lens L1 and the second convex lens L2 are both disposed in the vacuum chamber VC; p-polarization capture light and s-polarization capture light which are incident into the vacuum cavity VC form a light trap capture area in the vacuum cavity VC after being focused by a first convex lens L1 and a second convex lens L2 respectively;
the detection feedback device comprises a fourth reflector M4, a third convex lens L3, a second beam splitter BS2, a third beam splitter BS3, a fourth convex lens L4, a first D-shaped mirror DSM1, a second D-shaped mirror DSM2, a fifth reflector M5, a fifth convex lens L5, a sixth convex lens L6, a sixth reflector M6, a seventh convex lens L7, an eighth convex lens L8, a Z-axis balanced detector BPDZ, an X-axis balanced detector BPDX, a Y-axis balanced detector BPDY, a feedback circuit, a cooling light source CS, a fourth reflector BS4, a fifth reflector BS5, a Z-axis acousto-optic modulator AOMZ, a seventh reflector M7, a ninth convex lens L9, an X-axis acousto-optic modulator MX, an eighth reflector M8, a tenth convex lens L10, a ninth reflector M9, a Y-axis acousto-optic modulator M7, a ninth convex lens M874, a tenth acousto-optic modulator MY and an eleventh reflector 867;
the cooling light source CS generates cooling light, the cooling light is reflected and transmitted by the fourth light splitter BS4, and the Z-axis cooling light reflected by the fourth light splitter BS4 sequentially passes through the Z-axis acousto-optic modulator AOMZ, the seventh reflector M7, the ninth convex lens L9, the dichroic mirror DM of the optical tweezers device and the first convex lens L1 and then acts on the light trap capturing area in the vacuum cavity VC;
the cooling light transmitted by the fourth spectroscope BS4 is reflected and transmitted by the fifth spectroscope BS5, the ninth spectroscope M9 is arranged below the fourth spectroscope BS4, the tenth spectroscope M10 and the eleventh convex lens L11 are arranged up and down and are arranged below the vacuum chamber VC, and the Y-axis cooling light reflected by the fifth spectroscope BS5 sequentially passes through the ninth spectroscope M9, the Y-axis acousto-optic modulator AOMY, the tenth spectroscope M10 and the eleventh convex lens L11 and then acts on the light trap capture area in the vacuum chamber VC;
the X-axis cooling light transmitted by the fifth beam splitter BS5 sequentially passes through the X-axis acousto-optic modulator AOMX, the eighth reflector M8 and the tenth convex lens L10 and then acts on a light trap capturing area in the vacuum cavity VC;
the s-polarized capture light reflected by the first beam splitter BS1 of the optical tweezers device is reflected by the fourth reflector M4 and focused by the third convex lens L3 in sequence and then irradiates one detection end of the Z-axis balance detector BPDZ;
p-polarized captured light in the vacuum cavity VC passes through a light trap capture area, is transmitted by a second convex lens L2 and a second polarizing beam splitter PBS2 in sequence and then enters a second beam splitter BS2 to be reflected and transmitted, the p-polarized captured light reflected by a second beam splitter BS2 is divided into first p-polarized captured light and second p-polarized captured light after passing through a first D-shaped mirror DSM1, the first p-polarized captured light is reflected by a fifth reflector M5 in sequence and transmitted by a sixth convex lens L6 and then irradiates one detection end of the X-axis balanced detector BPDX, and the second p-polarized captured light irradiates the other detection end of the X-axis balanced detector BPDX after being transmitted by a fifth convex lens L5;
the p-polarized captured light transmitted by the second spectroscope BS2 is reflected and transmitted through the third spectroscope BS3, the p-polarized captured light reflected by the third spectroscope BS3 is divided into third p-polarized captured light and fourth p-polarized captured light after passing through the second D-shaped mirror DSM2, the third p-polarized captured light is sequentially reflected by a sixth reflector M6 and transmitted by an eighth convex lens L8 and then irradiates one detection end of the Y-axis balanced detector BPDY, and the fourth p-polarized captured light irradiates the other detection end of the Y-axis balanced detector BPDY after being transmitted by a seventh convex lens L7;
the p-polarized capture light transmitted by the third beam splitter BS3 irradiates the other detection end of the Z-axis balanced detector BPDZ after passing through the fourth convex lens L4;
the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ are respectively connected with the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ through corresponding feedback circuits, the feedback circuits process captured signals collected by the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ to form corresponding feedback signals, and then the feedback signals are output to control terminals of the acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ to achieve feedback regulation, so that the motion of the micro-nano particle MS is restrained.
2. The system for directly trapping particles with optical tweezers under high vacuum condition as claimed in claim 1, wherein:
carrying out differential detection on two detection ends of the Z-axis balance detector BPDZ to obtain Z-axis motion information of the micro-nano particle MS; the two detection ends of the X-axis balance detector BPDX perform differential detection to obtain X-axis motion information of the micro-nano particle MS; and carrying out differential detection on two detection ends of the Y-axis balance detector BPDY to obtain Y-axis motion information of the micro-nano particles MS.
3. The system for directly trapping particles with optical tweezers under high vacuum condition as claimed in claim 1, wherein: the straight edge of the first D-shaped mirror DSM1 is perpendicular to the motion direction of the X axis of the micro-nano particles, and the straight edge of the second D-shaped mirror DSM2 is perpendicular to the motion direction of the Y axis of the micro-nano particles.
4. The system for directly trapping particles with optical tweezers under high vacuum condition as claimed in claim 1, wherein: the vacuum degree in the vacuum cavity VC is high vacuum.
5. The system for directly trapping particles with optical tweezers under high vacuum condition as claimed in claim 1, wherein: the dichroic mirror DM is an optical element exhibiting different optical properties according to wavelength, and reflects the capture light and transmits the cooling light.
6. The system for directly trapping particles with optical tweezers under high vacuum condition as claimed in claim 1, wherein: and a light-transmitting optical window for light beam transmission/passing is arranged on the cavity wall of the vacuum cavity VC.
7. A method of trapping particles directly with optical tweezers under high vacuum conditions in a system according to any of claims 1-6, comprising the steps of:
1) turning on a capture light source LS;
2) adjusting the half-wave plate HWP so that light intensities of the p-polarized trapped light and the s-polarized trapped light incident to the vacuum chamber VC from the left and right sides thereof are equal;
3) turning on a cooling light source CS;
4) captured signals obtained by detection of the X-axis balance detector BPDX, the Y-axis balance detector BPDY and the Z-axis balance detector BPDZ are respectively fed back and controlled to the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY and the Z-axis acousto-optic modulator AOMZ through corresponding feedback circuits, so that the light intensity of cooling light of the X axis, the Y axis and the Z axis is controlled;
5) starting a support starting device LP to enable the micro-nano particles MS to be separated from the support starting device and enter an optical trap capture area of the vacuum cavity VC;
6) observing whether a stable capture signal is observed through an X-axis balance detector BPDX, a Y-axis balance detector BPDY and a Z-axis balance detector BPDZ;
7) if no stable captured signal is observed, adjusting the feedback coefficient of the corresponding feedback circuit, and repeating the steps 4) -6); if a stable capture signal is observed, the micro-nano particle MS is stably captured.
8. A method of directly trapping particles with optical tweezers under high vacuum conditions, according to claim 7, wherein: the feedback circuit sequentially performs time differentiation and inverse multiplication on captured signals detected by the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY or the Z-axis acousto-optic modulator AOMZ to obtain feedback signals, and the feedback signals are output to the X-axis acousto-optic modulator AOMX, the Y-axis acousto-optic modulator AOMY or the Z-axis acousto-optic modulator AOMZ to perform feedback control.
9. A method of directly trapping particles with optical tweezers under high vacuum conditions, according to claim 7, wherein: the stable capture signal is specifically represented as a resonance peak with stable intensity at the resonance frequency of the micro-nano particle MS.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110805978.5A CN113568181B (en) | 2021-07-16 | 2021-07-16 | System and method for directly capturing particles by using optical tweezers under high vacuum condition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110805978.5A CN113568181B (en) | 2021-07-16 | 2021-07-16 | System and method for directly capturing particles by using optical tweezers under high vacuum condition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113568181A CN113568181A (en) | 2021-10-29 |
| CN113568181B true CN113568181B (en) | 2022-07-12 |
Family
ID=78165155
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110805978.5A Active CN113568181B (en) | 2021-07-16 | 2021-07-16 | System and method for directly capturing particles by using optical tweezers under high vacuum condition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113568181B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115223430B (en) * | 2022-09-19 | 2022-12-16 | 之江实验室 | Vacuum optical tweezers experiment teaching device based on suspended nanoparticles |
| CN116417173B (en) * | 2023-06-12 | 2023-08-22 | 之江实验室 | Vacuum optical tweezers system for suspending nano particles |
| CN117629899A (en) * | 2024-01-26 | 2024-03-01 | 之江实验室 | Nanoparticle extinction section in-situ measurement method and device based on suspension optical tweezers |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170212424A1 (en) * | 2014-08-01 | 2017-07-27 | South University Of Science And Technology Of China | System and method for micro-nano machining by femtosecond laster two-photon polymerization |
| CN111913230A (en) * | 2020-06-12 | 2020-11-10 | 浙江大学 | Absolute gravimeter based on vacuum optical tweezers and measuring method |
| CN112880912A (en) * | 2021-01-08 | 2021-06-01 | 浙江大学 | Space resolution pressure measurement system and method based on vacuum holographic optical tweezers |
-
2021
- 2021-07-16 CN CN202110805978.5A patent/CN113568181B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170212424A1 (en) * | 2014-08-01 | 2017-07-27 | South University Of Science And Technology Of China | System and method for micro-nano machining by femtosecond laster two-photon polymerization |
| CN111913230A (en) * | 2020-06-12 | 2020-11-10 | 浙江大学 | Absolute gravimeter based on vacuum optical tweezers and measuring method |
| CN112880912A (en) * | 2021-01-08 | 2021-06-01 | 浙江大学 | Space resolution pressure measurement system and method based on vacuum holographic optical tweezers |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113568181A (en) | 2021-10-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113568181B (en) | System and method for directly capturing particles by using optical tweezers under high vacuum condition | |
| Li et al. | Millikelvin cooling of an optically trapped microsphere in vacuum | |
| CN112485163A (en) | Device and method for feeding back cooling particles in double-beam optical trap | |
| CN111913230B (en) | Absolute gravimeter based on vacuum optical tweezers and measuring method | |
| CN108169804B (en) | Atomic interference gravity gradient measurement method and device based on pyramid-like structure | |
| CN112880912B (en) | Space resolution pressure measurement system and method based on vacuum holographic optical tweezers | |
| CN103443656A (en) | Absolute gravimetric measurement device by atomic interferometry for geophysical applications particularly for monitoring hydrocarbon reservoirs | |
| CN109633858B (en) | Device and method for aligning focal points of correlation light beams in optical tweezers | |
| CN101592843A (en) | Dual-magnetic light trap system | |
| CN108426633B (en) | Vibration measurement method and device based on optical trap | |
| CN108181663B (en) | Atomic interference gravity acceleration measuring device based on pyramid-like structure | |
| Kawasaki et al. | High sensitivity, levitated microsphere apparatus for short-distance force measurements | |
| CN103869462B (en) | A kind of optical cavity ring-down technology that utilizes carries out splicing the device that mirror is total to phase control | |
| JP2023155115A (en) | Device and method for measuring optical flotation angular velocity based on geometric phase of solid atom spin | |
| CN102607701A (en) | Fourier transformation miniature spectrometer based on moving mirror of micro-electro-mechanical system | |
| CN114624153B (en) | Method and device for measuring radius of trapped particles of optical trap based on echo wall resonance mode | |
| Palau et al. | Theoretical model of the helium zone plate microscope | |
| Zheng et al. | Three-dimensional position measurement of a levitated nanoparticle in a vacuum by a Dove prism | |
| CN117007831A (en) | Closed-loop accelerometer device and method based on double-beam vacuum optical trap | |
| CN109061889B (en) | Optical cold atom trapping device | |
| CN116429239A (en) | Device for detecting vibration of nano mechanical resonator under low-temperature Jiang Citiao piece | |
| CN114252816B (en) | High-sensitivity magnetic field measuring device and method based on Faraday rotation | |
| Freise | The next generation of interferometry: multi-frequency optical modelling, control concepts and implementation | |
| Zhang et al. | Enhanced cold mercury atom production with two-dimensional magneto-optical trap | |
| CN111855505B (en) | Microsphere cluster state detection device and detection method applied to vacuum optical trap system |
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 |