Methods and apparatus for detecting particles and gases

Abstract

It solves the problems of related devices. An apparatus for detecting a property of a gas includes a light source (20) configured to emit light along at least one propagation axis (30). The apparatus includes a light detection device (40) including a light sensor (70) configured to output a sensor signal (75) and a lens device (50) having a lens surface (60) and configured to direct light emitted from the light source (20) and scattered by the gas to the light sensor (70). The apparatus further includes an actuator assembly (110) configured to move the light sensor (70) in a direction parallel to at least a first axis (150). The first axis (150), the propagation axis (30), and the lens surface (60) intersect such that the Scheimpflug condition (61) is achieved.

Description

[Technical Field]

[0001] This disclosure relates to a laser projection system, more specifically to a system for detecting gases and the properties of gases. [Background technology]

[0002] LiDAR, or laser radar, is an optical device for detection and ranging that can be used in an extremely wide range of environments, from industrial combustion furnaces to ecosystem monitoring. Unlike the currently prevalent topographic LiDAR systems that detect and range hard targets, atmospheric LiDAR has sufficient sensitivity to acquire continuous molecular echoes from perfectly clean air. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] US 11,169,272 [Overview of the project] [Problems that the invention aims to solve]

[0004] Differential Absorption LIDAR (DIAL) is a type of highly specific atmospheric LIDAR method. With this method, it is possible to obtain molecular absorption lines and concentration characteristics of target-specific gases for pulsed wavelength-variable lasers. In reality, high peak power (MW), short pulses (ns), narrow bandwidth (<pm), and wavelength variability are mutually contradictory. Such DIAL systems generally require a small team of laser physics doctors for their operation. Although some progress has been reported regarding lighter and smaller DIAL systems using micro LIDAR, their time resolution is still on the order of several tens of minutes. Therefore, DIAL systems are extremely expensive and there are only a handful of operations globally. The low resolution, (high) cost, and bulkiness of DIAL systems are hindering many practical applications such as industrial process optimization and mapping of greenhouse gas sources and flows.

[0005] A known alternative LiDAR method is described in US 11,169,272. This document describes an optical apparatus for using the Scheimpflug condition to analyze gas absorption lines at different distances within the same field of view. One problem with this apparatus is that the system requires a complex optical sensor apparatus suitable for focusing and sampling of received light corresponding to different distances. Such a system also requires satisfying multiple conditions, such as the Scheimpflug and Hinge rule during operation, but its flexibility during operation is extremely limited, as the parameters are not easily changed during execution because the optical conditions must be met. Furthermore, this type of array or two-dimensional imaging sensor can be extremely expensive, especially when combined with the kHz speed requirement for wavelengths longer than the silicon wavelength. Moreover, such apparatus generally imposes significant demands on the sensor assembly and processing unit in terms of speed, as they are inherently tied to the imaging sensor and processing. This means that implementation, operation, and maintenance can be complex and time-consuming.

[0006] The examples provided in this disclosure are intended to address the issues mentioned above. [Means for solving the problem]

[0007] In one view of the present disclosure, an apparatus for detecting the properties of a gas is provided. The apparatus includes a light source configured to emit light along at least one propagation axis; a photodetector configured to output a sensor signal; and a lens device including a lens surface and configured to direct (guide) light emitted from the light source and scattered by the gas toward the photodetector; and an actuator assembly configured to move the photodetector in a direction parallel to at least a first axis, wherein the first axis, the propagation axis and the lens surface intersect (with each other) such that a Scheimpflug condition is achieved.

[0008] Optionally, the actuator assembly is further configured to move the optical sensor in a direction parallel to a second axis corresponding to the optical axis of the lens device.

[0009] Optionally, the actuator assembly is further configured to move the optical sensor in a direction parallel to the third axis which is orthogonal to the second axis, and in a plane defined by the first and second axes.

[0010] Optionally, the actuator assembly is configured to move the optical sensor in a direction parallel to a fourth axis along the normals of the plane defined by the first and second axes.

[0011] The optical sensor is optionally placed in the sensor assembly.

[0012] Optionally, the light sensor is movable relative to the sensor assembly, and the actuator assembly includes a first actuator configured to move the light sensor.

[0013] Optionally, the sensor assembly is movable relative to the housing of the device, and the actuator assembly includes a second actuator configured to move the sensor assembly.

[0014] Optionally, the sensor assembly is movable relative to the housing of the apparatus along a rail.

[0015] Optionally, the optical sensor includes at least one of a single pixel, a quadrant of pixel(s), an array of pixel(s), a pixel matrix, and a position sensitive device (PSD) pixel.

[0016] Optionally, the optical sensor includes at least one column of pixel(s) aligned parallel to a first axis.

[0017] Optionally, the optical sensor includes at least one row of pixel(s) aligned parallel to a fourth axis.

[0018] Optionally, the optical sensor includes at least one of a photodiode, an avalanche photodiode, a photomultiplier tube (PMT), and a CMOS sensor.

[0019] Optionally, the optical sensor includes at least one of a transimpedance amplifier, a free silicon amplifier, a current amplifier, and a dynode amplifier.

[0020] Optionally, the optical sensor is configured to detect a signal generated by at least one of wavelength modulation spectroscopy, direct absorption spectroscopy, and / or frequency modulation spectroscopy.

[0021] Optionally, the light source is a wavelength tunable laser diode.

[0022] Optionally, the light source is controlled by the TDLAS method.

[0023] Optionally, the light source is controlled by the DIAL method.

[0024] Optionally, the light source includes an array of individual light sources arranged parallel to a fifth axis or perpendicular to the propagation axis, or parallel to the fourth axis.

[0025] Optionally, the light sensor includes a single sensor pixel.

[0026] Optionally, the device includes a sensor window positioned (placed) between the light sensor and the lens device.

[0027] Optionally, the sensor window includes a slit with a width adjustable along the first axis.

[0028] In another aspect of the present disclosure, a method for detecting the properties of a gas is provided. The method includes emitting light along at least one propagation axis; directing (guiding) the light scattered by the gas to a photosensor using a lens device having a lens surface; and imaging the volume of the gas at a specific distance from the device by moving the photosensor to a corresponding position along a first axis, characterized in that the first axis, the propagation axis and the lens surface intersect (with each other) such that a Scheimpflug condition is achieved.

[0029] These and other perspectives, features, and possible advantages of the embodiments of this disclosure will become apparent and will be apparent from the following description of the embodiments of this disclosure, with reference to the accompanying drawings. [Brief explanation of the drawing]

[0030] [Figure 1] A schematic plan view of an apparatus according to an example of this disclosure. [Figure 2] A diagram illustrating an application example corresponding to one example of this disclosure. [Figure 3] A schematic plan view of an apparatus according to an example of this disclosure. [Figure 4] A diagram of a device corresponding to an example of this disclosure. [Figure 5a] A schematic plan view of an apparatus according to an example of this disclosure. [Figure 5b] A schematic plan view of an apparatus according to an example of this disclosure. [Figure 6] A schematic perspective view of an apparatus according to an example of this disclosure. [Figure 7a] Enlarged view of a part of the device according to an example of this disclosure. [Figure 7b] Enlarged view of a part of the device according to an example of this disclosure. [Figure 8] Another enlarged view of a part of the apparatus according to an example of this disclosure. [Figure 9a] Another enlarged view of a part of the apparatus according to an example of this disclosure. [Figure 9b] Another enlarged view of a part of the apparatus according to an example of this disclosure. [Figure 10] A flowchart of the method according to an example of this disclosure. [Modes for carrying out the invention]

[0031] The following examples of a specific gas detection and particle detection device 100 are given in this disclosure. Throughout the specification, the same drawing reference numerals are used to identify corresponding components.

[0032] Figure 1 shows one embodiment of the apparatus 100. In some examples, the apparatus 100 is a gas detection device 100, and in some examples, the apparatus 100 is a particle detection device 90 (particle detection device) 100. The apparatus 100 is configured to guide light from a light source 20 and receive scattered light from one or more particles 90. One or more particles 90 are gas or hard matter located away from the apparatus 100. This may be both gas particles 90 and / or hard particles 90. One or more particles 90 may be ozone, nitrogen oxides (e.g., NO) X ), sulfur oxides (e.g., SO X), water, oxygen, nitrogen, hydrogen (H2), CO2, CO, CH4, acetylene C2H2, formaldehyde H2CO, hydrogen sulfide H2S, hydrogen chloride HCl, ammonia NH3, ethane C2H6, hydrogen fluoride HF, or any other gas that is naturally present or emitted in the atmosphere. In some other examples, one or more particles 90 may be additionally or alternatively particulate pollutants, such as dust, soot, or smoke.

[0033] In some cases, one or more particles 90 • Coarse particles with a diameter greater than 10 μm 90; ·(PM 10-2.5 Coarse particles 90 (also known as): generally particles 90 having a diameter greater than 2.5 μm and less than or equal to 10 μm; ·(PM 2.5 (Also known as) Fine particles 90: Generally, particles with a diameter of 2.5 μm or less; • Ultrafine particles and nanoparticles (nanoparticles) having a diameter of less than 2.5 μm It is possible.

[0034] Generally, the identification (detection) of coarse particles 90, fine particles 90, ultrafine particles 90, and nanoparticles 90 is desirable because these particles 90 can enter the lungs and damage the respiratory system. Furthermore, even if the effects of particles 90 on human health are disregarded, the identification (detection) and monitoring of particles 90 is extremely important for industries where particles 90 directly affect the quality of manufactured goods, such as processing industries and cleanroom environments. Particles 90 can include one or more particles 90 of sulfate ions, nitrate ions, ammonium ions, elemental carbon ions, organic carbon ions, silicon ions, and sodium ions. In some examples, particles 90 can be any airborne particles 90 having the sizes described above. The measurement of particle size 90 is well known and will not be further explained.

[0035] The apparatus 100 includes a data processing device 10. The data processing device 10 is configured to send control signals to one or more components of the apparatus 100 during operation. The data processing device 10 is also configured to generate an indication of whether one or more particles 90 are detected in the gas. In this way, the data processing device 10 is configured to drive a light source 20 and to process sensor signals 75 to determine the properties of the gas.

[0036] In some cases, a data processing unit 10 may be realized by dedicated (specific purpose) software (or firmware) running on one or more general-purpose or dedicated (specific purpose) arithmetic units (computers) 10. In this sense, each "element" or "means" of such an arithmetic unit 10 can be understood as conceptually equivalent to a method step; however, there is not necessarily a one-to-one correspondence between elements / means and specific parts of hardware or software routines. Parts of hardware may include different elements / means. For example, a processing unit may function as one element / means when executing one instruction, but as another element / means when executing another instruction. Furthermore, one element / means may be realized by one instruction in some cases and by multiple instructions in other cases. Such a software-controlled arithmetic unit 10 may include one or more processing units, such as a CPU ("Central Processing Unit"), a DSP ("Digital Signal Processor"), an ASIC ("Application-Specific Integrated Circuit"), analog and / or digital discrete components, or other programmable logic devices 10 such as an FPGA ("Field Programmable Gate Array"). The data processing unit 10 may further include system memory and a system bus that connects various system components, including the system memory, to the processing unit. The system bus may be one of several types of bus structures, including a memory bus or memory controller, a peripheral bus, and a local bus, using any of various bus architectures. The system memory may include computer storage media in the form of volatile and / or non-volatile memory such as read-only memory (ROM), random access memory (RAM), and flash memory.The dedicated software may be stored in system memory or on other interchangeable / non-exchangeable volatile / non-volatile computer storage media included in or accessible from the arithmetic unit 10, such as magnetic media, optical media, flash memory cards, digital tapes, solid-state RAM, solid-state ROM, etc. The data processing unit 10 may include one or more communication interfaces, such as serial interfaces, parallel interfaces, USB interfaces, wireless interfaces, network adapters, etc., and one or more data acquisition devices

[10] , such as AD converters. The dedicated software may be provided on any suitable computer-readable medium, including recording media and read-only memory of the data processing unit 10.

[0037] The distinction between copolarized and depolarized light in LiDAR can provide microstructural information about the LiDAR target. Single-scatter aerosol LiDAR can be defined as a type of atmospheric LiDAR that is sensitive to receiving echoes from clean air. In single-scatter aerosol LiDAR, the depolarization ratio (DoLP), defined as the ratio of the intensity of the perpendicular to the parallel components of the scattered light, allows for the distinction between spherical particles 90 and particles 90 with edges or irregular shapes, such as liquid droplets (droplets) and ice crystals. Furthermore, the sizing of the particles 90 can be determined by the distinction of signals from any of several wavelengths or based on signal intensity based on a priori knowledge of the particle distribution in the gas.

[0038] The data processing device 10 is configured to transmit a control signal 25 to the light source 20 so that the light source 20 emits light along the propagation axis 30.

[0039] Light emitted from the light source 20 travels along the propagation axis 30 until it reaches the particles 90 in the atmosphere. At least a portion of the emitted light from the light source 20 is backscattered from the particles 90 along the second axis 160 toward the photodetector 40. The second axis 160 is the light receiving path axis 160, for example, the path that the scattered light follows from the particles 90 toward the device 100.

[0040] The light detection device 40 includes a lens device 50 having a lens surface 60. The lens device 50 shown in Figure 1 is aligned along a second axis 160. While the second axis 160 is practically a single backscattering axis, there may be multiple different backscattering axes from different particles 90 located at different distances from the light detection device 40. The lens device 50 is configured to direct (guide) the light scattered by the scattering particles 90 towards the light sensor 70.

[0041] In one embodiment, the optical sensor 70 has a pixel array aligned to the image plane and is configured to output a sensor signal 75 to the data processing device 10. The image plane can be aligned along a first axis 150. The first axis 150, the lens plane 60, and the propagation axis 30 intersect at a first intersection 61 such that the Scheimpflug condition is met.

[0042] Furthermore, in some examples, the displaced image plane 82, the front focal plane 62 of the lens device 50, and the propagation axis 30 of the light source 20 optionally satisfy the Hinge rule at the second intersection 63. The data processing device 10 processes the sensor signal 75 from the light detection arrangement 40 to determine the pixel signal for one or more pixels of the light sensor 70. Satisfying the Hinge rule relationship between the light source 20 and the light detection device 40 is optional.

[0043] The lens device 50 may include at least one imaging lens including one or more optical refractive components and a mirror lens including a reflective refractive optical system. The lens device 50 has an F-number F / # and aperture TIFF0007863263000001.tif716 and focal length frec The lens device 50 may further include one or more optical filters. In some examples, the optical filters include interference filters, and in some examples, the optical filters include color-coated optical filters, and the optical filters may be band-pass, short-pass, long-pass, or a combination thereof.

[0044] The optical sensor 70 is a CMOS array detector, a low-pixel array detector, or a single-pixel detector such as a photodiode. By making the optical sensor 70 a single pixel, the complexity of the optical sensor 70 is reduced. The optical sensor 70 is optionally installed after the sensor window 702. Furthermore, the pixels of the optical sensor 70 are smaller, thereby improving the resolution. The optical sensor 70 is movable, and the movement of the optical sensor 70 will be described in more detail below with reference to Figures 3, 4, 5a, 5b, and 6. The optical sensor 70 is also configured to output a sensor signal 75. The movable optical sensor 70 has a sensor length TIFF0007863263000002.tif721 has a sensor tilt angle (θ) and multiple pixels. The pixels have a pixel height. TIFF0007863263000003.tif817 and pixel width (w pix ) has.

[0045] In some examples, the light sensor 70 includes a single movable pixel. In other examples, the height and width of the movable pixel are adjustable through one or more slits located in front of the pixel and behind the sensor window 702. The sensor window 702 is shown in Figures 7a and 7b and will be described in more detail below. The sensor window 702 may optionally include an adjustable slit component configured to control the scattered light received by the light sensor 70. The adjustable slit component will be described in more detail below in relation to Figures 7a and 7b. In some other examples, the light sensor 70 includes a small array of movable pixels. For example, the light sensor 70 includes an array of 2×2, 3×3, 4×4, 5×5, or n×n pixels, where n can be any number from 1 to 20, and the height and width of the array are adjustable through one or more slits located in front of the pixel and behind the sensor window 702.

[0046] In some other less preferred examples, the optical sensor 70 may include a movable linear CMOS array detector and may include at least one row of pixels aligned to an image plane aligned with a first axis 150. The movable linear CMOS array detector optical sensor 70 is further configured to output a sensor signal 75. The optical sensor 70 has a sensor length TIFF0007863263000004.tif721 has a sensor tilt angle (θ) and multiple pixels. The pixels have a pixel height. TIFF0007863263000005.tif817 and pixel width (w pix ) has.

[0047] Even after applying the Scheinproof principle or the Scheinproof principle and the hinge law, several design parameters still need to be considered. The device 100 may be designed with the following variables in mind: transmitter-receiver baseline separation distance. TIFF0007863263000006.tif79, receiver focal length f rec, and the inclination θ of the sensor with respect to the lens surface 60. The transmitter-receiver baseline separation distance is defined as the vertical distance between the lens device 50 and the propagation axis 30. The receiver focal length is defined as the vertical distance between the lens surface 60 and the front focal plane 62.

[0048] The device 100 includes an actuator assembly 110 configured to move the light sensor 70 parallel to or along the first axis 150. This means that the position of the light sensor 70 is adjustable, rather than providing a larger sensor that extends over a wider area. Thus, the light sensor 70 can be simulated as a larger sensor by moving the light sensor 70 through a volume of space using the actuator assembly 110.

[0049] This allows for the use of a smaller and less complex optical sensor 70, thus simplifying the operation of the device 100. Since the optical sensor 70 moves along the first axis 150, the Scheinproof principle and hinge law can be easily maintained without using a complex sensor. Adjusting the lens device 50 to change the focus to the optical sensor 70 would make the optical arrangement more complex, increasing the likelihood that the Scheinproof principle and / or hinge law cannot be maintained across a wide range of configurations.

[0050] Figure 2 shows the photodetector 40 of the apparatus 100. The photodetector 40 includes a base 200. The base 200 is a rigid structure for mounting one or more components of the apparatus 100 to the base 200. The base 200 is a planar structure extending in a plane parallel to the first axis 150 and the second axis 160. In some examples, the base 200 is a metal structure or other suitable rigid structure. This means that the components mounted on the base 200 are fixed relative to each other (in position) so as to maintain spatial and optical relationships.

[0051] The base 200 itself can optionally include one or more mounting holes 202 for fixing the apparatus 100 to a work surface (not shown) or other object. Alternatively, the mounting holes 202 are for attaching a lid (not shown) to protect the apparatus 100 during use. The mounting holes 202 are optionally located at the corners of the base 200 and include threaded holes 706 for receiving threaded bolts (not shown).

[0052] The base 200 can optionally include a component mounting plate 204 configured to receive components of the apparatus 100. In some examples, the component mounting plate 204 is machined from a stiff metal plate having predetermined mounting positions for receiving components of the apparatus 100. In some other examples, the base 200 does not have a component mounting plate 204, and instead, the components are directly attached to the base 200.

[0053] As shown in FIG. 2, the lens device 50 is attached to the first end 206 of the base 200. As described above, the lens device 50 can include at least one of an imaging lens including one or more light refracting components and a mirror lens including a reflective refracting optical system. The lens device 50 includes an F-number F / #, an aperture TIFF0007863263000007.tif716, and a focal length f rec and includes. The lens device 50 can further include one or more optical filters. In some examples, the optical filter includes an interference type optical filter. In some examples, the optical filter includes a color coating optical filter. The optical filter can be a band-pass type, a short-pass type, a long-pass type, or a combination of these types. The lens device 50 is aligned on the second axis 160.

[0054] The lens device 50 is also shown in FIG. 8 and will be briefly described herein with reference to FIG. 8. The figure is a perspective view of the lens device 50.

[0055] The lens device 50 includes a lens frame 800 to which one or more lenses and one or more optical filters (not shown for clarity) are mounted. The lens frame 800 includes two mounting bolts 802, 804 for mounting the lens device 50 to corresponding mounting holes in an optional component mounting plate 204.

[0056] In some examples, the lens assembly 50 includes an adjustment mechanism 806. The adjustment mechanism 806 is configured to fine-tune the position of the lens assembly 50 relative to the base 200 after the lens assembly 50 has been mounted on the base 200 and optionally on the component mounting plate 204. In some examples, the adjustment mechanism 806 is configured to move the lens arrangement 50 in a direction parallel to the fourth axis 180, which is perpendicular to the second axis 160. Thus, the adjustment mechanism 806 is configured to adjust the height of the lens assembly 50 above the base 200. This helps to align the lens assembly 50 on the second axis 160. In some examples, the means for adjusting the position of the lens assembly 50 relative to the base 200, such as the adjustment mechanism 806, is motorized to allow controlled and / or automatic adjustment. In some examples, the adjustment mechanism 806 is an actuator, such as a stepping motor. However, in some other examples, the adjustment mechanism 806 is a manually adjustable adjustment screw. This enables the optimization of maximizing the overlap between the synchrotron radiation 30 imaged along the second axis 160 and the (imaged) radiation (30) focused by the light sensor 70.

[0057] The position of the light sensor 70 shown in Figure 2 is decoupled from the position of the lens device 50. This means that even if there is some misalignment of the light sensor 70, as the light sensor 70 is moved along the first axis 150, the misalignment can be corrected by the adjustment mechanism 806 of the lens device 50. The misalignment can be corrected simultaneously by the adjustment mechanism 806 as the light sensor 70 is moved. This is in contrast to the conventional solution in array sensors, where the position of the lens device cannot be decoupled from the position of the light sensor, and therefore the positional height of the lens device must be matched with the synchrotron radiation.

[0058] Returning to Figure 2, the light source 20 will be described in more detail. In some examples, the light source 20 is a tunable diode laser. The light source 20 may include one or more of the following: a narrowband single-mode light source, a broadband multimode light source, a high-power multimode diode laser, a high-power multimode fiber laser, a high-power tapered amplifier using a tunable single-mode diode laser as a seed light, a high-power fiber amplifier using a tunable single-mode diode laser as a seed light, and a high-power tunable CO2 or solid crystal laser. In fact, the light source 20 can be any light source 20 suitable for generating light to be propagated to the gas to be analyzed. In some other examples, the light source 20 may be other types of light sources 20, such as non-coherent light sources like LEDs or incandescent light bulbs.

[0059] In one embodiment, the light source 20 is a 10W, 761nm, 2nm FWHM (full width at half maximum) CW (continuous wave) multimode laser diode. Acquisition of approximately 400 elastic spectral bands is performed in the range of 760nm to 762nm. This enables the resolution of numerous O2 absorption lines. Although O2 absorption lines are mentioned, this is illustrative, and other absorption lines of other gas molecules or particles 90 can be resolved. For example, any absorption line of a gas or the light scattering properties of the particles 90 mentioned in this disclosure can be detected. The absorption lines provide information about the concentration, pressure, and temperature of the air. Generally, the O2 concentration in the atmosphere is 21%, but local depletion after metabolism (substitution) or combustion can produce O2 holes. A decrease in O2 corresponds to an increase in CO2 and H2O. Therefore, a decrease in O2 can provide information, for example, about the current amount of metabolism. Alternatively, by determining (measuring) the fuel consumption of an engine, it may provide a means for standardizing aerosol emissions or a means for evaluating engine quality. This technology enables indirect evaluation of CO2, pressure, and temperature profiling.

[0060] To ensure good gas sensitivity of the light source 20, the data processing device 10 is configured to provide one or more parameters of the light source 20. In some examples, the data processing device 10 is configured to provide fine control of the temperature, current, and voltage driving characteristics of the light source 20. Furthermore, the data processing device 10 is configured to provide interference prevention measures for the light source 20.

[0061] In some examples, the data processing unit 10 is optionally configured to provide temperature control of the light source 20, which is achieved by using a thermistor (not shown), such as a negative temperature coefficient (NTC) thermistor, and a thermoelectric cooler (TEC) in a feedback loop. High-precision thermistor sampling is well known and can be achieved by a biased scheme or an unbiased scheme, and can be sampled by an analog-to-digital converter. The temperature can then be easily obtained by linearizing the voltage.

[0062] However, controlling and driving a TEC is not easy, because a large current needs to be switched in a controlled manner in two directions: one for heating and one for cooling. This large current (~several amperes) and the required speed generally result in an H-bridge configuration, similar to that used to drive an electric motor. However, this approach has significant drawbacks in high-sensitivity optical systems such as those described in this disclosure, because the large current requires switching electronics that can easily induce unwanted noise caused by both the switching hardware itself and the large current.

[0063] Therefore, in some examples, the data processing unit 10 is configured to generate and control current by optionally using a buck regulator or buck converter (not shown). Such converters typically cannot reduce current and are not suitable for current-driven applications. However, in one example, one or more buck converters are used in a synchronous topology because they can both reduce and supply (or source) current. By using two such buck converters, each output voltage can be adjusted independently, thus achieving control over the direction of current flow. The advantage is the high frequency at which these devices inherently operate, which can be in the range of several MHz, making them inherently quiet from the perspective of equipment operating at low frequencies. This is a significant and important advantage for achieving good sensitivity. Furthermore, this example allows for a smaller footprint due to fewer required components, and in addition, its driving scheme can operate at a 100% duty cycle without the need for dead time insertion required in well-known H-bridge configurations, providing a more energy-efficient and noise-free solution.

[0064] In another example, the drive configuration of the light source 20 is handled on an optional basis. Current implementations often rely on manual or semi-automatic calibration and testing procedures performed by operators during manufacturing, which determine the relaxation of drive characteristics such as voltage, current, temperature, and optical interference characteristics. This is completely decoupled from the light source 20 itself, making it a cumbersome, time-consuming, costly, and error-prone process.

[0065] In this example, the memory device (not shown) is optionally incorporated into the light source itself. Such a memory device may be read-only memory, e.g., EEPROM, flash, F-RAM, or other types of persistent memory. Alternatively, such a memory device may be a read-write device with persistent memory properties. The memory device includes a model and calibration values ​​of the light source readable by the instrument to automate the instrument's testing and calibration processes. Such information may be important to the subject matter of optical gas detection described herein, where even slight deviations from optimal conditions can easily and significantly degrade the quality and performance of the instrument. In another example, the data processing device 10 may write data back to the memory device, in which case identified possible problems, such as those related to lifespan, aging, current, voltage, and temperature deviations, are logged to the light source 20, which can be used to improve processes, troubleshooting, and traceability.

[0066] In another example, mitigation of optical interference may be treated optionally. This can be very important for light sources 20 with long coherence lengths, i.e., narrow-bandwidth light sources 20 for gas and particle detection. In some examples, the data processing unit 10 is configured to provide a form of dithering used to average out laser speckle, which is a major source of optical noise in the instrument. Dithering is achieved by the motion of a lens close to the light source 20, the light source 20 itself, the motion of a diffusive element, or the entire light source 20 assembly itself. This can be achieved by a motor, piezoelectric crystal, liquid lens, or impulse device. Driving these devices often requires very high voltages in the range of ±100V. Because the voltage range is significantly different from other high-sensitivity hardware, noise immunity and configurability are very important to the design.

[0067] For example, if the load changes or deteriorates over time, hardware configuration (modification) is always necessary in principle. In some cases, a general-purpose integrated solution capable of driving loads regardless of their electrical characteristics, such as different capacitances, resistances, and inductances, is optionally provided. This is achieved by a buck-boost converter (not shown) that functions as a high-voltage amplifier, such a buck-boost converter used, for example, in haptic devices, providing automatic feedback and loops for different types of loads that may also change over time when different driving patterns are used. In some cases, this buck-boost converter driver is combined with a simple digital-to-analog converter that generates any waveform that the high-voltage buck-boost converter outputs to the dithering device, is load-independent, and is self-referential to ensure proper function and motion of the dithering device.

[0068] In some examples, the data processing unit 10 is configured to transmit a control signal 25 to the laser diode of the light source 20 in order to control the laser diode in TDLAS (Tunable Diode Laser Absorption Spectroscopy) and / or DIAL (Differential Absorption lidar) operating modes. Since both the TDLAS and DIAL operating modes are known, they will not be described further. In some examples, the control signal transmitted from the data processing unit 10 to the light source 20 may be one or more control signals configured to control temperature (double buck), dithering (high voltage amplifier), and / or light source drive current (embedded data storage), as described above.

[0069] Figures 9a and 9b show an example of the light source 20 in plan view and side view, respectively.

[0070] In Figure 2, the light source 20 is shown positioned on the side of the base 200. The position of the light source 200

[20] is fixed relative to the base 200 during operation. In some examples, the light source 20 is fixed to the base 200 or to an accessory fixed to the base 200, as shown in Figures 9a and 9b.

[0071] For example, in some cases, the base 200 may extend below the light source 20 so that the light source 20 can be fixed to an optional component mounting plate 204. As shown in Figure 9a, the base 200 of the photodetector 40 is coupled to a lateral rail assembly 900. The lateral rail assembly 900 is fixed to the base 200. The light source 20 is mounted on a movable light source carriage 902 on the lateral rail assembly 900. The light source carriage 902 is configured to be fixed to the lateral rail assembly 900 by a clamp (not shown) or other suitable releaseable fastener. The lateral rail assembly 900 includes a pair of rails 904, and the light source carriage 902 slides along the rails 904. The rails 904 allow movement in a direction along a fifth axis 190 that is at an angle to the propagation axis 30. In some examples, the fifth axis 190 is perpendicular to the propagation axis 30, but in some other examples, the fifth axis 190 can be angled at any suitable angle with respect to the propagation axis 30. The movement of the light source carriage 902 along the fifth axis 190 means that the propagation axis 30 can move relative to the photodetector 40. In some other examples, the light source carriage 902 also enables relative movement of the light source 20 and the propagation axis 30 with respect to the photodetector 40 along different axes and different directions. The light source carriage 902 optionally includes a pivot mount 908 that allows the light source 20 to pivot relative to the light source carriage 902 in a first pivot direction 906. This allows the propagation axis 30 to be tilted relative to the base 200. Additionally or alternatively, the pivot mount 908 allows the light source 20 to pivot relative to the light source carriage 902 in a second pivot direction 910. In this embodiment, the first rotation direction 906 and the second rotation direction 910 are orthogonal. The first rotation direction 906 is perpendicular to the plane of the light source carriage 902. The second rotation direction 910 is parallel to the plane of the light source carriage 902. In some other examples, the rotation mount 908 allows for other motion relative to the photodetector 40. In some other examples, additionally or alternatively, the photodetector 40 is configured to move relative to the light source 20.In other words, the light detection device 40 is configured to tilt, pivot (rotate), or spin relative to the light source 20 at will.

[0072] In some other examples, the light source carriage 902 and the lateral rail assembly 900 are not used. Instead, both the base 200 and the light source 20 are mounted to the same rigid object, such as a workbench.

[0073] In some examples, the light source 20 includes a plurality of individual light sources 20 arranged parallel to a fourth axis 180 perpendicular to the transmission axis 30. In some examples, additionally or alternatively, the light source 20 includes a plurality of individual light sources 20 arranged parallel to a fifth axis 190 perpendicular to the propagation axis 30. This means that multiple light beams can propagate along the propagation axis 30. The plurality of light sources 20 can be identical or different. This may mean that the light source 20 includes a higher output, or that, for example, multiple light sources 20 of different frequencies or multiple polarizations can be emitted simultaneously or in a time-multiplexed manner.

[0074] The photodetector 40 will now be described in more detail with reference to Figures 3 and 4. Figure 3 is a schematic diagram of the photodetector 40. Figure 4 is a plan view of the photodetector 40. The photodetector 40 includes a sensor assembly 120. The sensor assembly 120 is attached to the base 200 at the second end 208 of the base 200 via a component mounting plate 204.

[0075] The sensor assembly 120 is mounted to the component mounting plate 204 via a sensor carriage 400. The sensor carriage 400 is fixed relative to the base 200. In some other examples described below with reference to Figures 5a, 5b, and 6, the sensor carriage 400 may be movable relative to the base 200.

[0076] Returning to Figure 4, the sensor assembly 120 includes a sensor plate 212 (best shown in Figure 7a) that is aligned with or parallel to the first axis 150. The surface of the sensor plate 212 is aligned with the first axis 150.

[0077] The optical sensor 70 includes an optical sensor housing 210 slidably mounted along a sensor plate 212 of a sensor assembly 120 via at least one sensor rail 700, for example, a pair of sensor rails 700 (best shown in Figures 7a and 7b). The sensor plate 212 includes a sensor window 702. The sensor window 702 is elongated and extends in a direction parallel to the first axis 150. The sensor window is also configured to intersect with the second axis 160. This allows reflected scattered light to be received through the sensor window 702. The optical sensor 70 directs the sensor window 702 toward the lens device 50. The sensor window 702, as shown in Figure 4, is separate from the optical sensor 70. In some other examples, the sensor window 702 is integrated into the optical sensor housing 210. In some examples, the sensor window 702 may be a circular hole rather than an elongated slot, as shown in Figures 7a and 7b. In this case, the sensor window 702 is provided (formed) on an additional plate (not shown) attached to the light sensor housing 210. In this case, the sensor window 702 is fixed to the light sensor 70, and the sensor window 702 and the light sensor 70 move together along the first axis 150. In some examples, the sensor window 702 optionally includes an adjustable slit component (not shown). The adjustable slit component is configured to change the position, size, and / or orientation of the aperture between the light sensor 70 and the lens device 50. This means that the adjustable slit component can select the amount of scattered light received by the light sensor 70. In some examples, the adjustable slit component is integrated into the sensor window 702. Alternatively, the adjustable slit component is a separate element mounted in front of the light sensor 70 or the sensor window 702.

[0078] The adjustable slit component includes an adjustable aperture configured to allow adjustment of the slit width. In some examples, the slit width extends in a direction parallel to the first axis 150, and the (slit) height extends along a direction parallel to the fourth axis 180. Thus, the adjustable slit component can selectively adjust the slit width in the direction of the first axis 150. This means that the adjustable slit component is adjustable to provide the most relevant optical signal to the optical sensor 70. The adjustable slit component includes a slit actuator (not shown) configured to adjust the size of the slit. The slit actuator can be operatively coupled to any suitable mechanism for adjusting the slit width, such as two movable plates, an iris, etc.

[0079] The light sensor 70 is mounted on a pair of sensor rails 700 so that it is aligned with the sensor window 702. The light sensor 70 is configured to align with the sensor window 702 when it is moved relative to the sensor plate 212. The pair of sensor rails 700 ensure that the light sensor 70 moves parallel to the first axis 150.

[0080] As described above, the light sensor 70 is movable via the actuator assembly 110. In the first example, the light sensor 70 is movable relative to the base 200 along the first axis 150. The movement of the light sensor 70 is schematically shown in Figure 3 by arrow 300. The actuator assembly 110 includes a first actuator 130 operationally coupled to the light sensor housing 210, and the light sensor 70 moves relative to the sensor plate 212 when the first actuator 130 is actuated.

[0081] In some examples, the light sensor 70 and the light sensor housing 210 are mounted on a rod 704 having a helical thread, which is mounted in a screw hole 706 of the sensor plate 212. As the rod 704 rotates, the helical thread of the rod 704 moves in and out of the screw hole 706 of the sensor plate 212. This causes the light sensor 70 to move along the first axis 150 toward or away from the first intersection 61. This favorably maintains the shineproof condition 61. In some examples, the first actuator 130 is an electric motor (not shown) and includes a drive gear mounted on the drive shaft of the electric motor which is operably coupled to the helical thread. Thus, the rotation of the drive shaft of the electric motor moves the rod 704 and adjusts the position of the light sensor 70.

[0082] In some other examples, the first actuator 130 may be of a different type. For example, the first actuator 130 may be any other suitable linear actuator, such as a pneumatic linear actuator, a hydraulic linear actuator, a linear servo, a stepping motor, a piezo motor, or any other suitable linear drive mechanism.

[0083] The configurations shown in Figures 3 and 4 represent a device 100 in which the optical sensor 70 is capable of moving along only one degree of freedom, for example, along the first axis 150. In some other examples, the optical sensor 70 is capable of moving in multiple different directions in addition to being capable of moving along the first axis 150. Figures 5a and 5b show a schematic configuration of a device 100 in which the optical sensor 70 is capable of moving in two or more directions relative to the optical detection device 40.

[0084] Figure 5a shows that the optical sensor 70 is movable along the first axis 150 and also along or parallel to the second axis 160. The second axis 160 is the optical axis of the lens device 50. The configuration that provides the movement of the optical sensor 70 and the movement of the optical sensor 70 along the first axis 150 is the same as that described with reference to the preceding figures (multiple).

[0085] The motion of the optical sensor 70 along the second axis 160 is provided by moving the sensor carriage 400 in a direction parallel to the second axis 160. The sensor carriage 400 includes a protruding foot (not shown) that is slidable within a carriage slot 402. The carriage slot 402 restricts the relative motion of the protruding foot from the sensor carriage 400 in a direction along the second axis 160 or in a direction parallel to the second axis 160, as indicated by arrow 500. The sensor carriage 400 is operationally coupled to a second actuator 140. The second actuator 140 is configured to move the sensor carriage 400 toward the first end 206 of the base 200 or toward the second end 208 of the base 200. In some examples, the second actuator 140 is another linear actuator. In some examples, the second actuator 140 is identical to the first actuator 130. In some other examples, the second actuator 140 may be any other suitable linear actuator, such as a pneumatic linear actuator, a hydraulic linear actuator, a linear servo, a stepping motor, a piezo motor, or any other suitable linear actuation mechanism.

[0086] Since the light sensor 70 is configured to move along the first axis 150 and the second axis 160, the light sensor 70 can move both parallel and perpendicular to the second axis 160. This means that the light sensor 70 can move to cover most of the light detection device 40.

[0087] Figure 5b shows the same configuration as shown in Figure 5a, except that the light sensor 70 is configured to move in a different direction. In this example, the actuator assembly 110 includes a third actuator (not shown). The third actuator is configured to move the light sensor 70 along the third axis 170 or in a direction parallel to the third axis 170, indicated by arrow 502. The third axis 170 is an axis perpendicular to the second axis 160, for example, the optical axis of the lens device 50. In some examples, a secondary sensor carriage (not shown) is attached to the sensor carriage 400. The secondary sensor carriage is attached to the sensor carriage 400 via a plurality of rails extending in a direction parallel to the third axis 170. The secondary sensor carriage is slidable relative to the sensor carriage 400 in a direction parallel to the third axis 170. The third actuator is identical to the second actuator 140 and is attached to the sensor carriage 400.

[0088] Figure 6 shows the same configuration as shown in Figure 5b, except that the light sensor 70 is configured to move along a different direction. In this example, the actuator assembly 110 includes a fourth actuator (not shown). The fourth actuator is configured to move the light sensor 70 along a fourth axis 180 or in a direction parallel to the fourth axis 180, indicated by arrow 600. The fourth axis 180 is an axis perpendicular to the second axis 160, for example, the optical axis of the lens device 50, and the third axis 170. In other words, moving the light sensor 70 along the fourth axis 180 adjusts the height of the light sensor 70 above the base 200. In some examples, a sensor carriage 400 is included. The sensor plate 212 can be attached to the sensor carriage 400 via a scissor linkage, worm gear motor, stepping motor, or piezo motor and driven by the fourth actuator. These types of actuators, such as scissor linkages, worm gear motors, stepping motors, and piezo motors, can all be actively or passively locked into a predetermined position. The sensor plate 212 is movable relative to the sensor carriage 400 along a direction parallel to the fourth axis 180 in accordance with the extension and retraction of the scissor linkage. The fourth actuator is identical to the second actuator 140 and is mounted on the sensor carriage 400. Alternatively, any other suitable mechanism can be used to adjust the height of the optical sensor 70 above the base 200.

[0089] In some examples, the light sensor 70 includes at least one of a single pixel, a quadrant of pixels, an array of pixels, a pixel matrix, or a position-sensitive device (PSD) pixel. The light sensor 70 may have at least one column of pixels aligned parallel to the first axis 150. The light sensor 70 may include at least one row of pixels aligned parallel to the fourth axis 180.

[0090] In some examples, the light sensor 70 includes at least one of a photodiode, an avalanche photodiode, or a photomultiplier tube (PMT). The light sensor (70) may also include at least one of a transimpedance amplifier, a free silicon amplifier, and a dynode amplifier.

[0091] In some examples, the optical sensor 70 is configured to detect signals generated by at least one of wavelength modulation spectroscopy, direct absorption spectroscopy, and / or frequency modulation spectroscopy.

[0092] The operation of the device 100 will now be explained with reference to Figure 10. Figure 10 shows a flowchart illustrating an example of how the device 100 operates.

[0093] In one embodiment, the data processing device 10 is configured to operate the device 100. The data processing device 10 transmits a control signal to emit light along the transmission axis 30, as shown in step 1000.

[0094] The data processing device 10 is configured to position (arrange) the optical sensor 70 and / or the sensor window 702 and / or the sensor window 702 (as shown in Figures 7a and 7b, for example) at predetermined positions along a plane formed by the sensor axis(s). The device 100 directs (guides) the light scattered by the gas to the optical sensor 70, as shown in step 1002. In some examples, the optical sensor 70 includes a single movable pixel. In this case, better signal detection is possible by moving the sensor window 702 and / or the slit together with the optical sensor 70. Optionally, the slit width and sensor position(s) are adjusted to be individually optimized for a target volume in space, including distance.

[0095] In step 1012, the data processing device 10 is configured to image the volume of gas at a specific distance. In step 1012, the data processing device 10 is configured to process the sensor signal 75 so as to optionally determine (find) a signal S when the light source 20 is operating, and determine (find) a background signal B when the light source 20 is not operating.

[0096] In step 1012, the data processing device 10 is also configured to optionally normalize (or standardize) the signal S using the background signal B. In one embodiment, the background signal B is subtracted from the signal S.

[0097] In step 1012, the data processing device 10 is also configured to optionally apply appropriate thresholds and corrections for non-constant range dependency. The result of the normalization step is an intensity signal as a function of sensor position. This needs to be converted to an intensity signal as a function of distance. Therefore, this step includes converting the raw intensity signal as a function of sensor position to an intensity signal as a function of distance.

[0098] In step 1012, the data processing device 10 is also configured to process the intensity signal as a function of distance in order to determine the presence of gas absorption imprints by obtaining a baseline model available from a multimode setup that observes light resonating with and not resonating with the target gas, or by scanning with a single-mode laser. The data processing device 10 can also optionally detect and analyze particles 90.

[0099] In step 1012, the data processing device 10 is also configured to optionally correlate the result of the processing step of the intensity signal as a function of distance with a result previously determined for noise reduction and / or to provide time information relating to that result.

[0100] The data processing device 10 is further configured to repeat one or more of the above steps as necessary.

[0101] As described above, the data processing device 10 is configured to perform a number of processing steps in steps 1004, 1006, 1008, and 1010 to set up the device 100 in order to move the optical sensor 70 to the correct position, which will be explained in more detail below.

[0102] The data processing unit 10 is configured to send a control signal to the first actuator 130 to move the light sensor 70 along the first axis 150, as shown in step 1004 of Figure 10. In some examples, the data processing unit 10 receives a sensor signal 75 from the light sensor 70 as the first actuator 130 moves the light sensor 70 along the first axis 150. When the data processing unit 10 determines that the light sensor 70 is in the correct position along the first axis 150, it sends a control signal to the first actuator 130. The motion along the first axis 150 corresponds to the distance of the detected light scattered backward from the particle 90 toward the photodetector 40. In some examples, the data processing unit 10 sends a control signal to the first actuator 130 so that the light sensor 70 moves along the first axis 150. In other examples, the data processing unit 10 moves the first actuator 130 over the entire distance (or range) of motion along the first axis 150. The data processing device 10 then determines the intensity of the detection light signal scattered backward from the particle 90 as a function of distance. In this way, the data processing device 10 is configured to determine the distance of the particle 90 from the photodetector 40.

[0103] When the data processing device 10 moves the optical sensor 70 to the required position along the first axis 150, the data processing device 10 is further configured to image the volume of gas at a specific distance from the device 100, as shown in step 1012. If the data processing device 10 is configured to perform only the motion of the optical sensor 70 along the first axis 150, the data processing device 10 proceeds from step 1004 to step 1012, as indicated by the arrow connecting step 1004 and step 1012.

[0104] Additionally, or alternatively, the data processing device 10 is configured to move the optical sensor 70 along the second axis 160, the third axis 170, and / or the fourth axis 180. In this case, the data processing device 10 proceeds from step 1004 to step 1006, step 1008, and step 1010. Furthermore, the data processing device 10 can skip from any of steps 1006, 1008, or 1010 to step 1012 without performing any of the other steps 1006, 1008, or 1010.

[0105] In some alternative examples, the data processing unit 10 is configured to continuously scan the optical sensor 70 to acquire all distances sequentially by moving the optical sensor 70 along the first axis 150. In some examples, the data processing unit 10 is configured to adjust the slit width of an adjustable slit component to improve the spatial resolution of the volume under test at a particular distance.

[0106] In some examples, in steps 1002, 1004, 1006, 1008, or 1010, the data processing unit 10 optionally sends a control signal to the slit actuator to fully open the slit. This results in a high signal and poor spatial resolution, but the data processing unit 10 can perform a coarse scan along the first axis 150. Next, the data processing unit 10 determines that the signals received in a narrow range are the target. In this way, the data processing unit 10 is configured to "lock on" to a specific range (or distance) of target. The data processing unit 10 may use one or more parameters of the received optical signal, such as intensity, distance of particle 90, etc., to select the specific range of target. Next, the data processing unit 10 sends a control signal to the slit actuator to narrow the slit width. By narrowing the slit width, the data processing unit 10 is configured to improve distance resolution while simultaneously increasing the data acquisition time.

[0107] Optionally, the data processing device 10 is configured to transmit a control signal to the second actuator 140 to move the optical sensor 70 along the second axis 160. Optionally, the data processing device 10 is configured to transmit a control signal to the third actuator to move the optical sensor 70 along the second axis 160. Optionally, the data processing device 10 is configured to transmit a control signal to the fourth actuator to move the optical sensor 70 along the fourth axis 180. The data processing device 10 is configured to control the motion of the second actuator 140, the third actuator, and the fourth actuator in the same manner as described for the first actuator 130.

[0108] This disclosure has been described above primarily with reference to several embodiments. However, as will be readily apparent to those skilled in the art, embodiments other than those disclosed above are equally possible within the scope and spirit of this disclosure, and this disclosure is defined and limited only by the appended claims.

[0109] In another example, two or more examples are combined. Features of one example can be combined with features of other examples.

[0110] The embodiments described herein have been explained with particular reference to the illustrated embodiments. However, it is clear that modifications and alterations may be made to the embodiments described within the scope of this disclosure.

Claims

1. A device for detecting the properties of a gas, The aforementioned device (100) A light source (20) configured to emit light along at least one propagation axis (30), A light detection device (40), however, the light detection device (40) is A light sensor (70) configured to output a sensor signal (75), and A lens device (50) including a lens surface (60) and configured to direct light emitted from the light source (20) and scattered by the gas toward the light sensor (70). including, Including, The first axis (150), the propagation axis (30), and the lens surface (60) intersect in such a way that the Scheimpflug condition (61) is achieved. The aforementioned device (100) A base (200), wherein the lens device (50) is attached to the base (200), and the light sensor (70) is movable relative to the base (200), and An actuator assembly (110) is configured to move the light sensor (70) toward or away from the intersection of the propagation axis (30) and the lens surface (60) in a direction at least parallel to the first axis (150), while maintaining the shineproof condition. Including, The actuator assembly (110) is further configured to move the light sensor (70) in a direction parallel to the second axis (160) corresponding to the optical axis of the lens device (50). A device characterized by the following.

2. In the apparatus according to claim 1, The actuator assembly (110) is further configured to move the light sensor (70) in a direction parallel to the third axis (170) which is perpendicular to the second axis (160), and in a plane defined by the first axis (150) and the second axis (160). A device characterized by the following.

3. In the apparatus according to claim 1, The actuator assembly (110) is configured to move the light sensor (70) in a direction parallel to the fourth axis (180) which is normal to the plane defined by the first axis (150) and the second axis (160). A device characterized by the following.

4. In the apparatus according to claim 1, The light sensor (70) is disposed in the sensor assembly (120). A device characterized by the following.

5. In the apparatus according to claim 4, The light sensor (70) is movable relative to the sensor assembly (120), and the actuator assembly (110) includes a first actuator (130) configured to move the light sensor (70). A device characterized by the following.

6. In the apparatus according to claim 4, The sensor assembly (120) is movable relative to the housing of the device (100), and the actuator assembly (110) includes a second actuator (140) configured to move the sensor assembly (120). A device characterized by the following.

7. In the apparatus according to claim 6, The sensor assembly (120) is movable along the rail (700) relative to the housing of the device (100). A device characterized by the following.

8. In the apparatus according to any one of claims 1 to 7, The light sensor (70) includes at least one of a single pixel, a quadrant of a pixel, an array of pixels, a pixel matrix, a position-sensitive device (PSD) pixel. A device characterized by the following.

9. In the apparatus according to any one of claims 1 to 7, The light sensor (70) includes at least one column of pixels aligned parallel to the first axis (150). A device characterized by the following.

10. In the apparatus described in claim 3, The light sensor (70) includes at least one row of pixels aligned parallel to the fourth axis (180). A device characterized by the following.

11. In the apparatus according to any one of claims 1 to 7, The light sensor (70) includes at least one of a photodiode, an avalanche photodiode, a photomultiplier tube (PMT), and a CMOS sensor. A device characterized by the following.

12. In the apparatus according to any one of claims 1 to 7, The light sensor (70) includes at least one of a transimpedance amplifier, a free silicon amplifier, a current amplifier, and a dynode amplifier. A device characterized by the following.

13. In the apparatus according to any one of claims 1 to 7, The light sensor (70) is configured to detect a signal generated by at least one of wavelength-modulated spectroscopy, direct absorption spectroscopy, and / or frequency-modulated spectroscopy. A device characterized by the following.

14. In the apparatus according to any one of claims 1 to 7, The light source (20) is a tunable laser diode. A device characterized by the following.

15. In the apparatus according to claim 14, The light source (20) is controlled by the TDLAS method. A device characterized by the following.

16. In the apparatus according to claim 14, The light source (20) is controlled by a DIAL method. A device characterized by the following.

17. In the apparatus described in claim 3, The light source (20) includes an array of individual light sources arranged parallel to a fifth axis (190) perpendicular to the propagation axis (30) or parallel to the fourth axis (180). A device characterized by the following.

18. In the apparatus according to any one of claims 1 to 7, The aforementioned light sensor (70) includes a single sensor pixel. A device characterized by the following.

19. In the apparatus according to any one of claims 1 to 7, The apparatus (100) includes a sensor window (702) positioned between the light sensor (70) and the lens device (50). A device characterized by the following.

20. In the apparatus according to claim 19, The sensor window (702) includes a slit having a width that is adjustable in the direction along the first axis (150). A device characterized by the following.

21. A method for detecting the properties of a gas, The aforementioned method, To emit light along at least one propagation axis (30), The light scattered by the gas is directed towards the light sensor (70) using a lens device (50) having a lens surface (60) and mounted on a base (200). Including, The first axis (150), the propagation axis (30), and the lens surface (60) intersect in such a way that the Scheimpflug condition (61) is met. The aforementioned method, While maintaining the shine-proof conditions, the optical sensor (70) is moved to a position corresponding to the first axis (150) relative to the base (200) toward or away from the intersection of the propagation axis (30) and the lens surface (60), and further, the optical sensor (70) is moved in a direction parallel to the second axis (160) corresponding to the optical axis of the lens device (50) to image the volume of gas at a specific distance from the device (100). Including, A method characterized by the following.

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