Device and method for determining a measured value

Abstract

Device (100), comprising: • a detector device (102) which is configured to: ◯ Receiving a modulated optical signal (104), wherein the modulated optical signal (104) has a first group delay, ◯ Changing a group delay of the received modulated optical signal (104) depending on a parameter value of at least one parameter, such that the modified modulated optical signal has a second group delay different from the first group delay, and ◯ Providing an electrical signal (108) for the modified modulated optical signal, wherein the electrical signal (108) has an electrical phase; and • an evaluation device (110) which is configured to detect the electrical phase of the electrical signal (108) and to determine the parameter value (112) of the at least one parameter using the detected electrical phase of the electrical signal (108).

Description

[0001] Various embodiments relate to a device and a method for determining a measured value.

[0002] In general, optical sensors can be used to detect various quantities, such as temperature, strain, humidity, etc. For example, an optical sensor can change an optical signal depending on the value of the measured quantity, and the changed optical signal can be evaluated to determine the value of the measured quantity. This can involve evaluating, for example, the optical phase of the optical signal or, after opto-electrical conversion, the amplitude of the electrical signal. However, evaluating the optical phase requires a costly receiver (e.g., a homodyne or heterodyne receiver). Furthermore, evaluating the optical phase is susceptible to even very small changes in the length of the measuring setup (i.e., less than 1 µm), which leads to significant inaccuracies.Various disturbances, such as noise and drift, lead to changes in the signal amplitude and thus to greater inaccuracies in signal amplitude evaluation. The signal amplitude is affected, for example, by fluctuations in the power of the optical signal source, changes in the attenuation of the optical components, operating point shifts of a transmit and / or receive module, etc. Therefore, it may be necessary to provide a device and method for determining a measurement that exhibit higher accuracy. Furthermore, it may be necessary to provide a device and method for determining a measurement that exhibit lower inaccuracies due to disturbances (e.g., lower susceptibility to interference). It may also be necessary to provide a device that is less expensive than other devices with comparable measurement accuracy.

[0003] US 2007 / 0 041 020 A1, US 2009 / 0 122 319 A1, and US 2016 / 0 356 823 A1 each describe an interferometer in which the amplitude of interference signals is evaluated. US 2020 / 0 209 020 A1 describes a system for measuring optical phase changes along an optical path in an optically transparent medium, wherein the system includes a phase and amplitude receiver that outputs a difference in the optical phases of two electromagnetic waves and an amplitude of the interference of the two electromagnetic waves.

[0004] DE 11 2015 000 886 T5 describes an interferometric sensor based on modulation phase detection, wherein a measured quantity induces an optical phase shift of interfering light waves and wherein a value of the measured quantity is determined by detecting this optical phase shift. US 2016 / 0 305 984 A1 describes a sensor in which a measured quantity induces an optical phase shift of orthogonal light waves and wherein a value of the measured quantity is determined based on this optical phase shift.

[0005] According to various embodiments, a device and a method for determining a measured value are provided, by means of which a measured value of a measured quantity can be determined with a lower susceptibility to interference.

[0006] According to various embodiments, a device can comprise a detector and an evaluation unit. The detector can be configured to: receive a modulated optical signal, wherein the modulated optical signal has a first group delay; modify a group delay of the received modulated optical signal depending on a parameter value of at least one parameter, such that the modified modulated optical signal has a second group delay different from the first; and provide an electrical signal for the modified modulated optical signal, wherein the electrical signal has an electrical phase. The evaluation unit can be configured to: detect the electrical phase of the electrical signal and determine the parameter value of the at least one parameter using the detected electrical phase of the electrical signal.

[0007] The device with the features of independent claim 1 constitutes a first example.

[0008] The electrical phase of the electrical signal is less susceptible to amplitude disturbances. Furthermore, the electrical phase of the electrical signal is less susceptible to changes in the length of the measuring arrangement. Therefore, determining the electrical phase of the electrical signal results in the device being less susceptible to interference compared to other optical sensor devices that, for example, evaluate the optical phase of an optical signal or the amplitude of an electrical signal.

[0009] The wavelength of the electrical signal can be more than three orders of magnitude longer than the wavelength of the optical signal. Changes in length have an inversely proportional effect on the accuracy of determining the phase of the signal when measuring its phase. Therefore, evaluating the electrical phase of the electrical signal can improve the accuracy of determining the value of the measured quantity.

[0010] Furthermore, evaluating the electrical phase of the electrical signal can reduce, or even prevent, the influence of amplitude noise (e.g., due to interference) on the measurement signal.

[0011] Evaluating the electrical phase of the electrical signal can be implemented (e.g., advantageously implemented) in a radio readout.

[0012] The detector device may include a signal-influencing device that may be configured to: receive the modulated optical signal, and change the group delay of the received modulated optical signal depending on the value of at least one parameter. The detector device may include an optical detector configured to provide the electrical signal for the modified modulated optical signal. The features described in this paragraph, in combination with the first example, constitute a second example.

[0013] The signal processing device can be configured such that changing the group delay of the received modulated optical signal as a function of a parameter value of at least one parameter exhibits the following characteristics: Transmission of the modulated optical signal, wherein the transmission characteristics of the signal processing device exhibit a group delay characteristic that depends on a parameter value of at least one parameter. The signal processing device can be configured to provide the transmitted modulated optical signal as the modified modulated optical signal. The features described in this paragraph, in combination with the second example, constitute a third example.

[0014] The optical detector may include a photodiode. The feature described in this paragraph, in combination with the second or third example, constitutes a fourth example.

[0015] The at least one parameter can be a physical parameter and / or a chemical parameter. The characteristics described in this paragraph, in combination with one or more of the first through fourth examples, constitute a fifth example.

[0016] The at least one parameter can include one or more parameters selected from the group consisting of: temperature, humidity, pH, electrical conductivity, thermal conductivity, biological substance, chemical substance, strain, pressure, electric field, and / or magnetic field. The characteristics described in this paragraph, in combination with one or more of the first through fifth examples, constitute a sixth example.

[0017] The device may further comprise a modulation device configured to generate the modulated optical signal for an optical signal. The features described in this paragraph, in combination with one or more of the first through sixth examples, constitute a seventh example.

[0018] The modulation device can be configured to generate the modulated optical signal by modulating the optical signal with an electrical modulation signal. The features described in this paragraph, in combination with the seventh example, constitute an eighth example.

[0019] The electrical modulation signal can be a high-frequency electrical modulation signal. The high-frequency electrical signal can have a frequency range from approximately 1 MHz to approximately 100 GHz. The characteristics described in this paragraph, in combination with the eighth example, constitute a ninth example.

[0020] The device may further comprise a light-generating device configured to generate the optical signal. The features described in this paragraph, in combination with one or more of the seventh to ninth examples, constitute a tenth example.

[0021] The optical signal can be a beam of light. The feature described in this paragraph, in combination with one or more of the seventh to tenth examples, constitutes an eleventh example.

[0022] The light beam can be a laser beam. The feature described in this paragraph, in combination with the eleventh example, forms a twelfth example.

[0023] The evaluation device may include a signal conditioning device configured to provide an amplified electrical signal, and the evaluation device is further configured such that determining the parameter value of the at least one parameter using the electrical phase of the amplified electrical signal is accomplished. The features described in this paragraph, in combination with one or more of the examples from the first to the twelfth, constitute a thirteenth example.

[0024] The evaluation device may further be configured such that determining the parameter value of the at least one parameter using the electrical phase of the electrical signal comprises: determining a phase difference between the electrical phase of the electrical signal and an electrical phase of a reference signal; and determining the parameter value of the at least one parameter using the determined phase difference. The features described in this paragraph, in combination with one or more of the first example up to the thirteenth example, constitute a fourteenth example.

[0025] The evaluation unit may include a local oscillator configured to provide a local oscillator signal. The evaluation unit may further be configured such that determining the parameter value of the at least one parameter using the electrical phase of the electrical signal comprises: determining a phase difference by comparing the electrical phase of the electrical signal with the local oscillator signal; and determining the parameter value of the at least one parameter using the determined phase difference. This has the effect, for example, that no transmission of a reference signal is required. The features described in this paragraph, in combination with one or more of the examples from the first to the thirteenth, constitute a fifteenth example.

[0026] The evaluation device may include an analog-to-digital converter configured to provide a digital signal for the electrical signal (e.g., a digital signal representation of the electrical signal). The evaluation device may further be configured such that determining the parameter value of the at least one parameter using the electrical phase of the electrical signal comprises: determining a modulation frequency using the digital signal; determining the electrical phase using the digital signal; determining a phase difference using the determined modulation frequency and the determined electrical phase; and determining the parameter value of the at least one parameter using the determined phase difference. The features described in this paragraph, in combination with one or more of the first through thirteenth examples, constitute a sixteenth example.

[0027] The evaluation unit may further be configured to sample the digital signal using one or more time-domain filters and / or one or more frequency-domain filters. The evaluation unit may also be configured such that determining the parameter value of the at least one parameter using the electrical phase of the electrical signal is equivalent to determining the parameter value of the at least one parameter using the sampled digital signal. The features described in this paragraph, in combination with the sixteenth example, constitute a seventeenth example.

[0028] A method may comprise: receiving a modulated optical signal, wherein the modulated optical signal has a first group delay; changing a group delay of the received modulated optical signal depending on a parameter value of at least one parameter, such that the modified modulated optical signal has a second group delay different from the first group delay; providing an electrical signal for the modified modulated optical signal, wherein the electrical signal has an electrical phase; detecting the electrical phase of the electrical signal; and determining the parameter value of the at least one parameter using the detected electrical phase of the electrical signal. The method described in this paragraph constitutes an eighteenth example.

[0029] They show Fig. 1A to 1D a device according to different embodiments; Fig. 2A to 2C each represent an exemplary evaluation device according to different embodiments; Fig. 3 exemplary measurement signals and one exemplary reference signal according to different embodiments; Fig. 4 a method for determining a measured value according to various embodiments.

[0030] The following detailed description refers to the accompanying drawings, which form part thereof and in which specific embodiments in which the invention can be implemented are shown for illustration purposes.

[0031] The term "processor" can be understood as any type of entity that allows the processing of data or signals. The data or signals can be processed, for example, according to at least one (i.e., one or more than one) specific function performed by the processor. A processor can be an analog circuit, a digital circuit, a mixed-signal circuit, a logic circuit, a microprocessor, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), a programmable gate array (FPGA), an integrated circuit, or any combination thereof. Any other type of implementation of the respective functions, which are described in more detail below, can also be understood as a processor or logic circuit.It is understood that one or more of the process steps described in detail herein can be executed (e.g., implemented) by a processor through one or more specific functions performed by the processor. The processor can therefore be configured to perform one of the procedures described herein or its components for information processing.

[0032] Various measurands can be detected using optical sensors. For example, the optical phase of an optical signal or, after opto-electrical conversion, the amplitude of an electrical signal can be evaluated. However, both of these methods are susceptible to interference, leading to inaccuracies in determining the measured value. Several embodiments relate to a device and a method for determining a measured value with reduced inaccuracy due to interference by detecting the electrical phase of the electrical signal after opto-electrical conversion and determining the measured value based on this.

[0033] Fig. Figures 1A to 1D show a device 100 according to various embodiments. According to these different embodiments, the device 100 may have an optical sensor or be an optical sensor.

[0034] With reference to Fig. 1A The device 100 can have a detector device 102. The detector device 102 can be configured to receive an optical signal. The optical signal can be a light beam (e.g., a laser beam). The detector device 102 can be configured to receive a modulated optical signal 104. The modulated optical signal 104 can be an amplitude-modulated optical signal. The modulated optical signal 104 can be a frequency-modulated optical signal. The modulated optical signal 104 can be a phase-modulated optical signal. The modulated optical signal 104 can be an optical signal consisting of a combination of different modulation formats (e.g., amplitude modulation, frequency modulation, phase modulation). The modulated optical signal 104 can, for example, be a modulated light beam (e.g., a modulated laser beam).For example, the modulated optical signal 104 can be generated by modulating an optical signal. The modulated optical signal 104 may exhibit a first group delay. The group delay of a signal is the time delay of the amplitude envelopes (in some aspects called amplitude envelopes) of the different sinusoidal components of the signal by a device (e.g., by a signal processing device).

[0035] According to various embodiments, the detector device 102 can be configured to provide a modified modulated optical signal for the received modulated optical signal 104. The detector device 102 can be configured to provide the modified modulated optical signal for the received modulated optical signal 104 depending on a parameter value of at least one parameter. In other words, the detector device 102 can be configured to modify the modulated optical signal 104 depending on a parameter value of the at least one parameter. According to various embodiments, the modified modulated optical signal can have a second group delay. The second group delay can be different from the first group delay.The detector device 102 can be configured to change the group delay of the modulated optical signal 104 depending on the value of at least one parameter. The group delay of the modulated optical signal 104 can be parameter-dependent.

[0036] According to various embodiments, a change in group delay can be uniquely assigned to a parameter value of at least one parameter. For example, a parameter value of at least one parameter within a predefined value range (e.g., a measuring range of the device, e.g., a measuring range of the optical sensor) can be uniquely assigned to a change in group delay.

[0037] The at least one parameter can be a measured quantity. The at least one parameter can, for example, be at least one physical parameter and / or at least one chemical parameter. For example, the at least one parameter can be one or more of the following: temperature, humidity, pH value, electrical conductivity, thermal conductivity, biological substance, chemical substance, strain, pressure, electric field, magnetic field, etc. To illustrate, the at least one parameter can be a temperature, and the device 100 can be an optical temperature sensor, and / or the at least one parameter can be a humidity sensor, and the device 100 can be an optical humidity sensor, etc.For example, the device 100 may be or have a building sensor, and the building sensor may, for example, be configured to detect moisture (e.g., on one or more walls).

[0038] The detector device 102 can further be configured to provide an electrical signal 108 for the modified modulated optical signal. The electrical signal 108 can have an electrical phase.

[0039] According to various embodiments, the device 100 may further comprise an evaluation unit 110. The evaluation unit 110 may be configured to determine the parameter value (112) of the at least one parameter. The evaluation unit 110 may be configured to determine the parameter value (112) of the at least one parameter using the electrical phase of the electrical signal 108. According to various embodiments, the evaluation unit 110 may comprise an evaluation circuit.

[0040] According to various embodiments, the detector device 102 can be configured to change the amplitude of the modulated optical signal 104 as a function of a parameter value of the at least one parameter. The electrical signal 108 can have an electrical amplitude. The evaluation device 110 can be configured to determine the parameter value (112) of the at least one parameter using the electrical phase and amplitude of the electrical signal 108.

[0041] The evaluation unit 110 can have one or more processors. The one or more processors (referred to as processors in various aspects) can, as described above, represent any type of logic-implementing entity. The processor can, for example, implement logic using a storage device and / or process data using the storage device.

[0042] According to various embodiments, a change in the group delay of the modulated optical signal 104 can lead to a phase shift of the electrical phase of the electrical signal 108 (e.g., be proportional). For example, the electrical phase of the electrical signal 108 can depend on the group delay (e.g., a change in the group delay).

[0043] With reference to Fig. In 1B, the detector device 102 can include a signal processing device 114. The signal processing device 114 can be configured to receive the modulated optical signal 104. The signal processing device 114 can be configured to provide the modified modulated optical signal 106 for the received modulated optical signal 104, depending on a parameter value of the at least one parameter. In other words, the signal processing device 114 of the detector device 102 can be configured to change a group delay of the modulated optical signal 104, depending on a parameter value of the at least one parameter. According to various embodiments, the signal processing device 114 can be configured to transmit the modulated optical signal 104 (e.g., in transmission).The transmission characteristics of the signal-influencing device 114 can depend on a parameter value of at least one parameter. For example, the signal-influencing device 114 can be configured to provide the transmitted modulated optical signal 104 as the modified modulated optical signal 106. The signal-influencing device 114 can include an optical sensor element. The optical sensor element can, for example, be or include an optical waveguide. According to various embodiments, the signal-influencing device 114 can have a group delay characteristic that depends on a parameter value of at least one parameter. According to various embodiments, the signal-influencing device 114 can have an amplitude characteristic that depends on a parameter value of at least one parameter.

[0044] The detector device 102 can include an optical detector 116. The optical detector 116 can be configured to provide the electrical signal 108 for the modified modulated optical signal 106. The optical detector 116 can be an opto-electrical converter (in some aspects referred to as an optoelectronic converter) or include an opto-electrical converter. The optical detector 116 can include a photodiode. In other words, the optical detector 116 can receive an optical signal, process it, and provide an electrical signal for the optical signal.

[0045] With reference to Fig. In 1C, the device 100 may further comprise a modulation device 120. The modulation device 120 may be configured to generate the modulated optical signal 104 for an optical signal 122. For example, the modulation device 120 may be configured to generate the modulated optical signal 104 by modulating the optical signal 122 with an electrical modulation signal. The electrical modulation signal may, for example, be a high-frequency electrical modulation signal. The high-frequency electrical signal may have a frequency range from approximately 1 MHz to approximately 100 GHz. The electrical modulation signal may, for example, be a sinusoidal electrical modulation signal. According to various embodiments, the modulation device 120 may be a modulatable diode (e.g.,a modulatable laser diode) and can be configured to generate the modulated optical signal 104 directly using the electrical modulation signal (e.g., without using an additional external optical signal). According to various embodiments, the modulation device 120 can be configured to generate the modulated optical signal 104 by means of opto-optical modulation.

[0046] With reference to Fig. 1D The device 100 may have a generating unit which may be configured to generate the optical signal. For example, in the case where the modulation unit 120 does not have a modulatable diode and is configured to generate the modulated optical signal 104 by modulating the optical signal 122 with an electrical modulation signal.

[0047] According to various embodiments, the device can include a light-generating device 124. The light-generating device 124 can be configured to generate the optical signal 122. The optical signal 122 can be a light beam, such as a laser beam. The light-generating device 124 can be a laser source and can be configured to generate a laser beam as the optical signal 122. The laser source can, for example, have a wavelength in the infrared range.

[0048] According to various embodiments, the light beam can be a free beam or a guided beam (e.g., a guided wave). For example, the device can have an optical waveguide, and the optical waveguide can be configured to transmit the light beam. For example, the optical waveguide can be configured to transmit the light beam to the detector device 102.

[0049] Fig. Figures 2A to 2C each show an evaluation unit 110 according to different embodiments.

[0050] According to various embodiments, the evaluation device can include a signal conditioning device 130. The signal conditioning device 130 can be configured to process the electrical signal 108. The signal conditioning device 130 can be configured to provide an amplified electrical signal 132 for the electrical signal 108. In other words, the signal conditioning device 130 can amplify the electrical signal 108. For example, the signal conditioning device 130 can include an amplifier. The evaluation device 110 can be configured to determine the parameter value (112) of the at least one parameter using the amplified electrical signal 132.

[0051] The evaluation unit 110 can be configured to determine a phase difference 134 and to determine the parameter value 112 of the at least one parameter using the determined phase difference 134. According to various embodiments, the device 100 can be configured (e.g., calibrated) such that the evaluation unit 110 can uniquely assign a parameter value of the at least one parameter to a determined phase difference 134. In other words, the device 100 can be calibrated with respect to a respective phase difference 134 for each parameter value of a plurality of parameter values ​​of the at least one parameter (e.g., a plurality of parameter values ​​within a measuring range). According to various embodiments, the phase difference 134 can be proportional to the parameter values ​​of the plurality of parameter values ​​of the at least one parameter.

[0052] With reference to Fig. 2A The evaluation unit 110 can be configured to determine a phase difference 134 between the electrical phase of the electrical signal 108 and an electrical phase of a reference signal 136. The evaluation unit 110 can be configured to determine a phase difference 134 between the electrical phase of the amplified electrical signal 132 and the electrical phase of the reference signal 136. The evaluation unit 110 can be configured to determine the parameter value 112 of at least one parameter using the determined phase difference 134.

[0053] The light-generating device 124 and the modulation device 120 can form a signal-generating device. According to various embodiments, the signal-generating device can be configured to provide the reference signal 136. For example, the device 100 can have a power divider. The power divider can be configured to provide a first electrical signal and a second electrical signal for the electrical modulation signal. The power divider can be configured to provide the first electrical signal to the modulation device 120, and the modulation device 120 can be configured to provide the modulated optical signal 104 (for example, for the first electrical signal in the case that the modulation device 120 is not a modulatable diode). The power divider can be configured to provide the second electrical signal as the reference signal 136 (e.g.,to provide an electrical reference signal to the evaluation unit 110. The power divider can, intuitively, split the electrical signal (e.g., the modulation signal) into the reference signal and the modulation signal.

[0054] Exemplary electrical signals 108 are in Fig. 3 shown. Fig. Figure 3 shows an exemplary first electrical signal 302 for a first parameter value of the at least one parameter and an exemplary second electrical signal 304 for a second parameter value of the at least one parameter that differs from the first parameter value. A phase difference (e.g., phase shift) between the first electrical signal 302 and the second electrical signal 304 is clearly visible. Fig. Figure 3 further shows a reference signal 306. As described above, the evaluation unit 110 can, according to various embodiments, determine a phase difference 134 between an electrical signal 108 (e.g., the electrical signal 302, e.g., the electrical signal 304) and the reference signal 136 (e.g., the reference signal 306). According to various embodiments, the phase difference is uniquely assigned to a parameter value of at least one parameter.

[0055] With reference to Fig. 2B The evaluation unit 110 may further comprise a local oscillator 138. The local oscillator 138 may be configured to provide a local oscillator signal 140. The evaluation unit 110 may be configured to determine a phase difference 134 by comparing the electrical phase of the electrical signal 108 with an electrical phase of the local oscillator signal. The evaluation unit 110 may be configured to determine a phase difference 134 by comparing the electrical phase of the amplified electrical signal 132 with an electrical phase of the local oscillator signal 140.

[0056] According to various embodiments, the evaluation device 110 can include a phase-locked loop. The phase-locked loop can be configured to receive the local oscillator signal 140 and the amplified electrical signal 132. The phase-locked loop can further be configured to provide a substantially constant phase difference between an amplified electrical signal serving as a reference and the local oscillator signal 140. Intuitively, the phase-locked loop can synchronize the local oscillator signal 140 and the received electrical signal (e.g., the electrical signal 108, e.g., the amplified electrical signal 132). The phase-locked loop can be configured to provide a phase difference 134 between the received amplified electrical signal 132 and the received local oscillator signal 140.The evaluation unit 110 can be set up to determine the parameter value 112 of at least one parameter using the phase difference 134.

[0057] With reference to Fig. In 2C, the evaluation unit 110 can include an analog-to-digital converter 142. The analog-to-digital converter 142 can be configured to provide a digital signal 144 for the amplified electrical signal 132 (e.g., a digital signal representation of the amplified electrical signal 132) and / or for the electrical signal 108. In essence, the analog-to-digital converter 142 can convert (e.g., digitize) the amplified electrical signal 132 into the digital signal 144.

[0058] The evaluation unit 110 can be configured to process the digital signal 144. According to various embodiments, the evaluation unit 110 can have at least one processor. The at least one processor can be configured to process the digital signal 144.

[0059] The evaluation unit 110 can be configured to determine a modulation frequency 146 using the digital signal 144. The modulation frequency 146 can be the modulation frequency 146 of the modulated optical signal 104. Intuitively, the modulation frequency 146 can be the frequency with which the modulated optical signal 104 is modulated (e.g., with which the modulated optical signal 104 is modulated by means of the modulation unit 120). According to various embodiments, the modulation frequency 146 can be selected depending on the type of at least one parameter (e.g., a temperature), a measuring range, a change in the electrical phase, a desired measurement accuracy, etc.The modulation frequency 146 can, for example, be in a range up to approximately 1 MHz, in a range from approximately 1 MHz to approximately 1 GHz, in a range from approximately 1 GHz to approximately 10 GHz, in a range from approximately 10 GHz to approximately 100 GHz, or in a range greater than 100 GHz. According to various embodiments, the change in the electrical phase of the electrical signal can be increased by increasing the modulation frequency 146 (e.g., while maintaining the same group delay characteristic).

[0060] The evaluation unit 110 can be configured to determine the electrical phase 148 using the digital signal 144. The electrical phase 148 can be the electrical phase of the electrical signal 108. The evaluation unit 110 can be configured to determine a phase difference 134 using the determined modulation frequency 146 and the determined electrical phase 148. The evaluation unit 110 can be configured to determine the phase difference 134 between the electrical phase 148 and the modulation frequency 146. For example, the evaluation unit 110 can be configured to determine a reference phase using the modulation frequency 146. The evaluation unit 110 can be configured to determine the phase difference 134 between the electrical phase 148 and the reference phase.The evaluation unit 110 can determine the parameter value 112 of at least one parameter using the determined phase difference 134.

[0061] According to various embodiments, the evaluation unit 110 can be configured to sample the digital signal 144 in a time domain. For example, the evaluation unit 110 can be configured to sample the digital signal 144 using one or more time domain filters.

[0062] According to various embodiments, the evaluation unit 110 can be configured to sample the digital signal 144 in a frequency range. For example, the evaluation unit 110 can be configured to sample the digital signal 144 using one or more frequency range filters. A frequency range filter can, for example, incorporate a Fourier transform.

[0063] The evaluation unit 110 can be configured to determine the modulation frequency 146 using a sampled digital signal. The evaluation unit 110 can be configured to determine the electrical phase 148 using a sampled digital signal.

[0064] Fig. Figure 4 shows a method 400 for determining a measured value according to various embodiments. Method 400 can, for example, be a method for evaluating one or more optical sensors.

[0065] Method 400 may include receiving a modulated optical signal (in 402). The modulated optical signal may have a first group delay.

[0066] Method 400 may provide a modified modulated optical signal for the received modulated optical signal depending on a parameter value of at least one parameter (in 404). For example, Method 400 may include modifying the modulated optical signal depending on a parameter value of at least one parameter. The modified modulated optical signal may have a second group delay. The second group delay may be different from the first group delay.

[0067] Method 400 may include providing an electrical signal for the modified modulated optical signal (in 406). For example, Method 400 may include opto-electrical conversion of the modified modulated optical signal into the electrical signal. The electrical signal may have an electrical phase.

[0068] Method 400 may include determining the parameter value of at least one parameter using the electrical phase of the electrical signal (in 408).

Claims

[1] Device (100) comprising: • a detector device (102) which is configured to: ◯ Receiving a modulated optical signal (104), wherein the modulated optical signal (104) has a first group delay, ◯ Changing a group delay of the received modulated optical signal (104) depending on a parameter value of at least one parameter, such that the modified modulated optical signal has a second group delay different from the first group delay, and ◯ Providing an electrical signal (108) for the modified modulated optical signal, wherein the electrical signal (108) has an electrical phase; and • an evaluation device (110) which is configured to detect the electrical phase of the electrical signal (108) and to determine the parameter value (112) of the at least one parameter using the detected electrical phase of the electrical signal (108). [2] Device (100) according to claim 1, wherein the detector device (102) comprises: • a signal interference device that is configured to: ◯ Receiving the modulated optical signal (104), o Changing the group delay of the received modulated optical signal as a function of a parameter value of at least one parameter; and • an optical detector configured to provide the electrical signal (108) for the modified modulated optical signal. [3] Device (100) according to claim 2, wherein the signal-influencing device is configured such that the changing of the group delay of the received modulated optical signal has a function as a function of a parameter value of the at least one parameter: • Transmission of the modulated optical signal (104), wherein the transmission characteristics of the signal-influencing device have a group delay characteristic that depends on a parameter value of at least one parameter. [4] Device (100) according to claim 2 or 3, wherein the optical detector comprises a photodiode. [5] Device (100) according to any one of claims 1 to 4, wherein the at least one parameter is a physical parameter and / or a chemical parameter. [6] Device (100) according to any one of claims 1 to 5, wherein the at least one parameter comprises one or more parameters selected from the group consisting of: • a temperature; • of moisture; • a pH value; • an electrical conductivity; • a thermal conductivity; • a biological substance; • a chemical substance; • a stretching; • a pressure; • an electric field; and / or • a magnetic field. [7] Device (100) according to any one of claims 1 to 6, further comprising: a modulation device which is configured to generate the modulated optical signal (104) for an optical signal. [8] Device (100) according to claim 7, wherein the modulation device is configured to generate the modulated optical signal (104) by modulating the optical signal with an electrical modulation signal. [9] Device (100) according to claim 7 or 8, further comprising: a light-generating device that is set up to generate the optical signal. [10] Device (100) according to any one of claims 1 to 9, wherein the evaluation device (110) has a signal conditioning device which is configured to provide an amplified electrical signal for the electrical signal, and wherein the evaluation device (110) is further configured such that determining the parameter value (112) of the at least one parameter using the electrical phase of the electrical signal (108) includes determining the parameter value (112) of the at least one parameter using the electrical phase of the amplified electrical signal. [11] Device (100) according to one of claims 1 to 10, wherein the evaluation device (110) is further configured such that the determination of the parameter value (112) of the at least one parameter is carried out using the electrical phase of the electrical signal (108): • Determining a phase difference between the electrical phase of the electrical signal and an electrical phase of a reference signal; and • Determining the parameter value (112) of at least one parameter using the determined phase difference. [12] Device (100) according to any one of claims 1 to 10, wherein the evaluation device (110) has a local oscillator configured to provide a local oscillator signal; and wherein the evaluation device (110) is further configured to determine the parameter value (112) of the at least one parameter using the electrical phase of the electrical signal (108): • Determining a phase difference by comparing the electrical phase of the electrical signal (108) with an electrical phase of the local oscillator signal; and • Determining the parameter value (112) of at least one parameter using the determined phase difference. [13] Device (100) according to any one of claims 1 to 10, wherein the evaluation device (110) comprises an analog-to-digital converter configured to provide a digital signal representation for the electrical signal (108); and wherein the evaluation device (110) is further configured such that the determination of the parameter value (112) of the at least one parameter using the electrical phase of the electrical signal (108) has: • Determining a modulation frequency using the digital signal; • Determining the electrical phase using the digital signal; • Determining a phase difference using the determined modulation frequency and the determined electrical phase; and • Determining the parameter value (112) of at least one parameter using the determined phase difference. [14] Device (100) according to claim 13, wherein the evaluation device (110) is further configured to sample the digital signal by means of one or more time domain filters and / or by means of one or more frequency domain filters; and wherein the evaluation device (110) is further arranged such that determining the parameter value (112) of the at least one parameter using the electrical phase of the electrical signal (108) includes determining the parameter value (112) of the at least one parameter using the sampled digital signal. [15] Method (300), comprising: • Receiving a modulated optical signal, wherein the modulated optical signal has a first group delay; • Changing the group delay of the received modulated optical signal as a function of a parameter value of at least one parameter, such that the modified modulated optical signal has a second group delay different from the first group delay; • Providing an electrical signal for the modified modulated optical signal, wherein the electrical signal has an electrical phase; • Detecting the electrical phase of the electrical signal; and • Determining the parameter value of at least one parameter using the detected electrical phase of the electrical signal.

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