Laser control device, optical tweezers generation system, laser control method, optical tweezers generation method, and program

Abstract

This laser control device controls the phase of light outputted from a spatial light modulator for generating the optical tweezers on the basis of the vibration frequency of fine particles captured by optical tweezers array.

Description

Laser control device, optical tweezers generation system, laser control method, optical tweezers generation method and program

[0001] The present invention relates to a laser control device, an optical tweezers generation system, a laser control method, an optical tweezers generation method, and a program. This application claims priority to Japanese Patent Application No. 2023-152361 filed in Japan on September 20, 2023, and Japanese Patent Application No. 2023-217754 filed in Japan on December 25, 2023, the contents of which are incorporated herein by reference.

[0002] There is a technique called optical tweezers that uses focused laser light to trap minute particles such as atoms. An array of many optical tweezers is called an optical tweezers array. Optical tweezers arrays are used, for example, in cold-atom quantum computers to individually trap and arrange multiple atoms. Cold-atom quantum computers are characterized by using laser light to cool atomic gases and using them as quantum bits. Optical tweezers are a technique that can be used to trap these cooled atoms.

[0003] When using an optical tweezers array to individually arrange multiple atoms, for example, the phase of the laser light irradiated to form the optical tweezers array is controlled by a spatial light modulator, and the light intensity distribution on the focal plane is controlled to form an array of focused points. Each optical tweezers then captures an individual atom. By equalizing the central intensity of each optical tweezers, the potential depth for capturing atoms constituting a quantum bit can be made uniform, reducing variations in the atom capture probability and the energy difference between the internal states of atoms. For example, Non-Patent Document 1 discloses equalizing the central intensity of an optical tweezers array.

[0004] F. Nogrette, H. Labuhn, S. Ravets, D. Barredo, L. Beguin, A. Vernier, T. Lahaye, and A. Browaeys, “Single-Atom Trapping in Holographic 2D Arrays of Microtraps with Arbitrary Geometries”, Phys. Rev. X 4, 021034 Published 23 May 2014

[0005] However, even if the central intensity of each optical tweezers in an optical tweezers array is uniform, if the curvature of the light intensity distribution near the center of each optical tweezers is nonuniform, the motion of each trapped atom will be nonuniform. Nonuniform motion of atoms arrayed in a cold-atom quantum computer results in nonuniform initialization and kinetic quantum state control, reducing the accuracy of quantum computing. In other words, in quantum gate operation, the controlled quantum state does not faithfully reproduce the desired quantum state. "Initialization" here refers to placing trapped atoms in an optical tweezers array in a predetermined energy state before setting them to a predetermined excited state. "Kinetic quantum state control" here refers to placing trapped atoms in a desired excited energy state by irradiating them with a predetermined laser. Furthermore, when manipulating a large number of atoms using optical tweezers with multiple focal points and attempting to position the atoms on the XY plane, there is a problem in that the positions of the trapped atoms also deviate from the XY plane due to the variation in the Z direction of each focal point relative to the plane. An object of the present invention is to provide a laser control device, an optical tweezers generation system, a laser control method, an optical tweezers generation method, and a program for arranging microparticles to be trapped by optical tweezers.

[0006] One aspect of the present invention is a control device that controls the phase of light output from a spatial light modulator that generates an optical tweezers array, based on the vibration frequency of atoms trapped by the optical tweezers.

[0007] One aspect of the present invention is an optical tweezers generation system comprising: a laser light source; a focusing optical system that focuses laser light from the laser light source to form an optical tweezers array that traps atoms; a measurement device that measures the vibrational frequency of the trapped atoms based on fluorescence from the atoms; and a control device that controls the phase of the laser light output from a spatial light modulator located in the focusing optical system based on the vibrational frequency.

[0008] One aspect of the present invention is a control method for controlling the phase of light output from a spatial light modulator that generates an optical tweezers array, based on the vibration frequency of atoms trapped by the optical tweezers array.

[0009] One aspect of the present invention is a method for generating optical tweezers, comprising the steps of forming an optical tweezers array that captures atoms by focusing laser light from a laser light source using a focusing optical system, measuring the vibrational frequency of the atoms captured by the optical tweezers array based on fluorescence from the atoms, and controlling the phase of the laser light output from a spatial light modulator arranged in the focusing optical system based on the vibrational frequency.

[0010] According to the present invention, it is possible to arrange the microparticles trapped by the optical tweezers.

[0011] FIG. 1 is a diagram illustrating a configuration of an optical tweezers generation system according to a first embodiment. FIG. 2 is a diagram illustrating an optical tweezers array generated by the optical tweezers generation system. FIG. 3 is a flowchart illustrating the operation of a control device according to a first embodiment. FIG. 4 is a diagram illustrating an example of light intensity distribution of an optical tweezers array before and after optimization. FIG. 5 is a diagram illustrating the trapping frequency (vibration frequency) of an atom trapped by the optical tweezers before control. FIG. 6 is a diagram illustrating the trapping frequency (vibration frequency) of an atom trapped by the optical tweezers after control. FIG. 7 is a diagram illustrating a configuration of an optical tweezers generation system according to a second embodiment. FIG. 8 is a diagram illustrating the principle of two-beam interferometry. FIG. 9 is a diagram illustrating an example of the configuration of an interference laser. FIG. 10 is a flowchart illustrating the operation of a control device according to a second embodiment.

[0012] First Embodiment Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a diagram showing the configuration of an optical tweezers generation system 1 according to a first embodiment. The optical tweezers generation system 1 according to the first embodiment includes a light source 10, a spatial light modulator 11, a control device 110, a dichroic mirror 12, a fluorescence observation camera 120, a fluorescence analysis device 130, an objective lens 13, and a measurement light source 14.

[0013] The light source 10 outputs laser light to the spatial light modulator 11 .

[0014] The spatial light modulator 11 modulates the phase of input light and outputs the modulated light so as to be focused at multiple points on the objective lens 13 via the dichroic mirror 12. The phase modulated by the spatial light modulator 11 is set by the two-dimensional position of the spatial light modulator 11 into which the light is input. The control device 110 controls the spatial light modulator 11 to change the phase of the light output from the spatial light modulator 11.

[0015] The dichroic mirror 12 reflects the light input from the spatial light modulator 11 and outputs it to the objective lens 13. The objective lens 13 focuses the light input from the dichroic mirror 12 to a focal point. By focusing the light, atoms can be trapped near the focal point. In the optical tweezers generation system 1, the spatial light modulator 11, the dichroic mirror 12, and the objective lens 13 form a focusing optical system.

[0016] Figure 2 shows an optical tweezers array generated by the optical tweezers generation system 1. In Figure 2, (a) shows the observed optical tweezers array, (b) shows the light intensity, and (c) shows the potential. The light intensity distribution of the optical tweezers takes on a mountain-like shape as shown in Figure 2. The stronger the light intensity, the lower the energy an atom experiences, resulting in a valley-like potential shape. This allows atoms to be trapped in regions of low potential. The control device 110 controls the spatial light modulator 11 to change the phase of the light output from the spatial light modulator 11, thereby generating the light intensity distribution of the optical tweezers shown in Figure 2, thereby trapping atom A at each focusing point.

[0017] The fluorescence observation camera 120 observes the fluorescence from the trapped atom A. The fluorescence from atom A passes through the objective lens 13 and the dichroic mirror 12 and reaches the fluorescence observation camera 120. The fluorescence analysis device 130 analyzes the fluorescence of atom A obtained from the fluorescence observation camera 120. Atomic vibration measurement is performed, for example, by applying Raman sideband spectroscopy to atom A to measure the vibrational frequency of atom A. That is, the fluorescence observation camera 120 and the fluorescence analysis device 130 measure the vibrational frequency of atom A by having the measurement light source 14 incident light of multiple frequencies on atom A, causing a Raman transition in atom A that raises the vibrational level by a unit amount, and measuring the frequency corresponding to the raised vibrational level. The fluorescence observation camera 120 and the fluorescence analysis device 130 function as measurement devices that measure the vibrational frequency of atom A. The vibrational frequency of atom A corresponds to the beam radius and curvature of the light intensity distribution in which atom A is trapped. When the curvature is large, the vibration frequency of atom A becomes large, and when the curvature is small, the vibration frequency of atom A becomes small.

[0018] As mentioned above, if the curvature of the light intensity distribution near the center of each optical tweezers is non-uniform, the motion of each trapped atom will be non-uniform. When considering applications to cold-atom quantum computers, this will reduce the accuracy of quantum computing, so it is very important to understand the variation in the curvature of the light intensity distribution by measuring the oscillation frequency.

[0019] The control device 110 controls the electric field of the light output from the spatial light modulator 11 based on the vibration frequency of the atom A in each optical tweezers. The control device 110 controls the electric field of the light output from a specific point on the spatial light modulator 11 based on, for example, the vibration frequency of the atom A in each optical tweezers.

[0020] The vibrational frequency of atom A in each optical tweezers changes with changes in the electric field of the light output from the spatial light modulator 11. The control device 110 may repeatedly control the electric field of the light output from the spatial light modulator 11 based on the vibrational frequency of atom A in each optical tweezers. The control device 110 may stop the control after controlling the electric field of the light output from the spatial light modulator 11 a predetermined number of times. The control device 110 may stop the control of the electric field of the light output from the spatial light modulator 11 when the vibrational frequency of atom A in each optical tweezers satisfies a predetermined condition. An example of a case where the vibrational frequency satisfies the predetermined condition is when the difference between the maximum and minimum values ​​of the vibrational frequency of atom A in each optical tweezers is smaller than a predetermined value. In this way, when the measured vibrational frequency falls within the predetermined condition, i.e., when the difference between the maximum and minimum values ​​of the vibrational frequency is smaller than a predetermined value, it means that the curvature of the light intensity distribution falls within a predetermined range.

[0021] The control device 110 calculates the position of the point (x ｓ , y ｓ ) the electric field A of the light output from ＳＬＭ (x ｓ , y ｓ ) and calculate the point (x ｓ , y ｓ ) is calculated by dividing the phase of the electric field of the light output from the ＳＬＭ (x ｓ , y ｓ ) is controlled to be in phase with the

[0022] In formula (1), m is the number of optical tweezers generated by the optical tweezers generation system 1. The control device 110 calculates the number of points (x ｓ , y ｓ ) necessary to generate m optical tweezers. ｓ , y ｓ ) the intensity A of the light output from ＳＬＭ (x ｓ , y ｓ ) is calculated.

[0023] In formula (1), w ｘ、ｍ and w ｙ、ｍ is the curvature adjustment value corresponding to the vibration frequency of atom A trapped by each tweezers. For example, w ｘ、ｍ is the curvature adjustment value corresponding to the vibration frequency of atom A in the x direction, and w ｙ、ｍ is a curvature adjustment value corresponding to the vibration frequency in the y direction of atom A. When the vibration frequency in the x direction of atom A is smaller than a predetermined value, the control device 110 adjusts w ｘ、ｍ In addition, when the vibration frequency of atom A in the x direction is larger than a predetermined value, the magnitude of w ｘ、ｍ The control device 110 reduces the magnitude of w ｘ、ｍ The control device 110 adjusts the w ｙ、ｍ The control device 110 adjusts w ｘ、ｍ and w ｙ、ｍ After adjusting the light intensity A ＳＬＭ (x ｓ , y ｓ ) is calculated, which allows us to adjust the curvature of each optical tweezers.

[0024] a ｍ is an amplitude adjustment value adjusted so that the central intensity of each optical tweezers is constant. The control device 110 adjusts a so that the electric field amplitude at the central position of each optical tweezers is constant. ｍ This allows the control device 110 to maintain a constant magnitude of the central intensity of the optical tweezers even after adjusting the curvature of the optical tweezers.

[0025] Δ ｍ (x ｓ , y ｓ ) is the point (x ｓ , y ｓ ) is the phase of the light output from the ｍ is the phase added to prevent interference between the optical tweezers.

[0026] 3 is a flowchart showing the operation of the control device 110 according to the first embodiment. The control device 110 acquires the vibration frequency of atom A trapped in each optical tweezers (step S101). The control device 110 controls the electric field of light output from the spatial light modulator 11 based on the vibration frequency (step S102). If the control device 110 has performed the control a predetermined number of times (step S103: YES), it ends the operation. If the control device 110 has not performed the control a predetermined number of times (step S103: NO), it performs the operation of step S101 again. By repeating the above steps, an optical tweezers array with uniform central intensity and curvature is generated, as shown in FIG. 4.

[0027] Example 1 An example of the first embodiment is described below. A system with a configuration similar to that of the optical tweezers generation system 1 according to the first embodiment was constructed. The light source 10 was an 850 nm laser light source. The spatial light modulator 11 was an 800 x 600 pixel liquid crystal spatial light modulator. The dichroic mirror 12 had a reflectance of 99% at 850 nm and a transmittance of 95% or more at 780 nm. The fluorescence observation camera 120 was a camera with high sensitivity to visible light, the objective lens 13 had an NA of 0.75, and the measurement light source 14 used a laser beam with a wavelength of 795 nm. The fluorescence analysis device 130 was a device capable of analyzing the trap frequency corresponding to the atomic energy transition using Raman sideband spectroscopy. The atoms to be trapped were rubidium (Rb). Rb atoms were filled in a vacuum chamber maintained at room temperature, and the Rb atoms were trapped using the optical tweezers array generated by the optical tweezers generation system. The control device 110 calculates the position of the point (x ｓ , y ｓ ) the electric field A of the light output from ＳＬＭ (x ｓ , y ｓ ) was calculated, and the spatial light modulator 11 was controlled to output the calculated electric field of light.

[0028] Fig. 5 is a diagram showing an example of the trapping frequency (vibration frequency) and potential shape of an atom trapped by the optical tweezers before control. Fig. 6 is a diagram showing an example of the trapping frequency (vibration frequency) and potential shape of an atom trapped by the optical tweezers after control by the control device 110 according to the present invention. In Figs. 5 and 6, the horizontal axis indicates the number assigned to each optical tweezers, and the vertical axis indicates the trapping frequency of an atom trapped by each optical tweezers.

[0029] Before control, the RMS (root mean square) of the trapping frequency was about 5%, whereas after control by the control device 110 according to the present invention, the RMS of the trapping frequency was 0.5% or less. As a result, the method described in this embodiment was able to homogenize the trapping frequency of atoms, i.e., the curvature of the light intensity distribution of the optical tweezers.

[0030] 7 is a diagram showing the configuration of an optical tweezers generation system 1 according to a second embodiment. The optical tweezers generation system 1 according to the second embodiment includes an interference laser 210 in addition to the components of the optical tweezers generation system 1 according to the first embodiment.

[0031] In the second embodiment, atom A is placed on the XY plane. The direction perpendicular to the XY plane is defined as the Z direction. The interference laser 210 irradiates the XY plane on which the atom is placed with two laser beams obliquely from above and below in the Z direction. The interference laser 210, the fluorescence observation camera 120, and the fluorescence analysis device 130 calculate the Z-direction position of the atom using two-beam interferometry. FIG. 8 illustrates the principle of two-beam interferometry. As shown in FIG. 7, the interference laser 210 irradiates the XY plane on which the atom is placed with two laser beams obliquely from above and below in the Z direction. Irradiation with the laser beams generates an interference fringe intensity pattern that spreads uniformly along the XY plane and whose intensity varies periodically in the Z direction. When irradiated with the laser beams, the atoms absorb the laser beams and emit fluorescence. Atoms irradiated with high-intensity laser beams emit strong fluorescence, while atoms irradiated with low-intensity laser beams emit weak fluorescence. When the interference fringe intensity pattern is scanned in the Z direction, the atoms emit fluorescence in response to changes in the intensity of the interference fringes. Therefore, by synchronizing the Z-direction component of the interference fringe intensity pattern with the fluorescence from the atoms, the Z-direction position of the atoms can be calculated.

[0032] For example, consider the case where atom A is slightly shifted in the Z direction from other atoms. When the maximum intensity pattern of the interference fringes is at Z = 0, the fluorescence from the other atoms is at its maximum, and the fluorescence from atom A is reduced to 1 / a compared to the fluorescence from the other atoms. On the other hand, when the maximum intensity pattern of the interference fringes is at Z = ΔL, the fluorescence from atom A is at its maximum, and the fluorescence from the other atoms is reduced to 1 / a of the fluorescence from atom A. In this case, atom A is calculated to be shifted by ΔL in the Z direction from the other atoms.

[0033] The interference laser 210 scans the interference fringe intensity pattern in the Z direction, and the fluorescence observation camera 120 and fluorescence analysis device 130 according to the second embodiment measure the varying intensity of the interference fringes. The Z-direction position of atom A is calculated by synchronizing the Z-direction position scanned by the interference laser 210 with the intensity of the interference fringes measured by the fluorescence observation camera 120 and fluorescence analysis device 130. In the second embodiment, the fluorescence observation camera 120 and fluorescence analysis device 130 function as measurement devices that measure the vibrational frequency of the atom, as well as measurement devices that measure the Z-direction position of the atom.

[0034] The interference laser 210 splits the laser beam output from the laser source into two beams and adjusts the direction of each beam. Figure 9 shows an example of the configuration of the interference laser 210. The interference laser 210 includes a laser source 220, a PBS (Polarizing Beam Splitter) 230, a piezo controller 240, mirrors M1-M2, and wave plates P1-P3. The laser source 220 outputs a laser beam. The laser beam output from the laser source 220 is reflected by mirror M1 and split into two laser beams by the PBS 230. One laser beam is reflected by mirror M2 and output to the array of atoms A, while the other laser beam is output directly to the array of atoms A. The angle of mirror M2 is controlled by the piezo controller 240, which adjusts the position at which an interference fringe intensity pattern is formed by irradiation with the laser beam. Wave plates P1-P3 are provided in the path of the laser beam to change the polarization state of the laser beam.

[0035] The control device 110 according to the second embodiment controls the electric field of the light output from the spatial light modulator 11 based on the vibration frequency of the atom A in each optical tweezers as well as the position of the atom in the Z direction.

[0036] The vibrational frequency and Z-direction position of atom A in each optical tweezers change with changes in the electric field of the light output from the spatial light modulator 11. The control device 110 may repeatedly control the electric field of the light output from the spatial light modulator 11 based on the vibrational frequency and Z-direction position of atom A in each optical tweezers. The control device 110 may stop the control after controlling the electric field of the light output from the spatial light modulator 11 a predetermined number of times. The control device 110 may stop the control of the electric field of the light output from the spatial light modulator 11 when the vibrational frequency and Z-direction position of atom A in each optical tweezers satisfy a predetermined condition. An example of a case where the vibrational frequency satisfies the predetermined condition is when the difference between the maximum and minimum values ​​of the vibrational frequency of atom A in each optical tweezers is smaller than a predetermined value and / or the maximum value of the difference in Z-direction position is smaller than a predetermined value.

[0037] The control device 110 calculates the shift of the point (x) of the spatial light modulator 11 by, for example, equation (2) obtained by adding a factor indicating the shift in the Z direction to equation (1). ｓ , y ｓ ) the electric field A of the light output from ＳＬＭ (x ｓ , y ｓ ) and calculate the point (x ｓ , y ｓ ) is calculated by dividing the phase of the electric field of the light output from the ＳＬＭ (x ｓ , y ｓ ) is controlled to be in phase with the

[0038] In formula (2), λ, f, and z ｍ The definitions of the letters other than π and π are the same as in formula (1). In formula (2), λ is the wavelength of the laser light output by the interference laser 210. f is the effective focal length from the spatial light modulator 11 to the arrangement of atoms A. z ｍ is the z-direction position of each atom A trapped by the optical tweezers, and π is the constant of the circumference of a circle.

[0039] 10 is a flowchart showing the operation of the control device 110 according to the second embodiment. The control device 110 acquires the vibration frequency of the atom A trapped by each optical tweezers (step S201). The control device 110 acquires the Z-direction position of the atom A trapped by each optical tweezers (step S202). The control device 110 controls the electric field of the light output from the spatial light modulator 11 based on the vibration frequency and the Z-direction position (step S203). The control device 110 adjusts, for example, the curvature adjustment value w ｘ、ｍ and w ｙ、ｍ and amplitude adjustment value a ｍ By adjusting the value of the polarizing beam, the electric field of the light output from the spatial light modulator 11 is controlled.

[0040] If the control device 110 has performed the control a predetermined number of times (step S204: YES), it ends the operation. If the control device 110 has not performed the control a predetermined number of times (step S204: NO), it performs the operation of step S201 again. If the control device 110 performs steps S201 and S202 again, the vibration frequency and z-direction position of atom A have changed because the electric field of the light output from the spatial light modulator 11 was controlled in step S203. By repeating the above steps, an optical tweezers array with uniform central intensity and curvature is generated, and the Z-direction positional deviation between atoms A captured by the optical tweezers is reduced.

[0041] (Example 2) An example of the second embodiment will be described below. A system having the same configuration as the optical tweezers generation system 1 according to the second embodiment was constructed. Conditions other than the interference laser 210, the control device 110, the fluorescence observation camera 120, and the fluorescence analysis device 130 were the same as those in the example of the first embodiment. The interference laser 210 scanned the interference fringe intensity pattern in the Z direction, and the fluorescence observation camera 120 and the fluorescence analysis device 130 measured the intensity of the changing interference fringes, thereby calculating the displacement of atom A in the Z direction. The control device 110 calculated the position of the point (x ｓ , y ｓ ) the electric field A of the light output from ＳＬＭ (x ｓ , y ｓ) was calculated, and the spatial light modulator 11 was controlled to output the calculated electric field of light.

[0042] By controlling the control device 110, the standard deviation of the Z-direction positions of rubidium atoms arranged on a two-dimensional plane was reduced from 130 nm to 70 nm. As a result, the optical tweezers generation system 1 according to the second embodiment was able to reduce the deviation of the arranged atoms A in the Z direction.

[0043] Although the optical tweezers generation system 1 according to the second embodiment adjusts the curvature of the optical tweezers and the position of atom A in the Z direction, it is also possible to adjust only the position in the Z direction without adjusting the curvature of the optical tweezers. In this case, the optical tweezers generation system 1 according to the second embodiment does not need to include the measurement light source 14. In this case, the fluorescence observation camera 120 and the fluorescence analysis device 130 according to the second embodiment do not need to measure the vibration frequency of the atom. In this case, the control device 110 according to the second embodiment calculates the vibration frequency of the atom A at the point (x ｓ , y ｓ ) the electric field A of the light output from ＳＬＭ (x ｓ , y ｓ ) is calculated, and the point (x ｓ , y ｓ ) is calculated by dividing the phase of the electric field of the light output from the ＳＬＭ (x ｓ , y ｓ ) is controlled to be in phase with the

[0044] The control device 110 according to the second embodiment controls the spatial light modulator 11 at a point (x ｓ , y ｓ ) is calculated by the electric field A ＳＬＭ (x ｓ , y ｓ ) is controlled to be the same as the phase of the electric field A calculated by the formula (3) ＳＬＭ (x ｓ , y ｓ ) changes its phase, which adjusts the position of atom A in the Z direction.

[0045] As described above, the optical tweezers generation system 1 according to the second embodiment can reduce the Z-directional deviation between atoms and arrange the atoms in a plane by controlling the electric field of the light that generates the optical tweezers based on the Z-directional position of the atoms captured by the optical tweezers.

[0046] According to the first or second embodiment, the optical tweezers generation system 1 controls the phase of light output from the spatial light modulator 11 that generates the optical tweezers array, based on the physical quantity of atom A trapped by the optical tweezers array. The optical tweezers generation system 1 according to the first embodiment controls the phase of light output from the spatial light modulator 11 that generates the optical tweezers array, based on the vibration frequency as the physical quantity of atom A. The optical tweezers generation system 1 according to the second embodiment controls the phase of light output from the spatial light modulator 11 that generates the optical tweezers array, based on the position in the Z direction as the physical quantity of atom A.

[0047] According to the first or second embodiment, the optical tweezers generation system 1 can homogenize the curvature of the light intensity distribution of the optical tweezers or reduce the Z-directional deviation of atoms arranged on the XY plane, thereby arranging the arrangement of atoms captured by the optical tweezers.

[0048] Other Embodiments One embodiment of the present invention has been described in detail above with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes and the like can be made within the scope that does not deviate from the gist of the present invention.

[0049] Although the optical tweezers in this embodiment capture atoms, the object to be captured is not limited to atoms. For example, the object to be captured may be a microparticle such as a nanoparticle or a bacterium. The dichroic mirror 12 may be replaced with a device having equivalent functions. For example, the dichroic mirror 12 may be a beam splitter or a half mirror. In this embodiment, the vibration of atoms is measured using the fluorescence observation camera 120 and the fluorescence analysis device 130, but the vibration measurement method is not limited to this. For example, the vibration may be measured from the intensity distribution of the optical tweezers array photographed by a camera or from scattered light from the captured microparticle.

[0050] Part or all of the control device 110 in the above-described embodiment may be implemented by a computer. In this case, a program for implementing this function may be recorded on a computer-readable recording medium, and the program may be loaded and executed by a computer system. Note that the term "computer system" as used herein includes an operating system (OS) and peripheral hardware. Furthermore, "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording medium" may also include media that dynamically store programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or telephone lines, or media that store programs for a fixed period of time, such as volatile memory within the computer system serving as the server or client. The program may be designed to implement part of the aforementioned functions, or may be capable of implementing the aforementioned functions in combination with a program already stored in the computer system. Furthermore, part or all of the control device 110 may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0051] According to the present invention, it is possible to arrange the microparticles trapped by the optical tweezers.

[0052] 1 Optical tweezers generation system, 10 Light source, 11 Spatial light modulator, 110 Control device, 12 Dichroic mirror, 120 Fluorescence observation camera, 130 Fluorescence analysis device, 210 Interference laser, 220 Laser source, 230 PBS (polarizing beam splitter), M1-2 Mirror, P1-3 Wave plate, 13 Objective lens, 14 Measurement light source, A Atom

Claims

1. A laser control device that controls the phase of light output from a spatial light modulator that generates the optical tweezers array based on the vibration frequency of a microparticle trapped by the optical tweezers array.

2. A laser control device as described in claim 1, wherein the intensity and phase of light output from the spatial light modulator are calculated using an equation for calculating the intensity and phase of light, the equation including a curvature adjustment value corresponding to the vibration frequency, a magnitude of the curvature adjustment value being changed based on the magnitude of the vibration frequency, and an amplitude adjustment value being changed in accordance with the change in the curvature adjustment value in order to maintain a constant central intensity for each optical tweezers.

3. An optical tweezers generation system comprising: a laser light source; a focusing optical system that focuses laser light from the laser light source to form an optical tweezers array for trapping microparticles; a measuring device that measures the vibration frequency of the trapped microparticle based on fluorescence from the microparticle; and a control device that controls the phase of the laser light output from a spatial light modulator arranged in the focusing optical system based on the vibration frequency.

4. A laser control method, comprising controlling the phase of light output from a spatial light modulator that generates an optical tweezers array, based on the vibration frequency of a microparticle trapped by the optical tweezers array.

5. A method for generating optical tweezers, comprising the steps of: forming an optical tweezers array that captures a microparticle by concentrating laser light from a laser light source using a focusing optical system; measuring the vibration frequency of the microparticle captured by the optical tweezers array based on fluorescence from the microparticle; and controlling the phase of the laser light output from a spatial light modulator arranged in the focusing optical system based on the vibration frequency.

6. A program for causing a computer to execute the laser control method according to claim 4.

7. A laser control device that controls the phase of light output from a spatial light modulator that generates the optical tweezers array based on a physical quantity of a microparticle trapped by the optical tweezers array.

8. A laser control device as described in claim 1 or 7, which controls the phase of light output from a spatial light modulator that generates the optical tweezers array based on the position in the Z direction, which is perpendicular to the XY plane, of a microparticle trapped by the optical tweezers array and placed in the XY plane.

9. A laser control device as described in claim 8, wherein the intensity and phase of light output from the spatial light modulator are calculated using an equation for calculating the intensity and phase of light, the equation including the Z-direction position of the microparticle and an amplitude adjustment value that changes with changes in the Z-direction position in order to keep the Z-direction position of each microparticle constant.

10. An optical tweezers generation system comprising: a laser light source; a focusing optical system that focuses laser light from the laser light source to form an optical tweezers array for trapping a microparticle; a measuring device that measures a physical quantity of the trapped microparticle based on fluorescence from the microparticle; and a control device that controls the phase of the laser light output from a spatial light modulator arranged in the focusing optical system based on the physical quantity.

11. A laser control method, comprising controlling a phase of light output from a spatial light modulator that generates an optical tweezers array, based on a physical quantity of a microparticle trapped by the optical tweezers array.

12. A method for generating optical tweezers, comprising the steps of: forming an optical tweezers array that captures a microparticle by concentrating laser light from a laser light source using a focusing optical system; measuring a physical quantity of the microparticle captured by the optical tweezers array based on fluorescence from the microparticle; and controlling the phase of the laser light output from a spatial light modulator arranged in the focusing optical system based on the physical quantity.

13. A program for causing a computer to execute the laser control method according to claim 11.

Images