Sensor unit and method for operating a sensor unit

Abstract

The invention relates to a sensor unit (100) with a waveguide (105, 105a, 105b) coupled to a ring resonator (115) by means of a coupling point (110). Furthermore, the sensor unit (100) comprises at least one sensor waveguide (130) bypassing the ring resonator (115) and a beam combining unit (120) designed to connect the waveguide (105, 105a, 105b) and the sensor waveguide (130) such that a waveguide light beam from the waveguide (105, 105a, 105b) interacts with a sensor waveguide light beam from the sensor waveguide (130). Finally, the sensor unit (100) comprises a detection unit (145) which has at least one detector (145a) for detecting states present at or output from the beam linking unit (120).

Description

State of the art

[0001] The present invention relates to a sensor unit and a method for operating a sensor unit, to a corresponding control device and to a corresponding computer program product.

[0002] Current optical gyroscopes are either too large to guarantee good sensitivity or not sensitive enough for chip-integrated applications. Such gyroscope designs make widespread availability and universal applicability difficult, so very precise measurements are expensive and only available for specific, specialized applications. Disclosure of the invention

[0003] Against this background, the approach presented here presents a sensor unit, a method for operating such a sensor unit, a control unit that uses this method, and finally a corresponding computer program product according to the main claims. Advantageous embodiments emerge from the respective subclaims and the following description.

[0004] Here, a sensor unit with the following features is presented: - a waveguide coupled to a ring resonator by means of a coupling point; - at least one sensor waveguide bypassing the ring resonator; - a beam combining unit configured to connect the waveguide and the sensor waveguide such that a waveguide light beam from the waveguide interacts with a sensor waveguide light beam from the sensor waveguide; and - a detection unit having at least one detector for detecting states present or output at the beam linking unit.

[0005] For example, this sensor unit can be compact, specially constructed on a substrate or integrated into a chip. In this case, a coupling point can be understood as, for example, a multimode interferometer or an arrangement of closely spaced waveguides (for example, within a range of one millimeter). This can be used to achieve entanglement of states such as photons in or at the two coupled time periods by means of the Hong-Ou-Mandel effect. A sensor waveguide can be understood as, for example, a waveguide that is guided through a corresponding sensor region. For example, the sensor waveguide can be wound or arranged in a spiral shape to enable the greatest possible length in a small installation space and thereby bring about a corresponding physical effect on a light guided in this waveguide when the sensor unit is moved.A beam combining unit can be understood as an optical component which is designed to couple the waveguide light beam which has been coupled with a light in the ring resonator to the sensor waveguide light beam and to supply at least one correspondingly coupled light beam to the detection unit or at least to one detector of this detection unit.

[0006] The approach proposed here is based on the realization that particularly robust and reliable detection of movement, especially rotation of the sensor unit, even over a wide temperature range, is possible by using the ring resonator to provide a first light beam as a waveguide light beam. This first light beam can then be coupled to a sensor waveguide light beam provided by the sensor waveguide in the sensor region and evaluated accordingly. This exploits the fact that two-mode or single-mode entangled photons, and thus squeezed light, can be generated in the ring resonator via four-wave mixing. On the other hand, a movement of the sensor unit in the sensor waveguide causes a change such as a phase shift due to physical effects.If both light paths are combined, the movement of the sensor unit can now be detected very precisely. The advantage of the approach presented here is that a very compact sensor system can now be used that measures the movement of the sensor unit very robustly and precisely and can also be implemented on-chip.

[0007] A particularly advantageous embodiment of the approach proposed here is one in which the sensor waveguide is arranged or wound in a spiral shape, at least in one section. Such an embodiment advantageously enables a very compact and space-saving design of such a sensor unit.

[0008] Furthermore, an embodiment of the approach proposed here is conceivable in which the beam combining unit is configured to couple light from the waveguide light beam with light from the sensor waveguide light beam to obtain a first coupling beam and / or to couple light from the sensor waveguide light beam with light from the waveguide light beam to obtain a second coupling beam, and wherein the beam combining unit is further configured to feed the first and / or second coupling beam to the detection unit. Such an embodiment of the approach proposed here offers the advantage of being able to create a very precisely measuring sensor unit through further mixing or entanglement of the photons in a correspondingly constructed beam combining unit.

[0009] According to a further embodiment of the approach proposed here, the detector can comprise at least a first detection element and a second detection element, wherein the first detection element is configured to receive light from the waveguide light beam or a phase-shifted light beam obtained from the waveguide light beam, and the second detection element is configured to receive the first coupling beam. Furthermore, the detector can be configured to provide a detection result by combining a detection result of the first and second detection elements, in particular wherein the detector is configured to additively and / or subtractively combine the detection results of the first and second detection elements.Such an embodiment of the approach proposed here offers the advantage of taking into account a physical effect in the interaction of the two light beams in the beam linking unit during the evaluation, whereby the received or detected light beams enable a very reliable and precise determination of a movement of the sensor unit.

[0010] Another possible embodiment of the approach proposed here is one in which the detection unit has at least one second detector for detecting states present at or output from the beam combining unit. For example, the second detector comprises at least a third detection element and a fourth detection element, wherein the third detection element is configured to receive light from the sensor waveguide light beam or a phase-shifted light beam obtained from the sensor waveguide light beam, and the fourth detection element is configured to receive the second coupling beam.Furthermore, for example, the second detector is configured to provide a detection result by combining a detection result of the third and fourth detection elements, in particular, the second detector is configured to additively and / or subtractively combine the detection results of the third and fourth detection elements. Such an embodiment of the approach proposed here also offers the advantage of appropriately taking into account a physical effect in the interaction of the two light beams in the beam combining unit during the evaluation, whereby the received or detected light beams enable a very reliable and precise determination of a movement of the sensor unit.

[0011] Specifically, according to a further embodiment, the detection unit can be configured to combine, in particular multiplicatively combine, a result provided by the detector and a result provided by the second detector to form a sensor signal. Such an embodiment offers the advantage of enabling precise and robust detection of a movement or rotation of the sensor unit using technically simple means by taking into account additional light beams that have been combined or linked by the beam combining unit. Specifically, this allows for a homodyne or heterodyne measurement to be realized, which, upon multiplication, results in a product measurement.

[0012] Furthermore, an embodiment of the approach presented here is conceivable in which the detection unit is designed to provide a sensor signal, wherein the sensor signal represents a rotation rate and / or rotation of the sensor unit. Alternatively or additionally, the beam combining unit can also comprise at least one multimode interferometer to couple and / or combine light from the waveguide light beam with light from the sensor waveguide light beam. Such an embodiment of the approach proposed here offers the advantage of being able to precisely measure, in particular, a private and / or rotation of the sensor unit. At the same time or additionally, the beam combining unit can, by using the multimode interferometer, technically simply exploit optical effects to couple and / or combine the waveguide light beam with the sensor waveguide light beam.

[0013] According to a further embodiment, a sensor waveguide input can also be provided, which is designed to couple light into the sensor waveguide and, by means of at least one connecting waveguide, to at least partially couple the received light into the ring resonator. This advantageously allows light that is coupled into the sensor unit at the sensor waveguide input, for example, to be simultaneously guided to the ring resonator, so that a corresponding optical interaction also occurs here, which is subsequently used to improve the precision in detecting the movement of the sensor unit.

[0014] Another advantage is an embodiment of the approach proposed here which further comprises at least one light source and / or a laser light source designed to emit light into the waveguide, in particular wherein a further light source and / or a further laser light source is provided which is designed to emit light into the sensor waveguide, in particular wherein the light source or the further light source is designed to emit light with different wavelengths. Such an embodiment offers the advantage, on the one hand, of a compactly constructed sensor unit and, on the other hand, of determining very precise measurement results by using the favorable properties of the light emitted by the light source and / or the further light source.

[0015] A particularly advantageous embodiment of the approach proposed here is one in which the light source and / or the laser light source can be used as a pump light source, and the further light source and / or the further laser light source can be used as a signal light source. Such an embodiment offers the advantage of efficiently utilizing the physical properties of the ring resonator to provide the quantum states, which can then be advantageously combined with the states of the sensor waveguide light in the beam combining unit. In this case, only the signal light source can be used, so that it serves as both a pump light source and a signal light source.

[0016] For this purpose, according to one embodiment of the approach presented here, a ring resonator designed to generate a quantum state using three-wave mixing, four-wave mixing, and / or the Kerr effect can be used particularly advantageously. A ring resonator designed in this way is, on the one hand, technically very simple to implement and, on the other hand, provides quantum states that can be advantageously used in the downstream beam combining unit.

[0017] Another advantageous embodiment of the approach proposed here is one in which the waveguide has at least two partial waveguides, between which the ring resonator is arranged. Such an embodiment offers the advantage that specific wavelengths can be coupled in and / or out more effectively than others. This also has the advantage that no interference and / or effects can arise in subsequent optical paths due to the action of a light source.

[0018] In order to specifically couple, for example, light from outside a substrate into a sensor unit and / or to couple light from inside a substrate out of the sensor unit, which is constructed integrally in its own substrate, according to a particularly advantageous embodiment of the approach proposed here, at least one grating coupler with or without a subsequent taper structure can be provided for coupling light into the waveguide or for outputting light in the beam combining unit to at least the detector of the detection unit. Alternatively, light can be coupled into the chip via a lateral coupling point with or without a subsequent taper structure.

[0019] A particularly advantageous embodiment of the approach proposed here is one in which at least one phase-shifting element is provided for varying a state guided on the waveguide and / or the sensor waveguide and / or in the beam combining unit. According to one embodiment, the sensor unit can also comprise a temperature sensor and / or an electro-optical modulator to modulate light in a component of the sensor unit using a signal from the temperature sensor and / or using the electro-optical modulator.Such an embodiment offers the advantage of being able to operate the sensor unit very efficiently and / or at particularly favorable operating points due to the possibility of a phase variation of a quantum state on a line unit in the sensor unit and / or by taking a temperature into account or by using the electro-optical modulator, especially in which the sensor unit can very sensitively or sensitively detect a specific physical quantity such as a rotation rate or a rotation.

[0020] An embodiment of the approach proposed here is advantageous as a method for operating a sensor unit according to one of the preceding claims, wherein the method comprises the following steps: - illuminating at least the waveguide and the sensor waveguide with one light each; and - Evaluating a received light received by at least the detector to obtain a sensor signal.

[0021] The light that is coupled into the waveguide and the sensor waveguide can be emitted by a common light source or by several separate light sources that can also be controlled separately.

[0022] The advantages mentioned above can also be realized in a technically simple and efficient manner using such an embodiment.

[0023] The approach presented here further provides a control unit configured to perform or implement the steps of a variant of a method presented here in corresponding devices. This embodiment of the invention in the form of a control unit also allows the problem underlying the invention to be solved quickly and efficiently.

[0024] In this case, a control unit can be understood as an electrical device that processes sensor signals and outputs control and / or data signals depending on them. The control unit can have an interface that can be implemented in hardware and / or software. In a hardware implementation, the interfaces can, for example, be part of a so-called system ASIC, which contains a wide variety of functions of the control unit. However, it is also possible for the interfaces to be separate integrated circuits or to consist at least partially of discrete components. In a software implementation, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

[0025] Also advantageous is a computer program product with program code that can be stored on a machine-readable medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out the method according to one of the embodiments described above when the program product is executed on a computer or a control unit.

[0026] The approach presented here is explained in more detail below using the attached drawings. They show: Fig. 1 a schematic representation of an embodiment of a sensor unit; Fig. 2 two schematic representations of different designs or connections of the ring resonator to the waveguide or the different sections of the waveguide; Fig. 3 a diagram illustrating a variance of a light intensity in the ring resonator as a function of a ring geometry; Fig. 4 a flowchart of an embodiment of a method; and Fig. 5 a block diagram of an embodiment of a control unit.

[0027] In the following description of advantageous embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of these elements is omitted.

[0028] Fig. 1 shows a schematic representation of an embodiment of a sensor unit 100. The sensor unit 100 comprises a waveguide 105, which is divided, for example, into two subsections 105a and 105b, which are coupled or entangled to a ring resonator 115 via a coupling point 110. Furthermore, the sensor unit 100 comprises a beam combining unit 120, which has an input 125 (for example in the form of a coupling point or a multimode interferometer) for receiving quantum states or photons from the waveguide 105 (i.e., waveguide light), and according to this embodiment, an output 126 coupled to the input 125 via the waveguide 105, a second output 128 coupled to the input 125 via a first combining waveguide 127, and a second input 129 for receiving sensor waveguide light.The sensor waveguide 130 can be fed with light from a light source, for example by means of an input 135, which here is also designed as a multimode interferometer.

[0029] The second input 129 is coupled to the output 126 via a second link waveguide 139. According to the Fig. 1, the input 125 and / or the second input 129 and / or the output 126 and / or the second output 128 of the beam combining unit 120 is designed, for example, in the form of a coupling point, a beam splitter or a multimode interferometer, so that states present at the components mentioned (for example from / at two waveguides) can couple or interfere with each other or a light beam is split at / onto two guides.

[0030] Furthermore, the Fig. 1, the embodiment of the sensor unit 100 includes the detector unit 145, which provides a sensor signal 147 representing, for example, a rotation rate and / or rotation of the sensor unit 100.

[0031] The detector unit 145 has, for example, a first detector 145a and a second detector 145b, wherein the first detector 145a comprises a first detection element 150a, which is designed to receive a waveguide light or a light signal derived from the waveguide light from the output 126. According to this exemplary embodiment, the first detector 145a further comprises a second detection element 150b, which is designed to receive a first coupling light beam (first coupling beam) 152 from the output 126, wherein the first coupling light beam 152 was obtained by coupling the waveguide light beam with the sensor waveguide light beam. Furthermore, the first detector 145a is designed to combine a detection result of the first detection element 150a with the detection result of the second detection element 150b, specifically to combine them additively and / or subtractively, in order to obtain a first detector signal.

[0032] The second detector 145b comprises a third detection element 150c, which is configured to receive a sensor waveguide light or a light signal derived from the sensor waveguide light from the second output 128. According to this exemplary embodiment, the second detector 145b further comprises a fourth detection element 150d, which is configured to receive a second coupling light beam (second coupling beam) 154 from the second output 128, wherein the second coupling light beam 154 was obtained by coupling the sensor waveguide light beam with the waveguide light beam. Furthermore, the second detector 145b is configured to combine a detection result of the third detection element 150c with the detection result of the fourth detection element 150d, specifically to combine them additively and / or subtractively, in order to obtain a second detector signal.

[0033] The detection unit 145 is configured according to the Fig. 1, the embodiment is further designed to combine the first and second detector signals with one another, for example to combine them multiplicatively, in order to obtain the sensor signal 147.

[0034] In addition, according to the Fig. In the exemplary embodiment for the sensor unit 100 shown in Figure 1, the input 135 is connected to the coupling point 110 via a connecting waveguide 157, so that light radiated or received via the input 135 can also be (at least partially) coupled into the ring resonator 115. However, it is also conceivable that only light from a (common) light source is coupled into the coupling point 110 and the sensor waveguide 130, which would then correspond to the further light source 170. In this case, the connecting waveguide 157 can then be understood, for example, as the first partial waveguide 105a.

[0035] Furthermore, according to the Fig. In the embodiment shown in Figure 1, a light source 165 is provided, which is configured, for example, as a pump laser light source and is designed to transmit light into the (first) partial section 105a of the waveguide 105. Alternatively or additionally, a further light source 170 is also provided, which is configured, for example, as a signal laser light source and is designed to transmit further light into the input 135.

[0036] It is also conceivable that grating couplers 175 are used to couple light from the light source 165 or the further light source 170 into the sensor unit 10 if this sensor unit 100 is integrated on a common substrate or chip and the light source 165 or the further light source 170 is arranged outside this substrate or the chip. Analogously, corresponding grating couplers 175 can also be used to couple corresponding quantum states or photons from the output 126 to the detector 145a and / or from the second output 128 to the second detector 145b, especially if one or more of the detectors of the detector unit 145 are not integrated on a common substrate with the other components of the sensor unit 100.

[0037] It is also conceivable to use phase shifters or phase shift elements 180 on and / or in individual conductor components of the components of the sensor unit 100, as described, for example, in the Fig. 1 by the black and white checkered boxes. For example, the phase shifting elements 180 are configured such that they are individually or jointly set with a fixed phase shift parameter or can be controlled such that they can control specific phase shifts or delays of states occurring on the respective conductor components. For this purpose, for example, a Fig. 1, which can control the individual phase-shifting elements 180. Such control of the phase-shifting element(s) 180 can be effected, for example, as a function of a signal from a temperature sensor 185, which is designed, for example, to detect a temperature in the region of the ring resonator 115. The phase shifters 180, the temperature sensor 185, and / or the detectors 145a and 145b can be linked in a control system to always keep the system in the most sensitive range.

[0038] Fig. 2 shows two schematic representations of different configurations or connections of the ring resonator 115 to the waveguide 105 or the different sections 105a and 105b of the waveguide 105. In the left representation from the Fig. 2 shows the arrangement or interlacing of the ring resonator 115 via the coupling point 115 with the two sections 105a and 105b of the waveguide 105. In the right-hand illustration of the Fig. Figure 2 shows an alternative arrangement of the ring resonator 115 between the first section 105a and the second section 105b of the waveguide 105. An auxiliary coupling point 200 is used, which is arranged opposite the coupling point 110, for example, halfway along the length of the ring resonator 115, and which is configured to output states that run in the ring resonator 115.

[0039] An architecture is used in which a quantum state is generated via three- or four-wave mixing in a ring resonator 115. This requires the ring resonator structure 115 and one or two lasers as light source(s). One part then corresponds to the pump laser 165 and the other to the signal laser 170. The pump laser pumps the ring resonator 115. Squeezed or coherently squeezed photons of the wavelength of the signal laser 170 and other wavelengths for which the resonator condition applies are then generated in the ring resonator 115 via the four-wave mixing. The signal laser 170 is guided into a sensor region 137. A phase shift occurs according to the Sagnac effect. If the signal laser 170 is subsequently mixed with the quantum state and detected, for example, using the product measurement, the Sagnac phase can be determined.

[0040] Light from one or two laser sources (e.g., of different wavelengths) is thus generated either directly on an optical chip or coupled into it via grating coupler structures 175 or edge coupling. In the second option, the laser can be positioned directly above the grating coupler 175 and guided from the grating coupler into a waveguide via a taper structure. With two lasers, one laser corresponds to a pump laser and the other to a signal laser. With one laser, this is split, with one part serving as a pump laser and the other as a signal laser.

[0041] The pump laser (or, in a second embodiment, both lasers) is then coupled into the ring resonator 115, for example, via a multimode interferometer or via evanescent waveguide coupling. Depending on whether only the pump laser 165 or both are coupled, the three- or four-wave mixing results in either squeezed or coherently squeezed photons of the same wavelength as the pump laser 165 or the signal laser 170, which are further described as a quantum state. These are coupled out either via the multimode interferometer 110 used for coupling in or via another one. The coupling out can be designed so that only the signal wavelength is coupled out at the desired coupling point.

[0042] This is shown schematically in Fig. 2. Two ring resonators are shown here. One with two numbered inputs and outputs, and one with three. The light couples into the ring resonator 115 via the first partial waveguide 105a. The coupling points 110 can be designed to couple out certain wavelengths better than others. For example, in the right-hand illustration, the coupling points 110 can be designed so that, for example, only the quantum state is coupled out at the second partial waveguide (or at the third output) 105b in the right-hand illustration. This has the advantage that no interference or effects due to the pump laser can arise in the further path.

[0043] A phase shifter 180 can be used both before and within the ring resonator 115 to control the resonance condition and coupling and thus also the generation of the quantum states.

[0044] The signal laser 170 is transmitted into a sensor region 137. This consists, for example, of the sensor waveguide 130, which is wound as a spiral or at least partially in a spiral structure 138. If the sensor unit 100 is rotated, the Sagnac effect acts on the sensor unit 100 and influences the phase of the light in the sensor region 137. Subsequently, the signal light after the sensor region 137, as well as the generated quantum states, are split into two parts at a beam splitter of the so-called first stage of the beam combining unit 120 with the two inputs 125 and 129, which are each recombined at a further second stage with the two outputs 126 and 128 of the beam combining unit 120 or in corresponding beam splitters. The first beam splitters or the inputs 125 and / or 129 can be symmetrical (50 / 50 split) or asymmetrical (e.g.: 90 / 10 split), while the second beam splitters or the outputs 126 and / or 128 are preferably symmetrical (50 / 50 split). A phase shifter 180 can be placed between the beam splitters or the inputs and / or outputs 125, 126, 128, 129.

[0045] This is preferably the case after the beam splitter 129 of the first stage of the signal laser 170 after the sensor region 137. The outputs 126, 128 of the beam splitters of the second stage are then each detected by a detector 145a or 145b.

[0046] The output signals of the individual beam splitters 126, 128 of the second stage can be either subtracted or added, and then these signals are multiplied together, for example. This results in a homodyne or heterodyne measurement at the output of each of the two second beam splitters 126, 128, which, when multiplied, results in a product measurement. The product measurement can then be used to measure the quantum state, such as the variance of the light.

[0047] Fig. Figure 3 shows a representation of the different measured quantum states as a function of the signal laser phase. The abscissa represents the phase of the signal laser in radians, and the ordinate represents the variance of the light in dB. It is advantageous to achieve high coupling (high κ) and low losses (low y) in the ring resonator, which can be seen from the characteristic curve 300, with the boundary line 310 representing vacuum noise. This remains constant over the light phase and is measured if no quantum states are generated in the ring resonator. If quantum states are generated and mixed with the signal laser at a specific phase, the curves 300 are measured, and a signal change occurs when the phase of the signal laser changes. This change, and thus the sensitivity of the system, is approximately π2 The sensitivity is also higher when the quantum states exhibit high squeezing, i.e., a high κ and a low γ.

[0048] Preferably, the phase of the signal laser 170 is adjusted by the phase shifter(s) 180 so that the curve in Fig. 3 is located at the steepest edge and thus in the range of highest sensitivity. With a control loop between the measured (sensor) signal 147 and the phase shifters 180, this range can be kept constant even during an applied rotation rate in order to realize a large detection range. This means that the sensitivity remains constant across different applied rotation rates.

[0049] In a further embodiment, the sensor or sensor unit 100 presented here can also include the temperature sensor 185 to detect external temperature fluctuations. In a control system with the phase shifter(s) 180, for example, the resonance condition or the phase of the light can then be controlled at each point.

[0050] In all variants, the detectors 145a and 145b can be manufactured directly integrated with the sensor unit 100, or a light or a signal is coupled in or out via grating couplers 175 and measured outside the (sensor unit) chip 100. The entire structure is, as already explained, in Fig. 1 is shown in detail. The two lasers are shown as light sources 165 and 170, respectively, whose light is coupled into a chip via grating couplers 175. It should be noted that, for example, the waveguide path of the signal laser 170 in the ring or the ring resonator 115 can also be omitted. Furthermore, any number of phase shifters 180 can be used, and it is also possible to use only the signal laser 170, which pumps the ring (and thus can also be used as the sole light source according to such an embodiment), generates squeezed light of the same frequency, and reaches a different part of the sensor region 137.

[0051] In a further embodiment, the signal laser 170 consists not only of light of one frequency, but of multiple frequency components, which, for example, correspond to the resonance conditions of the ring resonator 115. This can be achieved, for example, by using and combining multiple lasers as light sources, the laser itself having multiple resonance conditions and thus emitting multiple wavelengths, or the signal laser 170 of one wavelength splitting the light into multiple regions using, for example, electro-optical modulators. The electro-optical modulators can also be implemented chip-integrated in the waveguide 130, and thus the multiple wavelengths are used only in the signal path and for mixing the states at the beam splitters.

[0052] Fig. 4 shows a flowchart of an embodiment of a method 400 for operating a variant of a sensor unit presented here, wherein the method 400 comprises a step 410 of illuminating at least the waveguide with a light and a step 420 of evaluating a received light received by at least the detector in order to obtain a sensor signal.

[0053] Fig. 5 shows a block diagram of an embodiment of a control unit 500 for executing a variant of the method 400 for operating a variant of a sensor unit presented here, wherein the control unit has a unit 510 for controlling an illumination of at least the waveguide with a light and a unit 520 for evaluating a received light received by at least the detector in order to obtain a sensor signal.

[0054] The embodiments described and shown in the figures are selected only as examples. Different embodiments can be combined with each other completely or with regard to individual features. Furthermore, one embodiment can be supplemented by features of another embodiment.

[0055] Furthermore, the process steps presented here can be repeated and carried out in a different order than that described.

[0056] If an embodiment comprises an “and / or” link between a first feature and a second feature, this is to be read as meaning that the embodiment according to one embodiment has both the first feature and the second feature and according to another embodiment has either only the first feature or only the second feature.

Claims

[1] Sensor unit (100) with the following features: - a waveguide (105, 105a, 105b) coupled to a ring resonator (115) by means of a coupling point (110); - at least one sensor waveguide (130) bypassing the ring resonator (115); - a beam combining unit (120) configured to connect the waveguide (105, 105a, 105b) and the sensor waveguide (130) such that a waveguide light beam from the waveguide (105, 105a, 105b) interacts with a sensor waveguide light beam from the sensor waveguide (130); and - a detection unit (145) having at least one detector (145a) for detecting states present at or output from the beam linking unit (120). [2] Sensor unit (100) according to claim 1, wherein the sensor waveguide (130) is arranged or wound spirally at least in one section (138), in particular to form a sensor area (137). [3] Sensor unit (100) according to one of the preceding claims, wherein the beam combining unit (120) is configured to couple light from the waveguide light beam with light from the sensor waveguide light beam to obtain a first coupling beam (152) and / or to couple light from the sensor waveguide light beam with light from the waveguide light beam to obtain a second coupling beam (154), and wherein the beam combining unit (120) is further configured to supply the first (152) and / or second (154) coupling beam to the detection unit (145). [4] Sensor unit (100) according to claim 3, wherein the detector (145a) comprises at least a first detection element (150a) and a second detection element (150b), wherein the first detection element (150a) is designed to receive light from the waveguide light beam or a phase-shifted light beam obtained from the waveguide light beam and the second detection element (150b) is designed to receive the first coupling beam (152), and wherein the detector (145a) is designed to provide a detection result by linking a detection result of the first (150a) and second (150b) detection element, in particular wherein the detector (145a) is designed to additively and / or subtractively link the detection results of the first (150a) and second (150b) detection element. [5] Sensor unit (100) according to claim 4, wherein the detection unit (145) has at least one second detector (145b) for detecting states present at or output from the beam combining unit (120), in particular wherein the second detector (145b) comprises at least a third detection element (150c) and a fourth detection element (150d), wherein the third detection element (150c) is designed to receive light from the sensor waveguide light beam or a phase-shifted light beam obtained from the sensor waveguide light beam and the fourth detection element (150c) is designed to receive the second coupling beam (154), and wherein the second detector (145b) is designed to provide a detection result by combining a detection result of the third (150c) and fourth (150d) detection element, in particular wherein second detector (145b) is formed,to combine the detection results of the third (150c) and fourth (150d) detection elements additively and / or subtractively. [6] Sensor unit according to claim 5, wherein the detection unit (145) is designed to combine, in particular multiplicatively combine, a result supplied by the detector (145a) and a result supplied by the second detector (145b) to form a sensor signal (147). [7] Sensor unit (100) according to one of the preceding claims, wherein the detection unit (145) is designed to provide a sensor signal (147), wherein the sensor signal (147) represents a rotation rate and / or rotation of the sensor unit (110) and / or wherein the beam combining unit (120) comprises at least one multimode interferometer for coupling and / or combining light from the waveguide light beam with light from the sensor waveguide light beam. [8] Sensor unit (100) according to one of the preceding claims, with a sensor waveguide input (135) which is designed to couple a light into the sensor waveguide (130) and to couple a received light at least partially into the ring resonator (115) by means of at least one connecting waveguide (157). [9] Sensor unit (100) according to one of the preceding claims, which further comprises at least one light source (165) and / or a laser light source which is designed to emit a light into the waveguide (105), in particular wherein a further light source (170) and / or a further laser light source is provided which is designed to emit a light into the at least one sensor waveguide (155, 157), in particular wherein the light source (165) or the further light source (170) are designed to emit light with different wavelengths. [10] Sensor unit (100) according to one of the preceding claims, with at least one grating coupler (175) for coupling light into the waveguide (105) or for outputting light from the output (135) to at least the detector (145a) of the detection unit (145). [11] Sensor unit (100) according to one of the preceding claims, with at least one phase shifter element (180) for varying a state guided on the waveguide (105), the sensor waveguide (157) and / or the beam combining unit (120), and / or wherein the sensor unit has a temperature sensor (185) and / or an electro-optical modulator in order to modulate a light in a component of the sensor unit using a signal from the temperature sensor and / or using the electro-optical modulator. [12] Method (400) for operating a sensor unit (100) according to one of the preceding claims, wherein the method (400) comprises the following steps: - illuminating (410) at least the waveguide (105) and the sensor waveguide with one light each; and - evaluating (420) a received light received by at least the detector (145a) to obtain a sensor signal (147). [13] Control unit (500) which is designed to carry out and / or control the steps (410, 420) of a method (400) according to claim 11 in corresponding devices (510, 520). [14] Computer program product with program code for carrying out and / or controlling the steps (410, 420) of the method (400) according to claim 12, when the program product is executed on a control unit (500). [15] A machine-readable storage medium on which a computer program product according to claim 14 is stored.

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