Light reflector element and atomic device

Abstract

Light reflector element having several reflector surfaces oriented at different predefined angles with respect to a predefined direction of light incidence of the light reflector element, wherein the reflector surfaces are centered around a center of the light reflector element, e.g.The reflector element is arranged in a ring shape, wherein each pair of mutually associated reflector surfaces is arranged diametrically opposite each other with respect to the center of the light reflector element, such that light incident in the direction of the light irradiation is deflected by the reflector surfaces into light rays that run towards each other in different spatial directions and meet in a central axis that runs through the center in the direction of the light irradiation, characterized in that the light reflector element has one or more pairs of mutually associated reflector surfaces, in which one reflector surface of the pair is oriented with respect to the predefined direction of the light irradiation of the light reflector element at an angle in the range of 46° to 89° and the other reflector surface of the same pair is oriented with respect to the predefined direction of the light irradiation of the light reflector element at an angle in the range of 1° to 44°.

Description

[0001] The invention relates to a light reflector element having several reflector surfaces oriented at different predefined angles with respect to a predefined direction of light incidence of the light reflector element, wherein the reflector surfaces are arranged, for example, in a ring around a center of the light reflector element, with each pair of associated reflector surfaces being arranged diametrically opposite each other with respect to the center of the light reflector element, such that light incident in the direction of light incidence is deflected by the reflector surfaces into light rays that converge in different spatial directions and meet at a central axis that passes through the center in the direction of light incidence. The central axis is thus aligned parallel to the direction of light incidence.The light rays deflected by the reflector surfaces from several or all reflector surfaces can meet at the same point on the central axis, which then forms an interaction zone for cooling trapped atoms.

[0002] The invention further relates to an atomic device, e.g., an atom interferometer or a quantum gradiometer, with at least one such light reflector element. In general, the invention relates to the field of any atomic devices with an atom trap and atoms laser-cooled in the atom trap, in particular with a magneto-optical trap (MOT). In particular, the invention relates to atom interferometric gravimeters and gradiometers formed therefrom.

[0003] Atom interferometric gravimeters offer long-term stable, absolute gravity measurements. Compared to the widely used laser gravimeters (FG5X), their measurement principle allows for quasi-continuous data acquisition over extended periods and offers the prospect of higher accuracy. Portable and commercial instruments based on atom interferometric measurements have already been developed and operated on mobile platforms such as ships. A key component of an atom interferometric gravimeter is the source of cold atoms. These are typically based on laser cooling in magneto-optical traps and polarization gradient cooling. A three-dimensional magneto-optical trap requires not only magnetic fields but also light fields, which are typically directed antiparallel or nearly antiparallel along the three spatial axes to create an interaction zone for cooling the trapped atoms.This implies a comparatively complex setup with multiple beam-shaping optics and corresponding optical access points to the vacuum system in which the atoms are trapped and cooled. Specially designed pyramidal or lattice structures have been successfully used to create a beam geometry from a single incident laser beam that can effectively cool along all three spatial axes.

[0004] Another important application of atom interferometers is their use in gradiometers, where two spatially separated gravimeters are operated simultaneously. The first derivative of gravity, the gravitational gradient, can be derived from the difference signal. This results in common-noise rejection for the difference signal, meaning the gradiometer signal is only degraded by technical noise sources that affect the two gravimeters differently. It is particularly important that the two gravimeters are operated as symmetrically as possible to maximize the benefits of this noise rejection.

[0005] The state of the art in gradiometry with compact atom interferometers is well described in publication WO 2014 / 106811 A2. The gradiometer described therein consists of two (or three) interaction zones, in each of which laser light is directed onto an atomic ensemble from all six spatial directions. A single laser beam is used for this purpose, directed onto the interaction zones by two (or three) light reflector elements. The two light reflector elements are arranged such that the second light reflector element is located behind a central bore of the first light reflector element (or the third light reflector element has a central bore for the second light reflector element).

[0006] The technical challenge of acceleration measurements with cold atoms lies in the development of compact and robust devices capable of generating reliable measurement data and maintaining high sensitivity despite demanding and dynamic environmental conditions. These aspects are becoming increasingly important, particularly for gradiometric measurements, and the requirements for the sensors are high.

[0007] Current implementations for cooling and trapping atomic clouds for the subsequent interferometry process involve various pyramidal mirrors or lattice configurations of the 3D magneto-optical trap (3D-MOT). These types of 3D-MOTs have contributed to more compact setups for atom interferometers, as they require only a single laser beam or significantly reduce the number of necessary optical access points and fibers. However, the optical elements are complex to manufacture and can necessitate additional components in the setup, which can lead to unwanted polarization effects or phase disturbances. One challenge is achieving a uniform intensity distribution of the laser light along all three spatial axes for the 3D magneto-optical trap and molasses cooling.However, this is of great importance, as an uneven distribution of light affects the performance of the implemented laser cooling and can thus degrade the overall performance of the sensor.

[0008] Current implementations of pyramid-shaped MOTs are usually designed so that they illuminate four of the six spatial directions required for effective cooling using reflective surfaces. The remaining two directions are covered by the incident and reflected laser light field.

[0009] The typical variants with reflection at a 90° angle require a Liquid Crystal Variable Retarder (LCVR) in the retroreflection path to switch between the MOT phase and the interferometry phase or detection phase during the interferometry cycle if an energy transition favorable for detection is to be driven in the atom (e.g. a so-called closed transition).

[0010] Another disadvantage is that the center of the pyramid element must be illuminated, which can potentially interfere with the operation of nested interferometers or other measurement methods using laser-cooled atoms.

[0011] From DE 10 2020 102 222 A1, an atomic cooling device, in particular an atom trap, and a method for cooling or trapping atoms are known. From WO 2024 / 158341 A1, a mirror arrangement for a magneto-optical trap is known.

[0012] The invention is therefore based on the objective of providing an improved light reflector element and an atomic device formed therewith.

[0013] This problem is solved according to claim 1 by a light reflector element of the type mentioned above, wherein the light reflector element has one or more pairs of mutually associated reflector surfaces, in which one reflector surface of the pair is oriented with respect to the predefined direction of light incidence of the light reflector element at an angle in the range of 46° to 89° and the other reflector surface of the same pair is oriented with respect to the predefined direction of light incidence of the light reflector element at an angle in the range of 1° to 44°.The special feature of at least one pair of these reflector surfaces is that one reflector surface effectively deflects part of the incident light field at a steep angle to the direction of incidence, while the other reflector surface effectively deflects another part of the incident light field at a shallow angle to the direction of incidence, so that the vector contributions of the light field components can cover all spatial axes, which, for example, enables the realization of a three-dimensional atom trap.

[0014] The reflector surfaces thus deflect the light incident in the direction of incidence not orthogonally to the direction of incidence, but at an oblique angle to it. This can be implemented, for example, as a pyramid optic. Due to the optimized deflection direction of the reflector surfaces, incident light rays are deflected at an angle relative to the surface normal such that the vector contributions of the light fields continue to cover all spatial axes, i.e., they have components in all spatial axes, without the light passing through the light reflector element at the center having to be reflected back on itself for operation as a magneto-optical trap; that is, it does not have to be reflected back by a mirror arranged behind the light reflector element in the direction of incidence. This has the advantage that no controllable polarization element, such as an LCVR, is required to switch between the MOT phase and the interferometry phase.The detection phase during the interferometry cycle is no longer required in the retroreflex path, as such a retroreflex path is no longer needed for the magneto-optical trap itself. The elimination of the controllable polarization element also reduces phase errors in the atom interferometer caused by wavefront disturbances. Furthermore, it is possible to arrange the coils for the magneto-optical trap on or inside the vacuum chamber instead of around it.

[0015] Another advantage is that the center of the light reflector element does not need to be illuminated, which means that nested interferometers or other measurement methods with laser-cooled atoms are less disturbed.

[0016] The applications of the light reflector element are not limited to atom interferometers. A key advantage is the unobstructed access point behind the light reflector element in the direction of the light beam, eliminating the need for a mirror for retroreflection in the direction of the incident light beam. This access point can be used, for example, for an optical dipole trap, detection optics, an atom furnace, and similar devices in other atom-optical setups.

[0017] According to an advantageous embodiment of the invention, the light reflector element has one or more pairs of mutually associated reflector surfaces, in which one reflector surface of the pair is oriented at an angle of at least approximately 67.5° relative to the predefined direction of light incidence of the light reflector element, i.e., taking into account error tolerances, and the other reflector surface of the same pair is oriented at an angle of at least approximately 22.5° relative to the predefined direction of light incidence of the light reflector element. In this way, the effectiveness of a light reflector element as an atom trap can be made particularly efficient. By using several pairs of such mutually associated reflector surfaces, each arranged offset by a certain circumferential angle, three-dimensional confinement and cooling of the trapped atoms by the laser light can be achieved without a retroreflection path.The light rays deflected by the reflector surfaces then strike the central axis at a 45° angle.

[0018] According to an advantageous embodiment of the invention, in one or more pairs of mutually associated reflector surfaces, one reflector surface of the pair is oriented at an angle W1 with respect to the predefined direction of light incidence of the light reflector element, and the other reflector surface of the same pair is oriented at an angle W2 with respect to the predefined direction of light incidence of the light reflector element, wherein the sum of W1 and W2 is equal to or nearly equal to 90°. This makes it possible for light rays to be deflected obliquely by a pair of mutually associated reflector surfaces with one and the same direction of light incidence, and to converge on each other so that they meet at the central axis.

[0019] According to an advantageous embodiment of the invention, the number of pairs of corresponding reflector surfaces of the light reflector element is 3 or a multiple of 3. This allows for a simple design of the light reflector element and, consequently, simple and cost-effective manufacturing. Each pair of corresponding reflector surfaces can be arranged offset by a specific circumferential angle relative to an adjacent pair.

[0020] According to an advantageous embodiment of the invention, the light reflector element has at least one further pair of mutually associated reflector surfaces, in which both reflector surfaces of the pair are aligned at an angle of 45° with respect to a straight line that runs orthogonally to the predefined direction of light incidence of the light reflector element and intersects the central axis. Accordingly, in addition to the aforementioned pairs of reflector surfaces, one of which is arranged at an angle in the range of 46° to 89° and the other reflector surface is oriented at an angle in the range of 1° to 44°, the aforementioned at least one further pair of mutually associated reflector surfaces that do not have this oblique arrangement. These further reflector surfaces can be used, for example, to...Light rays that point towards each other are generated from the light rays incident in the direction of the light beam, which are directed orthogonally towards the central axis.

[0021] In one variant, the reflector surfaces of the second pair can be oriented at an angle of 45° or nearly 45° to the direction of the light incidence. This allows for a direct deflection of the light incident in the direction of the light incidence perpendicular to the central axis.

[0022] According to an advantageous embodiment of the invention, the light reflector element has, for each reflector surface of the further pair of associated reflector surfaces, at least one additional reflector surface associated with that reflector surface, which deflects incident light in the predefined direction of incidence of the light reflector element onto the associated reflector surface. A reflector surface of the further pair and an additional reflector surface associated with that reflector surface create an arrangement of reflector surfaces rotated relative to each other, enabling a particularly effective generation of light radiation in a direction orthogonal to the central axis. For example, the reflector surface of the further pair can be aligned parallel to the direction of incidence of the light. The additional reflector surface can then be aligned at an angle of 45° with respect to the predefined direction of incidence of the light reflector element.The light radiating in the direction of the light beam can be deflected by the additional reflector surface onto the associated reflector surface of the further pair and then deflected orthogonally from this reflector surface towards the central axis.

[0023] The reflector surfaces can be arranged circumferentially around the central axis at uniform angular intervals. The reflector surfaces of a pair of reflector surfaces can be diametrically opposed to each other with respect to the center of the light reflector element.

[0024] According to an advantageous embodiment of the invention, a light-transmitting section is arranged between circumferentially adjacent reflector surfaces, through which the light incident in the direction of incidence can pass through the light reflector element. Thus, in the light reflector element according to the invention, not only is a central inner region of the light reflector element designed to be light-transmitting, as in the prior art, but alternatively or additionally, cutouts are created between the reflector surfaces in the circumferential direction that are light-transmitting. Advantages can be achieved through such a design of the light reflector element: - Smaller area to be covered by the laser beam when light reflector elements are arranged one behind the other - Symmetrical intensity distribution in the interaction zones - Improved symmetries in the number of atoms in the two interaction zones - Corresponding improvement of the gradiometer signal through systematic effects - Minimization of the apparatus with advantages in terms of compactness - Lower required laser power and therefore reduced restrictions for compact design and power consumption

[0025] The invention enables an improved design of the light reflector elements, in which the division of the available laser light is achieved not by radial or transmittive segmentation, but by angle-dependent segmentation of the reflector surfaces. This allows for symmetry of the optical configuration. Simultaneously, the complexity of the light reflector elements is reduced, as they do not necessarily have to be made of transparent material and can be designed identically for all two, three, or more interaction zones. This simplifies manufacturing. Furthermore, the symmetry achieved through the use of identical optical elements reduces differential errors that could otherwise affect signal quality.

[0026] The reflector surfaces are designed to reflect light, in particular with a reflectance of essentially 100%. The reflector surfaces can be designed, for example, like mirrors. They can be configured as a single, continuous, flat reflector surface or as a multitude of individual reflector surfaces arranged side-by-side in a staggered pattern on the reflector element. A reflector surface can be distinguished from an adjacent one by being positioned at a different angle to the adjacent surface and / or offset from it. A reflector surface can, for example, be designed as a flat, reflective surface.

[0027] According to an advantageous embodiment of the invention, one, several, or all of the light-transmitting sections are designed as a free space in which no material is arranged. This has the advantage that the light reflector element can be designed and manufactured particularly simply. Alternatively, a light-transmitting filler material, e.g., a glass or plastic material, can also be arranged in one, several, or all of the light-transmitting sections.

[0028] According to an advantageous embodiment of the invention, the reflector surfaces are arranged at a distance from the center, so that a central light-transmitting section is formed around the center, through which the light incident in the direction of incidence can pass through the light reflector element. Through the central light-transmitting section, the light from the light source can, for example, be directed to a mirror arranged behind the light reflector element in the direction of incidence, or to a further light reflector element arranged behind it, through which the light is reflected back for the purpose of carrying out interferometry.

[0029] The light reflector element can be composed of multiple parts. For example, the individual reflector surfaces can be mounted as mirrored components on a base component that serves as a carrier for the reflector surfaces.

[0030] According to an advantageous embodiment of the invention, the light reflector element is designed as a monolithic component. This allows for very simple and cost-effective manufacturing of a light reflector element that is also mechanically very stable. Furthermore, this simplifies the integration of the light reflector element into an atom interferometer, and the adjustment process is simplified.

[0031] The aforementioned problem is also solved by a reflector arrangement comprising at least one first light reflector element and at least one second light reflector element, the second light reflector element being arranged behind the first light reflector element in the direction of light incidence. The first light reflector element is configured as a light reflector element of the type described above, i.e., as a light reflector element according to the invention. The second light reflector element can also be configured as a light reflector element according to the invention, but it can also be configured differently. Light radiating through the light-transmitting sections of the first light reflector element can strike the reflector surfaces of the second light reflector element. Such a reflector arrangement can advantageously form two interaction zones of a quantum gradiometer.The area required to be covered by the laser beam is relatively small. Furthermore, a symmetrical intensity distribution in the interaction zones can be easily achieved.

[0032] Advantageously, the first and second light reflector elements can be designed to have the same dimensions with respect to their optically effective reflector surfaces. It is also advantageous if the second light reflector element is arranged behind the first light reflector element along the same central axis in the direction of light incidence, i.e., concentrically to the first light reflector element.

[0033] The aforementioned problem is also solved by an atomic device, in particular an atom interferometer, comprising at least one laser light source and an atom trap. The trap has at least one first interaction zone for cooling trapped atoms by laser light from the laser light source incident on the trapped atoms from opposite directions. The atomic device has a first light reflector element of the type described above, wherein the light emission direction of the laser light source is aligned with the predefined light emission direction of the first light reflector element. The first interaction zone is at least partially formed by the first light reflector element. The advantages described above can also be realized in this way. The atomic device can be any type of atomic device with atoms laser-cooled in the atom trap. The atom trap can be designed as a magneto-optical trap (MOT).

[0034] The atom trap can be designed as a three-dimensional atom trap (e.g., 3D-MOT), in which the vector components of the laser light incident on the trapped atoms from opposite directions encompass all spatial axes in the first interaction zone. This also simplifies the construction of the atom device.

[0035] The magneto-optical trap functions as an atom trap designed to capture an atomic cloud. The magneto-optical trap incorporates a magnetic field device to create a magnetically active part of the atom trap. Furthermore, the atom interferometer includes at least one controllable laser light source, such as a laser, which emits light in a predefined direction onto the light reflector element(s) or reflector array. This achieves laser cooling of the trapped atoms in the interaction zone(s).

[0036] According to an advantageous embodiment of the invention, the atom trap on the side of the first light reflector element facing away from the laser light source is configured without a light beam path extending along the central axis. Accordingly, the retroreflection light path can be avoided, at least for cooling the atoms, thereby minimizing phase errors in the atom interferometer and simplifying the overall setup, in particular eliminating the need for an LCVR or similar component for controlling the reflected light.

[0037] According to an advantageous embodiment of the invention, the atomic device has at least two interaction zones for cooling trapped atoms by laser light directed onto the trapped atoms from opposite directions. The atomic device has a second light reflector element arranged behind the first light reflector element in the direction of the light incidence, and the second interaction zone is at least partially formed by the second light reflector element. The atomic device can, for example, have a reflector arrangement of the type described above. The second light reflector element can be configured as a light reflector element according to the invention, as described above, or as a differently designed light reflector element, for example, a light reflector element according to the prior art. The atomic device can, for example, be configured as a quantum gradiometer.

[0038] The invention is suitable, for example, for applications in the field of navigation, for rotation and acceleration measurements, e.g., as part of an inertial quantum measuring unit to support or replace conventional inertial measuring units, particularly in areas without a reliable global navigation system (GNSS).

[0039] For the purposes of the present invention, the indefinite term "a" is not to be understood as a numeral. Therefore, when, for example, a component is mentioned, this is to be interpreted as "at least one component". Where angles are specified in degrees, these refer to a circle of 360 degrees (360°).

[0040] The invention is explained in more detail below with reference to exemplary embodiments and drawings.

[0041] They show Fig. 1. An atomic device in a highly schematic side sectional view, Fig. 2 a light reflector element in top view, Fig. 3 the light reflector element according to Fig. 2 in side sectional view, Fig. 4 a light reflector element of a further embodiment in top view, Fig. 5 the light reflector element according to Fig. 4 in side sectional view, Fig. 6 a light reflector element of a further embodiment in top view, Fig. 7 the light reflector element according to Fig. 6 in side section view in another section plane, Fig. 8 the light reflector element according to Fig. 6 in perspective view, Fig. 9. Introduction of the laser light in the cooling configuration, Fig. 10. Introduction of the laser light in the interferometry configuration.

[0042] The Fig. Figure 1 shows an atomic device 20, e.g., an atom interferometer. The atomic device 20 has a coherent light source 8, e.g., a laser, through which the light 10 is emitted in the direction of incidence L. The atomic device 20 also has a vacuum chamber 17 in which a light reflector element 1 of the type described above is arranged, e.g., as in the Fig. 2, Fig. Figure 3 shows that the wave vector 11 of the incident light 10, which is aligned in the direction of incidence L with respect to the light reflector element 1, is directed towards an interaction zone 13 in which atoms can be trapped in an atom trap and cooled by the laser light. Additionally, the direction of the light from the light source 8 reflected at the reflector surfaces 4 is shown by wave vectors 12.

[0043] As can be seen, a pair of corresponding reflector surfaces has four different angles with respect to the direction of incidence L. The reflector surface 4 shown on the left has an angle of less than 45°, e.g., 22.5°, while the reflector surface 4 on the right has an angle greater than 45°, e.g., 67.5°. With this type of optics, a portion of the incident light field 10 with a vector component is deflected in the same direction as the wave vector 11, and another portion of the incident light field 10 with a vector component is deflected in the opposite direction to the wave vector 11. The opposing wave vectors 12 then meet in the interaction zone 13. The wave vectors 12 are thus antiparallel to each other. With such optics, all spatial axes can be covered by the vector contributions of the light field components.

[0044] In this way, vectorial light components appear in all six spatial directions in the interaction zone 13, so that a three-dimensionally acting atom trap can already be realized with the single light reflector element 1, without the need for reflection by a mirror behind the light reflector element 1. In this way, three-dimensional laser cooling of the atoms is possible with minimal effort.

[0045] The design of the light reflector element 1 allows a uniform light pressure on the atoms in the interaction zone 13 in the direction of the light irradiation L and opposite to the light irradiation direction L.

[0046] For the subsequent execution of an interferometry cycle, the atoms trapped in the atom trap, i.e., the interaction zone 13, can then be coupled out and fall, for example, into the vacuum chamber 17. The vacuum chamber 17 can contain optically transparent sight glasses or view ports through which the interferometry outputs can be evaluated using, for example, a camera or a photodiode. In addition, a mirror 14 for interferometry can be located on the side of the vacuum chamber 17 facing away from the light source 8. A detection system 15 for evaluating the interferometry outputs can, for example, be placed in front of a view port 16.

[0047] The mirror 14 can also be mounted inside the vacuum chamber 17. Alternatively, the mirror 14 can be mounted on a remotely controlled mirror holder, allowing the reflected portion of the light field to be tilted automatically to reduce its effect on the magneto-optical trap. Another alternative for minimizing its effect on the magneto-optical trap is to arrange, for example, a shutter between the lower sight glass 16 and the mirror 14.

[0048] The described embodiment of the optics also allows for a setup with two light reflector elements 1 arranged one behind the other, forming a reflector array. With such a reflector array 9, for example, a quantum gradiometer can be realized, making it possible to measure the gravitational gradient with a light source 8.

[0049] The Fig. Figure 2 shows the light reflector element 1. Fig. 1 in a top view, which Fig. Figure 3 shows the light reflector element 1 in a sectional view in the Fig. 2 shown central section plane 5. The light reflector element 1 according to the Fig. 2, Fig. 3 has a base body 3 on which several, in this case 6, reflector surfaces 4 are arranged uniformly distributed over a circumferential angle coordinate and are arranged obliquely with respect to a predefined direction of light incidence L of the light reflector element 1. The reflector surfaces 4 are each designed as mirror surfaces of a reflector body 7. The reflector surfaces 4 can be arranged in pairs opposite each other, i.e., two opposite reflector surfaces 4 form a pair a, b of reflector surfaces 4, although other arrangements are also conceivable. The reflector surfaces 4 are each arranged symmetrically opposite each other with respect to a center of the light reflector element 1, in particular point-symmetrically or mirror-symmetrically. The center of the light reflector element 1 is defined in Fig. 2 is illustrated by a central axis Z. The central axis Z runs through the center of the light reflector element 1 in the direction of light incidence L.

[0050] As can be seen, for example, three pairs a, b of reflector surfaces 4 can be present. The reflector surfaces 4 do not extend to the center of the light reflector element 1, but end before it, so that a central light-transmitting area 6 is present around the central axis Z. As the Fig. Figure 3 shows that the reflector surface a of the pair a, b of reflector surfaces 4 is oriented at an acute angle W1 to the direction of light incidence L, while the associated reflector surface b of the same pair a, b is oriented at an obtuse angle W2 to the direction of light incidence L. The sum of W1 and W2 is 90°. Due to the circumferentially offset arrangement of the three pairs a, b of reflector surfaces 4, the interaction zone 13 can be illuminated uniformly with light from all six spatial directions.

[0051] The light reflector element 1 can be manufactured from a raw component by machining, e.g., by milling. It is also possible to manufacture the light reflector element from two parts that are then fitted together. Advantageous illumination options for the light reflector element 1 include a Gaussian beam centered on the central axis Z, a "flat-top" or "top-hat" beam profile, or an annular beam profile.

[0052] Based on the Fig. 4 and Fig. Section 5 describes a further embodiment of a light reflector element 1. Fig. 5 again shows a cross-sectional view along the in Fig. 4. The central section plane 5 shown in Figure 4 reveals that the light reflector element 1 has a total of 12 reflector surfaces 4, arranged in the form of two concentric ring arrangements around the center or the light-transmitting central section 6. In the circumferential direction, the two ring-shaped arrangements of the reflector surfaces 4 are again arranged as in the embodiment of the Fig. 2 and Fig. 3, divided into six sectors. Each pair a, b of corresponding reflector surfaces 4 is formed by a reflector surface a, located on the outer ring and oriented at an angle W1 to the direction of light incidence L, and a reflector surface b, located opposite the reflector surface b on the inner ring and oriented at an angle W2 to the direction of light incidence L. The light rays are thus reflected downwards at a 45° angle by the reflector surfaces a in the outer ring and reflected upwards at a 135° angle by the reflector surfaces b on the inner ring. Illumination options: flat-top / top-hat beam profile, ring-shaped beam profile. Advantageous illumination options of the light reflector element 1 are a "flat-top" or "top-hat" beam profile centered on the central axis Z, or a ring-shaped beam profile.

[0053] Based on the Fig. 6, Fig. 7 to Fig. Section 8 describes a further embodiment of a light reflector element 1. The light reflector element 1 is in Fig. 6 shown in a top view. In the Fig. Figure 6 also shows the central section plane 5. The light reflector element 1 is located in the central section plane 5 according to... Fig. 6 a comparable structure to the light reflector element 1 according to Fig. 4, i.e. in the section plane 5, the following results for the light reflector element 1 according to Fig. 6 the same representation as in Fig. 5. Accordingly, there are also corresponding reflector surfaces a, b of a pair a, b, which are arranged at different radial distances from the center. However, there are only two pairs a, b of reflector surfaces 4.

[0054] The Fig. Figure 7 shows the light reflector element 1 in a sectional view in the Fig. Figure 6 shows the off-center section plane 19. As can be seen, the light reflector element 1 has a further pair c of corresponding reflector surfaces 4. These reflector surfaces 4 of the further pair c are aligned at an angle of 45° with respect to a straight line that runs orthogonally to the predefined direction of light incidence L of the light reflector element 1 and intersects the central axis Z. In addition, each of the reflector surfaces c of the further pair is assigned at least one additional reflector surface d, which deflects light incident in the direction of light incidence L onto the reflector surface c. This arrangement of reflector surfaces c, d allows an additional spatial direction of light for a three-dimensional magneto-optical trap to be generated, even with a ring-shaped incident light beam profile. In this embodiment, the coils of the magneto-optical trap can be mounted not on the axis of the overall element, but above or below it.Advantageous illumination options for the light reflector element 1 are a "flat-top" or "top-hat" beam profile centered on the central axis Z, or an annular beam profile. The... Fig. Figure 8 shows the light reflector element 1 according to the Fig. 6 and Fig. 7 in a perspective view, which further clarifies the lighting possibilities and the light deflections.

[0055] The reflector surfaces a and b in Fig. 2 and Fig. 3, which cause reflection at a steep or shallow angle, can alternatively be replaced by two elements rotated relative to each other, each deflecting by 90°, if this is preferable due to polarization properties.

[0056] An equivalent consideration applies to the light reflector element 1 in the Fig. 4 and Fig. 8, where the reflector surfaces a and b can alternatively be replaced by two elements rotated relative to each other, each deflecting by 90°. An arrangement of reflector surfaces c, d can be replaced by a single reflector surface c, which deflects the light directly from the predefined direction of incidence L by 90° towards the center.

[0057] The light reflector element 1 can be manufactured monolithically, e.g., by milling, pressing, or 3D printing, depending on the material, or alternatively, assembled from individual components. The reflection at the reflector surfaces can be optimized, depending on the requirements and the material of the overall element, e.g., by polishing or coating. Monolithic manufacturing offers the advantage of significantly reduced adjustment effort during component production, as well as potentially improved passive stability.

[0058] All variants of the light reflector element 1 are suitable for a 3D magneto-optical trap. The angles W1 and W2 can be chosen differently; the essential factor is the antiparallelism of the wave vectors of the reflected light fields.

[0059] In all variants of the light reflector element 1, the base body 3, e.g. in the form of a frame segment, can be provided with holes or recesses to allow further access, e.g. for the atom beam from a 2D magneto-optical trap for faster loading of the 3D magneto-optical trap or optical access.

[0060] Based on the Fig. 9 and Fig. Figure 10 schematically explains how the light 10 from the light source 8 can be introduced into the light reflector element 1 or into the vacuum chamber 17. The information in the Fig. 9 and Fig. The arrangement shown in Figure 10 can accordingly be positioned upstream of the light reflector element 1 or the vacuum chamber 17. Fig. Figure 9 shows the introduction of light 10 during the laser cooling of the atoms in the interaction zone 13, which Fig. Figure 10 shows the introduction of light 10 after the atoms have been extracted from the atom trap and during the interferometry process.

[0061] The in the Fig. 9 and Fig. The arrangement shown in Figure 10 includes an adjustable delay plate 24, e.g., an LCVR. A second delay plate 25 is arranged downstream of the adjustable delay plate 24 in the direction of light incidence L. A polarizing filter 26, e.g., a film or a polarizing beam splitter cube, is arranged downstream of the second delay plate 25. Optionally, a third delay plate 27 can be arranged downstream of the polarizing filter 26.

[0062] In the cooling configuration according to Fig. 9 The central light component 28 of the light 10 is blocked and therefore does not reach the light reflector element 1. In contrast, the outer light components 29 are transmitted through the described arrangement and reach the light reflector element 1.

[0063] In the interferometry configuration according to Fig. 10. The central light component 28.1 is transmitted through the described arrangement and can thus pass through the light reflector element 1. In contrast, the outer light components 29.1 are blocked in this configuration and do not reach the light reflector element 1.

[0064] The combination of elements 24, 25 and 26 enables switching between illumination of the decentralized reflector surfaces 4 of the light reflector element 1 or optionally of the light-transmitting central area 6. The targeted illumination of the center of the light reflector element 1 or the vacuum chamber 17 enables, for example in conjunction with other elements, e.g. a retroreflective mirror 14, the implementation of a beam configuration suitable for an atom interferometer.

[0065] The second delay element 25 can be configured to permanently block a ring-shaped area around the center. The order of delay elements 24 and 25 is interchangeable. The functionality of elements 24, 25, and 26 can also be implemented differently. The key feature is the ability to switch between illuminating the outer ring or, alternatively, the center.

Claims

[1] Light reflector element (1, 2) having several reflector surfaces (4) oriented at different predefined angles with respect to a predefined direction of light incidence (L) of the light reflector element (1, 2), wherein the reflector surfaces (4) are arranged around a center of the light reflector element (1, 2), e.g. in a ring shape, wherein respective pairs (a, b) of mutually associated reflector surfaces (4) are arranged diametrically opposite each other with respect to the center of the light reflector element (1, 2), such that light (10) incident in the direction of light incidence (L) is deflected by the reflector surfaces (4) into light rays (L2', L3') which extend towards each other in different spatial directions and meet in a central axis (Z) which passes through the center in the direction of light incidence (L), characterized by, that the light reflector element (1, 2) has one or more pairs (a, b) of the mutually associated reflector surfaces (4), in which one reflector surface (4) of the pair (a, b) is oriented at an angle in the range of 46° to 89° with respect to the predefined direction of light incidence (L) of the light reflector element (1, 2) and the other reflector surface (4) of the same pair (a, b) is oriented at an angle in the range of 1° to 44° with respect to the predefined direction of light incidence (L) of the light reflector element (1, 2). [2] Light reflector element according to claim 1, characterized by, that the light reflector element (1, 2) has one or more pairs (a, b) of the mutually associated reflector surfaces (4), wherein one reflector surface (4) of the pair (a, b) is oriented at an angle substantially equal to 67.5° with respect to the predefined direction of light incidence (L) of the light reflector element (1, 2), and the other reflector surface (4) of the same pair (a, b) is oriented at an angle substantially equal to 22.5° with respect to the predefined direction of light incidence (L) of the light reflector element (1, 2). [3] Light reflector element according to any of the preceding claims, characterized by, that in one or more pairs (a, b) of the mutually associated reflector surfaces (4) one reflector surface (4) of the pair (a, b) is oriented at an angle W1 with respect to the predefined direction of light incidence (L) of the light reflector element (1, 2) and the other reflector surface (4) of the same pair (a, b) is oriented at an angle W2 with respect to the predefined direction of light incidence (L) of the light reflector element (1, 2), wherein the sum of W1 and W2 is substantially equal to 90°. [4] Light reflector element according to any of the preceding claims, characterized by , that the number of pairs (a, b) of the corresponding reflector surfaces (4) of the light reflector element is equal to 3 or a multiple of 3. [5] Light reflector element according to any of the preceding claims, characterized by, that the light reflector element (1, 2) has at least one further pair (c) of the mutually associated reflector surfaces (4) in which both reflector surfaces (4) of the pair (c) are aligned at an angle of 45° with respect to a straight line that is orthogonal to the predefined direction of light incidence (L) of the light reflector element (1, 2) and intersects the central axis (Z). [6] Light reflector element according to claim 5, characterized by , that the light reflector element (1, 2) has for each reflector surface (4) of the further pair (c) of the mutually associated reflector surfaces (4) at least one additional reflector surface (d) associated with this reflector surface (4), which deflects incident light (10) in the predefined direction of light incidence (L) of the light reflector element (1, 2) onto the associated reflector surface (4) of the further pair (c). [7] Light reflector element according to any of the preceding claims, characterized by, that between circumferentially adjacent reflector surfaces (4) a light-transmitting section (5) is arranged, through which the light (10) incident in the direction of light incidence (L) can pass through the light reflector element (1, 2). [8] Light reflector element according to claim 7, characterized by , that one, several or all of the light-transmitting sections (5) are designed as a free space in which no material is arranged. [9] Light reflector element according to any of the preceding claims, characterized by , that the reflector surfaces (4) are arranged at a distance from the center, so that a central light-transmitting section (6) is formed around the center, through which the light (10) incident in the direction of light ray (L) can pass through the light reflector element (1, 2). [10] Light reflector element according to any of the preceding claims, characterized by, that the light reflector element (1, 2) is designed as a monolithic component. [11] Light reflector element according to any of the preceding claims, characterized by , that one, several or all of the reflector surfaces (4) are each designed as a flat surface. [12] Atomic device (20), in particular comprising at least one laser light source (8) and an atom trap, which has at least one first interaction zone (13) for cooling trapped atoms by laser light from the laser light source (8) shining onto the trapped atoms from opposite directions, characterized by , that the atomic device (20) has a first light reflector element (1) according to one of the preceding claims, wherein the light emission direction of the laser light source (8) is aligned in the predefined light emission direction (L) of the first light reflector element (1), wherein the first interaction zone (13) is formed at least partially by the first light reflector element (1). [13] Atomic device according to claim 12, characterized by , that the atom trap is designed as a three-dimensionally acting atom trap, wherein the vectorial components of the laser light shining from opposite directions onto the trapped atoms in the first interaction zone (13) encompass all spatial axes. [14] Atomic device according to claim 12 or 13, characterized by , that the atomic device (20) is designed on the side of the first light reflector element (1) facing away from the laser light source (8) without a light beam path running along the central axis (Z). [15] Atomic device according to claim 14, characterized by , that the atomic device (20) is designed without a mirror (14) arranged behind the first light reflector element (1) in the direction of light incidence (L), by which light (10) incident in the direction of light incidence (L) is reflected back in the opposite direction to the direction of light incidence (L). [16] Atomic device according to any one of claims 12 to 15, in particular quantum gradiometer, characterized by , that the atomic device (20) has at least two interaction zones (13) spaced apart from each other for cooling trapped atoms by laser light shining onto the trapped atoms from opposite directions, wherein the atomic device (20) has a second light reflector element (2) which is arranged behind the first light reflector element (1) in the direction of light incidence (L), wherein a second interaction zone (13) is formed at least partly by the second light reflector element (2).

Images