Light emitting device and method thereof, gas analysis system and method thereof

Abstract

An optical emission device and a method thereof, a gas analysis system and a method thereof, the optical emission device comprising: a light comb light source configured to generate an initial light signal; an encoding module configured to encode the initial light signal based on a preset comb encoding to form a to-be-processed light signal; and a modulation module configured to perform quantum noise compression on the to-be-processed light signal to form an outgoing light signal. The technical scheme belongs to the field of precision measurement, and through the synergistic architecture of "compressed optical comb + computational encoding", the optical comb spectrum technology is improved in multiple dimensions such as sensitivity, environmental adaptability, speed and system complexity.

Description

Technical Field

[0001] This invention relates to the field of precision measurement, and in particular to a light emitting device and method thereof, and a gas analysis system and method thereof. Background Technology

[0002] Optical frequency comb (OFC) spectral measurement technology, based on mode-locked laser technology, couples ultrashort time-domain pulses with equally spaced longitudinal modes in the frequency domain to form a phase-stable broadband coherent light source, providing a "frequency scale" for precision measurements. Its background stems from the need to simplify absolute frequency chains at the end of the last century, gradually replacing complex nonlinear links and becoming a bridge connecting microwaves and optical frequencies. It has propelled spectroscopy from scanning to parallel processing, achieving high resolution, wide bandwidth, and instantaneous capture, providing new tools for cold atom detection, deep space navigation, greenhouse gas remote sensing, and biological imaging. OFC spectroscopy exhibits significant comprehensive advantages in key indicators such as spectral coverage, spectral resolution, measurement speed, and detection sensitivity, providing a new technological path for applications such as simultaneous greenhouse gas detection, trace pollutant source monitoring, and real-time early warning of industrial leaks.

[0003] On the other hand, precision gas measurement plays an irreplaceable and fundamental role in fields such as environmental monitoring, industrial process control, energy security, biomedical diagnostics, and atmospheric science research. With the increasing urgency of addressing global climate change and the ever-increasing demands for refined management of industrial production processes, higher and higher requirements are being placed on the measurement accuracy, real-time performance, multi-component parallel detection capabilities, and long-term stability of parameters such as gas component concentration, temperature, and pressure.

[0004] While optical comb spectroscopy has the advantages of wide bandwidth and high resolution, it is limited by shot noise. The signal-to-noise ratio deteriorates rapidly as the power decreases, making it difficult to achieve rapid trace detection under low light conditions. Summary of the Invention

[0005] The problem addressed by this invention is how to improve the signal-to-noise ratio at low power in optical comb spectroscopy.

[0006] To address the above problems, the present invention provides a light emitting device, comprising: An optical comb light source is configured to generate an initial optical signal; an encoding module is configured to encode the initial optical signal based on a preset comb code to form an optical signal to be processed; and a modulation module is configured to perform quantum noise compression on the optical signal to be processed to form an outgoing optical signal.

[0007] Accordingly, the present invention provides a gas analysis system, comprising: A light emitting device, wherein the light emitting device is the light emitting device of the present invention; a receiving device, wherein the receiving device is configured to form a result electrical signal based on the light response generated after the target gas absorbs the emitted light signal; and an analysis device, wherein the analysis device is configured to analyze the target gas based on the comb coding and the result electrical signal.

[0008] Furthermore, the present invention also provides a light emission method, comprising: An initial optical signal is generated, which has an optical comb structure; the initial optical signal is encoded based on a preset comb code to form an optical signal to be processed; the optical signal to be processed is subjected to quantum noise compression to form an outgoing optical signal.

[0009] Accordingly, the present invention also provides a gas analysis method, comprising: The emitted light signal is emitted using the light emission method of this invention; a result electrical signal is formed based on the light response generated by the target gas after absorbing the emitted light signal; and the target gas is analyzed based on the comb-tooth encoding and the result electrical signal.

[0010] Compared with the prior art, the technical solution of the present invention has the following advantages: In this invention, based on a preset comb code, an optical signal to be processed is formed according to the initial optical signal. The optical signal to be processed is then subjected to quantum noise compression to form an output optical signal. The output optical signal is obtained by quantum noise compression of the optical signal to be processed. The output optical signal is in a compressed state, possessing a macroscopically average coherent amplitude and a compressed optical field with compressed orthogonal components of the target measurement. This is a chip-based, plug-and-play optical comb spectral architecture that does not require heterodyne phase-locked loops. By replacing power enhancement with quantum noise suppression, the resulting output optical signal still has a high signal-to-noise ratio at low power. This is a chip-based, low-temperature-required, plug-and-play light source paradigm and a high signal-to-noise ratio optical comb light source.

[0011] Correspondingly, in the gas analysis system and method, a result electrical signal is formed based on the photoresponse generated after the target gas absorbs the emitted light signal; the target gas is analyzed based on the comb-tooth encoding and the result electrical signal. Since the emitted light signal is in a compressed state where the shot noise of the target measurement orthogonal component is suppressed, the emitted light signal is already a noise-suppressed light signal with a high signal-to-noise ratio, especially at low power. The use of the emitted light signal eliminates the need for external cavity amplification to suppress shot noise. Analyzing the target gas using an emitted light signal with low shot noise allows for the formation of a result electrical signal with a high signal-to-noise ratio without increasing the emitted light power, introducing cryogenic devices, or relying on a target end reflector. This effectively improves the signal-to-noise ratio of the analysis results, particularly in low-power analysis, and is beneficial for rapid trace gas detection under weak light conditions.

[0012] In an optional embodiment of the present invention, the optical signal to be processed is subjected to amplitude quantum noise compression to form an emitted optical signal. The emitted optical signal is in an amplitude-compressed state, which has a macroscopically average coherent amplitude, and the noise of the amplitude orthogonal component is lower than the shot noise limit of the coherent state. Since the quantum noise of the emitted optical signal on the amplitude orthogonal component is lower than the shot noise limit of the coherent state, the shot noise contribution of the corresponding measurement channel can be reduced in the detection and analysis based on light intensity or photoacoustic response, which can effectively improve the signal-to-noise ratio of the detection and analysis results, especially the signal-to-noise ratio at low power.

[0013] In an optional embodiment of this invention, the initial optical signal is dispersed to form multiple comb-tooth optical signals. Based on a preset comb-tooth encoding, the transmission direction of the selected comb-tooth optical signal is changed to form the optical signal to be processed. By forming multiple comb-tooth optical signals through dispersion and selecting the comb-tooth optical signal by changing the transmission direction, it does not rely on phase preservation. Even if the phase information is destroyed during the process of the target gas absorbing the emitted optical signal and generating an optical response, stable reconstruction can still be achieved. The system has strong environmental adaptability, and the reconstruction result is stable and reliable.

[0014] In an optional embodiment of the present invention, the initial optical signal is dispersed in a preset direction using a grating and a virtual imaging phase array to form multiple comb-tooth optical signals. Both the grating and the virtual imaging phase array are solid-state devices with no moving parts, resulting in high optical path stability and precision, which helps to reduce the overall size, weight, and power consumption of the system.

[0015] In an optional embodiment of the present invention, multiple initial optical signals are encoded one by one based on comb coding in a preset coding sequence to form a light sequence to be processed; quantum noise compression is performed on each of the multiple light signals to be processed in the light sequence to form an emitted light sequence; a photoresponse sequence generated by the target gas absorbing the emitted light sequence is received to form a result electrical sequence; and the target gas is analyzed based on the coding sequence and the result electrical sequence. By setting comb coding in the coding sequence, the comb energy in the emitted light signal is utilized multiple times, improving utilization efficiency; for multiple independent measurements with approximately consistent noise statistics, after averaging or reconstruction processing, random noise can be reduced by approximately The regularity decreases, and the signal-to-noise ratio can be adjusted according to approximately The regularity of the signal is improved; at the same time, the comb coding enables the single-point detection signal to carry absorption information of different comb combinations, which is beneficial to improving the stability of absorption spectrum reconstruction.

[0016] In an optional embodiment of the present invention, the absorption spectrum of the target gas is obtained by analyzing the resulting electrical signal using a compressed sensing algorithm. Since the emitted light signal is in a compressed state, it possesses an extremely high initial signal-to-noise ratio, and the resulting electrical signal naturally also has a high signal-to-noise ratio. The compressed sensing algorithm can obtain high reconstruction results with fewer samples, effectively improving reconstruction speed and facilitating high-precision trace gas monitoring.

[0017] In the optional embodiment of this invention, the comb-tooth encoding is 0 / 1 intensity encoding, and the receiving device includes a single-point detector. The encoding module modulates the total light intensity of the initial optical signal based on the 0 / 1 intensity encoding method; the single-point detector of the receiving device only needs to record the electrical signal intensity of the result electrical signal, without relying on phase preservation. Even if the phase information is destroyed during the process of the target gas absorbing the emitted light signal and generating a light response, stable reconstruction can still be achieved. The system has strong environmental adaptability, and the reconstruction result is stable and reliable. Moreover, only a single-point detector is needed to achieve optical signal reception, eliminating the need for a high-pixel camera. When using a photoacoustic detector or a room-temperature photodetector including quartz tuning forks and piezoelectric ceramic elements, the use of cryogenic cooling equipment can be avoided, thus eliminating the need for cryogenic cooling equipment and effectively reducing the overall system size, weight, and power consumption. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a gas analysis system and its light emitting device that are consistent with some embodiments of the present invention.

[0019] Figure 2 This is a schematic diagram of the spectrum of the initial optical signal in an optical emitting device consistent with some embodiments of the present invention.

[0020] Figure 3This is a schematic diagram of the spectrum of the four comb codes and the optical signals to be processed corresponding to the four comb codes in an optical emitting device consistent with some embodiments of the present invention.

[0021] Figure 4 This is a schematic diagram in phase space of a first pre-formed optical signal, a second pre-formed optical signal, and the emitted optical signals in the amplitude-compressed state and the amplitude-inverse-compressed state formed in an optical emitting device consistent with some embodiments of the present invention.

[0022] Figure 5 This is a schematic diagram illustrating the absorption spectroscopy principle of the target gas in a gas analysis system consistent with some embodiments of the present invention.

[0023] Figure 6 This is a functional block diagram of the analysis device in a gas analysis system consistent with some embodiments of the present invention.

[0024] Figure 7 This is a schematic flowchart of a light emission method consistent with some embodiments of the present invention.

[0025] Figure 8 This is a flowchart illustrating the steps in an optical emission method consistent with some embodiments of the present invention, which encodes an initial optical signal based on a preset comb code to form an optical signal to be processed.

[0026] Figure 9 This is a schematic flowchart illustrating the step of quantum noise compression of the optical signal to be processed to form an emitted optical signal in an optical emission method consistent with some embodiments of the present invention.

[0027] Figure 10 This is a schematic flowchart of a gas analysis method consistent with some embodiments of the present invention. Detailed Implementation

[0028] As can be seen from the background technology, although optical comb spectroscopy has the advantages of wide bandwidth and high resolution, it is limited by shot noise. The signal-to-noise ratio deteriorates rapidly as the power decreases, making it difficult to achieve rapid trace detection under low light conditions.

[0029] In current precision gas measurements using optical comb spectroscopy, electro-optic modulated optical combs (EOM combs) are commonly used for detection. EOM combs are a stable, flexible, and programmable novel light source. They rely on milliwatt-level average power to suppress shot noise. However, in open optical paths without cooperating mirrors, with highly scattering media, or over long distances, the return power drops drastically to the femtowatt level, making it impossible for single-pixel detectors to provide a usable signal-to-noise ratio. Furthermore, in EOM combs, heterodyne dual-comb schemes fail due to phase information loss from scattering, hindering the realization of the advantages of wide-spectrum, high-resolution, and fast gas sensing.

[0030] It is evident that traditional electro-optic modulation optical combs suffer from problems such as weak echo and phase disorder.

[0031] Furthermore, optical comb spectroscopy faces other bottlenecks. At the system level, detection systems often require femtosecond lasers, low-noise microwave sources, and ultra-stable cavities, resulting in large, power-intensive, and vibration-resistant systems that are difficult to deploy outside the laboratory. At the environmental level, detection systems are often highly sensitive to environmental conditions; long-term phase drift necessitates frequent self-reference locking, increasing maintenance complexity. At the application level, while broadband brightness is high, single-frequency power is low, leading to low signal-to-noise ratios for target gases with weak absorption or strong scattering; parallel detection relies on high-pixel imaging devices, easily introducing trade-offs between electronic noise and bandwidth.

[0032] Furthermore, the lack of interface standards between optical comb spectroscopy technology and existing industrial equipment, along with the absence of unified data formats, calibration algorithms, and security protocols, hinders its integration with medical, environmental, and online production line monitoring applications. Theoretically, the carrier envelope phase dynamics and the noise generation mechanism of supercontinuum remain unclear, limiting the potential for improved accuracy. In short, optical comb spectroscopy is transitioning from a "scientific device" to a "general-purpose instrument," and size, stability, cost, interface, and standardization are key issues that urgently need to be addressed.

[0033] To address the technical problem, this invention provides an optical emission device and method that replaces traditional power requirements with quantum correlation noise. The aim is to provide a novel optical comb spectral architecture that is chip-based, plug-and-play, and does not require heterodyne phase-locked loops, so that the obtained emitted optical signal still maintains a high signal-to-noise ratio at low power.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] refer to Figure 1 The diagram shows a schematic representation of a light emitting device consistent with some embodiments of the present invention.

[0036] The light emitting device includes: The optical comb light source 110 is configured to generate an initial optical signal; the encoding module 120 is configured to encode the initial optical signal based on a preset comb code to form an optical signal to be processed; and the modulation module 130 is configured to perform quantum noise compression on the optical signal to be processed to form an outgoing optical signal.

[0037] The technical solution of the optical emitting device of the present invention will be described in detail below with reference to the accompanying drawings.

[0038] An optical comb light source serves as the light source to generate an initial light signal.

[0039] Specifically, an optical comb light source, also known as an optical frequency comb light source, is a light source capable of generating a series of optical frequency components with strictly equal frequency intervals and coherent phases across the optical spectrum. The spectral shape of the optical signal generated by an optical comb light source resembles a comb with equal spacing, hence the name "optical frequency comb." Moreover, optical comb light sources combine the high spectral resolution of traditional continuous lasers with the wide spectral coverage of broadband lasers, earning them the reputation of "optical rulers."

[0040] The initial optical signal generated by the optical comb light source has an optical comb structure, that is, the frequency domain of the initial optical signal contains multiple discrete and equally spaced comb teeth, and its spectrum is composed of a series of equally spaced coherent frequency comb teeth.

[0041] In some embodiments of the present invention, the optical comb light source is a single-comb light source. Specifically, the optical comb light source outputs only a single optical comb, and the initial optical signal is from a single optical comb, excluding a second optical comb. For example... Figure 1 In some embodiments shown, the optical comb light source 110 is a single-comb light source, and the initial optical signal is a single optical comb (e.g., Figure 2 (As shown). For example, the optical comb source 110 is a 1 GHz femtosecond coherent optical comb source, and the initial optical signal is a 1 GHz femtosecond coherent optical comb.

[0042] It should be noted that in some embodiments, the initial optical signal is a pulse signal. Specifically, the initial optical signal includes at least one optical pulse. For example... Figure 1 In some embodiments shown, the initial optical signal is a light pulse train, that is, one initial optical signal includes multiple light pulses.

[0043] It should also be noted that, Figure 2 In the spectrum diagram of the initial optical signal shown, the horizontal axis represents frequency and the vertical axis represents light intensity.

[0044] Among them, a 1GHz femtosecond coherent optical comb refers to an optical comb with a frequency interval of 1GHz, a time-domain pulse width on the order of femtoseconds (fs), and a strictly locked phase relationship between each comb tooth. It can be seen that the initial optical signal is an extremely precise and highly coherent "optical ruler" in both the time and frequency domains.

[0045] It should be noted that, Figure 2 The diagram illustrates the frequency distribution of the initial optical signal generated by the optical comb light source in some embodiments of the present invention, where the horizontal axis represents frequency and the vertical axis represents light intensity.

[0046] The encoding module is used to encode the initial optical signal according to the comb coding to form the optical signal to be processed.

[0047] Specifically, the encoding module receives the initial optical signal generated by the optical comb light source, and selects the corresponding comb teeth from the initial optical signal according to the comb tooth encoding to encode the initial optical signal and form the optical signal to be processed. The optical signal to be processed only includes the comb teeth selected by the encoding module and does not include the unselected comb teeth.

[0048] It should be noted that, as Figure 1 In some of the embodiments shown, the initial optical signal is an optical pulse train, and the optical signal to be processed is also an optical pulse train. In the pulse train of the optical signal to be processed, multiple pulses have the same comb code.

[0049] In some embodiments of the present invention, the encoding module includes: a dispersion unit configured to disperse an initial optical signal to form multiple comb-tooth optical signals; and a selection unit configured to select at least one from the multiple comb-tooth optical signals to form an optical signal to be processed based on a preset comb-tooth code. The dispersion unit disperses the initial optical signal so that different comb teeth in the optical comb of the initial optical signal are separated according to frequency, forming different comb-tooth optical signals respectively, providing a basis for subsequent comb-tooth selection; the selection unit selects the corresponding comb-tooth optical signal from the separated comb-tooth optical signals according to the comb-tooth code to form the optical signal to be processed.

[0050] By separating the comb teeth through dispersion for selection, the phase relationship between the optical signals of different comb teeth is not affected. In the optical signal to be processed after encoding, the optical signals of different comb teeth still maintain high coherence, which provides a good foundation for the formation of the subsequently compressed output optical signal.

[0051] like Figure 1 In some embodiments shown, the encoding module 120 includes a dispersion unit 121 and a selection unit 122. The dispersion unit 121 and the selection unit 122 are arranged along the optical path. The initial light signal generated by the optical comb light source 110 is collimated and expanded by the first collimator 192 and the second lens 193 before being incident on the dispersion unit 121; the dispersion unit 121 disperses the initial light signal, and the dispersed initial light signal is then incident on the selection unit 122. The second lens 193 includes at least one lens.

[0052] In some embodiments, the dispersion unit includes a dispersion element configured to disperse the initial optical signal in a preset direction to form multiple comb-tooth optical signals, wherein the preset direction is perpendicular to the incident direction of the initial optical signal. The dispersion element in the dispersion unit spatially separates different comb teeth in the initial optical signal, forming different comb-tooth optical signals respectively, without affecting the phase relationship between the different comb-tooth optical signals; the different comb-tooth optical signals still maintain high coherence.

[0053] In some embodiments, the preset direction includes at least one of an intersecting first direction and a second direction, both of which are perpendicular to the optical axis. The dispersive element in the dispersive unit can disperse the initial optical signal in a single direction or in two intersecting directions, so that the different comb teeth in the initial optical signal are separated in a one-dimensional or two-dimensional direction.

[0054] like Figure 1 In some embodiments shown, the dispersive element in the dispersive unit 121 disperses the initial optical signal in a first direction and a second direction to form multiple comb-tooth optical signals. For example, the first direction and the second direction are perpendicular to each other. Dispersing the different comb-tooth optical signals in the initial optical signal within a two-dimensional plane perpendicular to the optical axis enables higher comb-tooth resolution in a smaller space, effectively increases the number of comb-tooth optical signals, effectively improves the parallel processing capability of the encoding module, provides a good foundation for the selection of subsequent comb-tooth optical signals, and improves the accuracy and speed of comb-tooth selection.

[0055] like Figure 1 As shown, the dispersion unit 121 includes a first dispersion element 121a and a second dispersion element 121b arranged sequentially along the optical path. The first dispersion element 121a is configured to disperse the initial optical signal in a first direction; the second dispersion element 121b is configured to disperse the initial optical signal in a second direction.

[0056] like Figure 1 As shown, the first dispersive element 121a and the second dispersive element 121b successively disperse the received initial light along the first direction and the second direction, forming a plurality of comb-tooth light signals arranged sequentially along the first direction and the second direction to be incident on the selection unit 122.

[0057] In some embodiments, the dispersive element includes at least one of a grating and a virtual imaging phase array. For example... Figure 1 In some embodiments shown, one of the first dispersive element 121a and the second dispersive element 121b is a grating, and the other is a virtually imaged phased array (VIPA). For example, the first dispersive element 121a is a grating, and the second dispersive element 121b is a virtual imaged phased array. By cascading the grating and the virtual imaged phased array, high-resolution two-dimensional beam splitting over a wide spectral range can be achieved. Furthermore, both the grating and the virtual imaged phased array are solid-state devices with no moving parts, resulting in high optical path stability and accuracy. This significantly reduces system size, weight, and power consumption—by more than half—and allows for direct integration into UAVs or satellite platforms. Moreover, the optical path design with the grating in front and the virtual imaged phased array behind provides both high-precision beam splitting and highly flexible configuration options.

[0058] In some embodiments of the present invention, the comb-tooth encoding is 0 / 1 intensity encoding. 0 / 1 intensity encoding refers to encoding using binary intensity modulation. Specifically, the comb-tooth encoding is binary encoding, where 0 represents no signal intensity (e.g., no light) and 1 represents signal intensity (e.g., light). The encoding module modulates the light intensity of the initial optical signal according to the 0 / 1 intensity encoding, thereby forming the optical signal to be processed.

[0059] Specifically, the number of bits in the comb code corresponds one-to-one with the multiple comb optical signals divided by the dispersion unit. The value of one bit in the comb code indicates whether the corresponding comb optical signal is selected to form the optical signal to be processed. For example, when one bit in the comb code is "1", the corresponding comb optical signal is selected, and when one bit in the comb code is "0", the corresponding comb optical signal is not selected.

[0060] Example, Figure 3 The diagram shows the frequency distribution of the optical signal to be processed after selecting the comb optical signal based on the comb coding of 111111, 101011, 111001, and 101101 in some embodiments.

[0061] In some embodiments, the number of bits with a value of "1" in the comb-tooth encoding is multiple, so that the resulting optical signal to be processed includes multiple comb-tooth optical signals, and the resulting emitted optical signal has optical signals of multiple frequencies, thereby providing a good foundation for further improvement of the signal-to-noise ratio. When the resulting emitted optical signal is used for gas analysis, having optical signals of multiple frequencies in the generated emitted optical signal can further improve the signal-to-noise ratio of the obtained results.

[0062] It should be noted that, Figure 3 In the frequency distribution diagram of each optical signal to be processed, the horizontal axis represents frequency and the vertical axis represents light intensity.

[0063] In some embodiments, the selection unit is configured to change the transmission direction of the selected comb-tooth optical signal based on a preset comb-tooth code to form the optical signal to be processed. Based on the comb-tooth code, the selection unit actively deflects the selected comb-tooth optical signal towards a fixed direction, causing the unselected comb-tooth optical signal to deviate from this direction. This separates the selected and unselected comb-tooth optical signals in the propagation direction, and the comb-tooth optical signals deflected towards the fixed direction couple to form the optical signal to be processed. By changing the transmission direction of the comb-tooth optical signals to separate the selected and unselected signals, crosstalk of the unselected comb-tooth optical signals can be effectively suppressed.

[0064] like Figure 1In some embodiments shown, the selection unit 122 receives multiple comb-tooth optical signals formed by the dispersion unit 121, and actively causes the selected comb-tooth optical signal to be folded back along the original optical path and the unselected comb-tooth optical signal to deviate from the original optical path according to the comb-tooth encoding. The comb-tooth optical signals folded back along the original optical path are coupled to form the optical signal to be processed.

[0065] For example, selection unit 122 includes a Digital Micromirror Device (DMD). Specifically, the DMD adjusts the tilt of the mirror surface at the corresponding position based on comb coding to reflect comb-tooth light signals in the corresponding direction. The DMD switches independently according to the comb coding to achieve 0 / 1 modulation of the two-dimensional information of "photon number-frequency". The DMD has a high switching frequency. Setting a DMD with a high switching frequency in selection unit 122 can effectively improve analysis efficiency and speed. When the light emitting device is applied to a gas analysis system, it can effectively improve the spectral reconstruction speed. In some embodiments of the present invention, the light emitting device further includes a generation control module, which is configured to generate an encoding sequence, the encoding sequence including multiple comb codes; the generation control module is also configured to control the encoding module to encode multiple initial light signals one by one based on the comb codes in the encoding sequence to form a light sequence to be processed, the light sequence to be processed including multiple light signals to be processed, and the multiple light signals to be processed in the light sequence to be processed correspond one-to-one with the multiple comb codes in the encoding sequence.

[0066] like Figure 1 In some embodiments shown, the generation control module 160 generates an encoding sequence; the generation control module 160 is also connected to the selection unit 122 in the encoding module 120, and provides the encoding sequence to the selection unit 122 in the encoding module 120; the selection unit 122 receives the encoding sequence and encodes multiple initial optical signals one by one according to the comb coding in the encoding sequence to form an optical sequence to be processed.

[0067] It should be noted that in some embodiments, the generation control module is also configured to control the optical comb light source to generate an initial light sequence, which includes multiple initial light signals, and the number of initial light signals in the initial light sequence is the same as the number of comb codes in the coding sequence.

[0068] like Figure 1 In some embodiments shown, the generation control module 160 is also connected to the optical comb light source 110 (not shown in the figure). The generation control module 160 controls the optical comb light source 110 to generate an initial optical signal to form an initial optical sequence based on the number of comb teeth codes in the generated coding sequence.

[0069] It should be noted that in some embodiments of the present invention, the generation control module 160 controls the optical comb light source 110 to generate an initial optical signal according to the number of comb codes in the generated encoding sequence; in other embodiments of the present invention, the generation control module may also control the optical comb light source to generate an initial optical signal after generating a comb code to provide to the encoding module, so that the encoding module encodes the generated initial optical signal with the provided comb code, thereby realizing the sequential encoding of multiple initial optical signals.

[0070] like Figure 1 In some embodiments shown, the generation control module 160 controls the optical comb light source 110 to generate multiple initial optical signals sequentially to form an initial optical sequence based on the number of comb codes in the generated encoding sequence. The generation control module is also configured to control the encoding module to encode the multiple initial optical signals in the initial optical sequence one by one based on the comb codes in the encoding sequence to form a light sequence to be processed. It can be seen that both the light sequence to be processed and the initial optical sequence are time series.

[0071] It should be noted that in some embodiments of the present invention, the comb-tooth optical signal is incident perpendicularly to the selection unit. Injecting the comb-tooth optical signal perpendicularly to the selection unit effectively reduces the adjustment difficulty of the digital micromirror device, and is beneficial for improving encoding speed and encoding accuracy.

[0072] like Figure 1 In some embodiments shown, a first lens 124 is provided in the optical path between the dispersive unit 121 and the selection unit 122. The first lens 124 includes at least one lens. The first lens 124 focuses multiple comb-tooth light signals formed by the dispersive unit 121 so that the multiple comb-tooth light signals are perpendicularly incident on the selection unit 122.

[0073] It should also be noted that the multiple comb-like optical signals generated by the dispersive unit present a two-dimensional spectrum in the plane perpendicular to the optical axis. For example... Figure 1 In some embodiments shown, the light emitting device further includes: a beam splitter 194 located in the optical path between the dispersion unit 121 and the selection unit 122, the beam splitter 194 separating an imaging light signal from the plurality of comb-shaped light signals formed by the dispersion unit 121; and an imaging unit 195 located in the optical path of the imaging light signal. The arrangement of the beam splitter 194 and the imaging unit 195 enables real-time monitoring of the beam splitting results of the dispersion unit. For example, the imaging unit 195 may include a camera.

[0074] like Figure 1 In some embodiments shown, the selection unit 122 actively causes the selected comb tooth optical signal to be folded back along the original optical path to form the optical signal to be processed according to the comb tooth encoding; according to the principle of optical path reversibility, the optical signal to be processed will be transmitted along the original optical path and transmitted to the direction of the optical comb light source 110 via the dispersion unit 121.

[0075] like Figure 1 In some embodiments shown, the optical comb light source 110 is a 1 GHz femtosecond coherent optical comb light source, and the interval between the generated optical pulses is 1 nanosecond; the switching frequency of the digital micromirror device in the selection unit 122 is typically in the range of kHz to MHz; within one switching cycle of the digital micromirror device, the optical comb light source 110 generates one initial optical signal, which is a pulse train, and one initial optical signal includes multiple optical pulses; within one switching cycle, the digital micromirror device in the selection unit of the encoding module encodes multiple optical pulses of one initial optical signal according to the same comb tooth code, thereby forming the optical signal to be processed, which is also an optical pulse train, and multiple pulses in the pulse train of the optical signal to be processed have the same comb tooth code.

[0076] like Figure 1 As shown, in some embodiments of the present invention, the light emitting device further includes a circulator 191, which is configured to separate the optical path of the initial optical signal and the optical path of the optical signal to be processed. Specifically, the first port of the circulator 191 is connected to the output of the optical comb light source 110 to receive the initial optical signal; the second port of the circulator 191 is connected to the input of the encoding module 120, and the circulator 191 transmits the received initial optical signal to the encoding module 120. The circulator 191 also receives the optical signal to be processed generated by the encoding module 120 and transmits the received optical signal to be processed to the third port of the circulator 191 for output.

[0077] For example, such as Figure 1 As shown, the circulator 191 is located in the optical path between the first collimator 192 and the optical comb light source 110, and the second port of the circulator 191 is connected to the input terminal of the first collimator 192. The optical signal to be processed generated by the encoding module 120 is transmitted to the second port of the circulator 191 through the second lens 193 and the first collimator 192.

[0078] The modulation module is used to perform quantum noise compression on the optical signal to be processed to form the output optical signal.

[0079] Specifically, the modulation module receives the optical signal to be processed and performs quantum noise compression on it, thereby forming a compressed output optical signal. Quantum noise compression of the optical signal to be processed refers to reducing the quantum noise of a specific orthogonal component (e.g., amplitude or phase orthogonal component) of the optical signal to be processed, making it (e.g., amplitude orthogonal component) below the vacuum noise level, while allowing the noise of another orthogonal component (e.g., phase orthogonal component) to increase accordingly.

[0080] For example, the modulation module can perform amplitude quantum noise compression on the optical signal to be processed, thereby forming an amplitude-compressed state. Amplitude quantum noise compression refers to making the noise of the amplitude quadrature components of the optical signal lower than the shot noise limit. The quantum noise fluctuations of the amplitude quadrature components of the amplitude-compressed optical signal are lower than the lowest noise limit achievable in classical optical fields, i.e., lower than the shot noise limit (SNL).

[0081] The shot noise of the emitted optical signal generated by the modulation module is reduced. The compressed emitted optical signal is already an optical signal in which the noise of a certain orthogonal component is suppressed, and it has a high signal-to-noise ratio at low power. Therefore, the use of emitted optical signals with high signal-to-noise ratio can effectively suppress the noise of the corresponding orthogonal component in subsequent signals and effectively improve the signal-to-noise ratio of the corresponding orthogonal component at low power.

[0082] like Figure 1 As shown, in some embodiments of the present invention, the optical path of the initial optical signal and the optical path of the optical signal to be processed are separated by the circulator 191; the third port of the circulator 191 is connected to the input terminal of the modulation module 130, and the circulator 191 transmits the received optical signal to be processed to the modulation module 130.

[0083] For example, such as Figure 1 As shown, a second collimator 196 and a third lens 197 are also provided between the circulator 191 and the modulation module 130. The optical signal to be processed output from the third port of the circulator 191 is collimated and converged by the second collimator 196 and the third lens 197 before being incident on the modulation module 130.

[0084] In some embodiments of the present invention, the modulation module performs quantum noise compression on the optical signal to be processed based on the optical Kerr effect, and the modulation module includes a Kerr medium. The optical Kerr effect is a third-order nonlinear optical phenomenon, in which the refractive index of the medium changes linearly with the light intensity. During the passage of the optical signal through the Kerr medium, the amplitude fluctuations of the optical signal modulate the refractive index of the medium in real time, thereby producing a phase change in the phase of the optical field of the optical signal that is proportional to the instantaneous intensity, i.e., realizing self-phase modulation (SPM).

[0085] The optical Kerr effect is a third-order nonlinear optical effect that does not require strict phase matching conditions and can be realized simply by using a Kerr medium. It is easy to integrate with fiber optic systems or photonic chips, which is beneficial for achieving system miniaturization and low cost. Moreover, the self-phase modulation response time of the optical Kerr effect is extremely short, which is beneficial for the realization of broadband compression, pulse or high-speed optical information modulation.

[0086] Specifically, in the modulation module, a Kerr medium is introduced in one optical path, and phase modulation is performed in the other optical path. Quantum noise compression is achieved through the combined effect of the optical Kerr effect in one path and phase modulation in the other.

[0087] In some embodiments of the present invention, the modulation module has a nonlinear Mach-Zehnder interferometer (NMZI) structure. A Kerr medium is introduced into one arm of the Mach-Zehnder interferometer structure, and phase modulation is performed in the other arm to achieve quantum noise compression. Specifically, the modulation module includes: a beam splitting unit configured to split the optical signal to be processed into a first beam splitting signal and a second beam splitting signal; a first modulation unit including a Kerr medium configured to perform self-phase modulation on the first beam splitting signal to form a first pre-formed optical signal; a second modulation unit configured to phase-shift the second beam splitting signal to form a second pre-formed optical signal, wherein the second pre-formed optical signal and the first pre-formed optical signal have a preset phase difference; and a coupling unit configured to couple the first pre-formed optical signal and the second pre-formed optical signal to form an output optical signal.

[0088] The beam-splitting unit splits the optical signal to be processed into a first beam-splitting signal and a second beam-splitting signal to form the two arms of a Mach-Zehnder interferometer structure. Specifically, the beam-splitting unit may include a partial mirror.

[0089] In some embodiments, the beam splitting unit is an unbalanced beam splitting unit with a splitting ratio of N:1, where N≥1. The light intensities of the first and second beam split signals separated by the beam splitting unit are not equal. Specifically, the light intensity of the first beam split signal is greater than that of the second beam split signal.

[0090] For example, the beam splitting unit includes: a beam splitter.

[0091] The first modulation unit has a Kerr medium to enable self-phase modulation of the first optical signal, establishing a quantum correlation between amplitude fluctuations and phase, and providing a physical basis for quantum noise compression of the optical signal.

[0092] Specifically, the first split optical signal undergoes self-phase modulation in the Kerr medium of the first modulation unit to form a first pre-fabricated optical signal; such as Figure 4 As shown in the green crescent-shaped KERR, the first pre-fabricated optical signal is in a Kerr state.

[0093] In some embodiments, the Kerr medium includes: highly nonlinear optical fiber (e.g., dispersion-flattened optical fiber, photonic crystal fiber), integrated optical waveguide (e.g., silicon nitride thin film waveguide, lithium niobate thin film waveguide), bulk crystal (e.g., lithium niobate crystal, lithium tantalate crystal, gallium arsenide crystal), and glass (e.g., chalcogenide glass, heavy flint glass).

[0094] like Figure 1 In some of the embodiments shown, the first modulation unit 133 includes a polarization-maintaining high nonlinear fiber. High nonlinear fibers have a high nonlinear coefficient and strong nonlinear effects, enabling them to generate greater self-phase modulation with lower light intensity and shorter length, effectively reducing power consumption and improving efficiency.

[0095] The second modulation unit is used to cause a phase shift in the second beam splitting signal, thereby introducing a preset phase difference in the two arms of the Mach-Zehnder interferometer, providing a basis for the preparation of the compressed state.

[0096] Specifically, the second split signal undergoes a phase shift in the second modulation unit to form a second pre-fabricated optical signal; such as Figure 4 As shown in the red circle COH, the second pre-fabricated optical signal is in a coherent state (COH).

[0097] In some embodiments, the second modulation unit includes a phase shifter or a delay fiber. For example... Figure 1 In some of the embodiments shown, the second modulation unit 132 includes a phase shifter.

[0098] It should be noted that the second modulation unit introduces a preset phase difference between the two arms of the Mach-Zehnder interferometer, so that the degree of phase shift in the second beam splitting signal is determined based on the state of the outgoing light signal formed by the modulation module. For example, if the formed outgoing light signal is in an amplitude-compressed state, the second modulation unit introduces a 90° phase difference; if the formed outgoing light signal is in an amplitude-inversely compressed state (i.e., a phase-compressed state), the second modulation unit introduces a 270° phase difference.

[0099] The coupling unit is used to combine and couple the first pre-formed optical signal and the second pre-formed optical signal to form a compressed output optical signal.

[0100] Specifically, such as Figure 4 As shown, the first pre-fabricated optical signal is in a Kerr state, and the second pre-fabricated optical signal is in a coherent state. The combined coupling of the first and second pre-fabricated optical signals completes the movement of the quantum state in phase space, thereby realizing the preparation of an amplitude-squeezed state (SQZ) or an amplitude-anti-squeezed state (ANTI-SQZ). Figure 4 The yellow crescent-shaped SQZ shows an emitted light signal in an amplitude-compressed state, while the blue crescent-shaped ANTI-SQZ shows an emitted light signal in an amplitude-inversely compressed state. For example, the coupling unit includes a beam splitter.

[0101] It should be noted that, Figure 4 The schematic diagram of the emitted light signal in phase space shown indicates that the horizontal axis... and vertical axis These represent the two orthogonal quantum components of a single-mode optical field, also known as orthogonal operators for the Bosonic field. Similar to position and momentum in mechanics, they are two complementary directions describing quantum fluctuations in the optical field. If annihilation operators are used... and generating operators To represent a light field, it is often written as:

[0102] in, Typically, these correspond to orthogonal amplitude components, which are related to fluctuations in the light field amplitude, light intensity, or photon number. These typically correspond to orthogonal phase components and are related to optical field phase fluctuations. Since neither can be simultaneously and arbitrarily precisely determined, noise decreasing in one direction usually leads to increased noise in the other.

[0103] In a phase space diagram, the center of an optical field state represents its average complex amplitude, and the surrounding circular, elliptical, or meniscus regions represent the quantum noise distribution. The noise distribution of ordinary coherent states is approximately circular, such as... Figure 4 The red circular COH symbol indicates... and The noise in each direction is equal and both are within the shot noise limit. After the Kerr nonlinear effect, the noise distribution is sheared into a meniscus Kerr state, as shown below. Figure 4 The green crescent-shaped KERR is shown. Then, through weakly coherent coupling after phase shift, the phase space distribution is displaced. When the low-noise direction is aligned... When the axis is in a compressed state, it exhibits amplitude compression, such as Figure 4 The yellow crescent shape SQZ is shown in the middle; when When directional noise is amplified, it manifests as an amplitude-inverse compression state, such as... Figure 4 The blue crescent-shaped ANTI-SQZ is shown in the image.

[0104] like Figure 1In some embodiments shown, the beam splitting unit 131 receives the optical signal to be processed collimated and converged by the second collimator 196 and the third lens 197, and splits the optical signal to be processed into a first beam splitting signal and a second beam splitting signal. The first beam splitting signal is reflected by the first reflector 198 to the first modulation unit 133, which performs quantum noise compression on the received first beam splitting signal to form a first pre-formed optical signal that is incident on the coupling unit 134. The second beam splitting signal is incident on the second modulation unit 132, which performs phase shift on the received second beam splitting signal to form a second pre-formed optical signal with a preset phase difference from the first pre-formed optical signal. The second pre-formed optical signal is reflected by the second reflector 199 to the coupling unit 134. The coupling unit 134 couples the received first and second pre-formed optical signals to form a compressed outgoing optical signal.

[0105] In some embodiments of the present invention, the optical emitting device further includes a generation control module for generating an encoded sequence; the generation control module controls the encoding module to encode multiple initial optical signals one by one based on the comb coding in the encoded sequence to form a light sequence to be processed; the modulation module performs quantum noise compression on the multiple light signals to be processed in the light sequence to be processed to form an outgoing light sequence, the outgoing light sequence including multiple outgoing light signals, the multiple outgoing light signals of the outgoing light sequence corresponding one-to-one with the multiple light signals to be processed in the light sequence to be processed.

[0106] Accordingly, the present invention also provides a gas analysis system.

[0107] refer to Figure 1 The diagram shows a structural schematic of a gas analysis system consistent with some embodiments of the present invention.

[0108] The gas analysis system includes: The light emitting device is the light emitting device of the present invention; the receiving device 140 is configured to form a result electrical signal based on the light response generated after the target gas absorbs the emitted light signal; the analysis device 150 is configured to analyze the target gas based on the comb code and the result electrical signal.

[0109] Specifically, the light emitting device is the light emitting device of this invention. The specific technical solution for the light emitting device can be found in the foregoing. Figures 1 to 4 As shown.

[0110] Because the emitted light signal is in a compressed state where the shot noise of the target measurement quadrature component is suppressed, the emitted light signal is already a noise-suppressed light signal of the target measurement quadrature component. The signal-to-noise ratio (SNR) of the target measurement quadrature component of the emitted light signal is high, especially at low power. Therefore, the signal-to-noise ratio (SNR) of the resulting electrical signal formed by the photoresponse generated by the absorption of the emitted light signal by the target gas is also high, correspondingly exhibiting a high SNR at low power. The formation of the high SNR resulting electrical signal can effectively improve the SNR of the measurement result, effectively improving the SNR of low-power measurement results. The emitted light signal is incident on the target gas and propagates within the target gas; such as... Figure 5 As shown, during the transmission of the emitted light signal through the target gas, a portion of a specific frequency in the emitted light signal is absorbed by the molecules of the target gas, thereby generating a light response corresponding to that specific frequency. The generated light response carries the absorption information of the gas molecules.

[0111] like Figure 1 In some embodiments shown, the target gas is stored in the gas cavity 141. The emitted light signal generated by the modulation module 130 in the light emitting device is reflected to the gas cavity by the third reflector 188; the emitted light signal is incident into the gas cavity 141, and the target gas in the gas cavity 141 absorbs the emitted light signal and generates a corresponding light response.

[0112] In some embodiments of the present invention, the modulation module of the optical emitting device is configured to perform amplitude quantum noise compression on the optical signal to be processed to form an emitted optical signal. The emitted optical signal formed by the amplitude quantum noise compression of the optical signal to be processed by the modulation module is in an amplitude compressed state, with a macroscopic average coherent amplitude, and the noise of the amplitude orthogonal component is lower than the shot noise limit of the coherent state. The noise of the amplitude of the emitted optical signal is reduced, and the amplitude orthogonal component of the emitted optical signal has a high signal-to-noise ratio, especially at low power. The receiving module only needs to record the light intensity of the echo light signal formed after the target gas absorbs the emitted optical signal, or according to the photoacoustic response generated after the target gas absorbs the emitted optical signal, that is, only needs to record the light response generated after the target gas absorbs the emitted optical signal, to generate the corresponding result electrical signal. There is no need to rely on phase preservation. Even if the phase information is destroyed during the process of the target gas absorbing the emitted optical signal to generate the light response, stable reconstruction can still be achieved. The system has strong environmental adaptability and the reconstruction result is stable and reliable.

[0113] The gas analysis system also includes a receiving device. The receiving device receives the optical response generated by the target gas after absorbing the emitted light signal, and generates a result electrical signal based on the optical response.

[0114] The emitted light signal is already a noise-suppressed light signal. The signal-to-noise ratio of the resulting electrical signal formed by the photoresponse generated after the target gas absorbs the emitted light signal is also relatively high, exhibiting a high signal-to-noise ratio even at low power. The formation of the high signal-to-noise ratio resulting electrical signal can effectively improve the signal-to-noise ratio of the measurement results, effectively improve the signal-to-noise ratio of low-power measurement results, and is beneficial for rapid trace gas detection under weak light conditions.

[0115] In some embodiments of the present invention, the modulation module performs bright amplitude quantum noise compression on the optical signal to be processed, forming an emitted optical signal with a bright compressed state; the receiving device forms the result electrical signal based on the intensity of the echo optical signal formed after the target gas absorbs the emitted optical signal, or based on the photoacoustic response generated after the target gas absorbs the emitted optical signal. The emitted optical signal with a bright compressed state has high optical power, and the receiving device can directly receive the optical response alone to form the result electrical signal, without interference amplification or a local oscillator signal, to obtain the result electrical signal related to the optical response generated after the target gas absorbs the emitted optical signal; the receiving device does not need to set up complex devices such as phase locking and mode matching related to the local oscillator signal, the receiving device has a simple structure, high stability, and strong anti-interference performance.

[0116] like Figure 1 In some embodiments shown, the receiving device 140 is located inside the gas cavity 141. The receiving device 140 receives the photoacoustic response generated after the target gas absorbs the emitted light signal, and forms a result electrical signal based on the received photoacoustic response.

[0117] In some embodiments of the present invention, the encoding module encodes the initial optical signal based on comb coding with 0 / 1 intensity coding; the receiving device includes a single-point detector. A single-point detector is a detector that, unlike an array detector, only measures on a single spatial coordinate corresponding to the detector package. The encoding module in the optical emitting device encodes the initial optical signal based on 0 / 1 intensity encoding, realizing 0 / 1 modulation of the two-dimensional information of "photon number-frequency". The single-point detector in the receiving device only needs to record the total intensity change after modulation to generate the corresponding result electrical signal. It does not rely on phase preservation. Even if the phase information is destroyed during the process of the target gas absorbing the emitted light signal and generating a light response, stable reconstruction can still be achieved. The system has strong environmental adaptability and the reconstruction results are stable and reliable. Moreover, only a single-point detector is needed to realize the optical signal reception. There is no need for a high-pixel camera, which can effectively reduce the overall size, weight and power consumption of the system. It can obtain spectral accuracy comparable to that in the laboratory under extreme conditions of scattering medium, no target, and single photon flux, thus breaking through the inherent limitations of traditional optical comb gas trace monitoring schemes that "must have high power, must have cooperative reflection, and must have coherent reception".

[0118] In some embodiments, the single-point detector includes a photoacoustic detector. For example... Figure 1 In some embodiments shown, the photoacoustic detector includes a quartz tuning fork and a piezoelectric ceramic element. The photoacoustic detector operates based on the photoacoustic effect of matter. It offers advantages such as high sensitivity and a wide spectral range, which are beneficial for achieving and improving the accuracy of trace gas detection. Furthermore, the use of photoacoustic detectors eliminates the need for cryogenic refrigeration equipment. Specifically, the target gas absorbs the emitted light signal and generates periodic thermal release and acoustic response; this periodic thermal release and acoustic response cause the quartz tuning fork to vibrate; the piezoelectric ceramic element generates a resulting electrical signal based on the vibration of the quartz tuning fork.

[0119] In some embodiments of the present invention, the optical emitting device includes: a generation control module for generating an encoded sequence; an encoding module for encoding multiple initial optical signals one by one based on the comb coding in the encoded sequence to form a light sequence to be processed; a modulation module for quantum noise compression of multiple light signals to be processed in the light sequence to be processed to form an emitted light sequence; and a receiving device for receiving a light response sequence generated by the absorption of the emitted light sequence by a target gas to form a result electrical sequence, wherein the light response sequence includes multiple light responses, and the result electrical sequence includes multiple result electrical signals, wherein the multiple light responses of the light response sequence correspond one-to-one with the multiple emitted light signals of the emitted light sequence, and the multiple result electrical signals of the result electrical sequence correspond one-to-one with the multiple light responses of the light response sequence.

[0120] The analysis device is used to analyze the target gas by processing the electrical signal based on the comb-tooth encoding result.

[0121] Specifically, the analysis device is connected to the receiving device to receive the generated electrical signal; the analysis device is also connected to the encoding module of the optical emitting device to obtain a comb code; based on the comb code, the analysis device analyzes the resulting electrical signal to detect the target gas. For example, the analysis device analyzes the resulting electrical signal based on the comb code to obtain the absorption spectrum of the target gas, and analyzes the target gas according to the absorption spectrum.

[0122] The emitted light signal is in a compressed state, and its quantum noise has been suppressed in advance, resulting in a high signal-to-noise ratio (SNR), especially at low power. The resulting electrical signal generated by the light response after the emitted light signal is transmitted through the target gas also has a high SNR, even at low power. The analytical results obtained by the analytical device based on the high SNR result electrical signal are of high quality and have a high SNR, even at low power.

[0123] Moreover, the signal-to-noise ratio of the electrical signal received by the analysis device is high. Compared with the electro-optic modulation optical comb scheme, the signal-to-noise ratio is improved by about twice, which can obtain a smaller reconstruction error with the same number of samples, or shorten the sampling time with the same error.

[0124] In some embodiments of the present invention, the generation control module of the optical emitting device generates an encoded sequence; the encoding module encodes multiple initial optical signals one by one based on the comb coding in the encoded sequence to form a light sequence to be processed; the modulation module performs quantum noise compression on multiple light signals to be processed in the light sequence to be processed to form an emitted light sequence; the receiving device receives the light response sequence generated by the target gas absorbing the emitted light sequence to form a result electrical sequence; the analysis device analyzes the target gas according to the encoded sequence and the result electrical sequence. Based on the setting of the encoded sequence, the comb energy in the emitted light signal is utilized multiple times, improving the utilization efficiency; for N independent measurements with approximately consistent noise statistics, after coherent superposition or reconstruction processing, the signal can be accumulated by N times, and the random noise is usually accumulated by approximately The signal-to-noise ratio can be increased by approximately [number] times. The amplitude can be increased by a factor of 1; if averaging is used, the amplitude of random noise can be reduced by approximately 1 / The signal-to-noise ratio is reduced; it is evident that the method of gas analysis based on multiple comb-tooth encoding can improve the signal-to-noise ratio. This increases the signal-to-noise ratio by several times, thereby further improving the gas analysis results.

[0125] like Figure 1 In some of the embodiments shown, the analysis device 150 is connected to both the generation control module 160 and the receiving device 140 of the light emitting device, and receives the encoded sequence from the generation control module 160 and the result electrical sequence from the receiving device 140, respectively; the analysis device analyzes the result electrical sequence according to the encoded sequence to achieve the detection of the target gas.

[0126] It should be noted that, as Figure 1 In some of the embodiments shown, the analysis device 150 and the generation control module 160 may be integrated into the same electronic device 101. For example, the electronic device 101 may be a computer.

[0127] In some embodiments of the present invention, the analysis device includes a reconstruction module configured to analyze the resulting electrical signal based on comb coding to obtain the absorption spectrum of the target gas. The reconstruction module is used to invert the absorption spectrum of the target gas. Specifically, the reconstruction module is connected to both a receiving device and an encoding module to obtain the resulting electrical signal and comb coding, respectively; the reconstruction module also inverts the absorption spectrum of the target gas based on the resulting electrical signal and comb coding.

[0128] like Figure 6In some embodiments shown, the reconstruction module 251 of the analysis device 250 is connected to the generation control module 260 and receives the comb code from the generation control module 260; the reconstruction module 251 is also connected to the receiving device 240 and receives the result electrical signal from the receiving device 240; the reconstruction module 251 reconstructs the absorption spectrum of the target gas based on the comb code and the result electrical signal.

[0129] In some embodiments, the reconstruction module is based on comb coding and uses a compressed sensing algorithm to analyze the resulting electrical signal to obtain the absorption spectrum of the target gas. Compressed sensing (CS) is a signal processing technique that utilizes signal sparsity for undersampling reconstruction. The use of CS can reconstruct the complete absorption spectrum with fewer samples, effectively shortening the spectral acquisition time. Furthermore, the emitted light signal has a high initial signal-to-noise ratio, and the resulting electrical signal naturally has a high signal-to-noise ratio. The compressed sensing algorithm can further compress the number of samples, significantly improving the spectral reconstruction speed.

[0130] like Figure 6 In some of the embodiments shown, the signal-to-noise ratio of the result electrical signal received by the analysis device 250 is high. The high initial signal-to-noise ratio provided by the compressed state formed by quantum noise compression by the reconstruction module 251 can compress the number of samples to 2.5% of the Nyquist limit under the premise that the gas absorption spectrum is sparsity. Combined with the high-speed switching of the digital micromirror device, the switching frequency is as high as 10kHz, and the output speed of the 256-mode absorption spectrum is greatly improved. Compared with the point-by-point scanning scheme or the dual-comb interferometry scheme, the output speed of the absorption spectrum is increased by an order of magnitude.

[0131] In some embodiments, the analysis apparatus further includes a qualitative analysis module configured to determine the composition of the target gas based on the absorption spectrum of the target gas.

[0132] Absorption spectroscopy is obtained by the attenuation of light intensity caused by the absorption of a specific frequency portion of the emitted light signal by molecules in the target gas during transmission. Absorption spectroscopy can qualitatively identify the types of molecules in the target gas, thereby qualitatively analyzing the composition of the target gas. Moreover, the emitted light signal has a high initial signal-to-noise ratio, and the resulting electrical signal naturally has a high signal-to-noise ratio. The absorption spectrum of the target gas obtained by reconstructing the result electrical signal has a high signal-to-noise ratio, which can effectively ensure the accuracy of qualitative analysis of the target gas and realize the detection of trace components in the target gas.

[0133] Specifically, the analytical device stores a standard gas spectral database; the qualitative analysis module compares the absorption spectrum of the target gas with the data in the standard gas spectral database to qualitatively analyze the composition of the target gas.

[0134] In some embodiments, the analytical apparatus further includes a quantitative analysis module configured to determine the concentration of each component in the target gas based on the absorption spectrum of the target gas. The absorption spectrum, combined with the quantitative relationship between gas absorbance, concentration, and optical path length, can also be used to calculate the concentration of each component in the target gas, thus performing quantitative analysis of the target gas's components.

[0135] Specifically, the quantitative analysis module uses data from a standard spectral database to calculate the concentration of each component in the target gas based on the absorption spectrum of the target gas.

[0136] like Figure 6 In some embodiments shown, the analysis device 250 further includes a qualitative analysis module 252 and a quantitative analysis module 253; both the qualitative analysis module 252 and the quantitative analysis module 253 are connected to the reconstruction module 251 to receive the absorption spectrum of the target gas; the qualitative analysis module 252 and the quantitative analysis module 253 perform qualitative and quantitative analysis on the target gas respectively based on the absorption spectrum of the target gas.

[0137] It should be noted that the gas standard spectral database refers to a collection that stores standard absorption spectral data of known gas molecules and their related parameters, which is used as a benchmark reference for qualitative identification and quantitative inversion.

[0138] It should be noted that in the foregoing embodiments, the receiving device generates the resulting electrical signal based on the photoacoustic response generated after the target gas absorbs the emitted light signal; the receiving device includes a photoacoustic detector; the photoacoustic detector includes a quartz tuning fork and a piezoelectric ceramic element. In other embodiments of the present invention, the receiving device may also receive the light response to generate the resulting electrical signal using a detector based on other principles.

[0139] In some embodiments of the present invention, the receiving device generates the resulting electrical signal based on the intensity of the echo light signal formed after the target gas absorbs the emitted light signal; that is, the receiving device generates the resulting electrical signal based on the photoelectric response generated after the target gas absorbs the emitted light signal. The receiving device includes a photodetector; the photodetector includes a single-photon detector. A photodetector is a detector that operates based on the photoelectric effect of matter. Photodetectors have advantages such as fast response speed, simple structure, miniaturization, and high integration.

[0140] In some embodiments, shot noise in the emitted light signal is suppressed, and quantum noise of the amplitude orthogonal components can be suppressed by about 3 dB, reducing noise power by about half. In some exemplary embodiments, using such a high signal-to-noise ratio emitted light signal to analyze the target gas results in an echo light signal with a correspondingly extremely high signal-to-noise ratio at low power, enabling the single-photon detector in the receiving device to operate at 46 fW (approximately 10⁻⁶ fW).-3 Even with a photon / pulse-limiting echo signal, an absorption spectrum with a residual of less than 1% can still be reconstructed; in other embodiments, it is even possible to enable the single-photon detector in the receiving device to operate at a lower 5.3 fW (approximately 1.5 × 10⁻⁶). -4 The reconstruction of molecular absorption spectra from 530 nm to 1540 nm was achieved under the limiting echo light signal of photons / pulses, which reduced the optical power requirement by three orders of magnitude compared with the existing "EOM + camera" scheme.

[0141] In some embodiments of the present invention, the generation control module of the light emitting device generates an encoding sequence; the encoding module encodes multiple initial light signals one by one based on the comb coding in the encoding sequence to form a light sequence to be processed; the modulation module performs quantum noise compression on multiple light signals to be processed in the light sequence to be processed to form an outgoing light sequence; the target gas absorbs multiple outgoing light signals in the outgoing light sequence and generates an echo light sequence, the echo light sequence including multiple echo light signals, the multiple echo light signals of the echo light sequence corresponding one-to-one with the multiple outgoing light signals of the outgoing light sequence; the receiving device forms a result electrical sequence based on the photoelectric response of the multiple echo light signals in the echo light sequence; the analysis device analyzes the target gas based on the encoding sequence and the result electrical sequence.

[0142] It should be noted that, as Figure 1 In some of the embodiments shown, an oscilloscope 189 is also connected between the electronic device 101 and the receiving device 140 to display the resulting electrical signal generated by the receiving device 140.

[0143] In addition, the present invention also provides a method for emitting light.

[0144] refer to Figure 7 The diagram shows a schematic flowchart of a light emission method consistent with some embodiments of the present invention.

[0145] Light emission methods include: Step S110: Generate an initial optical signal, which has an optical comb structure; Step S120: Encode the initial optical signal based on a preset comb code to form an optical signal to be processed; Step S130: Compress the optical signal to be processed using quantum noise to form an outgoing optical signal.

[0146] The technical solution of the optical emission method of the present invention will be described in detail below with reference to the accompanying drawings.

[0147] First, step S110 is executed to generate an initial optical signal, which has an optical comb structure.

[0148] Specifically, the initial optical signal having an optical comb structure means that the initial optical signal contains multiple discrete and equally spaced comb teeth in the frequency domain, and its spectrum is composed of a series of equally spaced coherent frequency comb teeth.

[0149] Reference Figure 1 In some embodiments of the present invention, step S110, the step of generating an initial optical signal, includes: generating an initial optical signal through an optical comb light source.

[0150] In some embodiments of the present invention, step S110, the step of generating the initial optical signal, includes: generating the initial optical signal of a single optical comb. (Referring to the reference...) Figure 1 The initial optical signal is a single optical comb (such as...) Figure 2 (As shown). For example, the initial optical signal is a 1 GHz femtosecond coherent optical comb.

[0151] It should be noted that in some embodiments, the initial optical signal is a pulse signal. Specifically, the initial optical signal includes at least one optical pulse. For example... Figure 1 In some embodiments shown, the initial optical signal is a light pulse train, that is, one initial optical signal includes multiple light pulses.

[0152] It should also be noted that, Figure 2 In the spectrum diagram of the initial optical signal shown, the horizontal axis represents frequency and the vertical axis represents light intensity.

[0153] Among them, a 1GHz femtosecond coherent optical comb refers to an optical comb with a frequency interval of 1GHz, a time-domain pulse width on the order of femtoseconds (fs), and a strictly locked phase relationship between each comb tooth. It can be seen that the initial optical signal is an extremely precise and highly coherent "optical ruler" in both the time and frequency domains.

[0154] It should be noted that, Figure 2 The diagram illustrates the frequency distribution of the initial optical signal in some embodiments of the present invention, where the horizontal axis represents frequency and the vertical axis represents light intensity.

[0155] Continue to refer to Figure 7 The optical emission method further includes: performing step S120, encoding the initial optical signal based on a preset comb code to form an optical signal to be processed.

[0156] The step of encoding the initial optical signal based on the preset comb code to form the optical signal to be processed is used to encode the initial optical signal according to the comb code to form the optical signal to be processed.

[0157] Specifically, in the step of encoding the initial optical signal based on the preset comb code to form the optical signal to be processed, the corresponding comb is selected from the initial optical signal according to the comb code to encode the initial optical signal and form the optical signal to be processed. The optical signal to be processed only includes the comb selected by the encoding module and does not include the unselected comb.

[0158] It should be noted that, as Figure 1In some of the embodiments shown, the initial optical signal is an optical pulse train, and the optical signal to be processed is also an optical pulse train. In the pulse train of the optical signal to be processed, multiple pulses have the same comb code.

[0159] like Figure 8 As shown, in some embodiments of the present invention, step S120, encoding the initial optical signal based on a preset comb code to form an optical signal to be processed, includes: step S121, dispersing the initial optical signal to form multiple comb optical signals; step S122, selecting at least one from the multiple comb optical signals to form the optical signal to be processed based on the preset comb code. Dispersing the initial optical signal separates the different comb teeth in the optical comb according to frequency, forming different comb optical signals, providing a basis for subsequent comb selection; selecting the corresponding comb optical signal from the separated comb optical signals to form the optical signal to be processed.

[0160] By separating the comb teeth through dispersion for selection, the phase relationship between the optical signals of different comb teeth is not affected. In the optical signal to be processed after encoding, the optical signals of different comb teeth still maintain high coherence, which provides a good foundation for the formation of the subsequently compressed output optical signal.

[0161] Reference Figure 1 The step of encoding the initial optical signal based on the preset comb coding to form the optical signal to be processed includes: encoding the initial optical signal through a dispersion unit 121 and a selection unit 122 arranged along the optical path to form the optical signal to be processed. The initial optical signal is collimated and expanded before being incident on the dispersion unit 121; the dispersion unit 121 causes the initial optical signal to be dispersed, and the dispersed initial optical signal is then incident on the selection unit 122.

[0162] In some embodiments, the step of dispersing the initial optical signal to form multiple comb-tooth optical signals includes: dispersing the initial optical signal in a preset direction, wherein the preset direction is perpendicular to the incident direction of the initial optical signal. This separates the different comb teeth in the initial optical signal in the spatial domain, forming different comb-tooth optical signals respectively, without affecting the phase relationship between the different comb-tooth optical signals, and the different comb-tooth optical signals still maintain high coherence.

[0163] In some embodiments, the preset direction includes at least one of an intersecting first direction and a second direction, both of which are perpendicular to the optical axis. The initial optical signal is dispersed in a single direction or in two intersecting directions, causing the different comb teeth in the initial optical signal to separate in a one-dimensional or two-dimensional direction.

[0164] Reference Figure 1The step of dispersing the initial optical signal in a preset direction includes: dispersing the initial optical signal in a first direction and a second direction to form multiple comb-tooth optical signals. For example, the first direction and the second direction are perpendicular to each other. Dispersing the different comb-tooth optical signals in the initial optical signal within a two-dimensional plane perpendicular to the optical axis enables higher comb-tooth resolution in a smaller space, effectively increases the number of comb-tooth optical signals, effectively improves the parallel processing capability of the encoding module, provides a good foundation for the selection of subsequent comb-tooth optical signals, and improves the accuracy and speed of comb-tooth selection.

[0165] For example, such as Figure 1 As shown, the steps of dispersing the initial light signal in a first direction and a second direction include: dispersing the initial light signal in the first direction; and dispersing the dispersed initial light in the second direction. The initial light is dispersed sequentially along the first direction and the second direction to form multiple comb-shaped light signals arranged in sequence along the first direction and the second direction, which are then incident on the selection unit 122.

[0166] In some embodiments of the present invention, the step of encoding an initial optical signal based on a preset comb code to form an optical signal to be processed includes: encoding the initial optical signal based on 0 / 1 intensity coding to form the optical signal to be processed. 0 / 1 intensity coding refers to binary intensity modulation coding. Specifically, the comb code is a binary code, where 0 represents no signal intensity (e.g., no light) and 1 represents signal intensity (e.g., light). The step of encoding the initial optical signal includes: the encoding module modulating the light intensity of the initial optical signal according to the 0 / 1 intensity coding, thereby forming the optical signal to be processed.

[0167] Specifically, the number of bits in the comb code corresponds one-to-one with the multiple comb optical signals divided by the dispersion unit. The value of one bit in the comb code indicates whether the corresponding comb optical signal is selected to form the optical signal to be processed. For example, when one bit in the comb code is "1", the corresponding comb optical signal is selected, and when one bit in the comb code is "0", the corresponding comb optical signal is not selected.

[0168] Example, Figure 3 The diagram shows the frequency distribution of the optical signal to be processed after selecting the comb optical signal based on the comb coding of 111111, 101011, 111001, and 101101 in some embodiments.

[0169] In some embodiments, the number of bits with a value of "1" in the comb-tooth encoding is multiple, so that the resulting optical signal to be processed includes multiple comb-tooth optical signals, and the resulting emitted optical signal has optical signals of multiple frequencies, thereby providing a good foundation for further improvement of the signal-to-noise ratio. When the resulting emitted optical signal is used for gas analysis, having optical signals of multiple frequencies in the generated emitted optical signal can further improve the signal-to-noise ratio of the obtained results.

[0170] It should be noted that, Figure 3 In the frequency distribution diagram of each optical signal to be processed, the horizontal axis represents frequency and the vertical axis represents light intensity.

[0171] In some embodiments, the step of selecting at least one comb-tooth optical signal from multiple comb-tooth optical signals to form an optical signal to be processed, based on a preset comb-tooth code, includes: changing the transmission direction of the selected comb-tooth optical signal to form the optical signal to be processed, based on the preset comb-tooth code. Based on the comb-tooth code, the selected comb-tooth optical signal is actively biased towards a fixed direction, causing unselected comb-tooth optical signals to deviate from the aforementioned direction, thus separating the selected and unselected comb-tooth optical signals in the propagation direction. The comb-tooth optical signals biased towards the fixed direction are then coupled to form the optical signal to be processed. By changing the transmission direction of the comb-tooth optical signals to separate the selected and unselected comb-tooth optical signals, crosstalk from the unselected comb-tooth optical signals can be effectively suppressed.

[0172] like Figure 1 In some embodiments shown, the step of changing the transmission direction of the selected comb optical signal to form the optical signal to be processed includes: receiving multiple comb optical signals, and actively causing the selected comb optical signal to be folded back along the original optical path and causing the unselected comb optical signals to deviate from the original optical path according to the comb coding, and the comb optical signals folded back along the original optical path are coupled to form the optical signal to be processed.

[0173] Continue to refer to Figure 7 In some embodiments of the present invention, the light emission method further includes: step S160, generating an encoding sequence, the encoding sequence including: multiple comb codes. Step S120, encoding an initial optical signal based on a preset comb code to form a processed optical signal includes: encoding multiple initial optical signals one by one based on the comb codes in the encoding sequence to form a processed optical sequence, the processed optical sequence including: multiple processed optical signals, the multiple processed optical signals of the processed optical sequence corresponding one-to-one with the multiple comb codes of the encoding sequence.

[0174] like Figure 1As shown, in some embodiments, step S160, the step of generating the encoded sequence, includes: generating the encoded sequence through the generation control module 160; the generation control module 160 is also connected to the selection unit 122 in the encoding module 120, and provides the encoded sequence to the selection unit 122 in the encoding module 120, so as to control the selection unit 122 to encode multiple initial optical signals one by one according to the comb coding in the encoded sequence to form the optical sequence to be processed.

[0175] like Figure 1 In some embodiments shown, the step of generating the initial optical signal includes: generating multiple initial optical signals sequentially to form an initial optical sequence based on the number of comb codes in the generated coding sequence; and encoding each of the multiple initial optical signals according to the comb codes in the coding sequence to form the optical sequence to be processed, which includes: encoding each of the multiple initial optical signals in the initial optical sequence sequentially based on the comb codes in the coding sequence to form the optical sequence to be processed. It can be seen that both the optical sequence to be processed and the initial optical sequence are time series. (Continue to refer to...) Figure 7 The light emission method further includes: after forming the light signal to be processed, performing step S130 to compress the amplitude quantum noise of the light signal to be processed to form the emitted light signal.

[0176] Step S130, the step of performing amplitude quantum noise compression on the optical signal to be processed to form an outgoing optical signal, is used to perform quantum noise compression on the optical signal to be processed to form an outgoing optical signal.

[0177] Specifically, the step of quantum noise compression of the optical signal to be processed to form an output optical signal results in an output optical signal in a compressed state. Quantum noise compression of the optical signal to be processed refers to reducing the quantum noise of a specific orthogonal component (e.g., amplitude or phase orthogonal component) of the optical signal to be processed, making it (e.g., amplitude orthogonal component) below the vacuum noise level, while allowing the noise of another orthogonal component (e.g., phase orthogonal component) to increase accordingly.

[0178] For example, the steps of quantum noise compression of the optical signal to be processed to form the output optical signal include: performing amplitude quantum noise compression on the optical signal to be processed, thereby forming an amplitude-compressed state. Amplitude quantum noise compression refers to making the noise of the amplitude quadrature components of the optical signal lower than the shot noise limit. The quantum noise fluctuations of the amplitude-compressed optical signal on the amplitude quadrature components are lower than the lowest noise limit achievable in classical optical fields, i.e., lower than the shot noise limit (SNL).

[0179] The shot noise of the emitted optical signal is reduced. The compressed emitted optical signal is already an optical signal in which the noise of a certain orthogonal component is suppressed, and it has a high signal-to-noise ratio at low power. Therefore, the use of emitted optical signals with high signal-to-noise ratio can effectively suppress the noise of the corresponding orthogonal component in subsequent signals and effectively improve the signal-to-noise ratio of the corresponding orthogonal component at low power.

[0180] In some embodiments of the present invention, the step of quantum noise compression of the optical signal to be processed to form an output optical signal includes: quantum noise compression of the optical signal to be processed based on the optical Kerr effect. The optical Kerr effect is a third-order nonlinear optical phenomenon, in which the refractive index of the medium changes linearly with the light intensity. During the Kerr effect of the optical signal, the amplitude fluctuations of the optical signal modulate the refractive index of the medium in real time, thereby producing a phase change in the phase of the optical field of the optical signal that is proportional to the instantaneous intensity, i.e., realizing self-phase modulation (SPM).

[0181] The optical Kerr effect is a third-order nonlinear optical effect that does not require strict phase matching conditions and can be realized simply by using a Kerr medium. It is easy to integrate with fiber optic systems or photonic chips, which is beneficial for achieving system miniaturization and low cost. Moreover, the self-phase modulation response time of the optical Kerr effect is extremely short, which is beneficial for the realization of broadband compression, pulse or high-speed optical information modulation.

[0182] Reference Figure 9 In some embodiments of the present invention, step S130, which involves quantum noise compression of the optical signal to be processed to form an outgoing optical signal, includes: step S131, dividing the optical signal to be processed into a first split signal and a second split signal; step S132, using a Kerr medium to perform self-phase modulation on the first split signal to form a first pre-formed optical signal; step S133, performing phase shift on the second split signal to form a second pre-formed optical signal, wherein the second pre-formed optical signal and the first pre-formed optical signal have a preset phase difference; and step S134, coupling the first pre-formed optical signal and the second pre-formed optical signal to form an outgoing optical signal.

[0183] The step of dividing the optical signal to be processed into a first split signal and a second split signal is used to divide the optical signal to be processed into two parts.

[0184] In some embodiments, the step of splitting the optical signal to be processed into a first split signal and a second split signal includes: splitting the optical signal to be processed into a first split signal and a second split signal using an unbalanced splitting method, with a splitting ratio of N:1, where N≠1. The light intensities of the first split signal and the second split signal are not equal. Specifically, the light intensity of the first split signal is greater than that of the second split signal. Specifically, the step of splitting the optical signal to be processed into a first split signal and a second split signal includes: splitting the optical signal to be processed into a first split signal and a second split signal using a beam splitter.

[0185] The step of using Kerr medium to perform self-phase modulation on the first optical signal to form the first pre-formed optical signal is used to enable the first optical signal to undergo self-phase modulation, establish the quantum correlation between amplitude fluctuations and phase, and provide a physical basis for quantum noise compression of optical signals.

[0186] Specifically, the first split signal undergoes self-phase modulation in the Kerr medium to form the first pre-fabricated optical signal; such as Figure 4 As shown in the green crescent-shaped KERR, the first pre-fabricated optical signal is in a Kerr state.

[0187] The step of phase-shifting the second beam splitting signal to form a second pre-formed optical signal is used to cause a phase shift in the second beam splitting signal, thereby introducing a preset phase difference between the two parts of the optical signal to be processed, providing a basis for the preparation of the compressed state.

[0188] Specifically, the second split signal undergoes a phase shift in the phase shifter or delay fiber, forming a second pre-fabricated optical signal; such as Figure 4 As shown in the red circle COH, the second pre-fabricated optical signal is in a coherent state (COH).

[0189] It should be noted that in the step of phase-shifting the second beam splitter signal to form the second pre-formed optical signal, the introduced phase difference is determined based on the desired state of the emitted optical signal. For example, if the emitted optical signal is in an amplitude-compressed state, a 90° phase difference is introduced; if the desired emitted optical signal is in an amplitude-inverse-compressed state (i.e., a phase-compressed state), the second modulation unit introduces a 270° phase difference.

[0190] The step of coupling the first pre-formed optical signal and the second pre-formed optical signal to form an emitted optical signal is used to combine and couple the first pre-formed optical signal and the second pre-formed optical signal to form an emitted optical signal in a compressed state.

[0191] Specifically, the step of coupling the first pre-fabricated optical signal and the second pre-fabricated optical signal to form the emitted optical signal includes: coupling the first pre-fabricated optical signal and the second pre-fabricated optical signal through a beam splitter to form the emitted optical signal.

[0192] like Figure 4As shown, the first pre-fabricated optical signal is in a Kerr state, and the second pre-fabricated optical signal is in a coherent state. The combined coupling of the first and second pre-fabricated optical signals completes the movement of the quantum state in phase space, thereby realizing the preparation of an amplitude-squeezed state (SQZ) or an amplitude-anti-squeezed state (ANTI-SQZ). Figure 4 As shown in the yellow crescent-shaped SQZ, the emitted light signal is in an amplitude-compressed state, while as shown in the blue crescent-shaped ANTI-SQZ, the emitted light signal is in an amplitude-inverse-compressed state.

[0193] It should be noted that, Figure 4 The schematic diagram of the emitted light signal in phase space shown indicates that the horizontal axis... and vertical axis These represent the two orthogonal quantum components of a single-mode optical field, also known as orthogonal operators for the Bosonic field. Similar to position and momentum in mechanics, they are two complementary directions describing quantum fluctuations in the optical field. If annihilation operators are used... and generating operators To represent a light field, it is often written as:

[0194] in, Typically, these correspond to orthogonal amplitude components, which are related to fluctuations in the light field amplitude, light intensity, or photon number. These typically correspond to orthogonal phase components and are related to optical field phase fluctuations. Since neither can be simultaneously and arbitrarily precisely determined, noise decreasing in one direction usually leads to increased noise in the other.

[0195] In a phase space diagram, the center of an optical field state represents its average complex amplitude, and the surrounding circular, elliptical, or meniscus regions represent the quantum noise distribution. The noise distribution of ordinary coherent states is approximately circular, such as... Figure 4 The red circular COH symbol indicates... and The noise in each direction is equal and both are within the shot noise limit. After the Kerr nonlinear effect, the noise distribution is sheared into a meniscus Kerr state, as shown below. Figure 4 The green crescent-shaped KERR is shown. Then, through weakly coherent coupling after phase shift, the phase space distribution is displaced. When the low-noise direction is aligned... When the axis is in a compressed state, it exhibits amplitude compression, such as Figure 4 The yellow crescent shape SQZ is shown in the middle; when When directional noise is amplified, it manifests as an amplitude-inverse compression state, such as... Figure 4 The blue crescent-shaped ANTI-SQZ is shown in the image.

[0196] In some embodiments of the present invention, the step of performing quantum noise compression on the optical signal to be processed to form an outgoing optical signal includes: performing quantum noise compression on each of the multiple optical signals to be processed in the optical sequence to be processed to form an outgoing optical sequence, wherein the outgoing optical sequence includes multiple outgoing optical signals, and the multiple outgoing optical signals of the outgoing optical sequence correspond one-to-one with the multiple optical signals to be processed in the optical sequence to be processed.

[0197] Accordingly, the present invention also provides a gas analysis method.

[0198] refer to Figure 10 The diagram shows a flow chart of a gas analysis method consistent with some embodiments of the present invention.

[0199] Gas analysis methods include: Step S101: Emit an emitted light signal, wherein the light emission method of the emitted light signal is the light emission method of the present invention; Step S140: Generate a result electrical signal based on the light response generated by the target gas after absorbing the emitted light signal; Step S150: Analyze the target gas based on the comb code and the result electrical signal.

[0200] First, step S101 is executed to emit an outgoing light signal. The light emission method for the outgoing light signal is the light emission method of this invention. For the specific technical solution of the step of emitting the outgoing light signal, please refer to the foregoing. Figures 1 to 9 The example shown.

[0201] The emitted light signal is incident on the target gas and transmitted within the target gas; such as... Figure 5 As shown, during the transmission of the emitted light signal through the target gas, a specific frequency portion of the emitted light signal is absorbed by the molecules of the target gas, thereby generating a light response corresponding to that specific frequency. The generated light response carries the absorption information of the gas molecules. The emitted light signal is in a compressed state where the shot noise of the target measurement quadrature component is suppressed. The emitted light signal is already a light signal with suppressed noise of the target measurement quadrature component, and the signal-to-noise ratio of the target measurement quadrature component of the emitted light signal is high, especially at low power. Therefore, the signal-to-noise ratio of the resulting electrical signal formed based on the light response generated by the absorption of the emitted light signal by the target gas is also high, and correspondingly, it also has a high signal-to-noise ratio at low power. The formation of a high signal-to-noise ratio resulting electrical signal can effectively improve the signal-to-noise ratio of the measurement result and effectively improve the signal-to-noise ratio of the low-power measurement result.

[0202] In some embodiments of the present invention, the step of quantum noise compression of the optical signal to be processed to form an emitted optical signal in the optical emission method includes: amplitude quantum noise compression of the optical signal to be processed to form an emitted optical signal. The emitted optical signal formed by amplitude quantum noise compression of the optical signal to be processed is in an amplitude compressed state, has a macroscopic average coherent amplitude, and the noise of the amplitude orthogonal component is lower than the shot noise limit of the coherent state; the noise of the amplitude of the emitted optical signal is reduced, and the amplitude orthogonal component of the emitted optical signal has a high signal-to-noise ratio, especially at low power, it has an extremely high signal-to-noise ratio. It is only necessary to record the light intensity of the echo light signal formed after the target gas absorbs the emitted optical signal, or according to the photoacoustic response generated after the target gas absorbs the emitted optical signal, that is, only the light response generated after the target gas absorbs the emitted optical signal, to generate the corresponding result electrical signal. There is no need to rely on phase preservation. Even if the phase information is destroyed during the process of the target gas absorbing the emitted optical signal to generate the light response, stable reconstruction can still be achieved. The system has strong environmental adaptability and the reconstruction result is stable and reliable.

[0203] Continue to refer to Figure 10 The gas analysis method further includes: after emitting an emitted light signal, performing step S140 to form a result electrical signal based on the light response generated by the target gas after absorbing the emitted light signal.

[0204] The step of forming a result electrical signal based on the light response generated by the target gas after absorbing the emitted light signal is used to receive the light response generated by the target gas after absorbing the emitted light signal and to form a result electrical signal based on the light response.

[0205] The emitted light signal is already a noise-suppressed light signal with a high signal-to-noise ratio, especially at low power. Therefore, the resulting electrical signal formed based on the photoresponse generated after the target gas absorbs the emitted light signal also has a high signal-to-noise ratio, exhibiting a high signal-to-noise ratio at low power. The formation of the high signal-to-noise ratio resulting electrical signal can effectively improve the signal-to-noise ratio of the measurement results, and effectively improve the signal-to-noise ratio of low-power measurement results.

[0206] In some embodiments of the present invention, the step of compressing the bright amplitude quantum noise of the optical signal to be processed to form an emitted optical signal with a bright compressed state, and forming a result electrical signal based on the photoresponse generated by the target gas after absorbing the emitted optical signal, includes: forming the result electrical signal based on the light intensity of the echo optical signal generated by the target gas after absorbing the emitted optical signal, or based on the photoacoustic response generated by the target gas after absorbing the emitted optical signal. The emitted optical signal with a bright compressed state has high optical power. In the step of receiving the echo optical signal, the photoresponse can be directly received alone to form the result electrical signal, without interference amplification or a local oscillator signal, to obtain the result electrical signal related to the photoresponse generated by the target gas after absorbing the emitted optical signal; without phase locking and mode matching related to the local oscillator signal, the reception difficulty is low, the stability is high, and the anti-interference performance is strong.

[0207] like Figure 1 In some embodiments shown, the target gas is stored in the gas cavity 141. The emitted light signal is reflected into the gas cavity by the third reflector 188; the emitted light signal is incident into the gas cavity 141 and interacts with the target gas in the gas cavity 141; the target gas in the gas cavity 141 absorbs the emitted light signal and generates a photoacoustic response; the photoacoustic response is received, and a result electrical signal is formed based on the received photoacoustic response.

[0208] In some embodiments of the present invention, the initial optical signal is encoded using comb coding based on 0 / 1 intensity coding; the step of forming a result electrical signal based on the photoresponse generated by the target gas after absorbing the emitted optical signal includes: receiving the photoresponse generated by the target gas after absorbing the emitted optical signal through single-point reception, and forming the result electrical signal. Single-point reception refers to measurement at a single spatial coordinate corresponding to the detector package. Encoding the initial optical signal using 0 / 1 intensity coding enables 0 / 1 modulation of the two-dimensional information of "photon number-frequency". During the reception of the optical response, only the total intensity change after modulation needs to be recorded to generate the corresponding result electrical signal. There is no need to rely on phase preservation. Even if the phase information is destroyed during the process of the target gas absorbing the emitted optical signal to generate the optical response, stable reconstruction can still be achieved. The system has strong environmental adaptability and the reconstruction results are stable and reliable. Moreover, only a single-point detector is needed to realize the optical signal reception. There is no need for a high-pixel camera or cryogenic cooling, which can effectively reduce the overall size, weight and power consumption of the system. It can achieve spectral accuracy comparable to that in the laboratory under extreme conditions such as scattering media, no target, and single photon flux, thus breaking through the inherent limitations of traditional optical comb schemes that "must have high power, must cooperate in reflection, and must coherently receive".

[0209] In some embodiments, the step of forming a result electrical signal based on the photoresponse generated by the target gas after absorbing the emitted light signal includes: receiving the photoacoustic response generated by the target gas after absorbing the emitted light signal to form a result electrical signal. Receiving the photoacoustic response to form a result electrical signal has the advantages of high sensitivity and a wide spectral range, which is beneficial for the realization and improvement of accuracy of trace gas detection. Specifically, the target gas generates periodic thermal release and acoustic response after absorbing the emitted light signal; the periodic thermal release and acoustic response cause a quartz tuning fork to vibrate; and a piezoelectric ceramic element generates a result electrical signal based on the vibration of the quartz tuning fork.

[0210] In some embodiments of the present invention, the step of emitting an emitted light signal further includes: generating an encoding sequence; encoding multiple initial light signals one by one based on the comb coding in the encoding sequence to form a light sequence to be processed; performing quantum noise compression on multiple light signals to be processed in the light sequence to be processed to form an emitted light sequence; and receiving a receiving device receiving a light response sequence generated by the target gas absorbing the emitted light sequence to form a result electrical sequence, wherein the light response sequence includes multiple light responses, and the result electrical sequence includes multiple result electrical signals, wherein the multiple light responses of the light response sequence correspond one-to-one with the multiple emitted light signals of the emitted light sequence, and the multiple result electrical signals of the result electrical sequence correspond one-to-one with the multiple light responses of the light response sequence.

[0211] Continue to refer to Figure 10 The gas analysis method also includes: after generating the result electrical signal, performing step S150 to analyze the target gas based on the comb code and the result electrical signal.

[0212] The steps of analyzing the target gas based on the comb code and the resulting electrical signal are used to process the resulting electrical signal according to the comb code in order to achieve the analysis of the target gas.

[0213] Specifically, after receiving the result electrical signal and the comb code respectively, the result electrical signal is analyzed based on the comb code to achieve the detection of the target gas. For example, the analysis device analyzes the result electrical signal based on the comb code to obtain the absorption spectrum of the target gas, and analyzes the target gas based on the absorption spectrum.

[0214] The emitted light signal is in a compressed state, and its quantum noise has been suppressed in advance, resulting in a high signal-to-noise ratio (SNR), especially at low power. The resulting electrical signal, formed by the photoresponse generated by the absorption of the emitted light signal by the target gas, also has a high SNR, even at low power. The analytical results obtained based on the high SNR-based resulting electrical signal are of high quality and have a high SNR, even at low power.

[0215] The received electrical signal has a high signal-to-noise ratio. Compared with the electro-optic modulation optical comb scheme, the signal-to-noise ratio is improved by about twice. It can achieve a smaller reconstruction error with the same number of samples, or shorten the sampling time with the same error.

[0216] In some embodiments of the present invention, the step of emitting an outgoing light signal further includes: generating an encoding sequence; encoding multiple initial light signals one by one based on the comb-tooth encoding in the encoding sequence to form a light sequence to be processed; performing quantum noise compression on multiple light signals to be processed in the light sequence to be processed to form an outgoing light sequence; receiving the light response sequence generated by the target gas absorbing the outgoing light sequence to form a result electrical sequence; and analyzing the target gas according to the comb-tooth encoding and the result electrical signal includes: analyzing the target gas according to the encoding sequence and the result electrical sequence. Based on the setting of the encoding sequence, the comb-tooth energy in the outgoing light signal is utilized multiple times, improving utilization efficiency; moreover, the superposition of multiple signals results in a signal strength that is N times the strength of a single signal, while the noise is averaged to the noise of a single signal. This demonstrates that the method of gas analysis based on multiple comb-tooth encoding can improve the signal-to-noise ratio by a factor of 1; Therefore, it is evident that the method of gas analysis based on multiple comb-tooth encoding can improve the signal-to-noise ratio. This increases the signal-to-noise ratio by several times, thereby further improving the gas analysis results.

[0217] Reference Figure 5 In some embodiments, the step of analyzing the target gas based on the comb tooth code and the result electrical signal includes: analyzing the target gas using the analysis device 250 based on the comb tooth code and the result electrical signal.

[0218] In some embodiments of the present invention, the step of analyzing the target gas based on the comb code and the resulting electrical signal includes: analyzing the resulting electrical signal based on the comb code to obtain the absorption spectrum of the target gas.

[0219] In some embodiments, the step of analyzing the resulting electrical signal based on comb coding to obtain the absorption spectrum of the target gas includes: processing the resulting electrical signal using a compressed sensing algorithm based on comb coding to obtain the absorption spectrum of the target gas. Compressed sensing (CS) is a signal processing technique that utilizes signal sparsity for undersampling reconstruction. The use of CS can reconstruct the complete absorption spectrum with a smaller number of samples, effectively shortening the spectral acquisition time; moreover, the emitted light signal has a high initial signal-to-noise ratio, and the resulting electrical signal naturally has a high signal-to-noise ratio. The compressed sensing algorithm can further compress the number of samples, significantly improving the spectral reconstruction speed.

[0220] In some embodiments, the received result electrical signal has a high signal-to-noise ratio. The high initial signal-to-noise ratio provided by the compressed state formed by quantum noise compression can compress the number of samples to 2.5% of the Nyquist limit. Combined with the high-speed switching during digital micromirror operation, with a switching frequency of up to 10 kHz, the output speed of the 256-mode absorption spectrum is greatly improved. Compared with the point-by-point scanning scheme or the dual-comb interference scheme, the output speed of the absorption spectrum is increased by an order of magnitude.

[0221] In some embodiments, the step of analyzing the target gas based on the comb coding and the resulting electrical signal further includes: determining the composition of the target gas based on its absorption spectrum. The absorption spectrum is obtained by the attenuation of light intensity caused by molecules in the target gas absorbing a specific frequency portion of the emitted light signal during transmission. The absorption spectrum allows for the qualitative identification of the types of molecules in the target gas, thereby qualitatively analyzing its composition. Furthermore, the emitted light signal has a high initial signal-to-noise ratio, and the resulting electrical signal naturally has a high signal-to-noise ratio. The absorption spectrum of the target gas reconstructed based on the resulting electrical signal has a high signal-to-noise ratio, effectively ensuring the accuracy of the qualitative analysis of the target gas and enabling the detection of trace components in the target gas.

[0222] Specifically, in the step of determining the composition of the target gas based on its absorption spectrum, the absorption spectrum of the target gas is compared with the data in the gas standard spectral database to qualitatively analyze the composition of the target gas.

[0223] In some embodiments, the step of analyzing the target gas based on the comb code and the resulting electrical signal further includes: determining the concentration of each component in the target gas based on the absorption spectrum of the target gas. Based on the absorption spectrum, and combined with the quantitative relationship between gas absorbance and concentration and optical path, the concentration of each component in the target gas can also be calculated, and the components of the target gas can be quantitatively analyzed.

[0224] Specifically, in the step of determining the concentration of each component in the target gas based on the absorption spectrum of the target gas, the concentration of each component in the target gas is obtained by inversion calculation based on the data of the standard spectral database and the absorption spectrum of the target gas.

[0225] It should be noted that the gas standard spectral database refers to a collection that stores standard absorption spectral data of known gas molecules and their related parameters, which is used as a benchmark reference for qualitative identification and quantitative inversion.

[0226] It should be noted that, in the foregoing embodiments, the resulting electrical signal is formed based on the photoacoustic response generated after the target gas absorbs the emitted light signal. In other embodiments of the present invention, the light response reception and conversion can also be achieved through other means during the formation of the resulting electrical signal.

[0227] In some embodiments of the present invention, the step of forming a result electrical signal based on the photoresponse generated after the target gas absorbs the emitted light signal includes: forming a result electrical signal based on the photoelectric response generated after the target gas absorbs the emitted light signal, that is, forming the result electrical signal based on the light intensity of the echo light signal formed after the target gas absorbs the emitted light signal. The photoelectric conversion method based on the photoelectric effect has advantages such as fast response speed, simple structure, miniaturization, and high integration.

[0228] In some embodiments, shot noise in the emitted light signal is suppressed, with quantum noise of the amplitude orthogonal components suppressed by approximately 3 dB, and noise power reduced by about half. In some exemplary embodiments, using such a high signal-to-noise ratio emitted light signal to analyze the target gas results in an echo light signal with a correspondingly extremely high signal-to-noise ratio at low power, making 46 fW (approximately 10) -3 Even with the photon / pulse-limited echo signal, an absorption spectrum with a residual of less than 1% can still be reconstructed; in other embodiments, it is even possible to reconstruct an absorption spectrum with a residual of less than 1% at a lower 5.3 fW (approximately 1.5 × 10⁻⁶). -4 The photon / pulse extreme echo light signal can still reconstruct the molecular absorption spectrum from 530 nm to 1540 nm, reducing the optical power requirement by three orders of magnitude compared to the existing "EOM + camera" scheme.

[0229] In some embodiments of the present invention, the step of emitting an emitted light signal further includes: generating an encoded sequence; encoding multiple initial light signals one by one based on the comb coding in the encoded sequence to form a light sequence to be processed; performing quantum noise compression on multiple light signals to be processed in the light sequence to form an emitted light sequence; generating an echo light sequence after the target gas absorbs multiple emitted light signals in the emitted light sequence, the echo light sequence including multiple echo light signals, the multiple echo light signals in the echo light sequence corresponding one-to-one with the multiple emitted light signals in the emitted light sequence; forming a result electrical sequence based on the photoelectric response of the multiple echo light signals in the echo light sequence; and analyzing the target gas based on the encoded sequence and the result electrical sequence.

[0230] In summary, the technical solution of this invention, through the three-step collaborative approach of "source noise reduction, mid-stage encoding, and end-stage computation," and based on optical comb spectroscopy technology, uses quantum noise compression to overcome the multiple requirements of traditional optical combs, which "must have high power, must have a cooperative target, and must have phase locking," thereby providing a new generation of spectral solution that can be chip-based and deployed on a large scale.

[0231] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A light emitting device, characterized in that, include: An optical comb light source, wherein the optical comb light source is configured to generate an initial optical signal, and the optical comb light source is a single-comb light source; An encoding module is configured to encode the initial optical signal based on a preset comb-tooth encoding to form an optical signal to be processed. The encoding module includes: a dispersion unit configured to disperse the initial optical signal to form multiple comb-tooth optical signals; and a selection unit configured to select at least one from the multiple comb-tooth optical signals to form the optical signal to be processed based on the preset comb-tooth encoding. A modulation module configured to perform quantum noise compression on the optical signal to be processed to form an emitted optical signal, the modulation module comprising: a beam splitting unit configured to split the optical signal to be processed into a first beam splitting signal and a second beam splitting signal; a first modulation unit comprising a Kerr medium configured to perform self-phase modulation on the first beam splitting signal to form a first pre-formed optical signal; a second modulation unit configured to perform phase shifting on the second beam splitting signal to form a second pre-formed optical signal, the second pre-formed optical signal and the first pre-formed optical signal having a preset phase difference; and a coupling unit configured to couple the first pre-formed optical signal and the second pre-formed optical signal to form an emitted optical signal.

2. The light emitting device as described in claim 1, characterized in that, The dispersion unit includes a dispersion element configured to disperse the initial light signal in a preset direction to form multiple comb-tooth light signals, wherein the preset direction is perpendicular to the incident direction of the initial light signal.

3. The light emitting device as described in claim 2, characterized in that, The preset direction includes at least one of an intersecting first direction and a second direction, both of which are perpendicular to the optical axis.

4. The light emitting device as described in claim 3, characterized in that, The dispersive element includes at least one of a grating and a virtual imaging phase array.

5. The light emitting device as described in claim 1, characterized in that, The selection unit is configured to change the transmission direction of the selected comb optical signal based on a preset comb code to form the optical signal to be processed.

6. The light emitting device as claimed in claim 1, characterized in that, The comb teeth are encoded with 0 / 1 intensity.

7. The light emitting device as claimed in claim 1, characterized in that, Also includes: A generation control module is configured to generate an encoding sequence, the encoding sequence including multiple comb codes; the generation control module is also configured to control the encoding module to encode multiple initial optical signals one by one based on the comb codes in the encoding sequence to form a light sequence to be processed, the light sequence to be processed including multiple light signals to be processed, the multiple light signals to be processed in the light sequence to be processed corresponding one-to-one with the multiple comb codes in the encoding sequence; The modulation module performs quantum noise compression on each of the multiple optical signals to be processed in the optical sequence to be processed to form an outgoing optical sequence. The outgoing optical sequence includes multiple outgoing optical signals, and the multiple outgoing optical signals of the outgoing optical sequence correspond one-to-one with the multiple optical signals to be processed in the optical sequence to be processed.

8. A gas analysis system, characterized in that, include: A light emitting device, as described in any one of claims 1 to 7; A receiving device is configured to generate a result electrical signal based on the optical response generated by the target gas after absorbing the emitted light signal; An analytical device configured to analyze the target gas based on the comb code and the resulting electrical signal.

9. The gas analysis system as described in claim 8, characterized in that, The modulation module of the optical emitting device is configured to perform amplitude quantum noise compression on the optical signal to be processed to form an outgoing optical signal.

10. The gas analysis system as described in claim 9, characterized in that, The comb teeth are encoded with 0 / 1 intensity, and the receiving device includes a single-point detector.

11. The gas analysis system as described in claim 10, characterized in that, The single-point detector includes one of a photoacoustic detector and a photoelectric detector.

12. The gas analysis system as described in claim 11, characterized in that, The photoacoustic detector includes a quartz tuning fork and a piezoelectric ceramic element; the photodetector includes a single-photon detector.

13. The gas analysis system as described in claim 9, characterized in that, The modulation module is configured to perform bright amplitude quantum noise compression on the optical signal to be processed to form an outgoing optical signal; The receiving device generates the resulting electrical signal based on the intensity of the echo light signal formed after the target gas absorbs the emitted light signal, or based on the photoacoustic response generated after the target gas absorbs the emitted light signal.

14. The gas analysis system as described in claim 8, characterized in that, The analytical apparatus includes: A reconstruction module is configured to analyze the resulting electrical signal based on the comb-tooth encoding to obtain the absorption spectrum of the target gas.

15. The gas analysis system as described in claim 14, characterized in that, The reconstruction module, based on the comb-tooth encoding, uses a compressed sensing algorithm to process the resulting electrical signal to obtain the absorption spectrum of the target gas.

16. The gas analysis system as described in claim 14, characterized in that, The analytical device further includes: A qualitative analysis module is configured to determine the composition of the target gas based on the absorption spectrum of the target gas.

17. The gas analysis system as described in claim 14, characterized in that, The analytical device further includes: A quantitative analysis module is configured to determine the concentration of each component in the target gas based on the absorption spectrum of the target gas.

18. The gas analysis system as described in claim 8, characterized in that, The light emitting device also includes: A generation control module is configured to generate an encoding sequence, the encoding sequence including multiple comb codes; the generation control module is also configured to control the encoding module to encode multiple initial optical signals one by one based on the comb codes in the encoding sequence to form a light sequence to be processed, the light sequence to be processed including multiple light signals to be processed, the multiple light signals to be processed in the light sequence to be processed corresponding one-to-one with the multiple comb codes in the encoding sequence; The modulation module performs quantum noise compression on each of the multiple optical signals to be processed in the optical sequence to be processed to form an output optical sequence. The output optical sequence includes multiple output optical signals, and the multiple output optical signals of the output optical sequence correspond one-to-one with the multiple optical signals to be processed in the optical sequence to be processed. The receiving device forms a result electrical sequence based on the optical response sequence generated by the target gas absorbing the emitted light sequence. The optical response sequence includes multiple optical responses, and the result electrical sequence includes multiple result electrical signals. The multiple optical responses of the optical response sequence correspond one-to-one with the multiple emitted light signals of the emitted light sequence, and the multiple result electrical signals of the result electrical sequence correspond one-to-one with the multiple optical responses of the optical response sequence. The analysis device analyzes the target gas based on the encoded sequence and the resulting electrical sequence.

19. A method for emitting light, characterized in that, include: An initial optical signal is generated, the initial optical signal having an optical comb structure, and the initial optical signal being a single optical comb; The process of encoding the initial optical signal based on a preset comb code to form an optical signal to be processed includes: dispersing the initial optical signal to form multiple comb-tooth optical signals; and selecting at least one of the multiple comb-tooth optical signals to form the optical signal to be processed based on the preset comb code. The step of performing quantum noise compression on the optical signal to be processed to form an outgoing optical signal includes: dividing the optical signal to be processed into a first split signal and a second split signal; using a Kerr medium, performing self-phase modulation on the first split signal to form a first pre-formed optical signal; performing phase shift on the second split signal to form a second pre-formed optical signal, wherein the second pre-formed optical signal and the first pre-formed optical signal have a preset phase difference; and coupling the first pre-formed optical signal and the second pre-formed optical signal to form an outgoing optical signal.

20. The light emission method as described in claim 19, characterized in that, The step of dispersing the initial light signal to form multiple comb-tooth light signals includes: dispersing the initial light signal in a preset direction to form multiple comb-tooth light signals, wherein the preset direction is perpendicular to the incident direction of the initial light signal.

21. The light emission method as described in claim 19, characterized in that, The preset direction includes at least one of an intersecting first direction and a second direction, both of which are perpendicular to the optical axis.

22. The light emission method as described in claim 21, characterized in that, The step of selecting at least one of the plurality of comb-tooth optical signals to form the optical signal to be processed based on a preset comb-tooth code includes: changing the transmission direction of the selected comb-tooth optical signal to form the optical signal to be processed based on the preset comb-tooth code.

23. The light emission method as described in claim 19, characterized in that, The step of encoding the initial optical signal based on the preset comb coding to form the optical signal to be processed includes: encoding the initial optical signal based on 0 / 1 intensity coding to form the optical signal to be processed.

24. The light emission method as described in claim 19, characterized in that, Also includes: Generate an encoding sequence, the encoding sequence comprising: multiple comb codes; The step of encoding the initial optical signal based on the preset comb code to form the optical signal to be processed includes: encoding multiple initial optical signals one by one based on the comb code in the encoding sequence to form the optical sequence to be processed, wherein the optical sequence to be processed includes multiple optical signals to be processed, and the multiple optical signals to be processed in the optical sequence to be processed correspond one-to-one with the multiple comb codes in the encoding sequence. The step of performing quantum noise compression on the optical signal to be processed to form an outgoing optical signal includes: performing quantum noise compression on each of the multiple optical signals to be processed in the optical sequence to be processed to form an outgoing optical sequence, wherein the outgoing optical sequence includes multiple outgoing optical signals, and the multiple outgoing optical signals of the outgoing optical sequence correspond one-to-one with the multiple optical signals to be processed in the optical sequence to be processed.

25. A gas analysis method, characterized in that, include: The method for emitting an outgoing light signal is as described in any one of claims 19 to 24; Based on the optical response generated by the target gas after absorbing the emitted light signal, a result electrical signal is formed; The target gas is analyzed based on the comb tooth encoding and the resulting electrical signal.

26. The gas analysis method as described in claim 25, characterized in that, The step of transmitting an outgoing optical signal, specifically the step of performing quantum noise compression on the optical signal to be processed to form an outgoing optical signal, includes: performing amplitude quantum noise compression on the optical signal to be processed to form an outgoing optical signal.

27. The gas analysis method as described in claim 25, characterized in that, The comb teeth are encoded with 0 / 1 intensity coding; The step of forming a result electrical signal based on the light response generated by the target gas after absorbing the emitted light signal includes: receiving the light response generated by the target gas after absorbing the emitted light signal through a single-point reception method to form a result electrical signal.

28. The gas analysis method as described in claim 25, characterized in that, The step of performing amplitude quantum noise compression on the optical signal to be processed to form an outgoing optical signal includes: performing brightness amplitude quantum noise compression on the optical signal to be processed to form an outgoing optical signal; The step of forming a result electrical signal based on the photoresponse generated by the target gas after absorbing the emitted light signal includes: forming the result electrical signal based on the light intensity of the echo light signal generated by the target gas after absorbing the emitted light signal, or based on the photoacoustic response generated by the target gas after absorbing the emitted light signal.

29. The gas analysis method as described in claim 25, characterized in that, The step of analyzing the target gas based on the comb code and the resulting electrical signal includes: analyzing the resulting electrical signal based on the comb code to obtain the absorption spectrum of the target gas.

30. The gas analysis method as described in claim 29, characterized in that, The step of analyzing the resulting electrical signal based on the comb-tooth encoding to obtain the absorption spectrum of the target gas includes: processing the resulting electrical signal using a compressed sensing algorithm based on the comb-tooth encoding to obtain the absorption spectrum of the target gas.

31. The gas analysis method as described in claim 29, characterized in that, The step of analyzing the target gas based on the comb code and the resulting electrical signal further includes: determining the composition of the target gas based on the absorption spectrum of the target gas.

32. The gas analysis method as described in claim 29, characterized in that, The step of analyzing the target gas based on the comb code and the resulting electrical signal further includes: determining the concentration of each component in the target gas based on the absorption spectrum of the target gas.

33. The gas analysis method as described in claim 25, characterized in that, The step of emitting the emitted optical signal further includes: generating an encoding sequence, wherein the encoding sequence includes: multiple comb codes; The step of encoding the initial optical signal based on the preset comb code to form the optical signal to be processed includes: encoding multiple initial optical signals one by one based on the comb code in the encoding sequence to form the optical sequence to be processed, wherein the optical sequence to be processed includes multiple optical signals to be processed, and the multiple optical signals to be processed in the optical sequence to be processed correspond one-to-one with the multiple comb codes in the encoding sequence. The step of performing quantum noise compression on the optical signal to be processed to form an outgoing optical signal includes: performing quantum noise compression on each of the multiple optical signals to be processed in the optical sequence to be processed to form an outgoing optical sequence, wherein the outgoing optical sequence includes multiple outgoing optical signals, and the multiple outgoing optical signals of the outgoing optical sequence correspond one-to-one with the multiple optical signals to be processed in the optical sequence to be processed. The step of forming a result electrical signal based on the photoresponse generated by the target gas absorbing the emitted light signal includes: forming a result electrical sequence based on the photoresponse sequence generated by the target gas absorbing the emitted light sequence, wherein the photoresponse sequence includes multiple photoresponses, the result electrical sequence includes multiple result electrical signals, the multiple photoresponses of the photoresponse sequence correspond one-to-one with the multiple emitted light signals of the emitted light sequence, and the multiple result electrical signals of the result electrical sequence correspond one-to-one with the multiple photoresponses of the photoresponse sequence; The step of analyzing the target gas based on the comb code and the resulting electrical signal includes: analyzing the target gas based on the code sequence and the resulting electrical sequence.

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