Temperature drift compensation for photosensitive resistors

Abstract

The invention relates to a method for determining at least one compensated detector signal of at least one photodetector (120). The at least one photodetector (120) comprises at least one detector element (122) configured for generating at least one detector signal as a function of illumination of the at least one detector element (122). The method comprises the steps of: a) determining at least one dark detector resistance using at least one detector element (122) and inhibiting illumination of the at least one detector element (122); b) generating at least one bright detector signal using the at least one detector element (122) and allowing illumination of the at least one detector element (122); and c) determining at least one compensation detector signal for compensating for at least one temperature drift of the at least one detector element (122) using at least one evaluation unit (128) for evaluating the at least one dark sensor resistance and the at least one bright detector signal. The invention further relates to a method for determining at least one item of measurement information about at least one measurement object (114) by using at least one photodetector (120), a photodetector (120) and a spectrometer (110).

Description

Technical Field

[0001] The invention relates to a method for determining at least one compensated detector signal, a method for determining at least one item of measurement information about a measurement object, a photodetector and a spectrometer. Such a method and an apparatus can generally be used for research or monitoring purposes, in particular in the infrared (IR) spectral region, in particular in the near infrared (NIR) spectral region, and for detecting heat, flames, fire or smoke. However, other kinds of applications are also possible. Background Art

[0002] Optical spectroscopic methods, specifically in the near-infrared and mid-infrared spectral ranges, allow for a deep understanding of the molecular structure of an object by observing the vibrations of molecular bonds. Mid-infrared light can be used to excite fundamental vibrational modes with high finesse and absorption intensity, while the near-infrared spectral range enables the observation of higher modes (harmonics) and combination bands at lower absorption intensities. These advantages can make it possible to probe bulk objects and obtain information about molecular composition by using near-infrared spectroscopy. Therefore, NIR spectroscopy can be widely used in the life and natural sciences industry, the pharmaceutical industry, the materials science industry, the agricultural industry, the food industry or the pharmaceutical industry, for example for blood sugar measurement, pulse oximetry, fat content measurement, material classification, product fraud identification, etc.

[0003] However, in contrast to spectrometers operating in the visible, it is generally quite difficult to provide analytical equipment for the NIR wavelength range: silicon-based photodetectors are generally not suitable for light with wavelengths greater than 1.1 μm due to the band structure. However, indium, germanium or lead salts or thermopiles can be applied. Typically, NIR detectors in laboratory spectrometers as well as in benchtop spectrometers are usually thermoelectrically cooled using multiple stages, in particular in order to achieve low temperatures, high detection capabilities and stability against temperature drifts. However, thermoelectric cooling typically increases technical complexity, size and power consumption, which hinders the widespread application of NIR spectroscopy, for example for use in field analysis or in consumer devices.

[0004] Therefore, it is desirable to operate an IR spectrometer without cooling, wherein the detector material preferably works over a wide range of operating conditions and ambient temperatures. Therefore, when comparing the measurement results with a reference signal or when repeating measurements, it is necessary to compensate for the drift of the detector material caused by temperature in order to reduce the measurement noise.

[0005] In the prior art, devices and methods are known that apply a temperature correction based on a temperature sensor or on a second optical detector that is identical to the main detector.

[0006] JP H01110225A discloses a stable infrared radiometer without using mechanical parts such as choppers, which is implemented by monitoring the temperature of the optical system to compensate for the temperature drift at the zero point. A detector including a photodiode (such as InSb and HgCdTe) is placed in a vacuum container and cooled by liquid nitrogen. Infrared rays from the measuring point form an image on the light detection surface of the detector. The field of view of the detector is limited by the cold shield. The temperature of the optical system is monitored by a temperature sensor to use its output to compensate for the temperature drift at the zero point of the infrared radiometer.

[0007] CN 2359677 Y discloses an infrared optical fiber temperature measuring device for smelting and casting. The infrared optical fiber temperature measuring device comprises a positioning cylinder, a hemispherical reflector, a focusing lens, an optical fiber bundle, a filter, a detector and a temperature compensation circuit, wherein the positioning cylinder is close to the surface of molten steel, and the hemispherical reflector buckles one end of the positioning cylinder above the surface of the molten steel to be measured; the focusing lens is installed on the top of the hemispherical reflector, one end face of the optical fiber bundle is installed at the focal length position of the focusing lens, and the other end face is connected to the detector through the filter; the output end of the detector is connected to the temperature compensation circuit.

[0008] US 6852966 B1 discloses a method and apparatus for compensating a photodetector, which allows the adjustment and monitoring of the photodetector to be performed using a common digital controller. The controller accepts input of monitored operating parameters, including received signal strength and temperature. The controller provides a bias control signal as an output, which adjusts the positive or negative bias voltage supply of the photodetector. The controller maintains the bias voltage of the photodetector at a level that optimizes the gain and signal-to-noise ratio of the photodetector, thereby facilitating decoding of the received signal over a wide range of signal strengths and temperatures. The controller includes a corresponding digital signal strength compensator and a temperature compensator, the outputs of which are added using an adder to provide a bias control signal. The digital signal strength compensator also provides a monitoring signal as an output, the level of the monitoring signal corresponding to the actual signal strength received by the photodetector after compensating for the variable gain of the photodetector caused by the bias voltage level. A transceiver and a method and device for monitoring a photodetector are also disclosed.

[0009] US20110255075 A1 discloses a spectral measurement component and method for determining the temperature value of a detector of a spectrometer. Conventionally, a thermal temperature sensor is used to record the detector temperature in a photodetector in order to compensate for temperature fluctuations. Due to the limited distance between the detector and the temperature sensor, the accuracy of temperature detection is limited. The detector temperature should be able to be recorded effortlessly with high accuracy. In addition to a device for spectrally dividing incident light and an optical detector for spectrally resolving the spectral range of the divided light, a second optical detector for detecting a partial range of the spectral range is provided as a reference detector, wherein the sensitivity of the reference detector is substantially independent of temperature.

[0010] CN 109307550 A discloses a temperature compensation method for improving the stability of an optical power meter, and particularly relates to the technical field of temperature compensation of an optical power meter. The temperature compensation method for improving the stability of an optical power meter solves the following problem: when an existing optical power meter without a temperature compensation device is used for a long time for testing, the optical power meter is affected by the heating of the circuit itself and the temperature change of the surrounding environment, which leads to an increase in test uncertainty. The temperature compensation method for improving the stability of an optical power meter comprises the following steps: placing the optical power meter in a high and low temperature chamber, adjusting the temperature from -10°C to 40°C in sequence, recording the zero point value of different gears at each temperature point by a CPU module, and calculating the zero drift of the current gear caused by the temperature difference according to the reference temperature; and obtaining the optical power value detected by the photodetector through the CPU module, setting the current optical power detection gear, obtaining the real-time temperature detected by the temperature sensor, and sending the zero drift calibration factor to the secondary amplifier circuit through the temperature compensation circuit according to the temperature drift generated by the CPU module at the current gear according to the reference temperature for hardware circuit compensation.

[0011] JP S61213650A discloses an optical measuring device that can always perform correct measurements even when the measuring wavelength is different by compensating for the temperature characteristics of the spectral sensitivity. The radiant energy light from the object to be measured is converged by a lens and blocked by a slit, and then becomes parallel light through the lens. Then, the light is spectrally separated by a spectroscope, and the light is incident on each element of the detector as light of different wavelengths. The gradient or function of the rate of change of the spectral sensitivity of the measuring wavelength of each element of the detector is pre-stored in a memory. The temperature T of the detector is detected by a temperature sensor during measurement, and the output of each element of the detector is calculated and corrected by an arithmetic unit based on the gradient or function of each element of the memory and the temperature T of the sensor.

[0012] CN 103076087 A discloses a mid-infrared photodetector driving circuit, a detector component, and a detector component array. By adopting a compensation detector having the same dark resistance characteristics as the measuring detector and its driving circuit, compensation for the baseline drift of the detector with the ambient temperature is achieved, the amplitude of the change of the output baseline is reduced, and the impact on the dynamic range of the optical signal measurement is reduced; the driving circuit can also be used in a single mid-infrared photodetector component and in a mid-infrared photodetector component array, and a multi-channel measuring detector can be compensated by adopting a compensation detector, thereby meeting the needs of simultaneous measurement of multiple detectors, and greatly reducing the production cost and power consumption.

[0013] DE 102009026951 A1 discloses a spectral gas sensor having an infrared source, an absorption chamber, an optical filter and a detector having a detector element, which forms a measurement beam from the infrared source through the absorption chamber and the optical filter to the detector. The detector element is arranged in the measurement beam and generates a measurement signal. The detector is a pyroelectric detector with an internal temperature compensation device, which generates a temperature compensation result signal according to the measurement signal.

[0014] WO 2021 / 069544 A1 discloses a device (110) comprising: - at least one photoconductor (112) array (1 13), wherein each photoconductor (112) is configured to exhibit a resistance that is dependent on illumination of its photosensitive region, wherein at least one photoconductor (112) in the array (113) is designed to be a characterizing photoconductor (118); - at least one bias voltage source (116), wherein the bias voltage source (116) is configured to apply at least one alternating current bias voltage to the characterizing photoconductor (118) or to apply at least one direct current (DC) bias voltage to the characterizing photoconductor (118); - at least one photoconductor readout circuit (130), wherein the photoconductor readout circuit (130) is configured to determine a response voltage of the characterizing photoconductor (118) generated in response to the bias voltage, wherein the response voltage is proportional to a variable of the characterizing photoconductor (112) array (113), wherein the photoconductor readout circuit (130) is configured to determine the response voltage of the characterizing photoconductor (118) during operation of the photoconductor (112) array (113).

[0015] G. Iordache et al.: "Comparative Characterization of PbS MacroAnd Nano-Crystalline Photoresistive Detectors", Semiconductor Conference 2007, CAS 2007, IEEE, pp. 199-202, describes a comparative study of the photodetector performance of nano- and micro-crystalline PbS thin layers. Both types of PbS films are obtained using a chemical bath deposition method. To prepare the nanocrystalline films, short reaction times are used, while no doping Bi is added. At low radiation levels and room temperature (RT), the performance of macrocrystalline PbS is 6 times higher than that of its nanocrystalline counterpart. However, nanocrystal photodetectors show significantly lower optical quenching for high values ​​of RT and high performance at lower temperatures, with the optimum temperature being 150K. The low-frequency noise behavior is a superposition of 1 / f flicker noise at low frequencies and the generation of recombination and thermal noise at higher frequencies. For room temperature nanocrystal photodetectors, the scaling factor between the 1 / f noise of the series resistor and the DC dark current is 1.5 times larger.

[0016] US2010 / 141768 A1 discloses a method and apparatus for an infrared imager including a fast electrostatic shutter and offset compensation. The fast electrostatic shutter is used for video image correction, which includes image offset compensation, wherein corrections are made for temporal noise and scene non-uniformity. This method provides a shutter-free experience for the user because the image is only obscured one frame at a time. The method of manufacturing an electrostatic infrared shutter includes a conductive infrared transparent substrate, covering the conductive infrared transparent substrate with an insulating layer, depositing an adhesive and a thin film stack, delineating a working area, providing contacts, heat treating the assembly, and making the polymer non-reflective in the infrared.

[0017] “Multi-Single-Pixel thin-film encapsulated,” PbS Near-Infrared Detectors, April 14, 2022, pp. 1-3, is a brochure describing PbS near-infrared detectors provided by trinamiX GmbH.

[0018] Despite the advantages implied by the above-described apparatus and methods, there is still a need for improvement. Specifically, additional sensors or detectors are required to compensate for temperature-induced drift of the detector signal, which increases cost, complexity, and therefore error sensitivity of the apparatus and method. As an example, the additional detectors may fail or these additional detectors may themselves drift, specifically in a different manner than the primary detector.

[0019] Problem to be solved

[0020] The problem addressed by the present invention is therefore to provide methods and devices for compensating detector signals which at least substantially avoid the disadvantages of known methods and devices of this type.

[0021] In particular, it is desirable to provide a method and a device which ensures an accurate and reliable compensation of temperature drifts of a photodetector in a simple and safe manner, in particular without requiring the installation of additional components. Summary of the invention

[0022] This problem is solved by the invention having the features of the independent claims. Advantageous embodiments are listed in the dependent claims as well as in the entire description, which can be implemented individually or in any arbitrary combination.

[0023] In a first aspect of the invention, a method for determining at least one compensated detector signal of at least one photodetector is disclosed. The at least one photodetector comprises at least one detector element configured to generate at least one detector signal based on illumination of the at least one detector element. The method comprises the following steps:

[0024] a) determining at least one dark detector resistance using at least one detector element and inhibiting illumination of the at least one detector element;

[0025] b) generating at least one bright detector signal using at least one detector element and allowing illumination of the at least one detector element; and

[0026] c) determining at least one compensated detector signal for compensating at least one temperature drift of at least one detector element using at least one evaluation unit for evaluating at least one dark sensor resistance and at least one bright detector signal.

[0027] The method steps may be performed in the order indicated. However, it should be noted that a different order is also possible. The method may include additional method steps that are not listed. Further, one or more of the method steps may be performed once or repeatedly. Further, two or more of the method steps may be performed simultaneously or in a time-overlapping manner.

[0028] As used herein, the term "signal" is a broad term and will be given its ordinary and conventional meaning for ordinary technicians in the field and is not limited to special or custom meanings. The term can specifically refer to but is not limited to an observable change in at least one physical quantity. A signal can be or include an identification or function that conveys information about the at least one physical quantity. A signal can specifically be or include at least one of an electronic signal, an optical signal, or a photoelectric signal. A signal can be a variable signal, specifically a signal that changes over time. A signal can be or include at least one of the following: a variable voltage, a variable current, a variable charge, a variable resistance, or generally a variable electromagnetic wave. A variable electromagnetic wave can include at least one of the following: a variable amplitude, a variable frequency, or a variable phase. Other options are also feasible and are generally well known to technicians. A signal can be specifically generated by at least one detector. Therefore, a signal can specifically be or include at least one detector signal.

[0029] As used herein, the term "detector" is a broad term and will be given its ordinary and conventional meaning for ordinary technicians in the field and is not limited to special or custom meanings. The term may specifically refer to, but is not limited to, a measuring device configured to generate at least one measurement signal associated with at least one measurement object. The detector may be an electronic device or an optoelectronic device. The detector may be configured to generate at least one electronic signal, such as a current or a voltage. The detector may specifically be a photodetector. As used herein, the term "photodetector" is a broad term and will be given its ordinary and conventional meaning for ordinary technicians in the field and is not limited to special or custom meanings. The term may specifically refer to, but is not limited to, an optical detector or sensor configured to detect optical radiation, such as for detecting illumination and / or light spots generated by at least one light beam. The photodetector may include at least one substrate. A single photodetector may be a substrate having at least one single photosensitive area that generates a physical response to the irradiation of a given wavelength range. As described above, the photodetector includes at least one detector element. The photodetector may include a plurality of detector elements, which may be arranged in at least one of an array or a matrix. As used herein, the term "detector element" is a broad term and is to be given its ordinary and customary meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a unit of a photosensitive area of ​​a photodetector. The detector element may be configured for illumination, or in other words for receiving light radiation, and for generating at least one detector signal in response to illumination. The detector element may be located on a surface of the photodetector. The detector element may specifically be a single closed and uniform photosensitive area. However, other options may also be feasible.

[0030] As used herein, the term "detector signal" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a signal generated by at least one detector or at least one portion of a detector. Specifically, the detector signal may be generated by a detector element of a photodetector according to the present invention. As will be further outlined in detail below, the detector signal may be or include at least one of a dark detector signal or a bright detector signal. The detector signal may be or include at least one signal generated by the detector at a single point in time. The detector signal may be or include at least one signal generated by the detector over a period of time. The detector signal may be or include at least one pre-processed detector signal, such as a filtered or smoothed or amplified detector signal. The detector signal may be or include at least one of an analog signal or a digital signal. Specifically, the detector signal may be or include at least one compensated detector signal.

[0031] As used herein, the term "compensation" (including any grammatical variations thereof) is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and will not be limited to a special or custom meaning. The term may specifically refer to, but is not limited to, eliminating or correcting a physical effect, specifically an interfering influence or interference or disturbance. Compensation may be or may include measures against disturbances. Specifically, compensation may be temperature compensation, wherein temperature, or more specifically temperature changes, may be a disturbance of, for example, a detector. As an example, the responsivity of a photodetector, or more specifically a detector element, may be temperature-dependent. Therefore, changes in the ambient temperature of the detector element may result in additional changes in the detector signal that do not respond to the illumination of the photodetector. In other words, the detector signal may be affected by temperature drift. As used herein, the term "temperature drift" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and will not be limited to a special or custom meaning. The term may specifically refer to, but is not limited to, changes in an entity, specifically a detector signal, caused by temperature. More specifically, temperature drift may be caused by changes in the temperature of the detector element. When measuring the illumination illuminating a detector element, temperature drifts may typically be undesirable, in particular for reliable and accurate high-precision measurements. In general, in addition to temperature, other perturbations of the detector signal may in principle be conceivable, such as changes in the background illumination.

[0032] As used herein, the term "compensated detector signal" is a broad term and is to be given its ordinary and customary meaning to one of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a detector signal in which at least one perturbation of the detector signal, specifically a temperature drift, has been corrected or eliminated. In particular, the compensated detector signal may include information about the illumination that illuminates only the detector element. Additional variations of the detector signal, specifically due to temperature variations of the detector element, may be eliminated in the compensated detector signal.

[0033] As used herein, the term "illumination" is a broad term and will be given its ordinary and conventional meaning for ordinary technicians in the field and is not limited to a special or custom meaning. The term can specifically refer to, but is not limited to, optical radiation, specifically optical radiation in at least one spectral range of the visible light spectrum, the ultraviolet spectrum, or the infrared spectrum. The term "ultraviolet light" generally refers to electromagnetic radiation with a wavelength of 1nm to 380nm, preferably 100nm to 380nm. Further, the term "visible light" generally refers to a wavelength of 380nm to 760nm. Further, the term "infrared" (abbreviated as "IR") generally refers to a wavelength of 760nm to 1000μm, wherein a wavelength of 760nm to 3μm is generally referred to as "near infrared" (abbreviated as "NIR"). Preferably, the illumination for the typical purpose of the present invention is IR radiation, more preferably NIR radiation, especially radiation with a wavelength of 760nm to 3μm, preferably 1μm to 3μm. Illumination can specifically be optical radiation that illuminates a photodetector or more specifically a detector element. The illumination may be provided by at least one measurement object, wherein the provision may include at least one of reflection, transmission and emission. The illumination may, for example, be emitted by at least one radiation emitting element, such as at least one of a semiconductor-based radiation source or a thermal radiator, and then interact with the measurement object. The illumination may be modulated, for example, by using a modulated radiation emitting element. The term "illumination" may also be referred to herein as "optical radiation" or "light".

[0034] Step a) includes determining at least one dark detector resistance using at least one detector element and prohibiting illumination of at least one detector element. As used herein, the term "prohibiting illumination" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, preventing or preventing or blocking illumination of an entity, specifically a detector element. The detector element may not be illuminated to prohibit illumination. As an example, the radiation emitting element may be turned off or paused to prohibit illumination. Additionally or alternatively, the detector element may be covered to prohibit illumination. As an example, the photodetector may include at least one cover, such as a baffle, which is configured to at least temporarily cover the detector element. Step a) may include covering at least one detector element with at least one object, such as a cover, such as a baffle. Other options for prohibiting illumination of the detector element may be feasible.

[0035] At least one detector element may be configured to generate at least one dark detector signal in the absence of illumination. As used herein, the term "dark detector signal" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a signal generated by at least one detector element, wherein illumination of the detector element is prohibited when generating the signal. The dark detector signal may be independent of illumination of the detector element. The dark detector signal may depend on at least one intrinsic property of the detector element, specifically, a material property of at least one semiconductor comprised by the detector element. The dark detector signal may specifically depend on the temperature of the detector element. As an example, the dark detector signal may include a dark detector current. The dark detector current may be thermally induced by the spontaneous formation of free charge carriers within the semiconductor comprised by the dark detector. The dark detector signal may specifically include a dark detector resistance.

[0036] As used herein, the term "dark detector resistance" is a broad term and shall be given its ordinary and customary meaning for a person of ordinary skill in the art and shall not be limited to a special or custom meaning. The term may specifically refer to, but is not limited to, the resistance of at least one detector element in a state in which illumination of the at least one detector element is prohibited. In other words, the dark detector resistance may be the resistance of the detector element without illumination. The dark detector resistance may be independent of illumination of the at least one detector element. The dark detector resistance may depend on at least one intrinsic property of the at least one detector element, in particular, a material property of at least one semiconductor comprised by the at least one detector element. The dark detector resistance may specifically depend on the temperature of the at least one detector element. As is generally known to the skilled person, the electrical conductivity of a material typically depends on the number of free charge carriers within the material. Therefore, when the number of free charge carriers in the material changes, for example thermally induced or light induced as already mentioned above, the electrical conductivity of the material typically also changes.

[0037] Step b) includes using at least one detector element and allowing illumination of the at least one detector element to generate at least one bright detector signal. As used herein, the term "allowing illumination" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term specifically may refer to, but is not limited to, allowing or enabling illumination of an entity, specifically at least one detector element. As noted, at least one detector element may be illuminated by, for example, using a radiation emitting element for allowing illumination. At least one detector element may be uncovered to allow illumination. The beam path leading to at least one detector element may be free of objects that block illumination.

[0038] At least one detector element may be configured to generate at least one bright detector signal when illuminated. As used herein, the term "bright detector signal" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a signal generated by at least one detector element, wherein illumination of the detector element is allowed when the signal is generated. In other words, a bright detector signal may be generated by an illuminated detector element. The bright detector signal may depend on illumination of at least one detector element. The bright detector signal may include a photocurrent. The bright detector signal may include a bright detector resistance. As noted, illumination may also cause a change in the number of free charge carriers. The bright detector signal may further depend on at least one intrinsic property of the detector element, specifically, a material property of at least one semiconductor included in the detector element. The bright detector signal may depend on the temperature of the detector element. Therefore, the bright detector signal may be susceptible to temperature drift.

[0039] As indicated, at least one detector signal generated by at least one detector element may include at least one of a bright detector signal or a dark detector signal. As an example, a modulated radiation emitting element may be used to analyze a measurement object by utilizing a photodetector comprising a detector element. The detector signal may be a signal as generated by the detector element over a period of time. Thus, the detector signal may also be a modulated signal, such as a periodic signal comprising maximum and minimum values. A maximum value of the detector signal may refer to a bright detector signal. A minimum value of the detector signal may refer to a dark detector signal.

[0040] Step c) comprises determining at least one compensated detector signal using at least one evaluation unit for evaluating at least one dark sensor resistance and at least one bright detector signal for compensating at least one temperature drift of at least one detector element. As used herein, the term "evaluation" (including any grammatical variations thereof) is a broad term and is to be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, analyzing or interpreting data, specifically for determining at least one item of qualitative or quantitative information. Evaluation may include processing data, such as by using at least one relationship, specifically at least one function having at least one of a variable or predetermined parameter.

[0041] As used herein, the term "evaluation unit" is a broad term and will be given its ordinary and conventional meaning for a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a device configured to analyze or interpret data, specifically for determining at least one qualitative or quantitative information. The information may be obtained specifically by evaluating at least one detector signal generated by at least one detector element. The evaluation unit may be or may include at least one of an integrated circuit (particularly an application specific integrated circuit (ASIC)) or a data processing device, in particular a digital signal processor (DSP), a field programmable gate array (FPGA), a microcontroller, a microcomputer, a computer or an electronic communication unit (particularly a smart phone or a tablet). Other components may be feasible, in particular at least one pre-processing device or a data acquisition device. Further, the evaluation unit may include at least one interface, in particular at least one of a wireless interface or a wired interface. Further, the evaluation unit may be designed to fully or partially control or drive other devices, such as at least one photodetector. The evaluation unit may be particularly designed to perform at least one measurement cycle in which a plurality of detector signals may be picked up. The information as determined by the evaluation unit may particularly preferably be provided to at least one of the other device or the user in at least one of an electronic, visual, auditory or tactile manner. Further, the information may be stored in at least one data storage unit, in particular in an internal data storage unit as comprised by the spectral sensing device, in particular by the at least one evaluation unit, or in a separate storage unit to which the information may be transmitted via at least one interface. The at least one electronic communication unit may comprise the separate storage unit. The storage unit may particularly be configured to store at least one electronic table, such as at least one lookup table.

[0042] The evaluation unit can preferably be configured to execute at least one computer program, in particular at least one computer program that performs or supports the information generation step. For example, one or more algorithms can be implemented, which can perform a transformation into information by using at least one detector signal as at least one input variable. For this purpose, the evaluation unit can in particular include at least one data processing device, in particular at least one of an electronic data processing device or an optical data processing device, which at least one data processing device can be designed to generate information by evaluating at least one detector signal. Therefore, the evaluation unit can be designed to use at least one detector signal as at least one input variable and generate information by processing the at least one input variable. The processing can be performed in a continuous, parallel or combined manner. The evaluation unit can use an arbitrary process to generate the information, in particular to generate the information by calculation and / or using at least one stored and / or known relationship.

[0043] At least one photodetector may include at least one of an evaluation unit or a communication interface. The communication interface may be configured to perform at least one of the following: transmitting data from or to the evaluation unit or transmitting data within the evaluation unit. As used herein, the term "communication interface" is a broad term and will be given its ordinary and conventional meaning for those of ordinary skill in the art and is not limited to a special or custom meaning. Specifically, the term may refer to, but is not limited to, an object or element that forms a boundary configured for transmitting information. In particular, a communication interface may be configured to transmit information from a computing device (e.g., a computer), such as to send or output information to, for example, another device. Additionally or alternatively, a communication interface may be configured to transmit information to a computing device, such as a computer, such as to receive information. The communication interface may specifically provide a means for transmitting or exchanging information. In particular, the communication interface may provide a data transmission connection, such as Bluetooth, NFC, inductive coupling, etc. As an example, the communication interface may be or may include at least one port, the at least one port including one or more of a network or Internet port, a USB port, and a disk drive. The communication interface may include at least one web interface.

[0044] At least one evaluation unit may be at least partially cloud-based. As used herein, the term "cloud-based" is a broad term and will be given its ordinary and conventional meaning for those of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, outsourcing at least one evaluation unit or at least a portion thereof to at least partially interconnected external devices, specifically computers or computer networks with greater computing power and / or data storage capacity. The external devices may be arbitrarily distributed in space. The external devices may change over time, specifically according to demand. The external devices may be interconnected using the Internet. The external devices may each include at least one communication interface.

[0045] In step c), at least one compensated detector signal may be determined by using equation (1):

[0046]

[0047] Among them, S compS(T0, λ) refers to the compensated detector signal of the at least one detector element at a first temperature T0, wherein λ refers to the wavelength of the optical radiation illuminating the at least one detector element, wherein S(T0+ΔT, λ) refers to the bright detector signal of the at least one detector element at a second temperature T0+ΔT, wherein ΔT refers to the temperature change of the at least one detector element, wherein α(T0, λ) refers to the resistive responsivity of the at least one detector element at the first temperature T0 of the at least one detector element, wherein Γ is defined as

[0048]

[0049] Among them, γ α refers to a predetermined resistance responsivity coefficient of at least one detector element, and wherein γ R refers to a predetermined dark resistivity of at least one detector element. In other words, the bright detector signal may be measured after a typically undesirable temperature change ΔT of the detector element, wherein the temperature change ΔT may cause a temperature drift of the bright detector signal. However, the temperature drift may be compensated by using equation (1) to obtain an accurate and reliable measurement result.

[0050] As used herein, the term "responsivity" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and will not be limited to a special or custom meaning. The term may specifically refer to, but is not limited to, the relationship between at least one input and at least one output of a detector. The responsivity may be the input-output gain of the detector. According to at least one photodetector or more specifically at least one detector element of the present invention, the responsivity may be the relationship between an optical input and an electrical output. In other words, the responsivity may measure the electrical output (e.g., photocurrent or resistance) for each optical input (e.g., light intensity or irradiance). The responsivity may also be referred to as photosensitivity. As used herein, the term "resistance responsivity" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and will not be limited to a special or custom meaning. The term may specifically refer to, but is not limited to, the relationship between the input spectral irradiance I(λ) and the total output resistance R of at least one detector element. In other words, the resistance responsivity may relate the spectral irradiance of the light irradiating at least one detector element to the resistance of the at least one detector element caused thereby. In a linear approximation, the resistance of the at least one detector element may be described by using the resistance responsivity α of the at least one detector element according to the following equation:

[0051] R(I, T, λ) = R D (T)+α(T,λ)I(λ),

[0052] Among them, R D(T) refers to the temperature-dependent dark resistance of the at least one detector element, where T typically refers to temperature. The resistance responsivity α(T, λ) of the at least one detector element may be at least one of temperature-dependent or wavelength-dependent. In principle, nonlinear responses (e.g., quadratic or cubic factors) may additionally be used for higher-order approximations of the resistance.

[0053] As used herein, the term "resistance responsivity coefficient" (also known as γ α ) is a broad term and will be given its ordinary and customary meaning to one of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a coefficient for determining or at least approximating the resistance responsivity of at least one detector element based on a temperature change ΔT after the at least one detector element has undergone a temperature change ΔT. In a linear approximation, the resistance responsivity of the at least one detector element may be described using the resistance responsivity coefficient according to the following equation:

[0054] α(T0+ΔT,λ)=α(T0)+γ α ΔT.

[0055] As used herein, the term "dark resistivity" (also known as γ R ) is a broad term and will be given its ordinary and customary meaning to one of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a coefficient for determining or at least approximating the dark resistance of at least one detector element based on a temperature change ΔT after the at least one detector element has undergone a temperature change ΔT. In a linear approximation, the resistance responsivity of the at least one detector element may be described by using the dark resistance coefficient according to the following equation:

[0056] R D (T0+ΔT)=R D (T0)+γ R ΔT.

[0057] In principle, a nonlinear correlation (e.g. a quadratic factor or a cubic factor) may additionally be used for a higher order approximation of at least one of the dark resistance or the resistance responsivity. However, the nonlinear correlation may be negligible, in particular for small temperature changes ΔT of the at least one detector element, more particularly for ΔT<<T0. ΔT may be below 10K, in particular below 1K, more particularly below 0.1K.

[0058] γ α or γ RAt least one of the above may be predetermined in at least one calibration process of at least one detector element. As used herein, the term "calibration" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a process for initially predetermining a measurement characteristic or condition of a measuring device, specifically at least one photodetector, and more specifically at least one detector element. As an example, at least one reference with a known physical property may be used for calibration, specifically for comparing the measurement result with the known property. Calibration may further refer to a process for ensuring a predetermined measurement characteristic or condition, which may be performed regularly or irregularly after an initial calibration. Calibration may include, for example, adjusting or correcting a measurement characteristic or condition according to a known physical property of at least one reference. This may allow for enhanced robustness, reliability, and accuracy of the measurement.

[0059] γ R ΔT, for example, used as an item in equation (1), can be determined by using at least one baseline of at least one detector element. As used herein, the term "baseline" is a broad term and will be given its ordinary and conventional meaning for ordinary technicians in the field and is not limited to special or custom meanings. The term can specifically refer to but is not limited to a line or curve representing a minimum signal (such as a minimum signal intensity or a minimum signal count). The baseline can be or include an interpolation of the minimum value of a variable signal (such as a periodic signal). The baseline can be or include a function that fits the minimum value of the variable signal. As already pointed out in the previous example, a modulated radiation emitting element can be used to analyze the measurement object by utilizing a photodetector including a detector element. Therefore, the detector signal generated by at least one detector element within a selected time period can also be a modulated signal. The maximum value of the detector signal can refer to a bright detector signal. The minimum value of the detector signal can refer to a dark detector signal. The baseline can be an interpolation of the minimum value of the detector signal. Other options may be feasible. Generally, at least one baseline can be determined by using at least one dark detector signal. At least one baseline can be determined by using at least one dark detector resistor.

[0060] γ R ΔT, for example as used in equation (1), can be determined by using at least one dark detector resistor. R ΔT can be determined by using equation (2):

[0061] γ R ΔT=R D (T0+ΔT)-R D (T0), (2)

[0062] Among them, R Dis at least one dark detector resistance. Equivalently, the temperature change ΔT can be determined by using equation (3):

[0063]

[0064] Therefore, the temperature change ΔT can be measured by measuring at least one dark detector resistance R of at least one detector element. D , or more specifically at least one dark detector resistance R of at least one detector element D This may avoid the use of other measuring devices, such as additional optical detectors or temperature sensors, specifically for measuring the temperature. Determining the at least one dark detector resistance of the at least one detector element may typically already be part of the measurement routine, so that it may typically not require any additional effort. In any case, the at least one dark detector resistance of the at least one detector element may typically be easily obtainable or determinable, so that the measurement of the at least one dark detector resistance may be easily applicable. Thus, a reliable compensation for temperature drifts of the photodetector may be achieved in a simple and safe manner, in particular without the need to install additional components.

[0065] Γ, for example as used in equation (1), can be predetermined during the calibration of at least one of the at least one detector element or at least one further detector element. The at least one detector element and the at least one further detector element can be selected from the same class of detector elements. In other words, calibration of each detector element used individually can be avoided. Instead, calibration using only detector elements belonging to the same class can be sufficient. This can further assist in compensation of temperature drift. Γ can be a universal factor at least for a selected class of detector elements, because the resistance responsivity coefficient and the dark resistance coefficient typically exhibit a substantially linear correlation, as will be further detailed below with respect to experimental data. Γ can vary between different classes of detector elements. As used herein, the term "a class of detector elements" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term can specifically refer to, but is not limited to, a type or a group of substantially identical detector elements. A class of detector elements can include multiple detector elements having the same architecture or layout. Minor differences (such as manufacturing-related differences) can be negligible. In particular, one category of detector elements may include a plurality of detector elements comprising the same photosensitive material.

[0066] The method for determining at least one detector signal can be at least partially computer-implemented. With reference to the computer-implemented aspects of the present invention, one or more or even all of the method steps of the method according to one or more of the embodiments disclosed herein can be performed using a computer or a computer network. Therefore, typically, any of the method steps including the provision and / or manipulation of data can be performed using a computer or a computer network. Typically, these method steps can include any method steps, except for method steps that typically require manual work, such as providing samples and / or performing certain aspects of the actual measurement.

[0067] In another aspect of the invention, a method for determining at least one item of information about at least one measurement object is disclosed. At least one photodetector comprises at least one detector element, the at least one detector element being configured to generate at least one detector signal based on illumination of the at least one detector element. The method comprises the following steps:

[0068] i) using at least one measurement object to provide optical radiation and using at least one photodetector to generate at least one detector signal;

[0069] ii) determining at least one compensated detector signal according to any of the embodiments relating to a method for determining at least one compensated detector signal described above or in further detail below; and

[0070] iii) determining at least one item of measurement information about at least one measurement object using the at least one compensated detector signal.

[0071] The method steps may be performed in the order indicated. However, it should be noted that a different order is also possible. The method may include additional method steps that are not listed. Further, one or more of the method steps may be performed once or repeatedly. Further, two or more of the method steps may be performed simultaneously or in a time-overlapping manner.

[0072] As used herein, the term "measurement information" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, knowledge or evidence that provides a qualitative and / or quantitative description associated with at least one measurement, specifically at least one measurement object. The measurement information may include at least one of a physical property of the measurement object or a chemical composition of at least one measurement object. The physical property may specifically include an optical property, such as at least one absorbance of the measurement object and / or at least one emissivity of the measurement object. The chemical composition may specifically refer to qualitative and / or quantitative information about at least one material included in the measurement object.

[0073] As used herein, the term "measurement object" is a broad term and will be given its common and conventional meaning for those of ordinary skill in the art and is not limited to special or custom meanings. The term may specifically refer to, but is not limited to, any body selected from living and inanimate objects. The measurement object may specifically include at least one material that is subjected to research. The measurement object may generally refer to an object to be measured (e.g., for which a spectrum is to be recorded), wherein the measurement object may have any property in principle (e.g., any optical property or any shape). The measurement object may include at least one solid sample. However, other measurement objects such as fluids may also be feasible.

[0074] In step i), the optical radiation provided by at least one measurement object may include a wavelength of 300nm to 3000nm, specifically 500nm to 2500nm, more specifically 1400nm to 2000nm. As used herein, the term "providing" (including any grammatical variations thereof) is a broad term and will be given its ordinary and conventional meaning for ordinary technicians in the field and is not limited to special or custom meanings. The term may specifically refer to but is not limited to at least one of the following: reflection of optical radiation, specifically diffuse reflection; diffraction; transmission and emission. The optical radiation provided by the measurement object may indicate at least one of the physical properties of the measurement object (e.g., the optical properties and / or temperature of the measurement object) and the chemical properties of the measurement object (e.g., the chemical composition of the measurement object). As an example, the optical radiation provided by the measurement object may be emitted by at least one measurement object, specifically at least partially emitted toward at least one photodetector. Further, the optical radiation provided by at least one measurement object may be reflected, such as diffuse reflection, by at least one measurement object at least partially toward at least one photodetector. Furthermore, the optical radiation provided by the at least one measurement object may be transmitted through the at least one measurement object and at least partially directed toward the at least one photodetector. However, the at least one measurement object may also at least partially absorb the optical radiation, which may specifically indicate at least one physical property of the at least one measurement object and / or at least one chemical property of the at least one measurement object, such as the chemical composition of at least one material constituting the at least one measurement object.

[0075] As described above, step iii) comprises determining at least one item of measurement information about at least one measurement object using at least one compensated detector signal, specifically at least one compensated detector signal determined in step ii). As already discussed, at least one detector signal generated by at least one detector element may drift. Specifically, at least one detector signal may be affected by temperature drift. Therefore, directly using at least one detector signal to determine at least one item of measurement information may be inaccurate. Therefore, specifically for high-precision measurements, at least one detector signal should typically be corrected before determining at least one item of measurement information. To this end, specifically at least one compensated detector signal can be used, for example, to determine at least one item of measurement information about at least one measurement object by further evaluating the at least one compensated detector signal (such as by using at least one evaluation unit). The at least one evaluation unit can be configured to determine at least one item of measurement information about at least one measurement object using at least one compensated detector signal.

[0076] The method for determining at least one measurement information can be at least partially computer-implemented. With reference to the computer-implemented aspects of the present invention, one or more method steps or even all method steps of the method steps of the method according to one or more embodiments of the embodiments disclosed herein can be performed using a computer or a computer network. Therefore, generally, any method step in the method steps including the provision and / or manipulation of data can be performed using a computer or a computer network. Generally, these method steps can include any method steps, except for method steps that generally require manual work, such as providing samples and / or performing certain aspects of actual measurement.

[0077] For further details on the method for determining at least one item of measurement information, reference may be made to the description of the method for determining at least one compensated detector signal.

[0078] In another aspect of the present invention, a computer program is disclosed, which includes instructions, and when a computer executes the computer program, the instructions cause the computer to perform at least one of the methods according to any of the embodiments related to methods described in further detail above or below.

[0079] In another aspect of the present invention, a non-transitory computer-readable medium is disclosed. The non-transitory computer-readable medium includes instructions that, when executed by one or more processors, cause the one or more processors to perform at least one of the methods described in any of the embodiments related to methods described in further detail above or below.

[0080] In another aspect of the present invention, a photodetector for measuring optical radiation is disclosed. The photodetector is configured to perform at least one method according to any of the embodiments described in further detail above or below involving at least one of the following:

[0081] - a method for determining at least one compensated detector signal of at least one photodetector; or

[0082] - A method for determining at least one item of information about at least one measurement object.

[0083] The photodetector comprises at least one detector element.

[0084] The photodetector may further include at least one readout circuit configured to read out at least one detector signal. As used herein, the term "readout" is a broad term and will be given its ordinary and conventional meaning for those of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, an action or process of quantifying and / or processing at least one physical property and / or a change in at least one physical property detected by at least one device (specifically, by at least one measuring device, such as at least one photodetector or more specifically at least one detector element). The readout may include a single readout of a device (such as a detector element). Additionally or alternatively, the readout may include a readout of a group of devices (such as a group of detector elements). As used herein, the term "readout circuit" is a broad term and will be given its ordinary and conventional meaning for those of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, an electronic circuit configured to quantify and / or process at least one physical property and / or a change in at least one physical property detected by at least one measuring device (such as at least one photodetector or more specifically at least one detector element). The readout circuit may be configured to read out the at least one photodetector. The readout circuit may be configured to read out the at least one detector element. The at least one readout circuit may include at least one resistance meter configured to measure at least one resistance of the at least one detector element, such as at least one dark detector resistance or a light detector resistance.

[0085] At least one detector element may include at least one photoconductive material. The photoconductive material may be selected from at least one of PbS, PbSe, Ge, InGaAs, InSb or HgCdTe. The detector element may be configured as a photoconductor or a photodiode. The detector element may be optically active. The detector element may generate an electrical signal when illuminated. The integrated circuit may condition, amplify and / or digitize the light-induced electrical signal. At least one photodetector may include at least one of an evaluation unit or a communication interface, which is configured to perform at least one of the following: transmitting data from the evaluation unit or transmitting data to the evaluation unit or transmitting data within the evaluation unit. At least one evaluation unit may be at least partially cloud-based. At least one readout circuit, in particular at least one resistance meter, may be in particular wired to at least one of the at least one evaluation unit or the at least one communication interface.

[0086] For further details regarding the photodetector, reference may be made to the description of the method for determining at least one compensated detector signal or of the method for determining at least one item of measurement information.

[0087] In another aspect of the present invention, a spectrometer for spectrally analyzing optical radiation provided by at least one measurement object is disclosed. The spectrometer comprises:

[0088] at least one radiation emitting element configured for emitting optical radiation at least partially towards at least one measurement object; and

[0089] - at least one photodetector according to any of the embodiments relating to photodetectors described above or in further detail below.

[0090] As used herein, the term "spectrum" (including any grammatical variations thereof) is a broad term and will be given its ordinary and conventional meaning for a person of ordinary skill in the art and will not be limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a partition of optical radiation, wherein the spectrum consists of an optical signal defined by a signal wavelength and a corresponding signal intensity. In particular, the spectrum may include spectral information associated with at least one measurement object, such as the type and composition of at least one material forming the at least one measurement object, which spectral information may be determined by recording at least one spectrum associated with the at least one measurement object. As used herein, the term "spectrometer" is a broad term and will be given its ordinary and conventional meaning for a person of ordinary skill in the art and will not be limited to a special or custom meaning. The term may specifically refer to, but is not limited to, a device configured to determine spectral information by recording at least one measurement of at least one signal intensity associated with at least one corresponding signal wavelength of optical radiation and by evaluating at least one detector signal associated with the signal intensity.

[0091] As used herein, the term "radiation emitting element" is a broad term and will be given its ordinary and conventional meaning for ordinary technicians in the field and is not limited to a special or custom meaning. The term can specifically refer to, but is not limited to, a device configured to emit optical radiation. As an example, at least one radiation emitting element can be configured to emit a light beam toward at least one measurement object. However, the at least one radiation emitting element can also be configured to emit optical radiation isotropically (e.g., uniformly in all spatial directions), wherein only a portion of the emitted optical radiation can illuminate at least one measurement object. At least one radiation emitting element may include at least one of a semiconductor-based radiation source or a thermal radiator. At least one semiconductor-based radiation source may be selected from at least one of a light emitting diode (LED) or a laser (specifically, a laser diode). Other types of radiation emitting elements may also be feasible.

[0092] The spectrometer may further include at least one temperature stabilizing element, specifically a thermoelectric cooler. As used herein, the term "temperature stabilizing element" is a broad term and will be given its ordinary and conventional meaning for a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, an element or device configured to make the temperature of another element or device constant or smooth or stable. Specifically, at least one temperature stabilizing element may be configured to stabilize the temperature of at least one detector element. At least one temperature stabilizing element may be configured to maintain the temperature of at least one detector element at a predetermined level. However, at least one temperature stabilizing element may also be configured to stabilize the temperature of other components of the spectrometer (such as at least one radiation emitting element or a component located around at least one of the at least one detector element or at least one radiation emitting element). At least one temperature stabilizing element may be or include at least one thermoelectric cooler.

[0093] As used herein, the term "thermoelectric cooler" is a broad term and will be given its ordinary and conventional meaning to a person of ordinary skill in the art and is not limited to a special or custom meaning. The term may specifically refer to, but is not limited to, an electrically driven heat pump that is configured to transfer heat between at least two spatial regions, thereby generating a heat flux between the at least two spatial regions. Specifically, the thermoelectric cooler may be based on the Peltier effect to generate a heat flux. For this purpose, the thermoelectric cooler may in particular include at least one Peltier element. The direction of the heat flux may depend on the direction of the current applied to the thermoelectric cooler. Depending on the direction of the heat flux, the thermoelectric cooler may be used to cool at least one spatial region by transferring heat to at least one other spatial region, or to heat at least one spatial region by transferring heat from at least one other spatial region. Other options may also be feasible.

[0094] At least one evaluation unit may further be designed to completely or partially control or drive the spectrometer or a part thereof, such as a radiation emitting element. As described above, at least one photodetector may include at least one evaluation unit. However, the evaluation unit may also be at least partially arranged outside the at least one photodetector, such as arranged in the spectrometer. Therefore, the spectrometer may include at least one evaluation unit. Additionally or alternatively, at least one evaluation unit may be at least partially arranged outside the spectrometer, such as arranged in an external device (e.g., a computer, a smart phone, or a tablet). As described above, the evaluation unit may be at least partially cloud-based. The spectrometer may include at least one communication interface, which is configured to perform at least one of the following: transmitting data from the evaluation unit or transmitting data to the evaluation unit or transmitting data within the evaluation unit.

[0095] The spectrometer may further comprise at least one filter element configured for filtering the optical radiation or more particularly a selected wavelength of the optical radiation. The at least one filter element may particularly be positioned in the beam path before the at least one detector element. The spectrometer may comprise a plurality of detector elements and a plurality of filter elements, wherein the at least one filter element may be positioned in the beam path before the at least one detector element, wherein the plurality of filter elements may be configured for at least partially filtering different wavelengths.

[0096] For further details about the spectrometer, reference may be made to the description of the photodetector, the method for determining at least one compensated detector signal or the method for determining at least one item of measurement information.

[0097] In another aspect of the present invention, the use of a method for determining at least one item of information about a measurement object according to any of the embodiments of the method for determining at least one item of information about a measurement object described in further detail above or below, or at least one of the spectrometers described in any of the embodiments of the spectrometer described in further detail above or below for a purpose of use selected from the group consisting of: infrared detection applications; spectroscopy applications; exhaust gas monitoring applications; combustion process monitoring applications; pollution monitoring applications; industrial process monitoring applications; mixing or blending process monitoring; chemical process monitoring applications; food processing process monitoring applications; food preparation process monitoring; water quality monitoring applications; air quality monitoring applications; quality control applications; temperature control applications; motion control applications; emission control applications; gas sensing applications; gas analysis applications; motion sensing applications; chemical sensing applications; mobile applications; medical applications; mobile spectroscopy applications; food analysis applications; agricultural applications, in particular characterization of soil, silage, feed, crops or agricultural products, monitoring plant health; plastic identification and / or recycling applications; and textile identification and recycling applications.

[0098] The method and apparatus as disclosed herein have significant advantages over the prior art. Specifically, the method and apparatus disclosed herein can ensure accurate and reliable compensation for the temperature drift of the photodetector in a simple and safe manner. Such a method and apparatus may specifically not require the use of additional components (such as temperature sensors or additional optical detectors) to compensate for the temperature drift, which can typically be reflected in cost, complexity and error sensitivity. Instead, such a method and apparatus can use the measurement of the dark detector resistance of the detector element, which can already be part of a typical measurement routine or can at least be easy to implement. The calibration process can be further facilitated by using the basic linear correlation between the resistance responsivity coefficient and the dark resistance coefficient. Specifically, calibration of each detector element used can be avoided, so that factory calibration of the detector element type can be sufficient. Therefore, the method and apparatus as disclosed herein can also be suitable for everyday users without special training.

[0099] As used herein, the terms "having", "including" or "comprising" or any arbitrary grammatical variant thereof are used in a non-exclusive manner. Thus, these terms may refer to the absence of additional features in the entity described in this context in addition to the features introduced by these terms, or the presence of one or more additional features. As an example, the expressions "A has B", "A includes B" and "A contains B" may refer to the absence of other elements in A in addition to B (i.e., A consists only and solely of B), or the presence of one or more additional elements in entity A in addition to B (such as element C, elements C and D or even additional elements).

[0100] Further, it should be noted that the terms "at least one", "one or more", or similar expressions indicating that a feature or element may occur once or more than once are typically used only once when introducing the corresponding feature or element. In most cases, when referring to the corresponding feature or element, the expression "at least one" or "one or more" is not repeated, although the corresponding feature or element may occur once or more than once.

[0101] Further, as used herein, the terms "preferably", "more preferably", "particularly", "more particularly", "specifically", "more specifically" or similar terms are used in conjunction with optional features without limiting the possibilities of alternatives. Therefore, the features introduced by these terms are optional features and are not intended to limit the scope of the claims in any way. As the skilled person will recognize, the present invention can be implemented by using alternative features. Similarly, the features introduced by "in an embodiment of the present invention" or similar expressions are intended to be optional features, without any limitation on alternative embodiments of the present invention, without any limitation on the scope of the present invention, and without any limitation on the possibility of combining the features introduced in this manner with other optional or non-optional features of the present invention.

[0102] Summarizing and without excluding further possible embodiments, the following embodiments may be envisaged:

[0103] Embodiment 1: A method for determining at least one compensated detector signal of at least one photodetector, wherein the at least one photodetector comprises at least one detector element configured to generate at least one detector signal depending on illumination of the at least one detector element, the method comprising the following steps:

[0104] a) determining at least one dark detector resistance using at least one detector element and inhibiting illumination of the at least one detector element;

[0105] b) generating at least one bright detector signal using at least one detector element and allowing illumination of the at least one detector element; and

[0106] c) determining at least one compensated detector signal for compensating for at least one temperature drift of the at least one detector element using at least one evaluation unit for evaluating the at least one dark sensor resistance and the at least one bright detector signal.

[0107] Embodiment 2: The method according to the preceding embodiment, wherein in step c), the at least one compensated detector signal is determined by using equation (1):

[0108]

[0109] Among them, S compS(T0, λ) refers to the compensated detector signal of the at least one detector element at a first temperature T0, wherein λ refers to the wavelength of the optical radiation illuminating the at least one detector element, wherein S(T0+ΔT, λ) refers to the bright detector signal of the at least one detector element at a second temperature T0+ΔT, wherein ΔT refers to the temperature change of the at least one detector element, wherein α(T0, λ) refers to the resistive responsivity of the at least one detector element at the first temperature T0 of the at least one detector element, wherein Γ is defined as

[0110]

[0111] Among them, γ α refers to a predetermined resistance responsivity coefficient of at least one detector element, and wherein γ R Refers to a predetermined dark resistivity of at least one detector element.

[0112] Embodiment 3: The method according to the previous embodiment, wherein ΔT is lower than 10K, specifically lower than 1K, more specifically lower than 0.1K.

[0113] Embodiment 4: A method according to any one of the above two embodiments, wherein γ α or γ R At least one of is predetermined in at least one calibration process of the at least one detector element.

[0114] Embodiment 5: A method according to any one of the above three embodiments, wherein γ R ΔT is determined using at least one baseline of the at least one detector element.

[0115] Embodiment 6: The method according to any one of the above four embodiments, wherein γ R ΔT is determined by using the at least one dark detector resistor.

[0116] Embodiment 7: The method according to the previous embodiment, wherein γ R ΔT is determined by using equation (2):

[0117] γ R ΔT=R D (T0+ΔT)-R D (T0), (2)

[0118] Among them, R D refers to the at least one dark detector resistor.

[0119] Embodiment 8: A method according to any one of the six embodiments described above, wherein Γ is predetermined during the calibration process of at least one of the at least one detector element or at least one additional detector element, wherein the at least one detector element and the at least one additional detector element are selected from the same category of detector elements.

[0120] Embodiment 9: The method according to any one of the preceding embodiments, wherein step a) comprises covering the at least one detector element with at least one object.

[0121] Embodiment 10: A method according to any of the preceding embodiments, wherein the at least one photodetector comprises at least one of an evaluation unit or a communication interface, and the communication interface is configured to perform at least one of the following: transmitting data from the evaluation unit or transmitting data to the evaluation unit or transmitting data within the evaluation unit.

[0122] Embodiment 11: A method according to any of the preceding embodiments, wherein the at least one evaluation unit is at least partially cloud-based.

[0123] Embodiment 12: A method according to any of the preceding embodiments, wherein the method is at least partially computer-implemented.

[0124] Embodiment 13: A method for determining at least one item of measurement information about at least one measurement object by using at least one photodetector, wherein the at least one photodetector comprises at least one detector element configured to generate at least one detector signal depending on illumination of the at least one detector element, the method comprising the following steps:

[0125] i) using at least one measurement object to provide optical radiation and using at least one photodetector to generate at least one detector signal;

[0126] ii) determining at least one compensated detector signal according to any of the preceding embodiments; and

[0127] iii) determining at least one item of measurement information about at least one measurement object using the at least one compensated detector signal.

[0128] Embodiment 14: The method according to the preceding embodiment, wherein, in step i), the optical radiation provided by the at least one measurement object comprises a wavelength of 300 nm to 3000 nm, specifically 500 nm to 2500 nm, more specifically 1400 nm to 2000 nm.

[0129] Embodiment 15: A method according to any one of the aforementioned embodiments relating to a method for determining at least one item of information about a measurement object, wherein, in step iii), the at least one item of measurement information includes at least one of a physical property of at least one measurement object or a chemical composition of at least one measurement object.

[0130] Embodiment 16: The method according to any of the preceding embodiments relating to a method for determining at least one item of information about a measurement object, wherein the method is at least partially computer-implemented.

[0131] Embodiment 17: A computer program, comprising instructions, which, when executed by a computer, cause the computer to execute at least one of the methods described in any of the method embodiments described above.

[0132] Embodiment 18: A non-transitory computer-readable medium comprising instructions, which when executed by one or more processors, causes the one or more processors to perform at least one of the methods described in any of the method embodiments described above.

[0133] Embodiment 19: A photodetector for measuring optical radiation, wherein the photodetector is configured to perform at least one method according to any of the preceding embodiments involving at least one of the following:

[0134] - a method for determining at least one compensated detector signal of at least one photodetector; or

[0135] - a method for determining at least one item of measurement information about at least one measurement object,

[0136] Therein, the photodetector comprises at least one detector element.

[0137] Embodiment 20: The photodetector according to the preceding embodiment, further comprising at least one readout circuit configured to read out at least one detector signal.

[0138] Embodiment 21: The photodetector according to the preceding embodiment, wherein the at least one readout circuit comprises at least one resistance meter configured to measure at least one resistance of at least one detector element.

[0139] Embodiment 22: A photodetector according to any of the preceding embodiments relating to photodetectors, wherein the at least one detector element comprises at least one photoconductive material.

[0140] Embodiment 23: The photodetector according to the previous embodiment, wherein the photoconductive material is selected from at least one of PbS, PbSe, Ge, InGaAs, InSb or HgCdTe.

[0141] Embodiment 24: A photodetector according to any of the aforementioned embodiments involving photodetectors, wherein the at least one photodetector can be at least one of an evaluation unit or a communication interface, and the communication interface is configured to perform at least one of the following: transmitting data from the evaluation unit or transmitting data to the evaluation unit or transmitting data within the evaluation unit.

[0142] Embodiment 25: The photodetector according to any of the preceding embodiments relating to photodetectors, wherein the at least one evaluation unit is at least partially cloud-based.

[0143] Embodiment 26: A spectrometer for performing spectral analysis on optical radiation provided by at least one measurement object, the spectrometer comprising:

[0144] at least one radiation emitting element configured for emitting optical radiation at least partially towards at least one measurement object; and

[0145] - at least one photodetector according to any of the preceding embodiments relating to photodetectors.

[0146] Embodiment 27: The spectrometer according to the preceding embodiment, wherein the at least one radiation emitting element comprises at least one of a semiconductor-based radiation source or a thermal radiator.

[0147] Embodiment 28: The spectrometer according to the preceding embodiment, wherein the at least one semiconductor-based radiation source is selected from at least one of a light emitting diode (LED) or a laser, in particular a laser diode.

[0148] Embodiment 29: The spectrometer according to any of the above embodiments relating to the spectrometer further comprises at least one temperature stabilizing element, in particular a thermoelectric cooler.

[0149] Embodiment 30: The spectrometer according to any of the preceding embodiments relating to the spectrometer, wherein the at least one evaluation unit can be further designed to fully or partially control or drive the spectrometer or a part thereof.

[0150] Embodiment 31: Use of the method for determining at least one item of measurement information about a measurement object according to any of the aforementioned embodiments relating to a method for determining at least one item of information about a measurement object, or at least one of the spectrometers according to any of the aforementioned embodiments relating to a spectrometer for a purpose of use selected from the group consisting of: infrared detection applications; spectroscopy applications; exhaust gas monitoring applications; combustion process monitoring applications; pollution monitoring applications; industrial process monitoring applications; mixing or blending process monitoring; chemical process monitoring applications; food processing process monitoring applications; food preparation process monitoring; water quality monitoring applications; air quality monitoring applications; quality control applications; temperature control applications; motion control applications; emission control applications; gas sensing applications; gas analysis applications; motion sensing applications; chemical sensing applications; mobile applications; medical applications; mobile spectroscopy applications; food analysis applications; agricultural applications, in particular characterization of soil, silage, feed, crops or agricultural products, monitoring plant health; plastic identification and / or recycling applications; and textile identification and recycling applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0151] Other optional features and embodiments are preferably disclosed in more detail in the subsequent description of the embodiments in conjunction with the dependent claims. Wherein, as the skilled person will recognize, the corresponding optional features can be implemented in an independent manner and in any arbitrary feasible combination. The scope of the present invention is not limited by the preferred embodiments. The embodiments are schematically depicted in the accompanying drawings. Wherein, the same reference numerals in these drawings represent the same or functionally equivalent elements.

[0152] In the attached picture:

[0153] Figure 1 Schematically illustrates an exemplary embodiment of a spectrometer according to the present invention;

[0154] Figure 2 schematically illustrates an exemplary embodiment of a photodetector according to the present invention;

[0155] Figure 3 A flow chart showing an exemplary embodiment of a method for determining at least one compensated detector signal of at least one photodetector according to the present invention is shown;

[0156] Figure 4 , FIG. 5A to FIG. 5F , FIG. 6A to FIG. 6C shows experimental results of measuring an exemplary embodiment of a spectrometer according to the present invention;

[0157] Figure 7 A flow chart of an exemplary embodiment of a method according to the present invention for determining at least one item of measurement information about at least one measurement object by using at least one photodetector is shown. DETAILED DESCRIPTION

[0158] Figure 1 An exemplary embodiment of a spectrometer 110 according to the present invention is schematically shown. The spectrometer 110 is configured to perform spectral analysis on an optical radiation 112 provided by at least one measurement object 114. The optical radiation 112 provided by at least one measurement object 114 may include a wavelength of 300nm to 3000nm, specifically 500nm to 2500nm, more specifically 1400nm to 2000nm. Therefore, the optical radiation 112 provided by at least one measurement object 114 may be specifically IR radiation, more specifically NIR radiation. At least one measurement object 114 may have any shape and composition. At least one measurement object 114 may be a solid sample. However, at least one measurement object 114 may also be a fluid sample.

[0159] The spectrometer 110 comprises at least one radiation emitting element 116, which is configured to emit optical radiation 112 at least partially towards at least one measurement object 114. The optical radiation 112 emitted by the at least one radiation emitting element 116 can be modulated. The at least one radiation emitting element 116 can include at least one of a semiconductor-based radiation source or a thermal radiator. The at least one semiconductor-based radiation source can be selected from at least one of a light emitting diode (LED) or a laser, in particular, a laser diode. The at least one radiation emitting element 116 can be configured to emit the optical radiation 112 isotropically in all spatial directions. The at least one radiation emitting element 116 can be configured to anisotropically emit the optical radiation 112 in at least one spatial direction, in particular towards at least one measurement object 114, such as by generating at least one light beam 118.

[0160] The spectrometer 110 further comprises at least one photodetector 120 according to any of the embodiments relating to the photodetector 120 described above or in further detail below. Figure 2 An exemplary embodiment of the photodetector 120 is also schematically shown separately in FIG. Therefore, regarding the photodetector 120, it can be combined with Figure 1 and Figure 2112. The photodetector 120 is configured to measure the optical radiation 112. The photodetector 120 is further configured to perform at least one method according to any of the embodiments described in further detail above or below relating to at least one of the methods for determining at least one compensated detector signal of at least one photodetector 120 or the method for determining at least one measurement information about at least one measurement object 114. The photodetector 120 includes at least one detector element 122. The at least one detector element 122 may be a photosensitive region of the photodetector 120. The at least one detector element 122 may include at least one photoconductive material. The photoconductive material may be selected from at least one of PbS, PbSe, Ge, InGaAs, InSb, or HgCdTe. The photodetector 120 may include at least one readout circuit 124. The at least one readout circuit 124 may be configured to read out at least one detector signal generated by the at least one detector element 122. The at least one readout circuit 124 may include at least one resistance meter 126 configured to measure at least one resistance of the at least one detector element 122. The at least one readout circuit 124 may be connected to other components of the photodetector 120 , such as to at least one of the evaluation unit 128 or the communication interface 130 , for example by using at least one conducting wire 132 .

[0161] The photodetector 120 may include at least one of an evaluation unit 128 or a communication interface 130 configured to perform at least one of the following: transmitting data from, to, or within the evaluation unit 128. The at least one evaluation unit 128 may be at least partially cloud-based. In other words, the at least one evaluation unit 128 may be at least partially distributed in at least one cloud 134 for at least one of cloud computing or cloud storage. The at least one cloud 134 may specifically include at least one external device 136, such as a computer or a computer network. Figure 1 and Figure 2As shown, at least one evaluation unit 128 can be at least partially distributed within the photodetector 120, for example for performing a first signal processing on the detector signal read out by the at least one readout circuit 124, such as signal filtering or signal smoothing. Other signal processing or signal evaluation can be performed in a part of at least one evaluation unit 128 distributed on at least one external device 136 of at least one cloud 134. At least one external device 136 can specifically include more computing power or data storage capacity. Additionally or alternatively, at least one external device 136 can be more user-friendly or mobile, such as a smart phone. Different parts of at least one evaluation unit 128 can be at least partially interconnected via at least one communication interface 130. The communication interface 130 can be at least one of wireless or wired.

[0162] The spectrometer 110 may further include at least one temperature stabilizing element 138, in particular a thermoelectric cooler 140. The at least one temperature stabilizing element 138 may be specifically configured to stabilize the temperature of the spectrometer 110 or at least a portion thereof (such as at least one of the at least one radiation emitting element 116 or the photodetector 120). Figure 1 As shown, at least one temperature stabilization element 138 may be connected to at least one of the radiation emitting element 116 or the photodetector 120, for example, by at least one wire 132 for heat transfer. The at least one evaluation unit 128 may further be designed to completely or partially control or drive the spectrometer 110 or a part thereof, such as the temperature stabilization element 138, the at least one radiation emitting element 116 or the photodetector 120. The spectrometer 110 may further include at least one housing 142, which surrounds at least a part of the spectrometer 110, such as the temperature stabilization element 138, the radiation emitting element 116 or the photodetector 120. At least one external device 136 of the at least one cloud 134 may be arranged outside the at least one housing 142. The at least one housing 142 may include at least one window 144. The at least one window 144 may be at least partially transparent for the optical radiation 112. The spectrometer 110 may further include at least one filter element 146. The at least one filter element 146 may be configured for filtering the optical radiation 112, or more specifically a selected wavelength of the optical radiation 112. The at least one filter element 146 may specifically be positioned in the beam path before the at least one detector element 122.

[0163] In the following, about Figure 1An exemplary beam path of optical radiation 112 is depicted. At least one radiation emitting element 116 may emit optical radiation 112 as incident optical radiation 148, which passes through at least one window 128 toward at least one measurement object 114. The at least one measurement object 114 may at least partially reflect (particularly diffusely reflect) the incident optical radiation 148 in the form of reflected optical radiation 150 toward at least one detector element 122 of at least one photodetector 120. Furthermore, the at least one measurement object 114 may at least partially absorb the incident optical radiation 148, which may indicate at least one physical property or chemical composition of the at least one measurement object 114. The reflected optical radiation 150 may pass through at least one window 144 and at least one filter element 146 and then reach at least one detector element 122. The at least one detector element 122 may generate a corresponding detector signal, which may be read out using at least one readout circuit 124.

[0164] As already pointed out, Figure 2 An exemplary embodiment of a photodetector 120 according to the present invention is schematically shown. For the description of the photodetector 120, reference may be made to the above description of the spectrometer 110 to a large extent. As described above, the photodetector 120 is configured to perform at least one method according to any of the embodiments described above or below in further detail involving at least one of the methods for determining at least one compensated detector signal of at least one photodetector 120, or the method for determining at least one item of measurement information about at least one measurement object 114.

[0165] Figure 3 A flow chart of an exemplary embodiment of a method according to the invention for determining at least one compensated detector signal of at least one photodetector 120 is shown. The at least one photodetector 120 comprises at least one detector element 122 configured to generate at least one detector signal depending on illumination of the at least one detector element 122. The method comprises the following steps:

[0166] a) (indicated by reference numeral 152) determining at least one dark detector resistance using at least one detector element 122 and inhibiting illumination of at least one detector element 122;

[0167] b) (indicated by reference numeral 154) using at least one detector element 122 and allowing illumination of at least one detector element 122 to generate at least one bright detector signal; and

[0168] c) (denoted by reference numeral 156 ) determining at least one compensated detector signal for compensating at least one temperature drift of at least one detector element 122 using at least one evaluation unit 128 for evaluating at least one dark sensor resistance and at least one bright detector signal.

[0169] The method steps may be performed in the order indicated. However, it should be noted that a different order is also possible. The method may include additional method steps not listed herein. Further, one or more of the method steps may be performed once or repeatedly. Further, two or more of the method steps may be performed simultaneously or in a time-overlapping manner. The method steps may be at least partially computer-implemented.

[0170] In step c), at least one compensated detector signal may be determined by using equation (1):

[0171]

[0172] Among them, S comp (T0, λ) refers to the compensated detector signal of the at least one detector element 122 at a first temperature T0, wherein λ refers to the wavelength of the optical radiation 112 illuminating the at least one detector element 122, wherein S(T0+ΔT, λ) refers to the bright detector signal of the at least one detector element 122 at a second temperature T0+ΔT, wherein ΔT refers to the temperature change of the at least one detector element, wherein α(T0, λ) refers to the resistive responsivity of the at least one detector element 122 at the first temperature T0 of the at least one detector element 122, and wherein Γ is defined as

[0173]

[0174] Among them, γ α refers to a predetermined resistance responsivity coefficient of at least one detector element 122, and wherein γ R γ refers to a predetermined dark resistivity of the at least one detector element 122. ΔT may be lower than 10K, specifically lower than 1K, and more specifically lower than 0.1K. α or γ R At least one of γ may be predetermined during at least one calibration process of at least one detector element 122. R ΔT may be determined by using at least one baseline of at least one detector element 122. R ΔT can be determined by using at least one dark detector resistor. R ΔT can be determined by using equation (2):

[0175] γ RΔT=R D (T0+ΔT)-R D (T0), (2)

[0176] Among them, R D Γ refers to at least one dark detector resistance. Γ may be predetermined during a calibration process of at least one of the at least one detector element 122 or the at least one further detector element, wherein the at least one detector element 122 and the at least one further detector element may be selected from the same class of detector elements.

[0177] Step a) may include covering the at least one detector element 122 with at least one object. However, in addition or alternatively, step a) may include not illuminating the at least one detector element 122. As described above, the optical radiation 112 emitted by the at least one radiation emitting element 116 may be modulated. Thus, the optical radiation 112 received by the at least one detector element 122 may be modulated, such as with respect to Figure 4 This can also be used to determine the dark detector resistance of at least one detector element 122 without covering the at least one detector element 122 .

[0178] Figure 4 , FIG. 5A to FIG. 5F as well as FIG. 6A to FIG. 6C Experimental results of measurements performed using an exemplary embodiment of the spectrometer 110 according to the present invention are shown. Figure 4 A detector signal 158 is shown, which may be a typical signal of a detector element 122 comprising a photoconductive material. The detector signal 158 is obtained by using the optical radiation 112 emitted by the modulated radiation emitting element 116. The detector signal 158 is a signal S, which is measured in counts over a period of time, specifically over 1000 frames F. The detector signal 158 may exhibit a periodic evolution due to the modulation of the radiation emitting element 116. A maximum value of the detector signal 158 may correspond to a phase in which the detector element 122 is illuminated, and therefore to a bright detector signal. A minimum value of the detector signal 158 may correspond to a phase in which the detector element 122 is not illuminated, and therefore to a dark detector signal. A baseline 160 is fitted to the minimum value of the detector signal 156. The baseline 160 may directly correspond to the dark detector resistance R of the detector element 122. D The baseline 160 as well as the maximum value of the detector signal 158, ie, the bright detector signal, may exhibit temperature dependence for a fixed wavelength and spectral irradiance.

[0179] FIG. 5A to FIG. 5F An example of temperature drift is shown. Figure 5AThe measured signal of a photodetector 120 is shown, the photodetector comprising 256 detector elements 122 arranged in a detector array. In such an arrangement, the detector elements 122 may typically be referred to as pixels P. The measured signal therefore comprises an average bright detector signal per pixel. Figure 5B The bright detector signal of a selected pixel is shown over a time t of 150 s, during which time the bright detector signal shows a decrease. Each line shown represents the bright detector signal of one of the selected detector elements 122. This decrease in turn is related to the temperature increase. Figure 5C The temperature T of the photodetector 120 is shown to increase during the same time period. Figure 5D Shows Figure 5B The bright detector signals in are relative to their respective initial values ​​at 0 seconds. rel The reduced temperature dependency of the bright detector signal is emphasized. Further, the dark detector signal also shows a temperature dependency. Specifically, the temperature drift in the dark detector signal is proportional to the temperature. Figure 5E and Fig. 5F The corresponding baseline B is shown. Figure 5E It is shown that the average baseline shifts proportionally to temperature. Fig. 5F It is further shown that the baseline for a selected detector element 122 shifts proportionally to the temperature.

[0180] Temperature drifts can be avoided by using the proposed method for determining at least one compensated detector signal. FIG. 6A to FIG. 6C Experimental data corresponding to the application of the proposed temperature compensation scheme are shown. Fig. 6A Again, it shows Figure 5A The points indicate the clustering of multiple pixels with a single data point by determining the average value. Figure 6B It is shown that applying the proposed temperature compensation scheme can significantly improve the signal-to-noise ratio (SNR). In particular, a baseline-based temperature compensation is applied, which is better than applying an external sensor. The SNR of the uncompensated measurement signal is denoted by reference numeral 162. The SNR of the measurement signal compensated by using an external sensor is denoted by reference numeral 164. The SNR of the measurement signal compensated by using a baseline-based temperature compensation is denoted by reference numeral 166. These points refer to Fig. 6A It can be seen that for almost all pixels, the measured signal compensated using the proposed temperature compensation shows the overall highest SNR. Figure 6C Again the time temperature evolution of the photodetector 120 is shown.

[0181] The discussed temperature compensation scheme may in particular be applied when performing measurements on the at least one measurement object 114 . Figure 7A flow chart of an exemplary embodiment of a method according to the present invention for determining at least one item of measurement information about at least one measurement object 114 by using at least one photodetector 120 is shown. As described above, the at least one photodetector 120 comprises at least one detector element 122, which is configured to generate at least one detector signal depending on the illumination of the at least one detector element 122. The method comprises the following steps:

[0182] i) (indicated by reference numeral 168) using at least one measurement object 114 to provide optical radiation 112 and using at least one photodetector 120 to generate at least one detector signal;

[0183] ii) (indicated by reference numeral 170) determining at least one compensated detector signal according to any of the embodiments relating to a method for determining at least one compensated detector signal described above or in further detail below; and

[0184] iii) (indicated by reference numeral 172 ) determining at least one item of measurement information about the at least one measurement object 114 using the at least one compensated detector signal.

[0185] The method steps can be performed in the order indicated. However, it should be noted that different orders are also possible. The method may include additional method steps not listed herein. Further, one or more method steps in the method steps may be performed once or repeatedly. Further, two or more method steps in the method steps may be performed simultaneously or in a time-overlapping manner. The method steps may be at least partially computer-implemented. At least one item of measurement information may include at least one of the physical properties of at least one measurement object 114 or the chemical composition of at least one measurement object 114.

[0186] List of Reference Numerals

[0187] 110 Spectrometer

[0188] 112 Light Radiation

[0189] 114 Measurement Objects

[0190] 116 Radiation emitting element

[0191] 118 Beam

[0192] 120 Photodetector

[0193] 122 Detector element

[0194] 124 Readout circuit

[0195] 126 Resistance meter

[0196] 128 evaluation units

[0197] 130 Communication interface

[0198] 132 Wire

[0199] 134 Cloud

[0200] 136 External Devices

[0201] 138 Temperature stabilizing element

[0202] 140 Thermoelectric Cooler

[0203] 142 Housing

[0204] 144 Window

[0205] 146 Filter Components

[0206] 148 Incident Light Radiation

[0207] 150 reflected light radiation

[0208] 152 Step a)

[0209] 154 Step b)

[0210] 156 Step c)

[0211] 158 Detector signal

[0212] 160 Baseline

[0213] 162 Signal-to-noise ratio (SNR) of the uncompensated measurement signal

[0214] 164 Signal-to-noise ratio (SNR) of the measured signal compensated by using an external sensor

[0215] 166 Signal-to-noise ratio (SNR) of the measured signal compensated using baseline-based temperature compensation

[0216] 168 Step i)

[0217] 170 Step ii)

[0218] 172 Step iii)

Claims

1. A method for determining at least one compensated detector signal of at least one photodetector (120), wherein: The at least one photodetector (120) comprises at least one detector element (122) configured to generate at least one detector signal in dependence on illumination of the at least one detector element (122), wherein the at least one detector element (122) is configured as a photoconductor, the method comprising the following steps: a) determining at least one dark detector resistance using the at least one detector element (122) and inhibiting illumination of the at least one detector element (122); b) using the at least one detector element (122) and allowing illumination of the at least one detector element (122) to generate at least one bright detector signal; and c) determining at least one compensated detector signal for compensating at least one temperature drift of the at least one detector element (122) using at least one evaluation unit (128) for evaluating the at least one dark sensor resistance and the at least one bright detector signal, Therein, in step c), the at least one compensated detector signal is determined by using equation (1): Among them, S comp S(T0, λ) refers to the compensated detector signal of the at least one detector element (122) at a first temperature T0, wherein λ refers to the wavelength of the light radiation irradiating the at least one detector element (122), wherein S(T0+ΔT, λ) refers to the bright detector signal of the at least one detector element (122) at a second temperature T0+ΔT, wherein ΔT refers to the temperature change of the at least one detector element (122), wherein the temperature change ΔT is determined by measuring at least one dark detector resistance R of the at least one detector element (122). D is determined by, wherein α(T0, λ) refers to the resistance responsivity of the at least one detector element (122) at a first temperature T0 of the at least one detector element (122), wherein Γ is defined as Among them, γ α refers to a predetermined resistance responsivity coefficient of the at least one detector element (122), and wherein γ R Refers to a predetermined dark resistivity of the at least one detector element (122).

2. The method according to the preceding claim, wherein: γ α or γ R At least one of the detector elements (122) is predetermined in at least one calibration process of the at least one detector element (122).

3. The method according to any one of the preceding claims, wherein: γ R ΔT is determined using at least one baseline of the at least one detector element (122).

4. A method according to any one of the three preceding claims, wherein: γ R ΔT is determined by using the at least one dark detector resistor.

5. The method according to the preceding claim, wherein: γ R ΔT is determined by using equation (2): c R ΔT=R D (T0+ΔT)-R D (T0), (2) Among them, R D refers to the at least one dark detector resistor.

6. The method according to any one of the five preceding claims, wherein: Γ is predetermined during a calibration process of at least one of the at least one detector element (122) or at least one further detector element, wherein the at least one detector element (122) and the at least one further detector element are selected from the same category of detector elements.

7. A method according to any one of the preceding claims, wherein: The at least one photodetector (120) comprises at least one of an evaluation unit (128) or a communication interface (130) configured to at least one of: transmit data from, to or within the evaluation unit (128).

8. A method according to any one of the preceding claims, wherein: By outsourcing the at least one evaluation unit (128) or at least a portion thereof to an at least partially interconnected external device, the at least one evaluation unit is at least partially cloud-based.

9. A method according to any one of the preceding claims, wherein: The method is at least partially computer-implemented.

10. A method according to any one of the preceding claims, wherein: The at least one detector element (122) includes at least one photoconductive material, wherein the photoconductive material is selected from at least one of PbS, PbSe, Ge, InGaAs, InSb or HgCdTe.

11. A method for determining at least one item of measurement information about at least one measurement object (114) by using at least one photodetector (120), wherein: The at least one photodetector (120) comprises at least one detector element (122) configured to generate at least one detector signal in dependence on illumination of the at least one detector element (122), the method comprising the steps of: i) using the at least one measurement object (114) to provide optical radiation (112) and using the at least one photodetector (120) to generate at least one detector signal; ii) determining at least one compensated detector signal according to any one of the preceding claims; and iii) using the at least one compensated detector signal to determine at least one item of measurement information about the at least one measurement object (114).

12. A non-transitory computer readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform at least one of the following: - using at least one evaluation unit (128) for evaluating the at least one dark sensor resistance and the at least one bright detector signal to determine at least one compensated detector signal for compensating at least one temperature drift of the at least one detector element (122); or - using the at least one compensated detector signal to determine at least one item of measurement information about the at least one measurement object (114).

13. A photodetector (120) for measuring optical radiation, wherein: The photodetector (120) is configured to perform at least one of the following: - a method for determining at least one compensated detector signal of at least one photodetector (120) according to any one of claims 1 to 10; or - Method for determining at least one item of measurement information about at least one measurement object (114) according to claim 11, The photodetector (120) includes at least one detector element (122).

14. A spectrometer (110) for spectrally analyzing optical radiation provided by at least one measurement object (114), the spectrometer (110) comprising: at least one radiation emitting element (116) configured to emit optical radiation (112) at least partially towards the at least one measurement object (114); as well as - At least one photodetector (120) according to the preceding claim.

15. Use of the method for determining at least one item of measurement information about a measurement object (114) according to any of the preceding claims relating to a method for determining at least one item of measurement information about a measurement object (114), or at least one of the spectrometers (110) according to any of the preceding claims relating to a spectrometer (110) for a purpose of use selected from the group consisting of: infrared detection applications; spectroscopy applications; exhaust gas monitoring applications; combustion process monitoring applications; pollution monitoring applications; industrial process monitoring applications; mixing or blending process monitoring; chemical process monitoring applications; food processing process monitoring applications; food preparation process monitoring; water quality monitoring applications; air quality monitoring applications; quality control applications; temperature control applications; motion control applications; emission control applications; gas sensing applications; gas analysis applications; motion sensing applications; chemical sensing applications; mobile applications; medical applications; mobile spectroscopy applications; food analysis applications; agricultural applications, in particular characterization of soil, silage, feed, crops or agricultural products, monitoring plant health; plastic identification and / or recycling applications; and textile identification and recycling applications.

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