Sensor unit and method for operating a sensor unit

Abstract

The invention relates to a sensor unit (100) having a waveguide (210) with a first end (220) and a second end (230) opposite the first end (220). The sensor unit (100) comprises a beam splitter (200) configured to split a light beam received from the light source (105) and to guide a first sub-beam obtained into a first end (220) of the waveguide (210) and a second sub-beam into a second end (230) of the waveguide (210), the beam splitter (200) is further configured for conducting light from the first end (220) of the waveguide (210) to the detector unit (280) and light from the second end (230) of the waveguide (230) to the detector unit (280). Finally, the sensor unit (100) comprises a detector unit (280) which is designed to detect and evaluate light from the first end (220) of the waveguide (210) together with light from the second end (230) of the waveguide (230).

Description

TECHNICAL FIELD

[0001] The present application proceeds from a sensor unit and a method for operating a sensor unit. The subject matter of the present application is also a computer program. BACKGROUND

[0002] MEMS sensors are compact inertial sensors with mechanical vibrating Coriolis masses. However, due to the mechanical components of the inertial sensors, they are susceptible to Erschütterung, vibrations, Brownian noise and temperature changes. Chip-integrated optical sensors are less susceptible to these influences and thus achieve better performance at similar unit costs and structure sizes.

[0003] In order to detect the rotation speed, optical gyroscopes based on the Sagnac effect exist. In a chip-integrated implementation, light is continuously sent in two opposite directions into a coiled optical waveguide. Due to the Sagnac effect, the effective path lengths of the two light paths change when the system rotates. As a result, the phase of the light moves. After passing through the waveguide, the two light paths meet each other again and superimposition of the light waves takes place. Here, constructive and destructive interference occurs and light waves are generated whose intensity can be measured and can change proportionally to the rotation speed. However, only one axis of rotation can be measured thereby.

[0004] In addition, the rotation speed can be measured by means of optical mechanical coupling. By means of a Mach-Zehnder interferometer (MZI), a phase shift can be used as a measurement signal due to the influence of the moved Coriolis mass on the refractive index of the optical conductor or optical resonator. However, all known solutions have problems in terms of compact, chip-integrated, small structure space and highly sensitive and precise three-axis rotation speed detection. SUMMARY

[0005] In this context, a sensor unit according to the application is presented by means of the solution introduced here, a method for operating a sensor unit is additionally proposed, a sensor unit using the method is proposed and finally a corresponding computer program is proposed. By means of the measures listed below, advantageous extensions and improvements of the sensor unit according to the application can be achieved.

[0006] The present application proposes a sensor unit, which has the following features:

[0007] a waveguide having a first end and a second end opposite the first end;

[0008] a beam splitter, which is configured and arranged for splitting the light beam received from the light source and guiding a first sub-beam resulting therefrom into the first end portion of the waveguide and a second sub-beam into the second end portion of the waveguide, wherein the beam splitter is furthermore configured and arranged for conducting light from the first end portion of the waveguide to the detector unit and light from the second end portion of the waveguide to the detector unit; and

[0009] a detector unit, which is configured for detecting and analyzing the light from the first end portion of the waveguide together with the light from the second end portion of the waveguide.

[0010] For example, the waveguide can be understood as an optical fiber or a dielectric fiber, which is capable of guiding electromagnetic waves between the first end portion and the second end portion. The beam splitter can be understood as an optical element, which is capable of shaping and deflecting a light beam, for example dividing it into a plurality of sub-beams. For example, the beam splitter can be configured as a partially transmissive mirror or a partially transmissive prism or as a multi-mode interferometer in a chip-integrated manner, in order to pass the first sub-beam and deflect the second sub-beam. At the same time, the beam splitter can also be configured for deflecting the light exiting from the first end portion of the waveguide onto the detector unit and the light exiting from the second end portion of the waveguide likewise onto the detector unit. The beam splitter thus assumes the function of a directional element in reverse, in order to bundle and deflect the light from different directions into a common detector unit.

[0011] The approach presented here is based on the recognition that a waveguide can be transmitted bidirectionally and thus the effective length of the waveguide changes due to the Sagnac effect when the waveguide is moved, for example rotated. This enables an analysis of the interference between the light from the first end portion to the second end portion of the waveguide and the light from the second end portion to the first end portion of the waveguide, in order to obtain information about a quantity of the movement or rotation of the sensor unit, for example.

[0012] The approach presented provides the advantage that by using very few components, in particular a waveguide which is transmitted in two directions, a physical parameter can be measured efficiently. In addition to a very small structure group by making full use of the physical law of the Sagnac effect, this also enables an accurate and cost-advantageous measurement of a certain parameter by the sensor unit.

[0013] The following embodiment of the solution presented here is advantageous, in which the waveguide has a spiral structure and / or is configured as a Mach-Zehnder interferometer and / or has a phase-shifting element, and / or in which the beam splitter is configured as an at least partially transmissive mirror. Such an embodiment offers the advantage that only a small space requirement is necessary for the arrangement of the waveguide, or a desired pre-distortion of the photons can be achieved by using one or more corresponding phase-shifting elements, so that the physical variable can subsequently be determined very precisely. The use of an at least partially transmissive mirror as a beam splitter likewise enables a construction group with a small space requirement.

[0014] According to another embodiment, in order to make a construction group of the sensor unit as completely integrated as possible, a light source can be provided, which is configured and oriented for emitting a light beam onto the beam splitter. Here, in the case of the use of a chip-integrated optical component, the optical path can also be realized in a chip-integrated manner.

[0015] In addition, the following embodiment of the solution presented here can be considered, in which the detector unit is configured for obtaining a sensor signal, which represents a movement and / or a rotation of the sensor unit. Such an embodiment offers the advantage that such a sensor unit can detect a corresponding movement or rotation of the sensor unit particularly cost advantageously and still precisely.

[0016] In addition, the following embodiment of the solution presented here is advantageous, which has at least one Coriolis mass element, which is suspended in a manner movable in a vibration direction relative to at least one fixed point. Here, a vibrating Mach-Zehnder interferometer is provided, which is configured for detecting a movement of the Coriolis mass element in the vibration direction, in particular wherein the vibrating Mach-Zehnder interferometer is arranged with a predefined spacing from the Coriolis mass element, and / or the vibrating Mach-Zehnder interferometer is configured or arranged for detecting a movement of the sensor unit, which is different from the movement that can be detected by the waveguide and the detector unit. The Coriolis mass element can be understood as an element or body that is suspended in a manner movable relative to a fixed point, for example a housing. This type of embodiment of the solution presented here offers the advantage that further physical variables or further parameters, in particular movement parameters, can be detected by the sensor unit. Here, in particular in the case of the use or exploitation of optical correlations, a very precise detection of these variables or parameters can also be achieved.

[0017] Further, embodiments of the solution presented here can be considered in which the Coriolis mass element is suspended in a manner movable with respect to at least one further fixed point in a further vibration direction, wherein a further vibrating Mach-Zehnder interferometer is provided, which is configured for detecting the movement of the Coriolis mass element in the further vibration direction, in particular wherein the further vibrating Mach-Zehnder interferometer is arranged in a manner having a predefined further spacing from the Coriolis mass element, and / or wherein the further vibrating Mach-Zehnder interferometer is configured or arranged for detecting a movement of the sensor unit, which is different from the vibration direction and the movement that can be detected by the waveguide and the detector unit. Such embodiments offer the advantage that a particularly precise measurement of a physical quantity in the further movement direction or vibration direction is also achieved by using an optical measurement element for measuring this quantity. Here, in particular, the use of the Coriolis mass element can prove to be particularly advantageous if it is also used for measuring the quantity in the further movement direction or vibration direction. Thus, by using the Coriolis mass element jointly for the parameters or quantities in the vibration direction and the further vibration direction, a measurement element can be achieved which has a small space requirement.

[0018] According to a further embodiment of the solution presented here, a phase-shifting element can be provided on the path of the vibrating Mach-Zehnder interferometer and / or of the further vibrating Mach-Zehnder interferometer, and / or wherein at least one beam-splitting element is provided, which is configured for dividing the light incident on the beam-splitting element into sub-beams, which are each directed into the vibrating Mach-Zehnder interferometer and the further vibrating Mach-Zehnder interferometer. Such embodiments of the solution presented here offer the possibility that, by parameterization of the phase-shifting element, the sensitivity of the vibrating Mach-Zehnder interferometer or of the further vibrating Mach-Zehnder interferometer can be particularly advantageously set. The use of a corresponding beam-splitting element can achieve a compact construction of the sensor unit in which the light from the light source or from the auxiliary light source can be conducted into the respective vibrating Mach-Zehnder interferometer.

[0019] Furthermore, the following embodiment of the solution presented here is advantageous, in which a detection element is provided, which is configured for determining the movement of the Coriolis mass element in the vibration direction or in a further vibration direction in the case of an evaluation of the refractive index change, which is caused by a change in the distance between the Coriolis mass element and the path of the vibrating Mach-Zehnder interferometer and / or between the Coriolis mass element and the path of the further vibrating Mach-Zehnder interferometer. Such an embodiment offers the advantage that precise measurement results are obtained by optical effects, so that measurement value deterioration, for example caused by wear phenomena, has as little significant influence as possible during the operation of the sensor unit.

[0020] The following embodiment of the solution presented here can be realized particularly compactly and in a manner having a small space requirement, in which the light source is configured for conducting light into the vibrating Mach-Zehnder interferometer and / or into the further vibrating Mach-Zehnder interferometer. Such an embodiment offers the advantage that a compact and self-sufficiently usable sensor unit is realized by using a light source, for example realized in an integrated circuit having further components of the sensor unit, the principle of action of which can be disturbed as little as possible by external effects.

[0021] Furthermore, the above-mentioned advantages can also be achieved by an embodiment of the method presented here as a variant for operating the sensor unit presented here, which has the following steps:

[0022] - irradiating at least the beam splitter with light in order to direct the first sub-beam into the first end portion of the waveguide and the second sub-beam into the second end portion of the waveguide; and

[0023] - detecting and evaluating the light received in the detector unit in order to obtain a sensor signal.

[0024] The method can be implemented, for example, in software or hardware or in a hybrid form composed of software and hardware, for example in a controller or control unit.

[0025] Furthermore, the solution presented here realizes a control unit, which is configured for carrying out, controlling or implementing the steps of a variant of the method presented here in the respective device. By this implementation variant of the invention in the form of a control unit, the task on which the invention is based can also be solved quickly and efficiently.

[0026] To this end, the control unit can have at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface to sensors or actuators for reading in sensor signals of the sensors or for outputting data signals or control signals to the actuators, and / or at least one communication interface for reading in or outputting data embedded in a communication protocol. The computing unit can be, for example, a signal processor, a microcontroller or the like, wherein the memory unit can be a flash memory or a magnetic memory unit. The communication interface can be configured for reading in or outputting data wirelessly and / or wired, wherein a communication interface that can read in or output wired data can read in or output these data, for example, in an electrical or optical manner, from or into a corresponding data transmission line.

[0027] In the present case, the control unit is to be understood as an electrical appliance that processes sensor signals and outputs control signals and / or data signals therefrom. The control unit can have an interface that can be configured in a hardware and / or software manner. In a hardware configuration, the interface can be, for example, part of a so-called system ASIC that contains the various functions of the control unit. It is also possible, however, that the interface is a self-contained integrated circuit or at least partially composed of discrete structural elements. In a software configuration, the interface can be, for example, a software module that coexists with other software modules on a microcontroller.

[0028] Furthermore, the approach presented here implements a controller that is configured to execute, to operate or to implement the steps of a variant of the approach presented here in a corresponding device. Through this implementation variant of the invention in the form of a controller, the task on which the invention is based can also be solved quickly and efficiently.

[0029] To this end, the control unit can have at least one computing unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface to sensors or actuators for reading in sensor signals of the sensors or for outputting data signals or control signals to the actuators, and / or at least one communication interface for reading in or outputting data embedded in a communication protocol. The computing unit can be, for example, a signal processor, a microcontroller or the like, wherein the memory unit can be a flash memory or a magnetic memory unit. The communication interface can be configured for reading in or outputting data wirelessly and / or wired, wherein a communication interface that can read in or output wired data can read in or output these data, for example, in an electrical or optical manner, from or into a corresponding data transmission line.

[0030] In the current context, the controller can be understood as an electrical appliance that processes sensor signals and outputs control signals and / or data signals based on those signals. The controller can have an interface, which can be constructed in hardware and / or software. In a hardware-based construction, the interface can, for example, be part of a so-called system ASIC, containing various functions of the controller. However, it is also possible that the interface is a proprietary integrated circuit or at least partially composed of discrete structural elements. In a software-based construction, the interface can be, for example, a software module coexisting with other software modules on the microcontroller.

[0031] It is also advantageous to have a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium, such as a semiconductor memory, a hard disk memory, or an optical memory, and especially when the program product or program is executed on a computer or control unit, the program code is used to perform, implement, and / or manipulate the steps of the method described according to one of the foregoing embodiments. Attached Figure Description

[0032] Embodiments of the proposed solutions are shown in the accompanying drawings and described in more detail in the following description. The drawings show:

[0033] Figure 1 A schematic diagram illustrating an embodiment of the sensor unit described herein is shown;

[0034] Figure 2 A schematic diagram showing an embodiment of the first sensor element of the Sagnac gyroscope;

[0035] Figure 3 A schematic diagram showing the structure of the second sensor element;

[0036] Figure 4 A flowchart illustrating an embodiment of a method for operating a variant of the sensor unit described herein; and

[0037] Figure 5 A block diagram of an embodiment of a control unit for implementing a variation of a method for operating the sensor unit described herein is shown. Detailed Implementation

[0038] In the following description of advantageous embodiments of the invention, the same or similar reference numerals are used for elements shown in different figures that serve similar functions, wherein repeated descriptions of these elements are omitted.

[0039] Figure 1A schematic diagram of an embodiment of the sensor unit 100 described herein is shown. For example, the sensor unit 100 may be configured as an integrated semiconductor structure element. However, it is also conceivable that individual components of the sensor unit 100 are integrated only in a common chip and, for example, can receive light from an external light source 105. The light from the external light source 105, or light from a light source 105 that may be integrated on the chip along with other components of the sensor unit 100, is split in a dividing element 110 (e.g., an optical beamsplitter) and accordingly conducted via a first light conductor 112 to a first sensor element 115 and via a second light conductor 117 to a second sensor element 120. Here, for example, the first sensor element 115 may be configured as a Sagnac gyroscope, and the second sensor element 120 as a Coriolis gyroscope.

[0040] therefore, Figure 1 This diagram illustrates a combined, for example, chip-integrated structure consisting of a Sagnac gyroscope and an optomechanical gyroscope for measuring rotational speed in all three spatial directions. The same light source 105, such as a laser source, can be used for both sensor elements 115 and 120. For example, the Sagnac gyroscope, serving as the first sensor element 115, detects the rotational speed Ω around the Z-axis. The Coriolis gyroscope, serving as the second sensor element 120, detects the rotational speed around the x-axis and y-axis. Here, by using different gyroscopes, the accuracy of detecting the rotation of sensor unit 100 can be significantly improved through analysis of different physical parameters or their effects.

[0041] Figure 2 A schematic diagram is shown as an embodiment of the first sensor element 115 of the Sagnac gyroscope. Here, the sensor element 115 is fed by a light source 105 via a first optical conductor 112, from which light is incident onto a beamsplitter 200, configured, for example, as a partially transmissive mirror. Additionally, the first sensor element 105 includes a second zero waveguide having a first end 220 and a second end 230. Now, by means of the beamsplitter 200, light, more precisely, a sub-beam of light, is coupled from the first optical conductor 112 into the first end 220 of the waveguide 210, while another sub-beam of light is coupled from the first optical conductor 112 into the second end 230 of the waveguide 210. The two opposing beams now extend in the waveguide 210, as indicated by the double-headed arrow with reference numeral 240. In addition, waveguide 210 is arranged spirally in section 250 and additionally has a phase shifting element 260 in the region of the second end 230 so that a corresponding phase shift can be adjusted when passing through the phase shifting element 260.

[0042] Next, the sub-beams passing through waveguide 210 are directed again from the first end 220 and the second end 230 to beamsplitter 200, and then the corresponding sub-beams are guided to detector unit 280 via beamsplitter. Then, in detector unit 280, the movement or rotation of the first sensor element 115 can be inferred by using the interference between the two light beams. Alternatively, a circulator 285 can be provided in or on the light conductor 112, allowing light from light source 105 to pass through to beamsplitter 200. However, the light reflected back from beamsplitter 200 exits at another output on circulator 285. Therefore, light can be measured using a second detector unit 290 (e.g., a photodiode), and differential measurements can be performed using signals from detector unit 280. This allows for monitoring of functional capabilities or potential malfunctions or interference.

[0043] therefore, Figure 2 A schematic configuration of the proposed optical portion or first sensor element 115, serving as a rotational speed sensor for sensor unit 100, is shown. Light is continuously transmitted into waveguide 210 in two opposite directions. Due to the Sagnac effect, as the system or first sensor element 115, or generally sensor unit 100, rotates, the effectively traversed lengths of the two optical paths change. These effectively traversed lengths can then be detected by analyzing the interference of the two sub-beams extending through waveguide 210 in different directions.

[0044] Figure 3 A schematic diagram of the structure of the second sensor element 120 is shown, which is configured here as a Coriolis gyroscope. Conversely, a light source 105 (which is disposed externally relative to the sensor unit 100 or integrated on a common chip with the sensor unit 100) supplies a corresponding light beam to the second sensor element 120 via the second light conductor 117. The light beams from the second light conductor 117 are supplied to Mach-Zehnder interferometers via beam splitters 300, which, for better distinction, are referred to as vibrating Mach-Zehnder interferometer 310 and another vibrating Mach-Zehnder interferometer 320. Each of these vibrating Mach-Zehnder interferometers 310 or 320 includes a waveguide element 330 having a first path and a second path 337, respectively. A portion of the light coupled into the respective vibrating Mach-Zehnder interferometer 310 or 320 via the beam splitter 300 is guided into the second path. On the first path 335 of the corresponding vibrating Mach-Zehnder interferometer 310 or 320, an (optical) phase-shifting element 260 is provided so that, for example, the photon extending in the first path 335 can be changed in terms of phase or intensity.

[0045] Here, light extending through the vibrating Mach-Zehnder interferometer 310 can be analyzed by the detection unit 340 (e.g., if the interference effect is fully utilized). Similarly, light extending through another vibrating Mach-Zehnder interferometer 320 can be analyzed by another detection unit 345 (e.g., also if the interference effect is fully utilized). Furthermore, the Mach-Zehnder 310 and / or 320 can each have two outputs, and each output can be measured or monitored by a photodiode or detection unit. By subtracting the signals from the corresponding outputs of the Mach-Zehnder 310 and / or 320, differential measurement can be achieved, which improves the system's robustness.

[0046] Here, by analyzing the optical effect using a vibrating Mach-Zehnder interferometer 310 or another vibrating Mach-Zehnder interferometer 320, the motion of the Coriolis mass element 350 can be detected. This Coriolis mass element is suspended in a movable manner, for example, via a first spring 355 and a first fixed point 360 (e.g., part of the housing of the sensor unit 100) and / or via a second spring 365 and a second fixed point 370 (e.g., also within part of the housing of the sensor unit 100). Here, the Coriolis mass element 350 has a distance g from the second path 337 of the vibrating Mach-Zehnder interferometer 310. x Arranged in a manner that, and with an additional spacing g with the second path 337 of the other vibrating Mach-Zehnder interferometer 320. y The arrangement is as follows. Here, for example, the Coriolis mass element 350 can be driven along the z-direction and thus placed in vibration. Now, if an additional rotational force acts on the Coriolis mass element 350 in the x and / or y directions, the spacing g x and / or other spacing g y The resulting change causes a change in the refractive index of the material of the second path 337 of the waveguide 330 of the vibrating Mach-Zehnder interferometer 310 or another vibrating Mach-Zehnder interferometer 320, which in turn causes a change in the propagation time of light through the corresponding second path 337, which can then be detected in the detection unit 340 or another detection unit 345. Subsequently, the corresponding rotation of the sensor unit 100 or the second sensor element 120 in the x and / or y directions can be inferred from the results of the detection unit 340 and the other detection unit 345.

[0047] therefore, Figure 3A schematic configuration of the proposed optomechanical portion of the second sensor element 120, which serves as a rotational speed sensor for sensor unit 100, is shown. When the sensor or sensor unit 100 rotates Ω, the Coriolis mass or mass element 350 is deflected and interacts with the electric field of the photoconductor or the second path 337 of the corresponding vibrating Mach-Zehnder interferometer.

[0048] In summary, it can be noted that light from a light source or laser source can either be generated directly on the optical chip of sensor unit 100, or coupled into the optical chip via a grid coupler structure (not shown in the figures). In the second possibility, the laser or light source can be positioned directly above the grid coupler and can be guided from the grid coupler into the waveguide via a tapered structure.

[0049] For example, such as Figure 2 As shown, a Sagnac sensor is used to detect the rotational speed of sensor unit 100 in a spatial direction. The (laser) light is split at a first beam splitter 200 and passes through the sensor region of waveguide 210 clockwise and counterclockwise, respectively. The Sagnac effect operates in this sensor region, causing a phase shift according to the applied rotational speed. The surrounding laser beams (here, sub-beams) then re-meet in beam splitter 200. The resulting interference signal can be measured by means of a photodetector or detector unit 280, and the rotational speed can be determined thereby.

[0050] Similarly, the sensitivity of the Sagnac sensor can be improved by utilizing quantum states.

[0051] According to another embodiment, a ring gyroscope can be used instead. Figure 2 The sensor shown.

[0052] For example, optical-mechanical methods can be used to measure rotational speed in another spatial direction. Here, the sensor structural elements are derived from those used in MEMS sensors and... Figure 3 The Coriolis mass 350 shown corresponds to the second sensor element 120 in this sensor structure. The mass 350 is suspended in a movable manner, for example, on a corresponding mechanical spring structure 355 or 365, which in turn is mounted on a fixed substrate 360 ​​or 370. The mass can be electrostatically actuated, thereby inducing an oscillating motion in the driving direction along the z-axis. The mass 350 is also suspended in a movable manner in the detection direction. If the moved mass experiences a rotational speed Ω, the Coriolis force causes the moved mass 350 to move along the detection direction and thus results in a change in the spacing relative to the fixed structure.

[0053] Advantageously, this spacing change can be read out optically using a Mach-Zehnder interferometer. This coupling effectively causes a change in the refractive index in the arm (in this case, the second path 337) of the corresponding Mach-Zehnder interferometer MZI310 or 320, which results in phase accumulation of that arm 337 relative to the other arm 335.

[0054] The phase difference Δφ between the two arms of the MZI is used as the measurement signal for the proposed rotational speed sensor. This phase difference is achieved through... Given, where L is the length of the waveguide, g x or g y It is the distance between the waveguide of MZI and the Coriolis mass, and n eff This is the effective refractive index of the waveguide. The phase shift is, under a good approximation, proportional to the shift of the Coriolis mass in the detection direction, because... Where i = x, y represents the offset of the Coriolis mass in the detection direction. For high sensitivity, the arm of the MZI is placed near the Coriolis mass (~10-200 nm). Optical phase shifters (e.g., electro-optical phase shifters (Kerr or Polkels effect), heating elements, or corresponding dopants) on the other arm of the MZI ensure the phase shift between the two arms of the MZI in a manner independent of mechanical coupling. Thus, the phase offset can be tuned to maximize sensitivity to the offset.

[0055] The interference signal can be measured and the rotation speed can be determined by using photodetectors 340 or 345.

[0056] This concept can also be implemented in multi-axis arrangements or in arrangements with dual, moved masses to ensure differential analysis processing. Similarly, rotational velocities in all three spatial directions can be detected. For this, additional MZI structures are needed above or below the moved masses. A beam splitter distributes the laser beam onto the MZI structures in the three spatial directions.

[0057] Other optical methods for detecting changes in spacing are also possible.

[0058] When detecting rotational speed in all three spatial directions using an optomechanical method, the Sagnac gyroscope 115 generates an additional measurement signal for one of the three spatial directions. By combining these signals, errors can be corrected, the measurement range increased, and signal accuracy obtained over a longer time period.

[0059] The Sagnac gyroscope 115 and the Coriolis gyroscope 120 can use the same light source 105, such as a laser source.

[0060] Compared to current optical gyroscopes (which are very large or limited to measuring rotational speed along a single axis), the method presented here is based on a compact, chip-integrated sensor solution for measuring rotational speed in as many or all three spatial directions (x, y, z) as possible.

[0061] The following architecture is used: in this architecture, the rotational speed around the main axis is detected optically by means of the Sagnac effect, while the rotational speed around the other two axes is detected optomechanically.

[0062] The advantages of using the methods described here can be summarized as follows:

[0063] High sensitivity can be achieved by using such a sensor unit.

[0064] High accuracy can be achieved by using such a sensor unit.

[0065] Technically, it is easy to measure rotational speed in all three spatial directions.

[0066] Two gyroscopes can use the same optical components.

[0067] Both gyroscopes can use the same laser source.

[0068] Such a sensor unit only requires such a small structural size.

[0069] Known production methods can be utilized.

[0070] Figure 4 A flowchart illustrating an embodiment of a method 400 for operating a variant of the sensor unit described herein is shown, wherein method 400 includes a step 410 of illuminating at least the beam splitter with light to guide a first sub-beam into a first end of a waveguide and a second sub-beam into a second end of the waveguide. Furthermore, method 400 includes a step 420 of detecting and analyzing the light received in the detector unit.

[0071] Figure 5 A block circuit diagram is shown for an embodiment of a control unit for implementing a method 400 for operating a variation of the sensor unit described herein, wherein the control unit 500 has a unit 510 for manipulating the illumination of at least the beam splitter by means of light to guide a first sub-beam into a first end of the waveguide and a second sub-beam into a second end of the waveguide. Furthermore, the control unit 500 includes a unit 520 for manipulating the detection and analysis processing of light received in the detector unit to obtain sensor signals.

[0072] If an embodiment includes an "and / or" connection between the first feature and the second feature, this can be interpreted such that the embodiment, according to one implementation, has not only the first feature but also the second feature, and according to another implementation, has either only the first feature or only the second feature.

Claims

1. Sensor unit (100), having the following features: - a waveguide (210) having a first end (220) and a second end (230) opposite the first end (220); - a beam splitter (200) configured and arranged for splitting a light beam received from a light source (105) and directing a first sub-beam obtained thereby into a first end portion (220) of the waveguide (210) and a second sub-beam into a second end portion (230) of the waveguide (210), wherein, the beam splitter (200) is furthermore configured and arranged for conducting light from the first end (220) of the waveguide (210) to a detector unit (280) and for conducting light from the second end (230) of the waveguide (230) to the detector unit (280); and - a detector unit (280) configured for detecting and analytically processing light from the first end (220) of the waveguide (210) together with light from the second end (230) of the waveguide (230).

2. The sensor unit (100) according to claim 1, wherein The waveguide (210) has a spiral structure (250) and / or is configured as a Mach-Zehnder interferometer and / or has a phase shifting element (260), and / or wherein the beam splitter (200) is configured as an at least partially transmissive mirror.

3. Sensor unit (100) according to any one of the preceding claims, having a light source (105) configured and oriented for emitting a light beam onto the beam splitter (200).

4. The sensor unit (100) according to any one of the preceding claims, wherein The detector unit (280) is configured for obtaining a sensor signal representative of a movement and / or rotation of the sensor unit (100).

5. The sensor unit (100) according to any one of the preceding claims, having at least one Coriolis mass element (350) which is suspended in a manner movable in a vibration direction relative to at least one fixed point (360), wherein A vibratory Mach-Zehnder interferometer (310) is provided, which is configured for detecting a movement of the Coriolis mass element (350) in the vibration direction, in particular wherein the vibratory Mach-Zehnder interferometer (310) is arranged in a manner with a predefined spacing (g x ) from the Coriolis mass element (350), and / or the vibratory Mach-Zehnder interferometer (310) is configured or arranged for detecting a movement of the sensor unit (100), which is different from a movement that can be detected by the waveguide (210) and the detector unit (280).

6. The sensor unit (100) according to claim 5, wherein The Coriolis mass element (350) is suspended in a manner movable with respect to at least one further fixed point (370) along a further vibration direction, wherein a further vibrating Mach-Zehnder interferometer (320) is provided, which is configured for detecting a movement of the Coriolis mass element (350) along the further vibration direction, in particular wherein the further vibrating Mach-Zehnder interferometer (320) is arranged in a manner having a predefined further gap (g y ) to the Coriolis mass element (350), and / or wherein the further vibrating Mach-Zehnder interferometer (320) is configured or arranged for detecting a movement of the sensor unit (100) which is different from the vibration direction and from a movement detectable by the waveguide (210) and the detector unit (280).

7. The sensor unit (100) according to claim 5 or 6, wherein A phase shifting element (260) is provided on the path (337) of the vibrating Mach-Zehnder interferometer (310) and / or on the path (335) of the further vibrating Mach-Zehnder interferometer (335), and / or wherein At least one beam splitting element (300) is provided, which is configured for dividing light incident on the beam splitting element (300) into sub-beams, which are respectively directed into the vibrating Mach-Zehnder interferometer (310) and the further vibrating Mach-Zehnder interferometer (320).

8. Sensor unit (100) according to any one of claims 5 to 7, having a detection element (340, 345) configured for determining a movement of the Coriolis mass element (350) along the vibration direction or the further vibration direction in the case of an analytical processing of a change in the refractive index, which is caused by a change in the distance between the Coriolis mass element (350) and the path (337) of the vibrating Mach-Zehnder interferometer (310) and / or a change in the distance between the Coriolis mass element (350) and the path (335) of the further vibrating Mach-Zehnder interferometer (320).

9. The sensor unit (100) according to claims 5 to 8, wherein The light source (105) is configured for conducting light into the vibrating Mach-Zehnder interferometer (310) and / or the further vibrating Mach-Zehnder interferometer (320).

10. Method (400) for operating a sensor unit (100) according to any one of claims 1 to 9, wherein The method (400) has the following steps: - irradiating (410) at least the beam splitter (200) by means of light in order to direct a first sub-beam into the first end portion (220) of the waveguide (210) and a second sub-beam into the second end portion (230) of the waveguide (210); and - detecting (420) and evaluating the light received in the detector unit (280) in order to obtain a sensor signal.

11. Control unit (500), which is set up for carrying out and / or conducting the steps (410, 420) of the method (400) according to claim 10 in the respective units (510, 520).

12. Computer program, which is set up for carrying out and / or conducting the steps (410, 420) of the method (400) according to any one of the preceding claims.

13. Machine-readable storage medium, on which the computer program according to claim 12 is stored.

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