QUANTUM SENSOR SYSTEM FOR DETECTING ELECTROMAGNETIC RADIATION

Abstract

The present disclosure relates to a quantum sensor system for detecting electromagnetic radiation (EM). The quantum sensor comprises an element configured to shape and / or focus the EM radiation to generate an inhomogeneous field distribution in a region; at least two quantum sensors arranged at different locations in the region, each of which comprises a detection volume configured to interact with the EM radiation; at least one detector configured to detect an interaction of the EM radiation with each detection volume, the interaction indicating a power level of the EM radiation at the location of the respective detection volume; and a processor configured to determine a signal characteristic of the EM radiation based on a correlation of the power levels at the locations of the detection volumes.

Description

Technical area

[0001] The disclosure relates to quantum sensor systems for detecting electromagnetic radiation and to corresponding methods for detecting electromagnetic radiation. State of the art

[0002] In recent years, interest in the detection of electromagnetic radiation (EM) using quantum systems has increased significantly. The most common quantum systems include atoms in their ground state, excited atoms (especially in Rydberg states), or atom-like systems such as NV defects in diamonds. A quantum sensor using such a quantum system can, for example, detect EM radiation through resonant transitions between two energy states within the quantum system.

[0003] Depending on the specific quantum system and readout technique, most interactions exhibit saturation behavior at high power levels in the electromagnetic radiation. This can be due to decoherence effects caused by a large number of Rabi oscillations, the excitation of already saturated two-level systems, or interactions with other energy levels. This saturation behavior typically limits the dynamic range of the sensor.

[0004] Another problematic effect is power broadening. Power broadening describes the phenomenon where atomic transitions in the frequency domain broaden when a high-power electromagnetic wave is applied. This means that transitions at neighboring frequencies also respond. When analyzing the spectrum of a signal with power broadening, it may be impossible to distinguish a narrowband, high-power signal from a broadband, low-power signal. Summary

[0005] Therefore, there is a need to develop an improved quantum sensor system that enables a higher dynamic range.

[0006] This is achieved by the embodiments specified in the accompanying independent claim. Advantageous embodiments of the present disclosure are further defined in the dependent claims.

[0007] According to a first aspect, the present disclosure relates to a quantum sensor system for detecting electromagnetic radiation. The quantum sensor system comprises: an element configured to shape and / or focus the EM radiation to generate an inhomogeneous field distribution in a region; at least two quantum sensors arranged at different locations in the region, each of which includes a detection volume configured to interact with the EM radiation; at least one detector configured to detect an interaction of the EM radiation with each detection volume, the interaction indicating a power level of the EM radiation at the location of the respective detection volume; and a processor configured to determine a signal characteristic of the EM radiation based on a correlation of the power levels at the locations of the detection volumes.

[0008] This has the advantage that a quantum sensor system with a high dynamic range can be provided. Due to the large number of quantum sensors arranged at different locations within the inhomogeneous field, the system can measure radiation from the same source with different powers (i.e., amplitudes), for example, through different transition strengths in the measurement volumes.

[0009] Each quantum sensor can have its own detector. However, there can also be one detector for multiple quantum sensors, for example, if the detection volumes of these sensors are located directly next to each other or in close proximity.

[0010] The inhomogeneous field distribution can refer to an inhomogeneous local distribution of the amplitude of the EM radiation (i.e., the waves of the EM field) in the region. For example, the element can cause a gradual or instantaneous change in the amplitude of the EM radiation waves in the area where the quantum sensors are located, e.g., due to partial absorption of the EM radiation, so that the detection volumes of the two quantum sensors receive the EM radiation with different amplitudes.

[0011] The area can be a detection area in which the quantum sensors are arranged.

[0012] In one embodiment, the quantum sensor system further comprises a signal source configured to generate EM radiation based on a physical quantity to be analyzed.

[0013] The physical quantity in question could be, for example, an electric or magnetic field, pressure, or temperature. Information about this physical quantity can be obtained by detecting the electromagnetic radiation. The signal source can include an antenna for generating and / or emitting the electromagnetic radiation.

[0014] Instead of using a signal source to generate EM radiation based on the physical quantity, the physical quantity can also be measured directly with the quantum sensor. This is possible because most quantum systems are directly influenced by physical quantities (electrical / magnetic field, pressure, temperature), even if there is no "transducer" to convert the quantity into EM radiation (e.g., in the form of a signal source). However, depending on the measurement method, these influences can eventually exhibit saturation behavior. For example, static electric / magnetic fields shift the energy levels of atoms. If the shift is too large, a laser involved in the detection / excitation process is no longer resonant (and if the shift is increased further, eventually no effect can be observed).

[0015] In one embodiment, the at least two quantum sensors are arranged at locations within the region with different power levels, particularly different amplitudes, of the EM radiation, such that at least one of the quantum sensors can detect a power level of the EM radiation when the other quantum sensor is in saturation. This achieves the advantage of increasing the dynamic range of the quantum sensor system.

[0016] In particular, the saturation state of a quantum sensor can refer to the fact that the detection volume of the quantum sensor is saturated.

[0017] In one embodiment, the detection volumes of the at least two quantum sensors each comprise a number of atoms in a ground state or an excited quantum state. These atoms can, for example, be Rydberg atoms.

[0018] Each sensor volume can comprise a quantum system, which is formed, for example, from the respective number of atoms.

[0019] In one embodiment, at least one quantum sensor comprises a gas cell, wherein the number of atoms in the gas cell is stored in gaseous form.

[0020] A measurement volume can, for example, comprise a continuum of atoms distributed along the gradient of the inhomogeneous EM field.

[0021] In one embodiment, the quantum sensor system comprises at least one light source configured to illuminate the detection volumes of the at least two quantum sensors with a light beam, wherein the detection volumes are optically excited by the light beam; and / or the quantum sensor system comprises at least one field generator unit configured to generate an electric and / or magnetic field within the detection volumes of the at least two quantum sensors, wherein a resonance frequency of the number atoms in the detection volumes is changed by an amplitude of the electric and / or magnetic field.

[0022] The field generator unit can be a capacitor to generate an electric field. The light source can consist of one or more lasers.

[0023] For example, each quantum sensor can include a corresponding light source and field generator to optically, electrically and / or magnetically excite atoms in the measurement volume.

[0024] The interaction of EM radiation with the sensor volumes can excite resonance transitions between two energy states in the sensor volume.

[0025] In one embodiment, the detection volumes of the at least two quantum sensors are arranged separately from each other.

[0026] In one embodiment, the detection volumes of the at least two quantum sensors are arranged directly next to each other and / or at least partially overlapping along a gradient of the inhomogeneous field distribution of the EM radiation.

[0027] In one embodiment, the element consists of an antenna, e.g. a parabolic antenna.

[0028] In one embodiment, the element comprises an absorber designed to absorb at least some of the EM radiation.

[0029] According to a second aspect, the disclosure relates to a method for detecting electromagnetic radiation. The method comprises the steps of: shaping and / or focusing the EM radiation to generate an inhomogeneous field distribution in a region; receiving the EM radiation with at least two quantum sensors arranged at different locations in the region, each of the quantum sensors comprising a detection volume configured to interact with the EM radiation; detecting an interaction of the EM radiation with each detection volume, the respective interaction indicating a power level of the EM radiation at the location of the detection volume; and determining a signal property of the EM radiation based on a correlation of the power levels at the locations of the detection volumes.

[0030] In one embodiment, the method includes the further step of generating EM radiation based on a physical quantity to be analyzed.

[0031] In one embodiment, the at least two quantum sensors are arranged at locations in the area with different power levels, in particular different amplitudes, of the EM radiation, so that at least one of the quantum sensors can detect a power level of the EM radiation when the other quantum sensor is in saturation.

[0032] In one embodiment, the sensor volumes comprise a number of atoms that are optically, magnetically, and / or electrically excited to a quantum state. Alternatively, the number of atoms can also be in a ground state.

[0033] According to a third aspect, the disclosure relates to a quantum sensor system for detecting electromagnetic (EM) radiation. The quantum sensor system comprises: a quantum sensor arranged to receive the EM radiation, wherein the quantum sensor includes a detection volume configured to interact with the EM radiation on at least two different types of atoms and / or at least two different atomic transitions; at least one detector configured to detect interactions of the EM radiation with the detection volume on each of the at least two distinguishable types; and a processor configured to determine a characteristic signal of the EM radiation based on a correlation of the detected interactions.

[0034] For example, the quantum sensor system includes an element for shaping and / or focusing the EM radiation to create an inhomogeneous field distribution in an area, with the quantum sensor being located in that area.

[0035] In one embodiment, the quantum sensor system further comprises a signal source configured to generate EM radiation based on a physical quantity to be analyzed.

[0036] In one embodiment, the interactions of the EM radiation with the detection volume comprise at least two different types of atomic transitions in the detection volume in response to the EM radiation. These different atomic transitions can be an electrical and a magnetic transition, or two transitions with slightly different resonant frequencies.

[0037] In one embodiment, the at least two different atomic species interact with the EM radiation in at least two different ways. The different types of atoms can include rubidium and cesium atoms.

[0038] In one embodiment, the quantum sensor system comprises a gas cell in which the at least two different atomic species are stored in gaseous form. Brief description of the drawings

[0039] The aspects and embodiments of the present disclosure described above are explained in the following description of specific embodiments with reference to the accompanying drawings, in which: Fig. shows a schematic representation of a quantum sensor system for detecting EM radiation according to one embodiment; The Fig. show various arrangements of a quantum sensor system according to one embodiment; Fig. shows a schematic representation of a quantum sensor system for detecting EM radiation according to one embodiment; Fig. shows a schematic representation of a quantum sensor according to one embodiment; Fig. Figure 5 shows a flowchart of a method for detecting EM radiation according to one embodiment; and Fig. shows a flowchart of a method for detecting EM radiation according to one embodiment. Detailed descriptions of the embodiments

[0040] Fig. shows a schematic representation of a quantum sensor system 100 for detecting EM radiation according to one embodiment.

[0041] The quantum sensor system 100 comprises an element 101 configured to shape and / or focus the EM radiation to generate an inhomogeneous field distribution in an area; and at least two quantum sensors 106-1, 106-2 arranged at different locations in the area, each of the quantum sensors 106-1, 106-2 comprising a detection volume 102-1, 102-2 configured to interact with the EM radiation.The quantum sensor system 100 further comprises at least one detector 103-1, 103-2 configured to detect an interaction of the EM radiation with each detection volume 102-1, 102-2, wherein the interaction indicates a power level of the EM radiation at the location of the respective detection volume 102-1, 102-2; and a processor 104 configured to determine a signal characteristic of the EM radiation based on a correlation of the power levels at the locations of the detection volumes 102-1, 102-2.

[0042] As in Fig. As shown in Figure 1, for example, each quantum sensor 106-1, 106-2 can comprise a detection volume 102-1, 102-2 and a special detector 103-1, 103-2 for the detection volume 102-1, 102-2.

[0043] In particular, the power level of the electromagnetic radiation is related to its amplitude. Thus, the interaction of the electromagnetic radiation with each detection volume 102-1, 102-2 is also an indicator of the amplitude of the electromagnetic radiation at the location of the detection volume 102-1, 102-2.

[0044] The processor 104 can be a microprocessor and / or a controller. The processor 104 can be configured to determine a relationship between the power levels received at the sensing volumes 102-1, 102-2 of the two quantum sensors 106-1, 106-2.

[0045] The quantum sensor system 100 can further comprise a signal source 105 configured to generate EM radiation based on a physical quantity to be analyzed. The signal source 105 can include an antenna for emitting the EM radiation.

[0046] The physical quantity can be an electric or magnetic field strength, a pressure, or a temperature. The Processor 104 can be configured to derive information about the physical quantity from the determined signal characteristics of the EM radiation.

[0047] The quantum sensors 106-1, 106-2 and in particular the detection volumes 102-1, 102-2 are arranged at two (or more) different positions where the electromagnetic radiation has different field amplitudes and thus different powers.

[0048] The recording volumes 102-1, 102-2 can be, as in Fig. As shown in Figure 1, the detection volumes 102-1 and 102-2 can be arranged separately. Alternatively, they can be arranged directly next to each other and / or overlap at least partially along a gradient of the inhomogeneous field distribution. Each detection volume 102-1 and 102-2 can contain a quantum system.

[0049] If the detection volume 102-1 exhibits saturation behavior at a first position with a higher field amplitude, additional information about the EM radiation can be acquired by the second detection volume 102-2 at the second position (or other additional positions) with a lower field amplitude. Due to the lower field amplitude, the second detection volume 102-2 can withstand higher power levels from the signal source before saturating. In this way, the dynamic range of the quantum sensor system 100 is extended.

[0050] To determine the signal characteristics based on a correlation of the power levels and / or to determine information about the physical quantity, the Processor 104 can be configured to apply a calibration signal to the acquired power levels. The calibration signal can span different power levels and frequencies. If a linear antenna is used to shape / focus the EM radiation, e.g., onto a linear gradient, the calibration signal can be a single calibration curve.

[0051] Element 101 can be any means of shaping and / or focusing the EM radiation. For example, Element 101 can be an RF device such as a waveguide or stripline with an evanescent field around it, a parabolic antenna, or an absorber located in the area. Element 101 can also include a medium (e.g., an air-filled space) that attenuates the field.

[0052] For example, resonant transitions between two energy levels in the detection volumes 102-1 and 102-2 can be used to detect the EM radiation: If the EM radiation is resonant (or nearly resonant) with two energy levels in one of the detection volumes 102-1 or 102-2, it interacts with the detection volume and changes the state of the detection volume or a part of it. However, other types of transitions can also be used (e.g., strong shifts due to non-resonant interactions). The state of the atoms in the sensor volumes 102-1 and 102-2 can be read out by various means (e.g., optically or by detecting EIT for Rydberg atoms).

[0053] Each of the sensor volumes 102-1, 102-2 can contain a number of atoms in a ground state or an excited quantum state. The excited atoms could be, for example, Rydberg atoms. The atoms could be rubidium or cesium atoms.

[0054] For example, one or both of the measurement volumes 102-1, 102-2 can comprise a gas cell in which the number of atoms is stored in gaseous form.

[0055] Alternatively or additionally, at least one of the measurement volumes 102-1, 102-2 consists of a solid material, e.g. diamond, which has the number of atoms or atom-like systems such as NV defects.

[0056] The at least one detector 103-1, 103-2 can consist of one or more optical detectors, e.g., cameras. The detector(s) 103-1, 103-2 can detect an optical change in the detection volume 102-1, 102-2 due to an interaction of the detection volume with the EM radiation.

[0057] Fig. Figures 2A-C show various arrangements of the quantum sensor system 100 according to one embodiment. For the sake of simplicity, the Fig. 2A-C only the detection volumes 102-1, 102-2 of the quantum sensor system 100.

[0058] Fig. Figure 2A shows a quantum sensor system 100 used to measure the power / voltage level of a signal contained in a cable or waveguide. To access the signal with the atoms in the sensor volumes 102-1, 102-2, the signal in the cable or waveguide can be converted into the electric or magnetic field distribution via an antenna. Alternatively, the sensor volumes 102-1, 102-2 can be brought close to the field of the cable or waveguide. It is then possible to measure the field at two (or more) different positions with two different amplitudes.

[0059] Fig. This shows cases in which a far-field or homogeneous EM wave is analyzed. As in Fig. As shown in Figure 2B, for example, an inhomogeneous field distribution can be intentionally generated by focusing the EM input wave onto a single point using an antenna (not shown). Then, one measurement volume 102-1 can be placed at the focal point of the antenna, and the other measurement volume 102-2 at a position with lower amplitude. Alternatively, as shown in Fig. As shown in Figure 2C, an absorber can be added instead, e.g., between the detection volumes 101-1 and 102-2. The absorber can absorb at least part of the EM signal, so that the detection volume 101-2 behind the absorber receives the EM signal with a lower amplitude.

[0060] Fig. shows a schematic representation of a quantum sensor system 200 for detecting EM radiation according to one embodiment.

[0061] The quantum sensor system 200 comprises a quantum sensor 206 arranged to receive the EM radiation, wherein the quantum sensor 206 includes a detection volume 202 configured to interact with the EM radiation in at least two distinguishable ways based on at least two different atomic species and / or at least two different atomic transitions. The quantum sensor system 200 further comprises at least one detector 203 configured to detect interactions of the EM radiation with the detection volume 202 in each of the at least two distinguishable ways; and a processor 204 configured to determine a characteristic signal of the EM radiation based on a correlation of the detected interactions.

[0062] So instead of measuring the response of two (or more) separate sensor volumes, as is the case with the in Fig. In contrast to the system 100 shown in Figure 1, system 200 uses a single, potentially larger sensor volume containing various (more or less) stationary quantum systems to perform a spatially resolved measurement of the sensor response.

[0063] The processor 204 can be a microprocessor and / or a controller.

[0064] The quantum sensor system 200 can further comprise a signal source 205 configured to generate EM radiation based on a physical quantity to be analyzed. The signal source 205 can include an antenna for transmitting the EM radiation.

[0065] The interactions of the EM radiation with the detection volume 202 can include at least two different types of atomic transitions in the detection volume, e.g. an electrical and a magnetic transition or two transitions with slightly different resonance frequencies.

[0066] For example, a first transition is resonant with the electromagnetic field, while a second transition is not exactly resonant, resulting in a reduced transition strength compared to the first. Alternatively or additionally, the transitions could also be distinguished by the polarization of the electromagnetic field.

[0067] The at least two different atomic species are preferably arranged in the same sensor volume of the quantum sensor 206. The quantum sensor system 200 comprises, for example, a gas cell in which the different atomic species are arranged in gaseous form. The atomic species can include rubidium and cesium.

[0068] For example, the different transitions within the same sensor volume have different transition strengths and can be distinguished in the readout scheme. The different resonant transitions, for instance, require different energies. Therefore, if one of the resonant transitions is saturated due to a high signal level of the EM radiation, the other (weaker) transition can still be used to measure the signal level (and / or amplitude) of the EM radiation. In this way, the dynamic range of the quantum sensor system 200 is extended.

[0069] The EM signal characteristics and / or the physical quantity can be calculated theoretically (e.g., via a mathematical model) or with the help of a calibration curve based on the correlation of the detected interactions.

[0070] The detector 203 of the system 200 can be an optical detector, e.g. a camera that can detect optical changes in the detection volume 202 due to the interactions.

[0071] The in the Fig. The measurement methods shown combine high sensitivity with the ability to characterize strong EM signals due to a high dynamic range. For example, no conventional attenuators are used, which would reduce the sensitivity of the measurements.

[0072] Fig. Figure 4 shows a schematic representation of a quantum sensor 1 according to one embodiment. In one example, each of the quantum sensors 106-1, 106-2 of the system 100 can be in Fig. 1 or the quantum sensor 206 of system 200 in Fig. 3 according to the one in Fig. The quantum sensor 1 shown in section 4 can be configured. The sensor volume of the [unclear text] Fig. The example sensor 1 shown in Figure 4 is formed by a housing 5 containing a gas, e.g., cesium atoms. In the case of the sensor shown in Figure 4, the gas is contained within a housing 5. Fig. In the quantum sensor system 200 shown in Figure 3, another gas species may be present in the housing 5, e.g., rubidium.

[0073] The quantum sensor 1 comprises a camera 2 equipped with a lens system 3 to capture fluorescent light emitted by a gas contained within a hermetically sealed housing 5. The light emitted by the gas atoms inside the housing 5 can be filtered by a filter 4, which is adjusted to transmit the fluorescent light. The housing 5 is positioned between two permanent magnet rings 6 and 7, which serve as a magnetic field source. It should be noted that any type of magnetic field source, particularly coils, can be used. If coils are used, the field strength can be controlled by the driver. The housing 5 is placed on a base plate 8, which, in the simplest case, can serve only as a support.According to a preferred embodiment, the base plate 8 can be heated so that the housing 5, and thus the gas contained therein, can be kept at a desired and preferably constant temperature, for example 60 °C. This applies if the gas contains cesium atoms as reactants for carrying out the measurement. At 60 °C, the cesium atoms are in the gas phase.

[0074] The quantum sensor 1 comprises a source of an electric field, which in the illustrated embodiment is a pair of capacitors 9, 10 arranged on opposite sides of the housing 5. The capacitors 9, 10 each consist of a pair of electrodes 11, 12 and 14, 15, respectively, between which a dielectric material 13 and 16 is located. The capacitors 9, 10 generate an electric field that is static but inhomogeneous within the region of the housing 5. The strength of the electric field increases in the direction of the axis of symmetry.

[0075] It should be noted that the pair of magnetic rings 6, 7 defines an axis for the quantization states and the relative direction of the electric field influences the Stark shift. In the illustrated embodiment, which represents a preferred arrangement, the directions of the magnetic field and the electric field are essentially parallel.

[0076] The gas atoms in housing 5 are so-called Rydberg atoms, which are excited by a multitude of laser beams, designated by the numbers 17 and 18 in the diagram. The lasers are operated, for example, at wavelengths of approximately 850 nm, 852 nm, and 1470 nm, when three lasers are used as light sources to excite the outer electrons of the gas atoms in the active gas fraction of housing 5 to the Rydberg state.

[0077] The electromagnetic radiation to be measured is emitted by an antenna 19, which is preferably a horn antenna, so that the radiation can be focused inside the housing 5. To prevent any relative displacement of the antenna 19 with respect to the housing 5, a post is provided on the base plate 8 to support the antenna 19.

[0078] To improve the dynamic range, a decreasing intensity of the electromagnetic radiation towards the outer surface of the housing 5 is desired, and the capacitors 9 and 10 are controlled accordingly.

[0079] To analyze the electromagnetic radiation emitted by the antenna 19, the camera 2 detects the fluorescent light emitted by the gas atoms, in the preferred embodiment cesium atoms. Since the electric field generated by the capacitors 9 and 10 varies with the location within the housing 5, the resonant frequency for the electromagnetic radiation can depend on the location. Because the camera 2 produces a two-dimensional image, the intensity of the fluorescent light is detected with a special resolution. Thus, one dimension of the two-dimensional image reflects the frequency information, while the other dimension shows an intensity gradient to improve the dynamic range. In the Fig. In the arrangement shown in Figure 4, the source of the electromagnetic radiation, the source of the electric field and the camera 2 are preferably controlled simultaneously, i.e., an image is taken while the electric field is applied to the gas in the housing 5 and while the electromagnetic radiation to be measured also acts on the gas atoms.

[0080] It should be noted that, according to a preferred embodiment of the invention, the fluorescence light emitted by the cesium atoms is captured. It is also possible to detect laser light transmitted through the gas in the enclosure 5. The control unit 21 controls the camera 2, the laser sources 17 and 18, the emission of the radiation to be analyzed, and furthermore regulates the strength of the electric field by controlling the capacitors 9 and 10. In particular, the control unit 21 controls changes in the electric field strength and the operation of the microwave transmitter, namely the antenna 19. Such switching of the electric field and the microwave emission by the antenna 19 might be necessary if a narrowband laser is used and there is little or no additional gas in the enclosure 5.Switching the electric field and the electromagnetic radiation may be necessary, otherwise a narrowband laser and the gas in housing 5 would no longer resonate due to the Stark displacement.

[0081] Using a broadband laser as the light source (e.g., with a frequency greater than 30 GHz) would eliminate the need to switch the electric field. The same effect can be achieved by increasing the number of additional gas atoms in the housing 5. Thus, the desired line broadening can be adjusted by modifying the number of "active" gas atoms (Rydberg atoms) and additional gas atoms of a different type (filler gas). An increased amount of filler gas is preferred because it also serves to prevent unwanted movement of the active gas atoms during the measurement.

[0082] For the quantum sensors 106-1, 106-2 of the system 100 in Fig. 1 or the quantum sensor 206 of system 200 in Fig. However, other types of quantum sensors could also be used.

[0083] Fig. Figure 5 shows a flowchart of a method 50 for detecting EM radiation according to one embodiment. The method 50 can be compared with the one described in Figure 5. Fig. 1 quantum sensor system shown 100 will be carried out.

[0084] The method 50 comprises: shaping 52 and / or focusing the EM radiation to generate the inhomogeneous field distribution in the area; receiving 53 the EM radiation with at least two quantum sensors 106-1, 106-2 arranged at different locations in the area, each of the quantum sensors 106-1, 106-2 comprising a detection volume 102-1, 102-2 configured to interact with the EM radiation; detecting 54 an interaction of the EM radiation with each detection volume 102-1, 102-2, the respective interaction indicating a power level of the EM radiation at the location of the detection volume 102-1, 102-2; and determine 55 the signal characteristics of the EM radiation based on a correlation of the power levels at the locations of the detection volumes 102-1, 102-2.

[0085] In a first step, the procedure 50 can further include the step of generating 51 the EM radiation based on the physical quantity to be analyzed.

[0086] The at least two quantum sensors 106-1, 106-2 can be arranged at locations in the area with different power levels, in particular different amplitudes, of the EM radiation, so that at least one of the quantum sensors can detect a power level of the EM radiation when the other quantum sensor is in saturation.

[0087] The sensor volumes 102-1, 102-2 can comprise a number of atoms that are optically, magnetically and / or electrically excited to a quantum state.

[0088] Fig. Figure 6 shows a flowchart of a method 60 for detecting EM radiation according to one embodiment. The method 60 can be derived from the one described in Figure 6. Fig. The quantum sensor system 3 shown will be carried out in 200.

[0089] The method 60 comprises the following steps: Receiving 62 the EM radiation with a quantum sensor 206, wherein the quantum sensor 206 comprises a detection volume 202 configured to interact with the EM radiation on at least two different types of atoms and / or at least two different atomic transitions; detecting 63 interactions of the EM radiation with the detection volume 202 on each of the at least two distinguishable types; and determining 64 a signal characteristic of the EM radiation based on a correlation of the detected interactions.

[0090] As a first step, the procedure 60 can further include the following: generation 61 of the EM radiation based on the physical quantity to be analyzed.

[0091] All the features described above or depicted in the figures can be combined in any advantageous way within the scope of the disclosure.

Claims

[1] Quantum sensor system for the detection of electromagnetic radiation (EM), comprising: an element configured to shape and / or focus EM radiation to create an inhomogeneous field distribution in an area; at least two quantum sensors located at different points in the area, each of which includes a detection volume configured to interact with the EM radiation; at least one detector configured to detect an interaction of the EM radiation with each detection volume, the interaction indicating a power level of the EM radiation at the location of the respective detection volume; and a processor configured to determine a signal characteristic of the EM radiation based on a correlation of the power levels at the locations of the detection volumes. [2] Quantum sensor system according to claim 1, further comprising: a signal source configured to generate EM radiation based on a physical quantity to be analyzed. [3] Quantum sensor system according to claim 1, wherein the at least two quantum sensors are arranged at locations in the region with different power levels, in particular different amplitudes, of the EM radiation, such that at least one of the quantum sensors can detect a power level of the EM radiation when the other quantum sensor is in saturation. [4] Quantum sensor system according to claim 1, wherein the detection volumes of the at least two quantum sensors each comprise a number of atoms in a ground state or an excited quantum state. [5] Quantum sensor system according to claim 4, wherein at least one quantum sensor comprises a gas cell, wherein the number of atoms in the gas cell is stored in gaseous form. [6] Quantum sensor system according to claim 4, further comprising: at least one light source configured to illuminate the detection volumes of the at least two quantum sensors with a light beam, wherein the detection volumes are optically excited by the light beam; and / or at least one field generator unit configured to generate an electric and / or magnetic field within the detection volumes of the at least two quantum sensors, wherein a resonance frequency of the number of atoms in the detection volumes is changed by an amplitude of the electric and / or magnetic field. [7] Quantum sensor system according to claim 1, wherein the detection volumes of the at least two quantum sensors are arranged separately from each other. [8] Quantum sensor system according to claim 1, wherein the detection volumes of the at least two quantum sensors are arranged directly next to each other along a gradient of the inhomogeneous field distribution of the EM radiation and / or overlap at least partially. [9] Quantum sensor system according to claim 1, wherein the element comprises an antenna, such as a parabolic antenna. [10] Quantum sensor system according to claim 1, wherein the element comprises an absorber designed to absorb at least part of the EM radiation. [11] Method for detecting electromagnetic, EM, radiation, comprising the following steps: Shaping and / or focusing the EM radiation to generate an inhomogeneous field distribution in an area; Receiving the EM radiation with at least two quantum sensors arranged at different locations in the area, each of the quantum sensors comprising a detection volume configured to interact with the EM radiation; Detecting an interaction of the EM radiation with each detection volume, wherein the respective interaction specifies a power level of the EM radiation at the location of the detection volume; and Determination of a signal characteristic of the EM radiation based on a correlation of the power levels at the locations of the detection volumes. [12] The method of claim 11, further comprising the following step: The generation of EM radiation based on a physical quantity to be analyzed. [13] Method according to claim 11, wherein the at least two quantum sensors are arranged at locations in the region with different power levels, in particular different amplitudes, of the EM radiation, such that at least one of the quantum sensors can detect a power level of the EM radiation when the other quantum sensor is in saturation. [14] Method according to claim 11, wherein the sensor volumes comprise a number of atoms that have been optically, magnetically and / or electrically excited to a quantum state. [15] Quantum sensor system for the detection of electromagnetic, EM radiation, comprising: a quantum sensor arranged to receive EM radiation, wherein the quantum sensor comprises a detection volume configured to interact with the EM radiation in at least two distinguishable ways based on at least two different atomic species and / or at least two different atomic transitions; at least one detector configured to detect interactions of the EM radiation with the detection volume in each of the at least two distinguishable ways; and a processor configured to determine a signal characteristic of the EM radiation based on a correlation of the detected interactions. [16] Quantum sensor system according to claim 15, further comprising: a signal source configured to generate EM radiation based on a physical quantity to be analyzed. [17] Quantum sensor system according to claim 15, wherein the interactions of the EM radiation with the detection volume comprise at least two different types of atomic transitions in the detection volume in response to the EM radiation. [18] Quantum sensor system according to claim 15, wherein the at least two different atomic species interact with the EM radiation in at least two different ways. [19] Quantum sensor system according to claim 15, wherein the quantum sensor system comprises a gas cell in which the at least two different atomic species are stored in gaseous form in the gas cell.

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