DEVICE AND METHOD FOR PRODUCING OPTICAL TWEEZERS

Description

[0001] The present invention relates to a device and a method for producing optical tweezers. State of the art

[0002] Devices for generating optical tweezers, which are used, for example, to capture atoms for quantum computers, are generally known from the prior art. For example, US 2020 / 0185120 A1 describes a method for rearranging atoms in arrays, where the atoms are in the Rydberg quantum state. Furthermore, due to the arrangement of the acousto-optical deflectors used, the sliding movements of the atoms are highly correlated, which severely limits individual dynamic position control within the array. This is particularly due to the fact that when two acousto-optical deflectors are connected in series at an angle, the row generated by the first acousto-optical deflector is copied multiple times by the second acousto-optical deflector to create a 2D array. Thus, sliding operations cannot be performed for individual rows.

[0003] EP 4 016 400 A1 discloses a quantum computing device and a corresponding method.

[0004] WO 2022 / 157 256 A1 describes an arrangement for laser material processing.

[0005] The object of the present invention is to further develop a device for producing optical tweezers, preferably for trapping atoms for a quantum computer, as well as a corresponding method in such a way that the positions and the amplitudes of the optical tweezers can be adjusted dynamically and with microsecond accuracy, while furthermore an optical tweezers array with the largest possible fill factor is realized. Description of the invention: task, solution, advantages

[0006] The aforementioned object is achieved by a device for generating optical tweezers, which comprises a laser beam source for generating a laser beam. The device further comprises at least one acousto-optical deflector for generating an array of partial beams of the laser beam and a staircase mirror unit comprising at least one first staircase mirror for reducing a spacing of the partial beams of the array in at least one first direction. The laser beam source is, in particular, a high-power laser. A high-power laser, in particular, has a CW power of 10 to 100 watts. Above all, the device serves to trap atoms for a quantum computer using the optical tweezers, which form optical traps.

[0007] With the aid of the at least one acousto-optical deflector, an array of partial beams of the laser beam is generated, wherein the array comprises rows. An array is therefore preferably understood to be an arrangement in two dimensions. The partial beams are preferably aligned parallel to one another. Above all, the array is a 2D array. Adjacent rows can preferably have a constant row spacing. The partial beams form optical traps, particularly at the location of the atoms to be captured. For this purpose, the partial beams are primarily focused.

[0008] The rows of the array are preferably spaced apart in a first direction, while rows extend in a second direction. The first and second directions are preferably not fixed in position, but defined in relation to the array. They are relative directions. Thus, after a reflection from the array, the directions can change in absolute terms. The partial beams propagate in a third direction which is perpendicular to the first and second directions. The spacing of the partial beams in the first direction is therefore preferably understood to mean the row spacing. The partial beams can form columns in the second direction. Alternatively, the partial beams can be unevenly distributed within different rows so that no columns are formed. If columns are formed, the spacing of the partial beams in the second direction represents the column spacing. The distance between adjacent partial beams within a row orThe column spacing may differ from the row spacing. Furthermore, they may be of equal size. In particular, a row and / or a column of the array comprises more than 10, preferably more than 15, and most preferably more than 18, sub-beams.

[0009] The device comprises a staircase mirror unit comprising at least one first staircase mirror. The staircase mirror unit serves to reduce the row spacing of the partial beams of the array.

[0010] A stair mirror comprises a plurality of mirrors arranged offset from one another in two directions. Preferably, a stair mirror comprises more than 5, preferably more than 7, and most preferably more than 9 mirrors. According to the invention, all mirrors of a stair mirror are aligned parallel. Advantageously, all mirrors are arranged at an angle of 45° to the incoming light and thus also 45° to the outgoing light.

[0011] A stair mirror includes a stair distance between adjacent mirrors and a stair height. The stair height can also be understood as mirror height.

[0012] In particular, adjacent mirrors are offset from one another by a stairstep distance in the first direction and by a stairstep height in a direction perpendicular thereto. Adjacent mirrors are preferably offset by the stairstep distance in the first direction. The offset by a stairstep height occurs, in particular, in the propagation direction of the partial beams. The directions specified with respect to optical units, such as stairstep mirrors, refer to the incoming array, i.e., the array before a reflection.

[0013] The offset of the mirrors creates staircases, which gives the stair mirror its name. The mirrors have a minimum width perpendicular to the stair height and the stair spacing, which corresponds to the width of the array in the second direction at the location of the stair mirror.

[0014] The mirrors can be arranged separately. In other words, they can be individually adjustable. Furthermore, the mirrors can be formed as surfaces of a common component. Thus, only one adjustment of the common component is necessary.

[0015] By using the stair-step mirror unit, the array's row spacing can be significantly reduced, resulting in a particularly high fill factor. The fill factor is defined as the ratio of the 1 / e 2< diameter number of sub-beams, and thus the number of tweezers, per unit area. In other words, atoms trapped by the tweezers are more densely packed at a higher fill factor.

[0016] The stair mirror unit can be designed in multiple stages, especially two-stage or three-stage. Thus, the stair mirror unit can comprise several stair mirrors that are arranged in a cascade. Outgoing partial beams of a first-stage stair mirror, e.g., a first stair mirror, impinge on a stair mirror of the next stage, e.g., a second stair mirror. More preferably, outgoing partial beams of the second-stage stair mirror, e.g., a second stair mirror, impinge on a stair mirror of the next stage, e.g., a third stair mirror. The stair mirrors of different stages thus form a cascade. Each stair mirror is arranged such that adjacent mirrors are offset from one another in the first direction by a stair pitch.

[0017] The height of each stair riser is preferably smaller than its pitch. The ratio of stair height to pitch can be between 0.2 and 0.4. The pitch of a stair riser can preferably correspond to the height of the preceding stair riser, i.e., the pitch of the preceding step. In particular, the stair height and pitch are constant for each stair riser.

[0018] According to the invention, the stair-mirror unit comprises a second stair-mirror with mirrors, a stair-distance between adjacent mirrors and a stair-distance height, wherein the stair-distance of the second stair-mirror corresponds to the stair-height of the first stair-mirror. The partial beams of the array thus strike the first stair-mirror and subsequently the second stair-mirror. The distance between the partial beams in the first direction, i.e. the row spacing, is reduced. Specifically, the row spacing between adjacent partial beams after reflection at the first stair-mirror corresponds to the stair-height of the first stair-mirror. The stair-distance of the second stair-mirror corresponds to the stair-height of the first stair-mirror, so that the partial beams can fall on the corresponding mirrors of the second stair-mirror.After passing through the second stair mirror, the adjacent partial beams have a row spacing that corresponds to the stair height of the second stair mirror.

[0019] The device may further comprise a third stair mirror, wherein the third stair mirror also has mirrors, a stair spacing between adjacent mirrors, and a stair height. The stair spacing of the third stair mirror preferably corresponds to the stair height of the second stair mirror.

[0020] Overall, the row spacing is reduced using the stair-step unit, while the spacing within the rows remains unchanged. After passing through a multi-stage stair-step unit, the row spacing of adjacent partial beams is preferably reduced further and further at each stage.

[0021] The stair height of the mirrors of the first stair mirror preferably runs in the same absolute direction as the stair height of the third stair mirror. The stair spacing of the mirrors of the stair mirrors of the first stair mirror preferably runs in the same absolute direction as the stair spacing of the third stair mirror. The stair height of the second stair mirror preferably runs in the same direction as the stair spacing of the first and third stair mirrors, while the stair spacing of the second stair mirror can run in the same direction as the stair height of the first and third stair mirrors.

[0022] The stair heights of different stair levels of the same step preferably run in the same absolute direction. The stair spacing of different stair levels of the same step preferably runs in the same absolute direction.

[0023] The stair-mirror unit can preferably have several, preferably two, stair-mirrors per step. In such a case, one stair-mirror per step forms a cascade of stair-mirrors. If the stair-mirror unit has, for example, two first, two second, and two third stair-mirrors, these form two cascades of stair-mirrors. One part, for example half, of the partial beams can pass through a first such cascade, and the other part, for example half, of the partial beams can pass through a second cascade. Thus, for example, half of the formed partial beams can be coupled into each of the two sides of the stair-mirror unit.

[0024] The stair mirror unit can consist of one or more, for example, three, components. Each component can be monolithic. Each component can be wedge-shaped, with at least one stair mirror arranged on a side surface. The mirrors of a stair mirror are preferably formed as surfaces of a component and therefore do not need to be individually adjusted.

[0025] The stair mirror unit can, for example, have a wedge-shaped first component that can include a first and a third stair mirror. Most preferably, the first component comprises both a first and a third stair mirror on a first side surface. Furthermore, the component can also have a first and a third stair mirror on a second side surface. The at least one third stair mirror can be arranged in the tapered end region of the wedge-shaped first component.

[0026] Furthermore, the stair mirror unit can comprise a second component, which preferably comprises a second stair mirror on a first side surface. The first side surface of the second component primarily faces the first side surface of the first component.

[0027] In addition, the stair mirror unit can have a third component, which also preferably comprises a second stair mirror on a first side surface. The first side surface of the third component primarily faces the second side surface of the first component. The stair mirror unit is particularly mirror-symmetrical, preferably around a center line of the first component.

[0028] Furthermore, the second component and / or the third component are aligned with the first component such that partial rays, after reflection at the first stair mirror, impinge on the second stair mirror and, after reflection at the second stair mirror, impinge on the third stair mirror. The mirrors of the first stair mirror, the second stair mirror, and the third stair mirror are preferably aligned parallel to one another.

[0029] The device may further comprise a coupling unit for coupling the partial beams behind the at least one acousto-optical deflector into the stair-mirror unit. The coupling unit serves for the precise adjustment of the partial beams toward the stair-mirror unit.

[0030] The coupling unit can be designed as a stair-step mirror with mirrors, a stair-step spacing between adjacent mirrors, and a stair-step height. Adjacent mirrors are again arranged in the first direction of the array. The stair-step height of the coupling unit preferably corresponds to the stair-step spacing of the first stair-step mirror. Thus, an initial reduction in the distance between adjacent partial beams in the first direction already takes place at the coupling unit. The stair-step height of the coupling unit is also designed to be smaller than the stair-step spacing of the coupling unit. The mirrors of the coupling unit are preferably designed as separate mirrors that are individually adjustable. This allows, in particular, precise adjustment of the individual partial beams to one another or to the subsequent stair-step mirrors.

[0031] The coupling unit can be configured as an upstream stage of the stair mirror unit. Overall, a four-stage cascade of stair mirrors can thus be present. The coupling unit can be integrated into the stair mirror unit. For example, the coupling unit can be arranged on a component of the stair mirror unit and thus be formed monolithically with at least one stair mirror of the stair mirror unit.

[0032] The step spacing of the coupling unit can be between 10 mm and 40 mm, preferably between 20 mm and 30 mm, most preferably between 23 mm and 27 mm, or 25 mm. The step height is preferably between 6 mm and 10 mm, preferably between 7 mm and 9 mm, or 8 mm.

[0033] The device preferably comprises at least one Fourier lens. With the aid of the Fourier lenses, the discrete diffraction angles of the at least one acousto-optical deflector can be converted into preferably equidistant foci in an intermediate image plane. This can result in a telecentric arrangement on the image side. The object-side focal plane of the Fourier lenses can lie in the plane of the acousto-optical deflectors. The foci then lie in the image-side focal plane of the Fourier lenses, and the propagation directions of the partial beams are parallel to one another. In particular, the device comprises one Fourier lens per row of the array and / or per acousto-optical deflector. The Fourier lenses are arranged between the at least one acousto-optical deflector and the staircase mirror unit.

[0034] To adjust the partial beams, tiltable wedge plates, such as Risley prisms, and / or plane-parallel plates can be provided. Alternatively, laterally displaceable lenses, especially those with long focal lengths, can be provided. The focal length ratio of these lenses to the Fourier lenses determines the transmission ratio of the resulting displacement of the partial beams. The ratio of the focal length of the lenses to that of the Fourier lenses is preferably greater than 5, most preferably greater than 10.

[0035] Preferably, the stair pitch of the first stair riser corresponds to between 4 mm and 12 mm, preferably between 6 mm and 10 mm or between 7 mm and 9 mm. Furthermore, the stair pitch can be between 7.5 mm and 8.5 mm, most preferably 8 mm. The stair height of the first stair riser is in particular between 0.5 mm and 3.5 mm, preferably between 1 mm and 3 mm, further preferably between 1.5 mm and 2.5 mm, most preferably 2 mm.

[0036] The stair pitch of the second stair profile is in particular between 0.5 mm and 3.5 mm, preferably between 1 mm and 3 mm, further preferably between 1.5 mm and 2.5 mm, most preferably 2 mm. The stair height of the second stair profile is preferably between 0.25 mm and 0.75 mm, preferably between 0.4 mm and 0.6 mm, most preferably between 0.45 mm and 0.55 mm. Furthermore, the stair height can be 0.5 mm.

[0037] The stair pitch of the third stair profile is preferably between 0.25 mm and 0.75 mm, further preferably between 0.4 mm and 0.6 mm, most preferably between 0.45 mm and 0.55 mm. Furthermore, the stair pitch can be 0.5 mm. The stair height of the third stair profile is preferably between 0.1 mm and 0.3 mm, preferably between 0.15 mm and 0.2 mm, most preferably between 0.16 mm and 0.19 mm. Furthermore, the stair height can be 0.1875 mm.

[0038] The device preferably comprises a beam splitter unit for splitting the laser beam in the first direction, preferably into a column of partial beams. In other words, the laser beam is split into several partial beams in the first direction. This means that the beam splitter unit has, in particular, one input and several outputs in the first direction. The beam splitter unit can comprise several beam splitters. Furthermore, the beam splitter unit can be designed as an acousto-optical deflector.

[0039] The device can comprise a separate acousto-optical deflector for each row of the array to be formed. In particular, the device comprises a separate acousto-optical deflector for each partial beam leaving the beam splitter unit, for splitting the respective partial beam in a second direction and thus generating multiple rows and thus the array of partial beams. The spacing of the acousto-optical deflectors preferably corresponds to the spacing of the partial beams downstream of the beam splitter unit. Each acousto-optical deflector is designed, in particular, as a single-axis acousto-optical deflector with a single input and a plurality of outputs. The spacing of the outputs corresponds to the spacing of the partial beams in the second direction downstream of the Fourier lenses.

[0040] While the beam splitter unit generates a plurality of partial beams in the first direction, the acousto-optical deflectors each generate a row, creating an array. In particular, the staircase spacing of the coupling unit corresponds to the spacing of the acousto-optical deflectors.

[0041] Due to the structurally determined spacing of the acousto-optical deflectors, the row spacing is significantly greater than the spacing within a row. This significantly limits the fill factor. Although the spacing of the partial beams in the first direction initially corresponds to the spacing of the acousto-optical deflectors, this is reduced in the first direction by the stair-mirror unit and preferably the coupling unit. In particular, the row spacing of the partial beams of the array after the stair-mirror unit corresponds to the spacing of partial beams within the rows. In other words, the row spacing of the partial beams is adjusted to the spacing of adjacent partial beams within a row by means of the stair-mirror unit and, if applicable, the coupling unit. The stair-mirror unit, if applicable together with the coupling unit, is designed to reduce the row spacing by preferably approximately two orders of magnitude.While the row spacing after the acousto-optical deflectors is approximately a few centimeters, after passing through the staircase mirror unit it is approximately 200 micrometers.

[0042] Furthermore, the device can preferably comprise relay optics, which preferably has a microscope objective. The microscope objective can have a focal length between 5 mm and 50 mm, preferably between 30 mm and 35 mm, preferably 33 mm. Furthermore, the microscope objective can have a numerical aperture between 0.1 and 1.0, preferably between 0.4 and 0.6.

[0043] The relay optics are used to reduce the row spacing and the spacing between adjacent partial beams within a row. With the help of the relay optics, the dimensions of the entire array are reduced after passing through the stair-step mirror unit. Thus, the spacing in the first direction and the spacing in the second direction are reduced equally. The fill factor therefore remains unchanged.

[0044] In particular, the relay optics is designed in two stages, whereby both stages can have the same imaging ratio. Furthermore, the relay optics can have more than two stages. The relay optics preferably comprises two collimators arranged in front of the microscope objective and at least one lens arranged between the collimators, in particular a focus lens, in whose focal plane a further, preferably telecentric, second intermediate image can be formed. Furthermore, a focusing group of lenses can be arranged between the collimators. The first and / or the second collimator can have a focal length preferably between 200 mm and 300 mm.

[0045] The two-stage design reduces the size of the relay optics and thus the size of the entire device. In particular, the focusing group is located centrally between the collimators. Furthermore, the relay optics can be telecentric on both sides. The relay optics can consist of the two collimators, the focusing group, and the microscope objective. A group preferably includes more than two lenses.

[0046] The relay optics are primarily designed to image the array downstream of the staircase mirror unit reduced by a factor of at least 20, preferably at least 30, most preferably at least 50. After passing through the relay optics, the array comprises a row spacing and / or spacing of adjacent partial beams within a row of between 1 µm and 5 µm, preferably between 2 µm and 4 µm, most preferably approximately 3 µm.

[0047] After the relay optics, the partial beams form optical tweezers. Optical tweezers are designed to fix a single atom in its position. In particular, the device is used to fix atoms for a quantum computer. The atoms are, in particular, Rydberg atoms. This means that the atoms are excited. In detail, at least one electron in the electron shell is in a high state, namely a so-called Rydberg state. An atom can be fixed at the beam waist, i.e., the narrowest point, of a partial beam after the relay optics.

[0048] Furthermore, the device can comprise a unit for coupling in radiation for exciting atoms captured by the optical tweezers and / or for coupling out radiation originating from atoms captured by the optical tweezers. The unit is designed for coupling in and / or out in a pupil plane of the relay optics. The relay optics can have two pupil planes, namely a first and a second pupil plane. Coupling in and out in a pupil plane is particularly preferred, since this is where the beam waists of the partial beams lie and these are superimposed, so that the total diameter of all partial beams is minimal. Thus, no astigmatism is created by the tilted mirrors. The two pupil planes lie primarily between the first and second collimators, with one pupil plane preferably lying in the focal plane of the second collimator of the relay optics.

[0049] The device can be configured to shift the position of individual atoms. In particular, the shifting of atoms can occur during gate operations of a deep quantum computer algorithm. The movement of the atoms allows the connectivity—typically nearest-neighbor connectivity in Rydberg systems—to be dynamically changed. For example, shifting can create direct entanglement between atoms that were originally or later in the algorithm far apart. This enables the realization of a qubit register with dynamic connectivity beyond nearest neighbors.

[0050] The use of acousto-optical deflectors is particularly advantageous because they have the shortest possible response time and are thus designed to shift the partial beams and thus the positions of the optical tweezers in a matter of microseconds. This shift is achieved by changing a high-frequency signal used to control the respective acousto-optical deflector. This shifts the position of the optical tweezers, preferably proportional to the frequency shift. A change in the high frequency is thus directly translated into a change in the position of the optical tweezers.

[0051] Because each row can be assigned its own acousto-optical deflector, and precisely one deflector, the positions of trapped atoms within each row can be changed independently of each other. The spacing within each row can be changed, particularly on the microsecond scale. Sliding operations of trapped atoms are thus minimally correlated. The position shift can be performed as quickly and as parallel as possible, which is particularly advantageous since such a rearrangement in a quantum computer involves a large number of optical tweezers. The device thus serves as a central building block for a quantum computer.

[0052] Furthermore, the device is designed to change the amplitudes of the individual tweezers in one row independently of those in other rows, since each row of the array is assigned its own acousto-optical deflector. This is achieved by adjusting the amplitude of the high-frequency signal. Overall, the positions and amplitudes of the optical tweezers can thus be adjusted dynamically and with microsecond precision.

[0053] Furthermore, the invention may relate to a quantum computer comprising a device as described above.

[0054] In a further aspect, the present invention relates to a method for producing optical tweezers, preferably for trapping atoms for a quantum computer, wherein the method comprises generating a laser beam by means of a laser beam source.

[0055] The method further comprises generating an array of partial beams by means of at least one acousto-optical deflector and reducing a row spacing of the partial beams of the array by means of a stair-mirror unit, comprising at least a first stair-mirror, wherein the first stair-mirror comprises mirrors, a distance between adjacent mirrors, and a stair height. According to the invention, the stair-mirror unit comprises a second stair-mirror, which comprises mirrors, a stair spacing between adjacent mirrors, and a stair height, wherein the stair spacing of the second stair-mirror corresponds to the stair height of the first stair-mirror. All mirrors of the first and second stair-mirror each have a parallel alignment.

[0056] In particular, the method comprises splitting the laser beam into partial beams in the first direction by means of a beam splitter unit and splitting each partial beam into a row and thus generating the array of partial beams by means of a respective acousto-optical deflector.

[0057] The method may further comprise coupling the partial beams of the array into the stair-mirror unit, preferably by means of a coupling unit. Furthermore, the method may comprise passing through the stair-mirror unit, namely reflection at the first stair-mirror and preferably at the second stair-mirror and further preferably at the third stair-mirror. The spacing of the partial beams in the first direction is reduced both at the coupling unit and at each stair-mirror of the stair-mirror unit. Furthermore, the method may comprise a further reduction in the spacing of the partial beams both in the first direction and in the second direction, preferably by means of relay optics, which may have a microscope objective.

[0058] In particular, the method is to be carried out by means of the above-mentioned device and the device is designed to carry out the method. Short description of the characters

[0059] They show in a purely schematic representation: Figure 1: a device for generating optical tweezers; Figure 2: an array of partial beams, Figure 3: a detailed view of the device of the Figure 1 , and Figure 4: and an enlarged view of the stair mirror unit of the Figure 3 ; Figure 5: a process diagram of a method for producing optical tweezers. Preferred embodiments

[0060] Figure 1shows a schematic representation of a device 10 for producing optical tweezers. The device 10 comprises a laser beam source 11, which couples out a laser beam 12. Furthermore, the device 10 comprises several acousto-optical deflectors 13, a beam splitter unit 13a, which splits the laser beam 12 into a plurality of partial beams 14, namely a column 15a in this example, and a plurality of acousto-optical deflectors 13b for splitting the partial beams 14 into rows 15c. The rows 15c extend into the image plane, so that the individual partial beams in Figure 1 are not visible. This creates an array 15 of partial beams 14.

[0061] Fourier lenses 33 are also shown purely schematically. Each row of the array 15 is assigned its own Fourier lens 33. Furthermore, a coupling unit 29 is shown, after which the partial beams 14 of the array 15 pass through the staircase mirror unit 16. This is followed by a relay optics 40, after which the partial beams 14 form optical tweezers.

[0062] In Figure 2 The array 15 of partial beams 14 is shown in the first direction 50 and the second direction 51. The third direction 52, in which the partial beams propagate, extends into the image plane. The partial beams 14 are in the example of the Figure 2 arranged in columns 15a with a distance 15b between partial beams in a row and rows 15c with a row spacing 15d.

[0063] Section 2A shows how the row spacing 15d is significantly larger than the spacing 15b of partial beams in a row. This is primarily due to the size of the acousto-optical deflectors 13b. As shown in Section 2A, the array 15 is located after the Fourier lenses, primarily in the focal plane of the Fourier lenses, if no stair-step mirror unit is used.

[0064] In section 2B, the array 15 is shown after passing through the stair-step mirror unit 16. More precisely, the array is positioned in the focal plane of the Fourier lenses when using the stair-step mirror unit 16. The row spacing 15d is significantly reduced. It now corresponds to the spacing 15b between adjacent partial beams in a row.

[0065] In Section 2C of the Figure 2 the distance 15d of the partial beams in a row and the row distance 15d after passing through the relay optics 40 are reduced again, preferably by a factor of 50 compared to section 2B.

[0066] In Figure 3 is a more detailed view of the device 10 of the Figure 1 While the beam splitter unit is not visible, the acousto-optical deflectors 13b and the Fourier lenses 33 are visible. Each row of the array 15 is assigned a Fourier lens 33. At the location of the Fourier lenses 33, the first direction 50 of the array runs in Figure 3 horizontally, while the second direction 51 is vertical. Figure 3 The beams shown after the acousto-optical deflectors 13 are columns 15a of the array 15. This shows the row spacing 15d. The spacing 15b of partial beams in a row is so much smaller in comparison that it Figure 3 cannot be recognized.

[0067] In Figure 3only the ten lowest rows 15c of the array 15 are shown, which are coupled to one side of the staircase mirror unit 16. Further rows 15c of the array 15 are coupled to the other side of the staircase mirror unit 16, which will be described in more detail below.

[0068] The partial beams 14 pass through the Fourier lenses 33 and then impinge on the coupling unit 29, which consists of several mirrors 30. The coupling unit 29 is characterized by a fixed stair pitch 29a and a fixed stair height 29b. The mirrors 30 are thus each offset by a stair height 29b and a stair pitch 29a.

[0069] The staircase mirror unit 16 is shown in greater detail in the upper right section of the Figure 3As can be seen, the stair mirror unit 16 consists of three components: a first component 17, a second component 18, and a third component 19, which are wedge-shaped. The end regions, where these taper to a point, face each other. The first component 17 is mirror-symmetrical.

[0070] The first component 17 has a first side surface 17a and a second side surface 17b. On each of the two aforementioned side surfaces, a first stair mirror 25 is arranged with mirrors 30 and a stair spacing 25a between adjacent mirrors 30 and a stair height 25b (see upper section of the Figure 3 and Figure 4 ).

[0071] The second component 18 has a first side surface 18a, which is opposite the first side surface 17a of the first component 17. Furthermore, the third component 19 has a first side surface 19a, which is opposite the second side surface 17b of the first component 17. The first side surface 18a of the second component 18 and the first side surface 19a of the third component 19 each have a second stair mirror 26 with a stair spacing 26a and a stair height 26b between mirrors 30 (see also the lower section of the Figure 3 and Figure 4 ).

[0072] A further, even more detailed representation is shown in the lower detailed representation of the Figure 3The mirrors 30 of the second stair mirrors 26 on the second component 18 and the third component 19 can be seen more clearly. Furthermore, it can be seen how the first component 17 has a first end region 17c. In the first end region 17c of the first component 17, a third stair mirror 27 is arranged on each of the two side surfaces of the first component 17, with a stair spacing 27a and a stair height 27b.

[0073] The stair-mirror unit 16 is followed by the relay optics 40, which consists of two collimators 40a and a focusing lens group 40b arranged between them. The relay optics 40 further includes a microscope objective 40c. An output mirror 41 is arranged between the second collimator 40a and the microscope objective 40c. The output mirror 41 lies in a pupil plane 42, which is optimally suited for coupling in radiation to excite trapped atoms or for coupling out radiation from trapped atoms. A second intermediate image plane 43 can be arranged downstream of the lens group 40b.

[0074] The row spacing 15d of the partial beams was initially reduced by means of the staircase mirror unit 16 and the coupling unit 29. A further reduction of both the row spacing 15d and the spacing 15b of partial beams in a row then takes place via the relay optics 40, among other things, through the microscope objective 40c.

[0075] In Figure 4 is an enlarged view of the stair mirror unit 16 from Figure 3 The first component 17 is clearly visible, with first stair mirrors 25 arranged on both sides on the respective side surfaces 17a, 17b. Furthermore, three mirrors 30 of the coupling unit 29 are visible. Their stair spacing 29a and their stair height 29b are clearly visible.

[0076] Due to the offset arrangement of the mirrors 30 of the coupling unit 29, these represent a stair mirror. Furthermore, the second component 18 and the third component 19 of the stair mirror unit 16 can be seen, which have a second stair mirror 26 on the respective first side surfaces 18a, 19a. In the enlarged illustration on the right side of the Figure 4In particular, the first end region 17c of the first component 17 is clearly visible. A third stair mirror 27 with the stair spacing 27a and the stair height 27b is arranged on the side surfaces 17a and 17b.

[0077] Figure 5 shows a process diagram of a method 100 for producing optical tweezers, which comprises producing 103 an array 15 of partial beams 14 and reducing 106 a row spacing 15d of the array, in other words the spacing of the partial beams of the array 15 in at least a first direction 50.

[0078] First, the method 100 may comprise splitting 101 the laser beam 12 of a laser beam source 11 into partial beams 14 in the first direction and subsequently splitting 102 the thus generated partial beams in a second direction 51 and thus into rows 15c. In this way, the array 15 is generated 103.

[0079] Subsequently, the partial beams 14 of the array 15 can be coupled 104 into the stair-mirror unit 16 and pass through 105 the stair-mirror unit 16. In this way, the row spacing 15d of the partial beams 14 is reduced 106. A further reduction 108 of the spacing of the partial beams 14 of the array 15 in both directions is achieved in particular by passing through 107 a relay optics 40. Reference symbol

[0080] 10Device 11Laser beam source 12Laser beam 13Acousto-optic deflector 13aBeam splitter unit 13Acousto-optic deflector 14Partial beams 15Array 15aColumn 15bSpacing within a row 15cRow 15dRow spacing 16Staircase mirror unit 17First component 17aFirst side surface of the first component 17bSecond side surface of the first component 17cFirst end region of the first component 18Second component 18aFirst side surface of the second component 19Third component 19aFirst side surface of the third component 25First stair 25aStair spacing of the first stair 25bStair height of the first stair 26Second stair 26aStair spacing of the second stair 26bStair height of the second stair 27Third stair 27aStair spacing of the third stair 27bStair height of the third stair 29 Coupling unit 29a Staircase distance of the coupling unit 29b Staircase height of the coupling unit 30 mirrors 33Fourier lenses 40 Relay optics 40a Collimator 40b Focusing lens group 40c Microscope objective 41 Output mirror 42 Pupil plane 43 Second intermediate image plane 50first direction 51second direction 52third direction 100Method for producing optical tweezers 101Dividing the laser beam into partial beams in a column 102Dividing the partial beams into rows 103Creating an array of partial beams 104Coupling the partial beams of the array into the staircase mirror unit 105Passing through the staircase mirror unit 106Reducing a row spacing of the partial beams of the array 107Passing through the relay optics 108Reducing the row spacing and spacing of the partial beams in a row

Claims

1. Device (10) for the production of optical tweezers, comprising a laser beam source (11) for generating a laser beam (12), and at least one acousto-optical deflector (13) for generating an array (15) of partial beams (14) of the laser beam (12), wherein the array (15) comprises rows (15c), wherein the device (10) has a staircase mirror unit (16) comprising at least one first staircase mirror (25) for reducing a row spacing (15d) of the partial beams (14) of the array (15), wherein the first staircase mirror (25) comprises mirrors (30), a staircase spacing (25a) between adjacent mirrors (30) and a staircase height (25b), wherein the staircase mirror unit (10) comprises a second staircase mirror (26), wherein the second staircase mirror (26) comprises mirrors (30), a staircase spacing (26a) between adjacent mirrors (30) and a staircase height (26b), characterized in that the staircase spacing (26a) of the second staircase mirror (26) corresponds to the staircase height (25b) of the first staircase mirror (25), wherein all mirrors of the first staircase mirror have a parallel alignment and wherein all mirrors of the second staircase mirror have a parallel alignment.

2. Device (10) according to claim 1, characterized in that the staircase mirror unit (16) is formed with several steps, preferably with two or three steps.

3. Device (10) according to claim 1 or 2, characterized in that the staircase mirror unit (16) comprises a third staircase mirror (27), wherein the third staircase mirror (27) comprises mirrors (30), a staircase spacing (27a) between adjacent mirrors (30) and a staircase height (27b), wherein the staircase spacing (27a) of the third staircase mirror corresponds to the staircase height (26b) of the second staircase mirror (26).

4. Device (10) according to one of the preceding claims, characterized in that the device (10) comprises a coupling unit (29) for coupling the partial beams into the staircase mirror unit (16), wherein the coupling unit (29) comprises mirrors (30), a staircase spacing (29a) between adjacent mirrors (30) and a staircase height (29b), wherein the staircase height (29b) of the coupling unit (29) corresponds to the staircase spacing (25a) of the first staircase mirror (25).

5. Device (10) according to one of the preceding claims, characterized in that the staircase height (25b) of the first staircase mirror (25) is smaller than the staircase spacing (25a) of the first staircase mirror (25) and / or the staircase height (26b) of the second staircase mirror (26) is smaller than the staircase spacing (26a) of the second staircase mirror (26) and / or the staircase height (27a) of the third staircase mirror (27) is smaller than the staircase spacing (27b) of the third staircase mirror (27), and / or the staircase height (29b) of the coupling unit (29) is smaller than the staircase spacing (29a) of the coupling unit (29).

6. Device (10) according to one of the preceding claims, characterized in that the staircase spacing (25a) of the first staircase mirror (25) is between 4 mm and 12 mm, preferably between 6 mm and 10 mm, most preferably between 7 mm and 9 mm, and / or the staircase height (25b) of the first staircase mirror (25) is between 0.5 mm and 3.5 mm, preferably between 1 mm and 3 mm.

7. Device (10) according to one of the preceding claims, characterized in that the staircase spacing (26a) of the second staircase mirror (26) is between 0.5 mm and 3.5 mm, preferably between 1 mm and 3 mm, and / or the staircase height (26b) of the second staircase mirror (26) is between 0.25 mm and 0.75 mm, preferably between 0.4 mm and 0.6 mm.

8. Device (10) according to one of claims 3 to 7, characterized in that the staircase spacing (27a) of the third staircase mirror (27) is between 0.25 mm and 0.75 mm, preferably between 0.4 mm and 0.6 mm, and / or the staircase height (27b) of the third staircase mirror (27) is between 0.10 mm and 0.30 mm, preferably between 0.150 mm and 0.20 mm.

9. Device (10) according to one of the preceding claims, characterized in that the device (10) comprises a beam splitter unit (13a) for splitting the laser beam (12) into partial beams (14) in a first direction (50), wherein the device (10) comprises one acousto-optic deflector (13b) per partial beam (14) for dividing the partial beams (14) into rows (15c) and thus for generating the array (15) of partial beams (14).

10. Device (10) according to one of the preceding claims, characterized in that the device (10) comprises a relay optics (40) comprising a microscope objective (40c) for reducing the row spacing (15d) and the spacing of partial beams (14) within a row, wherein the partial beams (14) after the relay optics (40) form optical tweezers for capturing atoms.

11. Device (10) according to one of the claims, characterized in that the device (10) has a unit for coupling radiation for exciting atoms captured by means of the optical tweezers and / or for decoupling radiation originating from atoms captured by means of the optical tweezers, wherein the unit is configured for coupling and / or decoupling in a pupil plane (42) of the relay optics (40).

12. Method (100) for producing optical tweezers, wherein the method (100) comprises generating (103) an array (15) of partial beams (14) by means of at least one acousto-optic deflector (13), wherein the array (15) comprises rows (15c), wherein the method (100) comprises a reduction (1069) of a row spacing (15d) of the partial beams (14) of the array (15) by means of a staircase mirror unit (16) having at least a first staircase mirror (25), wherein the first staircase mirror (25) comprises mirrors (30), a staircase spacing (25a) between adjacent mirrors (30) and a staircase height (25b), wherein the staircase mirror unit (10) comprises a second staircase mirror (26), wherein the second staircase mirror (26) comprises mirrors (30), a staircase spacing (26a) between adjacent mirrors (30) and a staircase height (26b), characterized in that the staircase distance (26a) of the second staircase mirror (26) corresponds to the staircase height (25b) of the first staircase mirror (25), and wherein all mirrors of the first staircase mirror have a parallel alignment and wherein all mirrors of the second staircase mirror have a parallel alignment.