OPTOELECTRONIC COMPONENT AND METHOD FOR GENERATING AN OUTPUT SIGNAL

Abstract

An optoelectronic component (10) is designed as a self-mixing interferometer and comprises a laser (11), a driver (20) with an output coupled to the laser (11), a signal input (21), a comparator (22) with an input (23) coupled to the signal input (21), a time-to-digital converter (25) with an input (26) coupled to an output (24) of the comparator (22), and a signal evaluation circuit (30) with an input (31) coupled to an output (27) of the time-to-digital converter (25), and with an output (32). The signal evaluation circuit (30) is designed to provide an output signal (SOUT) at the output (32). A method for generating an output signal (SOUT) is also provided.

Description

[0001] This patent application claims priority from German patent application 10 2022 130 571.6, the disclosure of which is hereby incorporated by reference. TECHNICAL FIELD

[0002] An optoelectronic component, a distance measuring arrangement with the optoelectronic component and a method for generating an output signal are provided. BACKGROUND

[0003] Distances can be measured using various methods. One example is time-of-flight configurations, where electromagnetic radiation is emitted toward a target at a first time, the radiation is reflected by the target, and the reflected radiation is detected by a photodetector at a second time. The distance to the target can be calculated based on the duration between the first and second times. However, this method is difficult to apply for short distances. For short distances, a self-mixing interferometer, or SMI, can be used.

[0004] The object of the present application is to provide an optoelectronic component, a distance measuring arrangement and a method for generating an output signal which are capable of measuring a distance with high accuracy.

[0005] This object is achieved by the subject matter of the independent claims. Further embodiments and developments are specified in the dependent claims. SUMMARY

[0006] In one embodiment, an optoelectronic component comprises a laser, a driver with an output coupled to the laser, a signal input, a comparator with an input coupled to the signal input, a time-to-digital converter with an input coupled to an output of the comparator, and a signal evaluation circuit. The signal evaluation circuit comprises an input coupled to an output of the time-to-digital converter. The signal evaluation circuit is designed to provide an output signal at an output of the signal evaluation circuit.

[0007] Advantageously, the comparator serves to precisely determine a point in time at which the time-to-digital converter, abbreviated TDC, starts and / or stops its operation in order to determine a duration.

[0008] In one embodiment, the optoelectronic component is designed as a self-mixing interferometer. In one example, the electromagnetic radiation emitted by the laser and other electromagnetic radiation, such as reflected electromagnetic radiation, mix within the optoelectronic component, e.g., within the laser.

[0009] In one embodiment of the optoelectronic component, the laser is embodied as a vertical cavity surface-emitting laser, abbreviated VCSEL, edge-emitting laser, or edge-emitting semiconductor laser. The electromagnetic radiation emitted by the laser is, for example, light. The electromagnetic radiation lies in a range between 400 nm and 2000 nm, in a range between 600 nm and 1300 nm, in a range between 840 nm and 1040 nm, or in a range between 920 nm and 960 nm. The laser is, for example, operated in pulsed mode, i.e. the laser is operated with pulses. In one example, the laser does not continuously emit electromagnetic radiation. Alternatively, the laser continuously emits electromagnetic radiation; for example, the laser emits modulated electromagnetic radiation that is added to a fundamental value of the electromagnetic radiation.

[0010] In one embodiment of the optoelectronic component, the comparator is implemented as a Schmitt trigger circuit or as an amplifier. The amplifier is, for example, an operational amplifier. The amplifier has a high gain. For example, the amplifier's gain factor is greater than 10, greater than 100, or greater than 1000.

[0011] In one example, the comparator is implemented as a comparator with hysteresis, such as a Schmitt trigger circuit. In another example, the comparator is implemented as a comparator without hysteresis.

[0012] In one embodiment of the optoelectronic component, the driver is designed to supply a laser current to the laser. The laser current has a pulse shape. A pulse of the laser current is repeated periodically.

[0013] In one embodiment of the optoelectronic component, the TDC is designed to measure a duration between two edges and generate a time-of-flight signal depending on the duration between the two edges. The time-of-flight signal can be referred to as a pulse width signal. The time-of-flight signal is designed, for example, to contain information about the duration of a pulse. The duration of the pulse can be referred to as the width or length of the pulse. Alternatively, the time-of-flight signal is designed, for example, to contain information about the duration between the edges of two pulses. The edges can be rising or falling edges.

[0014] In one embodiment of the optoelectronic component, an input signal is tapped at the signal input. A control signal is tapped at an input of the driver and / or applied to the driver input.

[0015] In one embodiment of the optoelectronic component, the first edge is a rising edge of the laser current, an edge of the control signal (this edge of the control signal triggers the rising edge of the laser current), an edge of the input signal, or an edge of a signal derived from the input signal. The second edge is another edge of the input signal or another edge of the signal derived from the input signal.

[0016] In one example, the first edge represents the beginning of the laser current pulse, which can be detected at an input or output side of the driver and at an output side of the photodetector. The second edge is detected at the photodetector output via the comparator and is a function of a distance difference. The distance difference results, for example, from the movement of a target relative to a starting position.

[0017] In an alternative embodiment of the optoelectronic component, the first edge is an edge of the input signal or an edge of a signal derived from the input signal. The second edge is a falling edge of the laser current, an edge of the control signal (this edge of the control signal triggers the falling edge of the laser current), another edge of the input signal, or another edge of the signal derived from the input signal.

[0018] In one example, the second edge represents the end of the laser current pulse, which can be detected at the driver input or output and at the photodetector output. The first edge is detected at the photodetector output via the comparator and is a function of the distance difference.

[0019] In one example, the first edge and the second edge are detected at the photodetector output via the comparator. For example, the first edge and the second edge are both a function of the distance difference, or one of the first and second edges is a function of the distance difference.

[0020] In one embodiment of the optoelectronic component, the signal evaluation circuit is designed to linearize the propagation time signal supplied by the TDC.

[0021] In one embodiment of the optoelectronic component, the signal evaluation circuit is designed to linearize the propagation time signal by generating a distorted signal by distorting the propagation time signal and to generate an undistorted signal by equalizing the distorted signal.

[0022] In one embodiment of the optoelectronic component, the distorted signal is generated by distorting the propagation time signal by polynomial or piecewise polynomial evaluation of the propagation time signal.

[0023] In one embodiment of the optoelectronic component, the undistorted signal is generated by equalizing the distorted signal using the equation: YU(n)=function_unwrap(YW(n),C, Y_SMI_PERIOD), where YU(n) is the nth value of the undistorted signal, YW(n) is the nth value of the distorted signal, C is an integer, and Y_SMI_PERIOD is a constant. The constant is the SMI period and is determined, for example, during manufacturing or calibration. C is, for example, a positive integer, a negative integer, or 0.

[0024] In a further development of the optoelectronic component, the undistorted signal is generated by equalizing the distorted signal using the equation: YU(n)=function_unwrap(YW(n),C, Y_SMI_PERIOD,RESET), where YU(n) is an nth value of the undistorted signal, YW(n) is an nth value of the distorted signal, C is an integer, Y_SMI_PERIOD is an SMI period, and RESET is a start or reset value.

[0025] In one embodiment of the optoelectronic component, the signal evaluation circuit comprises a lookup table and is designed to linearize the propagation time signal using the lookup table.

[0026] In one embodiment of the optoelectronic component, the signal evaluation circuit is designed to generate the output signal by filtering and / or amplifying the undistorted signal. The filtering is implemented, for example, as a digital high-pass filter. Advantageously, the filtering removes a large, undesirable DC component (this DC component may also contain low-frequency components). After the high-pass filtering, digital amplification is performed to set a specific microphone sensitivity.

[0027] In one embodiment of the optoelectronic component, the TDC comprises a time-to-voltage converter and a voltage-to-digital converter. The time-to-voltage converter is coupled to the input of the TDC. The time-to-digital converter is coupled to an output of the time-to-voltage converter and to the output of the TDC.

[0028] In one embodiment of the optoelectronic component, the signal input is coupled to the laser. The signal input is designed to receive a laser voltage tapped from the laser. The laser voltage exhibits, for example, a self-mixing interferometer effect, abbreviated to the SMI effect.

[0029] In one embodiment, the optoelectronic component comprises a photodetector with an output coupled to the signal input. The photodetector is, for example, one of a group consisting of a photodiode, a phototransistor, a pinned photodiode, and a light-emitting diode (LED). The LED is reverse-biased to function as a photodiode. A photodetector current generated by the photodetector exhibits, for example, the SMI effect.

[0030] In one embodiment, a distance measuring arrangement comprises the optoelectronic component and a target. The laser is designed to emit electromagnetic radiation. The electromagnetic radiation is, for example, light in the visible range. The target is designed to emit electromagnetic radiation as reflected radiation to the optoelectronic component. The optoelectronic component is designed to detect the reflected radiation. In other words, an input signal that depends on the reflected radiation is provided, generated, or tapped at an input side of the optoelectronic component; for example, the input signal depends on the phase and amplitude of the reflected electromagnetic radiation. More precisely, the target is designed to emit a portion of the electromagnetic radiation as reflected radiation to the optoelectronic component.The optoelectronic component is designed to detect or evaluate part of the reflected radiation.

[0031] In one example, the portion of reflected radiation is detected by the photodetector or laser. The portion of reflected radiation mixes with the electromagnetic radiation in the optoelectronic component, e.g., the laser.

[0032] In one embodiment, the distance measuring arrangement is designed such that the reflected radiation from the target is transmitted by the laser to the photodetector or by the photodetector to the laser. In the second case, the reflected radiation is transmitted, for example, directly from the target to the photodetector. The photodetector is designed to detect part of the reflected radiation. In one example, the target, the photodetector and the laser are on a straight line. The target is located at one end of the straight line. The positions of the photodetector and the laser on the straight line can be swapped. For example, the reflected radiation is absorbed by the laser; the reflected radiation influences the laser in such a way that the emitted light changes and thus the radiation observed by the photodetector is different.

[0033] In one embodiment of the distance measuring arrangement, the signal evaluation circuit is designed such that the output signal of the optoelectronic component is an audio signal. !

[0034] In one embodiment of the distance measuring arrangement, the target is a microphone diaphragm or a display. Advantageously, a movement of the diaphragm or display, caused, for example, by an audio signal, is detected by the optoelectronic component. A value of the movement is referred to as the distance difference.

[0035] The optoelectronic component described above is particularly suitable for the distance measuring system. The features described in connection with the optoelectronic component can therefore also be used for the distance measuring system, and vice versa.

[0036] In one embodiment, a method for generating an output signal comprises: Emission of electromagnetic radiation by a laser, Generating an input signal at a signal input depending on a reflected radiation, Generating a comparator signal by comparing the input signal or a signal derived from the input signal with a threshold value by a comparator, Generating a runtime signal by a TDC depending on the comparator signal and Providing an output signal by a signal evaluation circuit depending on the propagation time signal.

[0037] Advantageously, the comparator provides a start signal or a stop signal or a start and a stop signal with a duration that is converted into a digital value by the TDC.

[0038] The optoelectronic component and the distance measuring arrangement described above are particularly suitable for the method for generating an output signal. The features described in connection with the optoelectronic component and the distance measuring arrangement can therefore be used for the method, and vice versa.

[0039] In one example, the method is applied using the diaphragm of a microphone or microphone housing. Alternatively, the method can also be used with a mobile phone display as the diaphragm, thus eliminating the need for a conventional microphone or microphone housing.

[0040] In one example, the method performs direct position sensing (DPS) using SMI. The optoelectronic component is designed for high-resolution measurement of distances during membrane movements, i.e., for the realization of an acoustic-digital readout method. The optoelectronic component is characterized by a high signal-to-noise ratio (SNR), low cost, and low power consumption. The optoelectronic component enables high-resolution measurement of membrane or target distance (e.g., high-resolution membrane / target movement beyond lambda / 2), fast detection of membrane / target movements, direct measurement of the pulse length from an SMI response using the steep edge of the frame, and pulsing of the VCSEL current at a high rate (a sampling frequency fs is measured in Hz) at a low duty cycle to generate an SMI response by heating the VCSEL.

[0041] In one example, the pulses of the laser current have a pulse rate in a range between 30 kHz and 300 kHz, or between 60 kHz and 200 kHz, or between 70 kHz and 180 kHz. In a low-power microphone configuration, the pulse rate is, for example, 75 kHz. The duration of a pulse of the laser current is in a range between 0.1 µs and 50 µs, or in a range between 0.2 µs and 30 µs, or in a range between 0.2 µs and 2 µs. Typically, the duration is, for example, 0.9 µs. The output signal of the optoelectronic component has, for example, one value per pulse. Therefore, the sampling frequency of the optoelectronic component is equal to or lower than the pulse rate. The sampling frequency in Hertz is sometimes also referred to as the number of samples / second.

[0042] In one example, the distance measurement array estimates / tracks with high resolution and low distortion the displacement of a diaphragm used to read acoustic pressure changes in the audible range in terms of frequency and dynamic range, i.e., an optical microphone solution. The distance measurement array can also be used when a non-traditional diaphragm, such as a display in a mobile phone, is used as the diaphragm. The distance measurement array also resolves displacement beyond lambda / 2, e.g., with the same resolution, which traditional open-loop / closed-loop tracking with lambda tuning cannot achieve. The distance measurement array can be used to track / estimate diaphragm movements or other distance changes.

[0043] In one example, the distance measurement array uses the pulsed VCSEL current to generate the SMI response. This saves significant VCSEL drive power compared to closed-loop / open-loop solutions. The distance measurement array is designed for direct position sensing, abbreviated DPS. The distance measurement array requires only one frame, which reduces VCSEL drive power. The distance measurement array directly measures the pulse length from the beginning of the VCSEL pulse to the steep frame edge, or alternatively from the steep frame edge to the end of the VCSEL pulse. The distance measurement array does not perform an amplitude-based measurement. This makes the distance measurement array superior in terms of shot noise rejection. The complexity of the distance measurement array is low, as it requires only a few one-time programmable bits (e.g., approximately 200 bits) and analog-to-digital conversions.The distance measurement circuitry runs at a fraction of the speed of other systems. The distance measurement system for DPS can track a single wavenumber in the SMI response, allowing it to support measurements beyond lambda / 2 of the membrane deflection. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The following description of illustrations of examples or embodiments can further illustrate and explain aspects of the optoelectronic component, the distance measuring arrangement, and the method for generating an output signal. Arrangements, processes, devices, and circuit blocks with the same structure or the same effect are provided with equivalent reference numerals. To the extent that arrangements, processes, devices, and circuit blocks in different illustrations correspond to one another in terms of their function, their description will not be repeated for each of the following illustrations. The Fig. show exemplary embodiments of a distance measuring arrangement with an optoelectronic component; the Fig. show exemplary signals and characteristics of a distance measuring arrangement with an optoelectronic component, and the Fig. show further exemplary signals and features of a distance measuring arrangement with an optoelectronic component. DETAILED DESCRIPTION

[0045] Fig. shows an exemplary embodiment of a distance measuring arrangement 40 with an optoelectronic component 10. The distance measuring arrangement 40 comprises the optoelectronic component 10 and a target 14. The optoelectronic component 10 comprises a laser 11 and a signal input 21. The optoelectronic component 10 comprises an integrated circuit 12. The integrated circuit 12, abbreviated IC, can be implemented as an application-specific integrated circuit, abbreviated ASIC. A driver 20 of the IC 12 (as shown in the Fig. The laser 11 (shown) is coupled to the integrated circuit 12 via the signal input 21. The integrated circuit 12 contains, for example, an output 13. The optoelectronic component 10 is implemented as a self-mixing interferometer. The laser 11 is implemented as a surface-emitting laser with a vertical resonator. The target 14 is a microphone diaphragm or a display. The target 14 can function as a mirror.

[0046] The driver 20 of the IC 12 supplies a laser current IVC to the laser 11. The laser 11 emits electromagnetic radiation SE. The target 14 supplies a portion of the electromagnetic radiation SE as reflected radiation SR to the optoelectronic component 10. The reflected radiation SR is fed to the laser 11, and the reflected radiation SR mixes with the electromagnetic radiation SE, creating the self-mixing interferometer effect, abbreviated to the SMI effect. The optoelectronic component 10 detects a portion of the reflected radiation SR; more precisely, the laser 11 detects the reflected radiation SR. A laser voltage UVC is tapped between the two terminals of the laser 11. The laser voltage UVC is a function of the reflected radiation SR (the SMI signal with the steep edge is included in the laser voltage UVC). The laser voltage UVC contains information about the distance d between the laser 11 and the target 14.The laser voltage UVC is an input signal SIN of the optoelectronic component 10. An output signal is provided at the output 13 of the integrated circuit 12. The output signal contains the information about the distance d. As shown in . Fig. As can be seen, the target 14 moves or vibrates due to an audio signal AUD. The target 14 moves a distance called the distance difference Δd. The output signal of the optoelectronic component 10 is an audio signal.

[0047] Fig. shows an exemplary embodiment of a distance measuring arrangement 40 with an optoelectronic component 10, which is a further development of the Fig. The optoelectronic component 10 contains a photodetector 15. The photodetector 15 is coupled to the integrated circuit 12. The photodetector 15 is thus coupled to the integrated circuit 12 via the signal input 21. The photodetector 15 generates a photodetector current IPD. The photodetector current IPD is the input signal SIN of the optoelectronic component 10.

[0048] The distance measuring arrangement 40 is arranged such that the reflected radiation SR is guided by the laser 11 to the photodetector 15. The photodetector 15 detects a portion of the reflected radiation SR. The reflected radiation SR is the optical SMI signal with the steep edge, which is detected by a comparator 22 (shown in the Fig. ).

[0049] The optoelectronic component 10 is designed for a microphone with optical readout. The readout is based on self-mixing interference (SMI): A laser beam emitted by the VCSEL 11 is directed onto a reflecting membrane (representing the target 14), which moves with the applied sound pressure AUD. The reflected laser radiation SR is returned to the VCSEL 11, influencing the operation of the VCSEL 11 through light interference or radiation interference. Since the reflected radiation SR experiences a different phase shift depending on the membrane position, the total radiation intensity changes. This can be detected either by detecting the radiation intensity with the photodetector 15 (power or current readout) or by detecting the voltage / current characteristic (e.g., voltage readout) of the laser 11. A phase shift of the reflected radiation SR can be calculated as follows: φ0=2π⋅2dλ, where λ is the wavelength of the radiation of the laser 11 and d is the distance between the laser 11 and the target 14.

[0050] The IC 12 includes, for example, the readout with a TDC 25, etc. The IC 12 or the ASIC is responsible for controlling / generating a VCSEL drive current IVC and detecting the current IPD from the photodiode 15. The IC 12 can also measure the voltage UVC across the VCSEL 11. Furthermore, the IC 12 is responsible for estimating the pulse length signal from the SMI response (d-variations) and converting it into audio signals; this is the algorithm part of the DPS systems. A method / distance measurement arrangement 40 that estimates / tracks the deflection of the diaphragm with high resolution and low distortion, which is used to read out the acoustic pressure changes AUD in the audible range in terms of frequency and dynamic range, i.e., an optical microphone solution. The distance measurement arrangement can be used to track / estimate any distance changes, not just those applicable to microphones. The optoelectronic component 10 is designed to track membrane movements.

[0051] In an alternative embodiment not shown, the distance measuring arrangement 40 is arranged such that the reflected radiation SR is guided directly to the photodetector 15. Thus, an optical path from the target 14 to the photodetector 15 is free of the laser 11.

[0052] In an alternative embodiment (not shown), the photodetector 15 is arranged at a different location in the beam path. In one example, the photodetector is embodied as a semitransparent photodiode located between the laser 11 and the target 14. The radiation from the laser 11 passes through the photodiode 15 before striking the target 14, and the reflected radiation SR also passes through the photodiode 15 before striking the laser 11 again.

[0053] Fig. shows an exemplary embodiment of a distance measuring arrangement 40 with an optoelectronic component 10, which is a further development of the Fig. The optoelectronic component 10 comprises a driver 20, the output of which is coupled to the laser 11. An output of a control circuit 34 of the optoelectronic component 10 is connected to an input of the driver 20. The driver 20 is designed as an amplifier, buffer, pulse generator, or clock generator. The amplifier is implemented, for example, as an operational transconductance amplifier, abbreviated OTA. The laser current IVC has a pulse shape. The pulses of the laser current IVC are, for example, rectangular. The value of a pulse of the laser current IVC lies in a range between 0.1 mA and 20 mA or between 0.5 mA and 5 mA.

[0054] The optoelectronic component 10 comprises the photodetector 15 with an output coupled to the signal input 21. The optoelectronic component 10 comprises a comparator 22, whose input 23 is coupled to the signal input 21, a time-to-digital converter 25 (TDC for short), whose input 26 is coupled to an output 24 of the comparator 22, and a signal evaluation circuit 30, whose input 31 is coupled to an output 27 of the TDC 25. The comparator 22 is designed, for example, as a Schmitt trigger circuit. The comparator 22 thus exhibits hysteresis. The signal evaluation circuit 30 has an output 32.

[0055] The driver 20 supplies the laser current IVC to the laser 11. The laser current IVC is in the form of a pulse. The laser current IVC contains a series of pulses. One pulse of the pulse series is repeated periodically. The photodetector 15 generates the photodetector signal IPD, which represents the input signal SIN. The input signal SIN is fed via the signal input 21 to the input 23 of the comparator 22. The comparator 22 generates a comparator signal SCOM depending on the input signal SIN. The comparator 22 compares the input signal SIN with a threshold value ITH and generates the comparator signal SCOM as a result of the comparison. The comparator signal SCOM contains pulses t(n), t(n+1), as shown in Fig. The comparator signal SCOM is fed to the TDC 25. The comparator signal SCOM is applied to input 26 of the TDC 25. The TDC 25 generates a propagation time signal YT or YT(n) depending on the comparator signal SCOM. "n" stands for the number of a sample, e.g., the nth pulse or the nth propagation time signal YT. The propagation time signal YT is fed to the signal evaluation circuit 30. The signal attenuation circuit 30 generates the output signal SOUT at output 32 depending on the propagation time signal YT. The output signal SOUT is a digital audio signal.

[0056] The comparator 22 detects, for example, two edges of the input signal SIN applied to the signal input 21 or two edges of a signal derived from the input signal SIN. The TDC 25 measures a duration between the two edges and generates the propagation time signal YT depending on the duration between the two edges. As shown in Fig. As shown on the left, the photodetector current IDP and thus the input signal SIN have a first edge at which the input signal SIN rises above the threshold value ITH. Furthermore, the photodetector current IDP and thus the input signal SIN have a second edge at which the input signal SIN rises above the threshold value ITH. The first and second edges are rising edges.

[0057] In one example, the comparator 22 is designed to generate the comparator signal SCOM such that the comparator signal SCOM indicates the distance between the first edge and the second edge. For example, the comparator signal SCOM contains a pulse with a duration equal to the distance between the first and second edges. The TDC 25 is designed to generate the propagation time signal YT by digitizing this duration. For example, the TDC uses the rising edge of the pulse of the comparator signal SCOM as a start signal and the falling edge of the pulse of the comparator signal SCOM as a stop signal. As shown in Fig. As shown, the comparator signal SCOM has a pulse t(n) and a pulse t(n+1) following the pulse t(n). The duration of the pulse t(n) is shorter than the duration of the pulse t(n+1), as can be seen from the curve in Fig. emerges.

[0058] Alternatively (as in Fig. (explained below), the TDC 25 measures the duration between the beginning of a pulse of the laser current IVC and an edge of the input signal SIN, or alternatively, between an edge of the input signal SIN and an end of the pulse of the laser current IVC. Typically, an edge of the input signal SIN used for the comparator 22 is a steep edge.

[0059] Advantageously, the use of the steep edge of the frame allows for a precise determination of a point in time. In one example, the steep edge of the input signal SIN is applied via comparator 22 to a start input of the TDC 25, and a signal derived from a control signal CNT of the driver 20 is applied to a stop input of the TDC 25. The derived signal is a falling edge of the control signal CNT, which controls the driver 20.

[0060] The signal evaluation circuit 30 linearizes the propagation time signal YT supplied by the TDC 25. The signal evaluation circuit 30 performs several processes or steps to provide the output signal SOUT. In a first process 37, the signal evaluation circuit 30 generates a distorted signal YW by distorting the propagation time signal YT. In a second process 38, the signal evaluation circuit 30 generates an undistorted signal YU by equalizing the distorted signal YW. In a third process 39, the signal evaluation circuit 30 generates the output signal SOUT by amplifying and / or filtering the undistorted signal YU. Amplification is performed to adjust the gain. The filtering is, for example, high-pass filtering or band-pass filtering. The propagation time signal YT, the distorted signal YW, the undistorted signal YU, and the output signal SOUT are digital signals (the "(n)" stands for the nth sample).

[0061] In one example, the signal evaluation circuit 30 is implemented as a digital logic circuit, e.g., as a combinational digital logic circuit or state machine. The signal evaluation circuit 30 consists of at least one of logic gates, flip-flops, and one-time programmable bits. The logic cells are described at a register transfer level, abbreviated to RTL. In one example, the signal evaluation circuit 30 is independent of a computer, microprocessor, and microcontroller.

[0062] In an alternative example, the signal evaluation circuit 30 is embodied as a microprocessor or microcontroller. The signal evaluation circuit 30 comprises, for example, a memory for storing a computer program product. The computer program product comprises instructions for causing the optoelectronic component 10 or the distance measuring arrangement 40 to perform the method described here.

[0063] The method for generating the output signal SOUT comprises emitting electromagnetic radiation SE by the laser 11, generating the input signal SIN at the signal input 21 as a function of the reflected radiation SR, generating the comparator signal SCOM by comparing the input signal SIN or a signal derived from the input signal SIN with the threshold value ITH by the comparator 22, generating the propagation time signal YT by the TDC 25 as a function of the comparator signal SCOM, and providing the output signal SOUT by the signal evaluation circuit 30 as a function of the propagation time signal YT. The threshold value ITH has, for example, a positive or negative value or is 0.

[0064] The distance measuring arrangement 40 is designed such that the laser current IVC is pulsed for approximately 0.9 µs at a rate of, for example, 150 kHz. This excitation is used for the DPS readout algorithm. Each pulse of the laser current IVC heats the laser 11, which generates an SMI response due to the change in the laser wavelength lambda λ. Each SMI response is shifted in phase / time, which changes when the optical distance d changes by the distance difference Δd. The DPS readout algorithm estimates this phase / time shift using the comparator 22.

[0065] In an alternative embodiment, as in Fig. As shown, the signal input 21 is coupled to the laser 11 and receives a laser voltage UVC tapped at the laser 11. The laser voltage UVC is provided between the two terminals of the laser 11. The input signal SIN is the laser voltage UVC.

[0066] In an alternative embodiment, indicated by dashed lines, the optoelectronic component 10 comprises a subtracting / adding circuit 28 connecting the photodetector 15 to the input 23 of the comparator 22. Thus, an input signal of the comparator 22 is equal to the photodetector current IPD minus or plus a reference value. The reference value is, for example, constant or variable. The subtracting / adding circuit 28 is optional and can be replaced by a connecting line. The subtracting / adding circuit 28 subtracts the reference value from the input signal SIN or adds the reference value to the input signal SIN during the pulse to set the threshold value for the comparator 22. Typically, the input signal SIN is a current. A second input of the comparator 22 can be connected to ground; in this case, the threshold value ITH of the comparator 22 is, for example, equal to 0 or a small value.

[0067] In another embodiment, the subtracting / adding circuit 28 subtracts the average value of the input signal SIN from the input signal SIN or adds the average value of the input signal SIN to the input signal SIN during one pulse.

[0068] In an alternative embodiment not shown, the comparator 22 is hysteresis-free.

[0069] Fig. shows an exemplary embodiment of details of an optoelectronic component 10, which is a further development of the Fig. illustrated embodiments. The method for DPS comprises four basic steps or processes: comparator input circuit, time-to-digital conversion, time warping, and SMI unwrapping. The comparator 22 is part of an analog input circuit. The comparator 22 performs edge detection. The duration t(n) is a signal with a second level and variable length. The comparator 22 is additionally coupled, for example, to the driver 20 or to the control circuit 34 in order to control the pulses of the laser current IVC. The TDC 25 comprises an oscillator 29. Furthermore, the TDC 25 comprises a counter circuit. The oscillator 29 is, for example, a ring oscillator. The TDC 25 performs a time-to-digital conversion by counting time (e.g., by counting the pulses of oscillator 29) for the period that represents the input of the TDC 25. There are many possible approaches for implementing the TDC 25.

[0070] The TDC 25 performs a digital conversion of the pulse length t(n) and generates the propagation time signal YT(n). The TDC 25 has an additional input 33. The control circuit 34 is coupled to the additional input 33. The control circuit 34 supplies the control signal CNT to the additional input 33. In one example, the additional input 33 is a start input and the input 26 is a stop input. Thus, the TDC 25 begins the duration measurement with an edge (e.g., a rising edge) of a pulse of the control signal CNT and ends the measurement with an edge of the comparator signal SCOM, e.g., with a falling edge of the pulse t(n) or t(n+1).

[0071] The TDC 25 thus generates the time-of-flight signal YT depending on the duration between the first and second edges. The first edge is an edge of the control signal CNT (which is almost identical to a rising edge of the laser current IVC or an edge of the input signal SIN). The second edge is another edge of the input signal SIN or another edge of the signal derived from the input signal SIN. The comparator signal SCOM supplies the second edge to input 26 of the TDC 25.

[0072] In the digital domain, the first process or block 37 temporally distorts the propagation time signal YT(n), which depends on the wavelength λ, to generate the distorted signal YW(n). The distorted signal YW(n) is undistorted in the second process or block 38 to generate the undistorted signal YU. In the third process or block 39, the undistorted signal YU(n) is amplified with an amplifier to perform a sensitivity adjustment and generate the output signal SOUT.

[0073] Equalizing the distorted signal YW(n) to the undistorted signal YU(n) is realized, for example, by the following calculations or steps, which are implemented in a digital design of the second process 38 in the Fig. used. Y_SMI_period is a constant determined during calibration and lies, for example, in a range between 100 ns and 2000 ns, typically = 600 ns. C is a constant that lies, for example, in a range between 0 and 1.0; typically 0.5;. unwrap is initialized to zero at power-up. Equalization is a method or algorithm that samples the distorted signal YW(n) sample by sample and performs the procedure or operation described below.

[0074] The method for calculating the undistorted signal YU(n) includes the following calculations or steps: Calculate for each input sample: diff(n) = YW(n) - YW(n-1); If diff(n) > C · Y_SMI_period begin unwrap = unwrap - Y_SMI_period; elseif diff(n) < - C · Y_SMI_period begin unwrap = unwrap + Y_SMI_period; else unwrap = unwrap; end YU(n) = YW(n) + unwrap;

[0075] The undistorted signal can therefore be calculated using the following equation: YU(n)=function_unwrap(YW(n),C, Y_SMI_PERIOD, RESET) RESET is a start or reset value. In one example, RESET = 0.

[0076] In an alternative embodiment, input 26 of the TDC 25 is a start input, and the other input 33 of the TDC 25 is a stop input. The TDC 25 generates the time-of-flight signal YT depending on the duration between the first and second edges. The first edge is an edge of the input signal SIN (this edge is the rising edge, which is close to the end of the pulse of the input signal SIN). The second edge is an edge of the control signal CNT (which is almost identical to a falling edge of the laser current IVC).

[0077] Fig. shows an exemplary embodiment of a detail of an optoelectronic component 10, which is a further development of the Fig. illustrated embodiments. The TDC 25 includes a time-to-voltage converter 35 coupled to the input 26 of the time-to-digital converter 25. The TDC 25 includes a voltage-to-digital converter 36 connected to an output of the time-to-voltage converter 35 and to the output 27 of the time-to-digital converter 25.

[0078] Fig. shows an exemplary embodiment of signals from a distance measuring arrangement 40 with an optoelectronic component 10, which represents a further development of the embodiments shown above. The photodetector current IPD is shown as a function of a time t. The photodetector current IPD at a distance difference Δd=0 is labeled A, and the photodetector current IPD at a distance difference Δd=117.5 nm is labeled B: The optoelectronic component 10 pulses the laser current IVC for approximately 0.9 µs at a rate of 150 kHz. Each pulse heats the laser 11, which generates an SMI response due to the change in wavelength λ. Each SMI response is shifted in phase / time, which changes as the optical distance d changes. The readout algorithm estimates this phase / time shift. This stimulus is used for the DPS readout algorithm.

[0079] The optoelectronic component 10 measures the time from the start of the laser current IVC pulse to a steep positive edge of the SMI response. The steep edge of the SMI response is chosen to minimize the influence of the noise from the photodetector 15. The start pulse can be the control signal CNT for the driver 20 or derived from the current IVC of the laser itself by another comparator of the optoelectronic component 10. The control signal CNT is already digital. The control signal CNT is a pulse signal. In one example, a pulse of the control signal CNT has a length of a desired pulse of the laser current IVC or has a different length.

[0080] Alternatively, the duration from the steep edge of the input signal to the end of the laser current IVC or the control signal CNT to the driver 34 is measured by the TDC 25. Thus, the steep edge of the input signal SIN is provided either at a start input of the TDC 25 or at a stop input of the TDC 25.

[0081] The DPS output values: {Δt1, Δt2} = {0.35 µs, 0.55 µs}

[0082] The SMI response repeats itself for every λ / 2 change in the optical distance d. In the example in Fig. with Δd = 117.5 nm and Δd = 117.5 nm + 471 nm (approximately A / 2 = 470 nm). This corresponds to a 2 π (also written as 2π) change in the SMI phase. A simple equalization algorithm that keeps track of how many 2π have passed solves the AOP problem. AOP stands for acoustic overload point, which is defined as the maximum operating amplitude of the acoustic signal, typically 130 dBspl. In a typical implementation, the phase can change by more than 2π at a level of about 110 dB, meaning that the SMI signal has been equalized by 2π. The equalization process 38 performs this algorithm to determine the number of 2π that have occurred, or the wavenumber of the current. In DPS, the output is specified in seconds, so the period of the SMI signal for one frame is measured in seconds.

[0083] Fig. shows an exemplary embodiment of signals from a distance measuring arrangement 40 with an optoelectronic component 10, which is a further development of the embodiments presented above. Various SMI responses from the PD output are recorded during a 0.9 µs pulse. The membrane is in the rest position, i.e., there is no change in the optical distance d. The pulses of the laser current IVC have a duty cycle in the range between 1% and 20%. The position and number of the SMI periods change with a value of the laser current IVC. The SMI periods and their changes result from the heating characteristics of the laser 11. The optoelectronic component 10 is designed such that it can process several SMI periods within the same pulse, e.g., by measuring the period duration up to the last steep edge. If the value of the laser current IVC is too low (in this example, of the laser 11, e.g.,at IVC=2.0 mA), SMI occurs, but no frames appear, making it unusable for DPS.

[0084] The Fig. show exemplary embodiments of signals of a distance measuring arrangement 40 with an optoelectronic component 10, which represents a further development of the embodiments shown above. Fig. The physical relationships are explained. In DPS, the self-heating of the VCSEL 11 is used to generate the SMI modulation.

[0085] In Fig. The laser current IVC is shown as a function of time t. The VCSEL 11 is thus exposed to two pulses of the laser current IVC.

[0086] In Fig. A temperature change ΔT is shown as a function of time t. The laser current IVC thus leads to heating of the VCSEL 11.

[0087] In Fig. and also in Fig. The wavelength λ of the laser 11 is shown as a function of time t. Due to the temperature change ΔT, the wavelength is tuned.

[0088] In Fig. The photodetector current IPD is shown as a function of time t. Each pulse contains an SMI modulation.

[0089] In Fig. A first pulse of the photodetector current IPD is plotted against time t. In this example, there are two SMI periods in the first pulse (and also in the second pulse). They have different widths and are denoted T1 and T2. The two SMI periods arise from the change in wavelength over time according to a phase transition equation (even if Lopt(t) is constant): φ(t)=2 π 2 Lopt(t) / λ(t); where Lopt(t) is the optical distance that changes with time t as the membrane of the target 14 moves, φ(t) is a phase of the radiation SE emitted by the laser 11 (the phase of the radiation φ(t) is the excitation phase), and λ(t) is a wavelength of the radiation SE emitted by the laser 11.

[0090] Even if Lopt(t) is constant, the wavelength λ(t) changes (e.g., due to the heating of the laser resonator, e.g., a VCSEL resonator). According to the excess phase equation, the photodetector current IPD is determined as in Fig. shown top left. The two SMI periods are stretched differently in time because dλ / dt is not a flat curve: A higher dλ / dt leads to a shorter SMI period, a lower dλ / dt to a longer SMI period.

[0091] As a result, a phase shift caused by membrane displacement causes a smaller time shift in SMI period T1 than in SMI period T2. Furthermore, the time shift is not the same within each SMI period because the rate of change dλ / dt of lambda also varies within each SMI period. This results in a distortion that follows the curve of the rate of change of lambda λ. In short, if the phase (t) is shifted by membrane displacement, the phase shift also depends on the rate of change of lambda λ.

[0092] In Fig. The first period T1 is measured from a first peak or a first maximum of the input signal SIN (e.g., the photodetector current IPD) to a second peak or a second maximum of the input signal SIN. The second period T2 is measured from a second peak or a second maximum of the input signal SIN to a third peak or a third maximum of the input signal SIN.

[0093] Fig. shows an exemplary embodiment of signals from a distance measuring arrangement 40 with an optoelectronic component 10, which represents a further development of the embodiments shown above. Shown are the photodetector current IPD, a modified value IPD_hpf, the comparator signal SCOM, and the laser current IVC as a function of time t. The modified value IPD_hpf is the photodetector current IPD from which an average value of the photodetector current IPD is subtracted. The modified value IPD_hpf is, for example, an example of a signal derived from the input signal SIN.

[0094] At a first time t1, a pulse of the laser current IVC begins. The pulse of the laser current IVC ends at a sixth time t6.

[0095] The photodetector current IPD rises above a threshold value ITH at a second time t2, which occurs after the first time t1. The photodetector current IPD falls below the threshold value ITH at a third time t3, which occurs after the second time t2.

[0096] The photodetector current IPD rises above the threshold value ITH for a second time at a fourth time t4, which occurs after the third time t3. The photodetector current IPD falls below the threshold value ITH at a fifth time t5, which follows the fourth time t4. The sixth time t6 follows the fifth time t5.

[0097] For example, the following durations can be used to provide a signal at input 26 of the TDC 25: - the period of the first period of the input signal SIN (which is the photodetector current IPD or the laser voltage UVC or a signal derived from IPD or UVC): t3-t2 - the period of the second period of the input signal SIN: t5-t4 - the duration between the two rising edges of the input signal SIN: t4-t2 - the duration between the two falling edges of the input signal SIN: t5-t3 - the period between the beginning of the pulse of the laser current IVC and the beginning of the first period of the input signal SIN: t2-t1 - the period between the beginning of the pulse of the laser current IVC and the beginning of the second period of the input signal SIN: t4-t1 - the duration between the start of the pulse of the laser current IVC and the end of the first period of the input signal SIN: t3-t1 - the duration between the beginning of the pulse of the laser current IVC and the end of the second period of the input signal SIN: t5-t1

[0098] Alternatively, other signals or derived signals or durations can be used. Multiple durations can also be used, e.g., t3-t2 and t5-t4, or alternatively, t2-t1 and t4-t1; thus, multiple period durations are used for each VCSEL pulse.

[0099] As explained below, typically the time between the start of the pulse of the laser current IVC and the start of the second period of the input signal SIN (namely t4-t1) is used for the time-to-digital conversion by the TDC 25.

[0100] The DPS readout algorithm is performed as follows: The time from the start pulse t1 to the last steep frame edge t4 is measured by the optoelectronic component 10. This pulse length t4-t1 is the t(n) sample value, which in Fig. shown below. As the diaphragm deflection increases and the steep edge falls outside the pulse window, the optoelectronic component 10 only measures the time until the second steep edge. In this case, there is a jump to another frame, and the measured time must be equalized to process the frame jump (diaphragm deflection Δd > λ / 2). Only the comparator output at a positive edge is used. The comparator output at a negative edge is not used.

[0101] The DPS measures the time from the start pulse to the last steep edge, i.e., the last SMI period in the pulse. Comparator 22 with hysteresis triggers, for example, at zero crossing. The rising edge of the start trigger signal marks the beginning of the pulse. The rising edge of the comparator signal SCOM indicates the current frame position (in time). The output of DPS is the time from the rising edge of the start trigger signal to the rising edge of the stop signal. In one example, there are three time measurements within a pulse.

[0102] In an alternative embodiment, the optoelectronic component 10 measures a duration, wherein the duration begins with the steep edge of the input signal SIN (e.g., the last steep edge of the input signal SIN) and ends with the falling edge of the control signal CNT to the driver 20 or the falling edge of the laser current ICV. Thus, the steep edge of the input signal SIN is used as the start pulse, and the end pulse is the falling edge of the control signal CNT to the VCSEL driver 20 or of the laser current ICV.

[0103] The Fig. show exemplary embodiments of signals and characteristic curves of a distance measuring arrangement 40 with an optoelectronic component 10, which represents a further development of the embodiments shown above. The optoelectronic component 10 performs DPS input / output characteristic linearization using time warping. The input / output characteristic is linearized by shifting each original YT(n) into a new range or a new sample value designated YW(n). This is possible because the IO curve is monotonic within an SMI period. The distortion is then performed by polynomial fitting of a function, e.g.: YW(n)=f(x)=Warp(x) and x=YT(n), or YW(n)=f(YT(n) to stretch the time samples YT(n). In an example: YW(n)=f(x)=a+b x+c x2+d x3+e x4 where x=YT(n) and a, b, c, d and e are coefficients (c is nonzero; d is zero or nonzero; e is zero or nonzero).

[0104] The adjustment of Warp(x) is based on the input / output response, abbreviated as IO response, and the desired output signal SOUT has a linear slope. The shape of the distortion is determined by the heating response of the laser 11. One method for determining the IO response can be investigated, for example, by applying acoustic stimuli greater than λ / 2. Another linearization method can also be used.

[0105] In Fig. is the response to a linear sweep of the distance difference Δd. A time difference Δt is plotted as a function of the distance difference Δd. The time difference Δt is the duration between the fourth time t4 and the first time t1 (other measures as mentioned above can also be used). YT(n) in the above equation is the time difference Δt in Fig. The difference Δt could theoretically be obtained by plotting each measured YT(n) against the distance difference Δd, increasing Δd in small steps for each sample. An example of an SMI period is: SMI period = 900 ns - 250 ns = 650 ns

[0106] In Fig. The time distortion y = Warp(x) is shown to obtain a linear IO response. y is plotted against x. The arrow indicates a distorted SMI period = 950 ns - 175 ns = 1.125 µs. In Fig. The corresponding distortion function f(x) = warp(x) and x=YT(n) is shown, where x, Δt is on the x-axis. The function f(x) can be approximated by a polynomial or a piecewise polynomial or another function. This function is implemented in digital hardware / software in the second process 38 in the Fig. implemented. The approximated function can be called f_app(x). The distortion function is designed to stretch the original DPS samples YT(n) to establish a linear relationship between Δd and YW(n).

[0107] In Fig. The IO response is shown for an entire SMI period. The time difference Δt is plotted against the distance difference Δd. The relationship is linear. In Fig. The distorted output of the measured input YT(n) is shown: YW(n)=f_app(YT(n)). Example: The laser current IVC = 4 mA.

[0108] Fig. show exemplary embodiments of signals and properties of a distance measuring arrangement 40 with an optoelectronic component 10, which represents a further development of the embodiments shown above. To handle membrane deflections > λ / 2, equalization is performed. The equalization algorithm calculates the difference: diff(n)=y(n)−y(n−1).

[0109] If abs(diff(n)) is greater than 0.5 SMI period, a frame jump has occurred. The sign of diff(n) determines whether the SMI period should be subtracted or added to perform equalization. The equalization scheme works under the condition that the heating is large enough to have at least one SMI period within the pulse duration (i.e., t6-t1) of the laser current IVC. Fig. the response to a linear sweep of the distance difference Δd is shown; the time difference Δt is shown as a function of the distance difference Δd.

[0110] In Fig. the original DPS response is labeled A and the distorted DPS response is labeled B.

[0111] In Fig. the distorted DPS response is marked B and the unbiased response is marked C.

[0112] In Fig. The time difference Δt is shown as a function of the sample number N. The original DPS output is marked F, the Py-distorted DPS output is marked G, and the undistorted Py-distorted output is marked H.

[0113] The Fig. show exemplary embodiments of signals and properties of a distance measuring arrangement 40 with an optoelectronic component 10, which represents a further development of the embodiments shown above.

[0114] In Fig. A simulated heat transfer function is shown; this illustrates a temperature change ΔT as a function of time t. In Fig. The power P supplied to the laser 11 is shown as a function of time t. The power P is a heating power. The power P has approximately the shape of a rectangular pulse. In Fig. A simulation of an input Δd and an output Δt is explained. The time difference Δt is shown as a function of the distance difference Δd divided by 470 nm. Δd / 470 nm is equal to the number of SMI periods. The time t(n) increases linearly with the distance difference Δd (IVC = 4 mA).

[0115] The invention is not limited to the description of the embodiments. Rather, the invention encompasses any novel feature and any combination of features, in particular any combination of features in the claims, even if the feature or combination of features itself is not explicitly stated in the claims or embodiments. List of reference symbols 10 optoelectronic component 11 lasers 12 integrated circuits 13 Exit 14 Target 15 Photodetector 20 drivers 21 Signal input 22 Comparator 23 Entrance 24 Exit 25 time-to-digital converters 26 Entrance 27 Exit 28 subtracting / adding circuit 29 Oscillator 30 Signal evaluation circuit 31 Entrance 32 Exit 33 additional entrance 34 Control circuit 35 time-voltage converters 36 voltage-to-digital converters 37-39 Process 40 Distance measuring arrangement AUD audio signal CNT control signal d distance IPD photodetector current IVC laser current ITH threshold SCOM comparator signal SE electromagnetic radiation SIN input signal SIN output signal SR reflected radiation t time t1-t6 time point UVC laser voltage YT runtime signal YU undistorted signal YW distorted signal Δd distance difference Δt time difference λ wavelength QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 130 571.6

[0001]

Claims

[1] An optoelectronic component (10) designed as a self-mixing interferometer and comprising: - a laser (11), - a driver (20) having an output coupled to the laser (11), - a signal input (21), - a comparator (22) having an input (23) coupled to the signal input (21), - a time-to-digital converter (25) having an input (26) coupled to an output (24) of the comparator (22), and - a signal evaluation circuit (30) having an input (31) coupled to an output (27) of the time-to-digital converter (25) and having an output (32), wherein the signal evaluation circuit (30) is designed to provide an output signal (SOUT) at the output (32). [2] The optoelectronic component (10) according to claim 1, wherein the laser (11) is designed as a surface-emitting laser with a vertical resonator. [3] The optoelectronic component (10) according to claim 1 or 2, wherein the comparator (22) is designed as a Schmitt trigger circuit or as an amplifier. [4] The optoelectronic component (10) according to any one of claims 1 to 3, wherein the driver (20) is designed to supply a laser current (IVC) to the laser (11) such that the laser current (IVC) has a pulse shape and a pulse is repeated periodically. [5] The optoelectronic component (10) according to claim 4, wherein the time-to-digital converter (25) is designed to measure a duration between a first and a second edge and to generate a propagation time signal (YT) depending on the duration between the first and the second edge. [6] The optoelectronic component (10) according to claim 5, wherein an input signal (SIN) is tapped at the signal input (21) and a control signal (CNT) is tapped at an input of the driver (20), wherein the first edge is a rising edge of the laser current (IVC), an edge of the control signal (CNT), an edge of the input signal (SIN) or an edge of a signal derived from the input signal (SIN), and wherein the second edge is a further edge of the input signal (SIN) or a further edge of the signal derived from the input signal (SIN). [7] The optoelectronic component (10) according to claim 5, wherein an input signal (SIN) is tapped at the signal input (21) and a control signal (CNT) is tapped at an input of the driver (20), wherein the first edge is an edge of the input signal (SIN) or an edge of a signal derived from the input signal (SIN), and wherein the second edge is a falling edge of the laser current (IVC), an edge of the control signal (CNT), a further edge of the input signal (SIN) or a further edge of the signal derived from the input signal (SIN). [8] The optoelectronic component (10) according to one of claims 1 to 7, wherein the signal evaluation circuit (30) is designed to linearize a propagation time signal (YT) provided by the time-to-digital converter (25). [9] The optoelectronic component (10) according to claim 8, wherein the signal evaluation circuit (30) is designed to linearize the propagation time signal (YT) by - generating a distorted signal (YW) by distorting the propagation time signal (YT), and - Generating an undistorted signal (YU) by equalizing the distorted signal (YW). [10] The optoelectronic component (10) according to claim 9, wherein the generation of a distorted signal (YW) is carried out by distorting the propagation time signal (YT) by polynomial or piecewise polynomial evaluation of the propagation time signal (YT). [11] The optoelectronic component (10) according to claim 9 or 10, wherein generating an undistorted signal (YU) is done by equalizing the distorted signal (YW) using the following equation YU(n)=function_unwrap(YW(n),C,Y_SMI_PERIOD), where YU(n) is an nth value of the undistorted signal, YW(n) is an nth value of the distorted signal, C is an integer and Y_SMI_PERIOD is a constant. [12] The optoelectronic component (10) according to one of claims 9 to 11, wherein the signal evaluation circuit (30) is designed to generate the output signal (SOUT) by filtering and / or amplifying the undistorted signal (YU). [13] The optoelectronic component (10) according to one of claims 1 to 12, wherein the time-to-digital converter (25) comprises - a time-voltage converter (35) coupled to the input (26) of the time-digital converter (25), and - a voltage-to-digital converter (36) connected to an output of the time-to-voltage converter (35) and to the output (27) of the time-to-digital converter (25). [14] The optoelectronic component (10) according to one of claims 1 to 13, wherein the time-to-digital converter (25) comprises an oscillator (29). [15] The optoelectronic component (10) according to one of claims 1 to 14, wherein the driver (20) is designed to supply a laser current (IVC) to the laser (11), and wherein the signal input (21) is coupled to the laser (11) and is designed to receive a laser voltage (UVC) tapped at the laser (11). [16] The optoelectronic component (10) according to any one of claims 1 to 14, wherein the optoelectronic component (10) comprises a photodetector (15) having an output coupled to the signal input (21). [17] A distance measuring arrangement (40) comprising the optoelectronic component (10) according to one of claims 1 to 16, and a goal (14), wherein the laser (11) is designed to emit electromagnetic radiation (SE), wherein the target (14) is designed to deliver the electromagnetic radiation (SE) as reflected radiation (SR) to the optoelectronic component (10), and wherein the optoelectronic component (10) is designed to detect the reflected radiation (SR). [18] The distance measuring arrangement (40) according to claim 17, wherein the distance measuring arrangement (40) is designed such that the reflected radiation (SR) is transmitted by the laser (11) to a photodetector (15) or is transmitted by the photodetector (15) to the laser (11), and wherein the photodetector (15) is designed to detect a portion of the reflected radiation (SR). [19] The distance measuring arrangement (40) according to claim 17 or 18, wherein the signal evaluation circuit (30) is designed to generate the output signal (SOUT) such that the output signal (SOUT) of the optoelectronic component (10) is an audio signal, and wherein the target (14) is a diaphragm of a microphone or a display. [20] A method for generating an output signal (SOUT), comprising: - Emission of electromagnetic radiation (ER) by a laser (11), - generating an input signal (SIN) at a signal input (21), - generating a comparator signal (SCOM) by comparing the input signal (SIN) or a signal derived from the input signal (SIN) with a threshold signal (ITH) by a comparator (22), - generating a runtime signal (YT) by a time-to-digital converter 25 as a function of the comparator signal (SCOM), and - Providing an output signal (SOUT) by a signal evaluation circuit (30) as a function of the propagation time signal (YT).

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