Optical path difference measurement method and device, electronic equipment, storage medium and product
By using a multi-wavelength and femtosecond light source optical path difference measurement method, the problem of interference imaging quality caused by large optical path differences in space array telescope systems has been solved, enabling accurate measurement and control under different optical conditions and supporting high-precision optical path difference measurement between spacecraft.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-24
- Publication Date
- 2026-03-13
AI Technical Summary
In space array telescope systems, irregular atmospheric motion and insufficient mechanical stability of the telescope array lead to large differences in optical path length, affecting the quality of interferometric imaging. Existing optical path length detection methods are inaccurate under low brightness and high propagation loss conditions.
Using an initial multi-wavelength light source and an initial femtosecond light source, the optical path difference is calculated by controlling the propagation of the light beam along the propagation path and converting it into an electrical signal. The optical path difference is then determined by combining multi-wavelength interferometry and the time-of-flight method.
It enables accurate optical path difference measurement under various scientific observation lighting conditions, ensuring the quality of combined light interferometry imaging, supporting precise measurement and control throughout the entire orbital observation cycle, and achieving measurement accuracy at the micrometer level.
Smart Images
Figure CN121655840A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of aerospace technology, and in particular to a method, apparatus, electronic device, storage medium, and product for measuring optical path difference. Background Technology
[0002] For space array telescope systems (refer to...) Figure 9 As shown, to achieve beam combining interferometry imaging, the sub-beams collected and transmitted to the beam combiner by each collector's sub-telescope must maintain a high degree of consistency in pointing and optical path. The difference in optical path between sub-beams is a key factor affecting the interference quality. However, the irregular movement of the Earth's atmosphere introduces optical path variations that are relatively large compared to the wavelength, and the telescope array also lacks sufficient mechanical stability, thus exacerbating the difficulty of optical path calibration. Therefore, certain technical means are needed to detect the optical path in real time.
[0003] In related technologies, methods such as focal plane detection, pupil plane detection, and far-field analysis are commonly used to determine the optical path difference for different media or paths by analyzing the collected scientific observation light. These methods rely on the state parameters generated during the propagation of the scientific observation light. If the state parameters of the scientific observation light are poor, such as low brightness or high propagation loss, the measurement results will be inaccurate. Summary of the Invention
[0004] This disclosure is made in view of the above-mentioned problems. This disclosure provides a method, apparatus, electronic device, storage medium, and product for measuring optical path difference.
[0005] According to one aspect of this disclosure, a method for measuring optical path difference is provided, comprising: Determine the propagation path of the scientific observation light from the spacecraft and the initial signal source; wherein, the initial signal source includes: an initial multi-wavelength source and an initial femtosecond source; The initial signal light source is controlled to propagate along the propagation path, and the target signal light is obtained after the beam returns; The target signal light is converted into an electrical signal to obtain the target electrical signal; The optical path difference of the propagation path is obtained by calculating the optical path difference based on the target electrical signal.
[0006] Furthermore, according to another embodiment of one aspect of this disclosure, the target signal light includes a first target signal light and a second target signal light; The step of converting the target signal light into an electrical signal to obtain the target electrical signal includes: The first target signal light is photoelectrically converted to obtain a first electrical signal; the first target signal light is the signal light source after the initial multi-wavelength light source has propagated along the propagation path. The second target signal light is photoelectrically converted to obtain a second electrical signal; wherein, the second target electrical signal is the signal light source after the initial femtosecond light source has propagated along the propagation path; The target electrical signal is determined based on the first electrical signal and the second electrical signal.
[0007] Furthermore, according to another embodiment of one aspect of this disclosure, the first target signal light is photoelectrically converted to obtain a first electrical signal, including: The first target signal light is subjected to polarization analysis to obtain the polarized target signal light; The polarized target signal light is photoelectrically converted to obtain a first electrical signal.
[0008] Furthermore, according to another embodiment of one aspect of this disclosure, the second target signal light is photoelectrically converted to obtain a second electrical signal, including: Determine the local oscillator of the initial femtosecond light source; Based on the local oscillator light source, the second target signal light is subjected to signal cross-correlation processing to obtain a cross-correlation signal light source; The cross-correlation signal light source is photoelectrically converted to obtain a second electrical signal.
[0009] Furthermore, according to another embodiment of one aspect of this disclosure, calculating the optical path difference based on the target electrical signal to obtain the target optical path difference of the propagation path includes: Based on the first electrical signal, the first optical path difference corresponding to the initial multi-wavelength light source is determined; Determine the second optical path difference corresponding to the initial femtosecond light source; The target optical path difference is determined based on the first optical path difference and the second optical path difference.
[0010] Furthermore, according to another embodiment of one aspect of this disclosure, determining the first optical path difference corresponding to the initial multi-wavelength light source based on the first electrical signal includes: The initial multi-wavelength light source is filtered to obtain a filtered multi-wavelength light source; After polarization analysis of the filtered multi-wavelength light source, photoelectric conversion is performed to obtain the control dual-frequency electrical signal; Multi-wavelength interferometric measurement processing is performed based on the reference dual-frequency electrical signal and the first electrical signal to obtain an optical path difference containing multiple ambiguity periods, and the optical path difference containing multiple ambiguity periods is determined as the first optical path difference.
[0011] Furthermore, according to another embodiment of one aspect of this disclosure, determining the second optical path difference corresponding to the initial femtosecond light source includes: Determine the first time and the second time, respectively, of the initial signal light source to and from the first and second light collectors in the propagation path; Based on the time-of-flight method, the first time and the second time are processed to obtain the first distance and the second distance between the first light collector and the second light collector and the beam combiner in the propagation path, respectively. The second optical path difference is determined based on the first distance and the second distance.
[0012] Furthermore, according to another embodiment of one aspect of this disclosure, determining the target optical path difference based on the first optical path difference and the second optical path difference includes: Determine the positional deviation of the light observed in scientific studies; The first optical path difference is deblurred based on the second optical path difference to obtain the third optical path difference; The target optical path difference is determined based on the positional deviation, the third optical path difference, and the second optical path difference for the propagation path of the initial signal light source.
[0013] According to another aspect of this disclosure, an optical path difference measuring device is provided, comprising: The signal generation module is used to determine the propagation path of the scientific observation light of the spacecraft and the initial signal source; wherein, the initial signal source includes: an initial multi-wavelength source and an initial femtosecond source; The propagation module is used to control the initial signal light source to propagate along the propagation path, and the target signal light is obtained after the beam returns; The conversion module is used to convert the target signal light into an electrical signal to obtain the target electrical signal; The calculation module is used to calculate the optical path difference based on the target electrical signal to obtain the target optical path difference of the propagation path.
[0014] According to another aspect of this disclosure, a computer device is provided, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of a method for measuring optical path difference.
[0015] According to another aspect of this disclosure, a computer-readable storage medium is provided having a computer program / instructions stored thereon, which, when executed by a processor, implement the steps of a method for measuring optical path difference. According to another aspect of this disclosure, a computer program product is provided, including a computer program / instructions that, when executed by a processor, implement the steps of a method for measuring optical path difference.
[0016] As will be described in detail below, this disclosure describes a method, apparatus, electronic device, storage medium, and product for calculating optical path difference according to embodiments of the present disclosure. By controlling the propagation path of an initial signal light source through scientific observation light, a target signal light is obtained, and the target signal light is processed to obtain the optical path difference of the propagation path. Since this method allows adjustment of the initial signal light source according to actual needs, it is unaffected by the state parameters of the scientific observation light, resulting in more accurate measurement results.
[0017] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description
[0018] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.
[0019] Figure 1 This is a flowchart of a method for measuring optical path difference provided in an embodiment of this disclosure.
[0020] Figure 2 This is a schematic diagram of the structure of an optical path difference measurement system, which is provided as an embodiment of the present disclosure for measuring optical path difference.
[0021] Figure 3 A schematic diagram of the time-position error curve of a femtosecond pulse signal processing device for measuring optical path difference according to an embodiment of this disclosure.
[0022] Figure 4 A schematic diagram of the time-error curve of a femtosecond pulse signal processing device for a method of measuring optical path difference provided in this embodiment of the present disclosure.
[0023] Figure 5 A schematic diagram of the time-position error curve of a dual-frequency interferometric signal processing device for measuring optical path difference provided in an embodiment of this disclosure.
[0024] Figure 6 A schematic diagram of the time-error curve of a dual-frequency interferometric signal processing device for measuring optical path difference provided in an embodiment of this disclosure.
[0025] Figure 7 This is a schematic diagram of an optical path difference calculation device provided in an embodiment of the present disclosure.
[0026] Figure 8This is a schematic diagram of an electronic device provided in an embodiment of the present disclosure.
[0027] Figure 9 A schematic diagram of the structure of an array telescope provided as an embodiment of the prior art. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of this disclosure more apparent, exemplary embodiments according to this disclosure will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments of this disclosure. It should be understood that this disclosure is not limited to the exemplary embodiments described herein.
[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0030] In this document, the term "and / or" merely describes a relationship, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.
[0031] Research has shown that scientific observation of light involves collecting and focusing light rays using an optical telescope. When scientific observation light propagates in different media or along different paths, differences in refractive index or path length can cause optical path differences, which leads to difficulties in optical path calibration.
[0032] In related technologies, methods such as focal plane detection, pupil plane detection, and far-field analysis are commonly used to determine the optical path difference of different media or paths by performing focal plane detection, pupil plane detection, and far-field analysis on the acquired scientific observation light. These processing methods rely on the state parameters generated during the propagation of the scientific observation light. If the state parameters of the scientific observation light are poor, such as low brightness or high propagation loss, the measurement results will be inaccurate.
[0033] Based on the above research, this disclosure provides a method for measuring optical path difference. By controlling the propagation path of the initial signal light source through the scientific observation light, a target signal light is obtained. The target signal light is then processed to obtain the optical path difference of the propagation path. Since this method allows adjustment of the initial signal light source according to actual needs, it is unaffected by the state parameters of the scientific observation light, resulting in more accurate measurement results.
[0034] To facilitate understanding of this embodiment, a method for measuring optical path difference disclosed in this disclosure will first be described in detail. The execution entity of the optical path difference calculation method provided in this disclosure is generally an electronic device with a certain computing capability. In some possible implementations, the optical path difference calculation method can be implemented by a processor calling computer-readable instructions stored in memory.
[0035] Reference Figure 1 The diagram shows a flowchart of a method for measuring optical path difference according to an embodiment of this disclosure. The method includes steps S101 to S104, wherein: S101. Determine the propagation path of the scientific observation light of the spacecraft and the initial signal source; wherein, the initial signal source includes: the initial multi-wavelength source and the initial femtosecond source.
[0036] In the embodiments of this disclosure, the propagation path of the scientific observation light inside the spacecraft payload is the path of the scientific observation light after processing to reach the beam combiner.
[0037] Among them, the processing of light for scientific observation includes at least one of the following: beam shortening and aberration correction.
[0038] Here, the beam combiner includes at least one of the following: a beam shrinking mirror, an optical delay line, and a beam combiner. After the processed scientific observation light reaches the beam combiner, the processed scientific observation light is processed by the above-mentioned device to obtain the corresponding interferometric image of the scientific observation light.
[0039] Then, astronomical information in scientifically observed light can be extracted based on the aforementioned interferometric imaging.
[0040] Here, the initial signal source can be understood as an active laser, that is, a laser beam actively emitted using laser technology. Among them, the initial multi-wavelength source can be an initial dual-frequency source.
[0041] S102. Control the initial signal light source to propagate along the propagation path, and obtain the target signal light after the beam returns.
[0042] In the embodiments of this disclosure, firstly, the initial signal light source can be controlled to pass through a beam splitter to obtain a split signal light source.
[0043] Afterwards, the beam-splittered signal light source passes through the circulator and beam splitter before reaching the propagation path. Finally, the target signal light after propagating along the propagation path is collected.
[0044] S103. Convert the target signal light into an electrical signal to obtain the target electrical signal.
[0045] In the embodiments of this disclosure, the target signal light (i.e., the first target signal light and the second target signal light hereinafter referred to as the first target signal light and the second target signal light) corresponding to the initial multi-wavelength light source and the initial femtosecond light source can be photoelectrically converted to obtain the target electrical signal.
[0046] S104. Calculate the optical path difference based on the target electrical signal to obtain the target optical path difference of the propagation path.
[0047] In the embodiments of this disclosure, the optical path difference can be calculated for the target electrical signals (i.e., the first electrical signal and the second electrical signal below) corresponding to the initial multi-wavelength light source and the initial femtosecond light source, respectively, to obtain the target optical path difference of the propagation path.
[0048] In the embodiments of this disclosure, firstly, the propagation path of the scientific observation light of the spacecraft and the initial signal source are determined; wherein, the initial signal source includes: an initial multi-wavelength source and an initial femtosecond source; secondly, the initial signal source is controlled to propagate along the propagation path, and the target signal light is obtained after the beam returns; thirdly, the target signal light is converted into an electrical signal to obtain a target electrical signal; finally, the optical path difference is calculated based on the target electrical signal to obtain the target optical path difference of the propagation path.
[0049] In the above implementation, the target signal light is obtained by controlling the propagation path of the initial signal light through the scientific observation light, and the optical path difference of the propagation path is obtained by processing the target signal light. Since this scheme allows adjustment of the initial signal light source according to actual needs, it is unaffected by the state parameters of the scientific observation light, resulting in more accurate measurement results.
[0050] In an optional embodiment, the target signal light includes a first target signal light and a second target signal light; The target signal light is converted into an electrical signal to obtain the target electrical signal, which specifically includes the following steps: First, the first target signal light is photoelectrically converted to obtain the first electrical signal; the first target signal light is the signal light source after the initial multi-wavelength light source propagates along the propagation path. Secondly, the second target signal light is photoelectrically converted to obtain a second electrical signal; wherein, the second target electrical signal is the signal light source after the initial femtosecond light source has propagated along the propagation path; Finally, the target electrical signal is determined based on the first and second electrical signals.
[0051] In the embodiments of this disclosure, the first target signal light corresponding to the initial multi-wavelength light source can be determined, that is, the first target signal light obtained after the initial multi-wavelength light source passes through the propagation path.
[0052] Since the first target signal light is determined after the initial multi-wavelength light source has traveled through its propagation path, it is necessary to perform photoelectric conversion on the first target signal light based on the dual-frequency characteristics of the multi-wavelength light source to obtain the first electrical signal.
[0053] The dual-frequency characteristic includes at least one of the following: frequency and phase.
[0054] Then, the second target signal light corresponding to the initial femtosecond light source can be determined, that is, the second target signal light obtained after the initial femtosecond light source passes through the propagation path.
[0055] Since the second target signal light source is determined after the initial femtosecond light source has traveled its propagation path, it is necessary to perform photoelectric conversion on the first target signal light based on the femtosecond characteristics of the multi-wavelength light source to obtain the first electrical signal.
[0056] The femtosecond characteristics include at least one of the following: pulse shape, pulse width, and carrier envelope phase.
[0057] Here, the first electrical signal and the second electrical signal can be collectively referred to as the target electrical signal.
[0058] In an optional embodiment, the first target signal light is photoelectrically converted to obtain a first electrical signal, specifically including the following steps: The first target signal light is subjected to polarization analysis to obtain the polarized target signal light; The polarized target signal light is photoelectrically converted to obtain the first electrical signal.
[0059] In embodiments of this disclosure, it can be achieved through the following Figure 2 The analyzer in the middle performs polarization analysis on the first target signal light to obtain the polarized target signal light.
[0060] Then, the polarized target signal light can be controlled to pass through the first photoelectric processing device (i.e., such as...). Figure 2 The PD1 shown is used for photoelectric conversion to obtain the first electrical signal.
[0061] In an optional embodiment, the second target signal light is photoelectrically converted to obtain a second electrical signal, specifically including the following steps: First, determine the local oscillator source of the initial femtosecond light source; Secondly, cross-correlation processing is performed on the signal light of the second target based on the local oscillator light source to obtain the cross-correlation signal light source; Finally, the cross-correlation signal light source is photoelectrically converted to obtain a second electrical signal.
[0062] In the embodiments of this disclosure, firstly, the local oscillator light source of the initial femtosecond light source can be subjected to signal cross-correlation processing to obtain a first cross-correlation signal (i.e., the aforementioned cross-correlation signal light source). Secondly, the second target signal light can be subjected to signal cross-correlation processing to obtain a second cross-correlation signal.
[0063] Finally, a second electrical signal can be obtained by photoelectric conversion based on the first cross-correlation signal and the second cross-correlation signal.
[0064] Among them, it can be based on the following Figure 2 The cross-correlation processing module performs cross-correlation processing. Here, the cross-correlation processing module includes: multiple half-wave plates, polarizing beam splitters (PBS), multiple collimators, lenses, and periodically polarized potassium titanium phosphate (PPKTP).
[0065] In an optional embodiment, the optical path difference is calculated based on the target electrical signal to obtain the target optical path difference of the propagation path, specifically including the following steps: First, based on the first electrical signal, the first optical path difference corresponding to the initial multi-wavelength light source is determined; Then, determine the second optical path difference corresponding to the initial femtosecond light source; Finally, the target optical path difference is determined based on the first optical path difference and the second optical path difference.
[0066] In the embodiments of this disclosure, the first electrical signal is converted from the first target signal light, and the light source is the signal after the initial multi-wavelength light source propagates.
[0067] Therefore, after acquiring the first electrical signal, spectral analysis can be performed on the first electrical signal to separate the spectral components corresponding to the two frequencies of the multi-wavelength light source, and their phase relationship can be analyzed to obtain the phase difference.
[0068] Then, based on this phase difference, the first optical path difference corresponding to the initial multi-wavelength light source can be determined.
[0069] Here, the second electrical signal is converted from the second target signal light, and this light source is the signal after the initial femtosecond light source has propagated.
[0070] Therefore, the second electrical signal can be analyzed using autocorrelation and spectral interferometry techniques to measure the changes in the time and frequency domain characteristics of the femtosecond pulse, thereby determining the relative phase delay of different frequency components and obtaining the second optical path difference corresponding to the initial femtosecond source.
[0071] Finally, the target optical path difference can be determined by combining the first optical path difference and the second optical path difference.
[0072] Here, since both reflect the optical path changes of different light sources and each has its advantages, a weighted fusion method can be used. The weights are adjusted according to the specific application scenario and measurement requirements to obtain a target optical path difference that more accurately reflects the actual propagation path, providing fundamental data for subsequent optical measurements and applications.
[0073] In an optional embodiment, the first optical path difference corresponding to the initial multi-wavelength light source is determined based on the first electrical signal, specifically including the following steps: First, the initial multi-wavelength light source is filtered to obtain the filtered multi-wavelength light source. Secondly, the filtered multi-wavelength light source is polarized and then photoelectrically converted to obtain the control dual-frequency electrical signal; Finally, based on the comparison of the dual-frequency electrical signal and the first electrical signal, multi-wavelength interferometry is performed to obtain the optical path difference containing multiple ambiguity periods, and the optical path difference containing multiple ambiguity periods is determined as the first optical path difference.
[0074] Here, you can... Figure 2 The analyzer shown performs polarization processing on the filtered multi-wavelength light source. Then, it controls the filtered multi-wavelength light source after polarization processing to undergo photoelectric conversion through the second photoelectric processing transpose (PD2) to obtain the reference dual-frequency electrical signal.
[0075] After that, it can be done through Figure 2 The dual-frequency interference signal processing module shown performs multi-wavelength interferometric measurement processing on the control dual-frequency electrical signal and the first electrical signal to obtain the first optical path difference.
[0076] Among them, the multi-wavelength interferometry method can improve the measurement ambiguity range to the millimeter level by synthesizing wavelengths, obtain nanometer-level displacement measurement results through the interference of beat frequency signals, and since the measurement accuracy of femtosecond laser is higher than the length of the ambiguity range, high-precision optical path difference results can be determined without ambiguity.
[0077] In an optional embodiment, the second optical path difference corresponding to the initial femtosecond light source is determined based on the second electrical signal, specifically including the following steps: First, determine the first and second times of the first and second light collectors in the round-trip propagation path of the initial signal source, respectively. Secondly, based on the time-of-flight method, the first and second times are processed to obtain the first distance and the second distance between the first and second light collectors and the beam combiner in the propagation path, respectively. Finally, based on the first distance and the second distance, the second optical path difference is determined.
[0078] In the embodiments of this disclosure, a dual femtosecond pulsed laser can be used, and the time-of-flight method can be employed based on the principle of optical asynchronous sampling to determine the round-trip time of the initial femtosecond light source.
[0079] Here, the initial femtosecond light source can be calculated from Figure 2 The absolute distance values from the first and second light collectors to the beam combiner are shown as first distance L1 and second distance L2, respectively, with an accuracy better than 10 micrometers.
[0080] Here, in a vacuum environment (n=1), the absolute value of the difference between the first distance L1 and the second distance L2 can be determined as the second optical path difference C2. The second optical path difference C2 satisfies the following condition: C2=|L1-L2|.
[0081] Reference Figure 2 The diagram shown is a structural schematic of an optical path difference measurement system according to an embodiment of this disclosure, comprising: The system includes a propagation path consisting of multiple light collectors, a navigation camera, and a reflector; multiple beam splitters; multiple analyzers; multiple photoelectric processing devices; a dual-frequency interference signal processing device; a cross-correlation processing module; and a femtosecond pulse signal processing device.
[0082] Among them, the propagation path consisting of multiple light collectors, navigation cameras, and reflectors, and multiple beam splitters belong to the observation optical system; multiple analyzers, multiple photoelectric processing devices, dual-frequency interference signal processing devices, cross-correlation processing modules, and femtosecond pulse signal processing devices belong to the active laser internal metrology optical system.
[0083] The observation optical system and the active laser internal metrology optical system are designed with a common optical path.
[0084] Among them, the light collector is used to collect the signal light source; the navigation camera is used to ensure that the laser is effectively transmitted to the measurement target; the beam splitter is used to split the signal light source; and the polarizer is used to analyze the polarization of the signal light from the first target.
[0085] The photoelectric processing device is used to perform photoelectric conversion on the polarized target signal light and the initial multi-wavelength light source; the dual-frequency interference signal processing device is used to calculate the optical path difference of the first electrical signal to obtain the first optical path difference; the femtosecond pulse signal processing device is used to calculate the optical path difference of the second electrical signal to obtain the second optical path difference.
[0086] The cross-correlation processing module includes: multiple half-wave plates, a polarizing beam splitter (PBS), multiple collimators, lenses, and periodically polarized potassium titanium phosphate (PPKTP); used to perform cross-correlation processing on the second target signal light and the initial femtosecond light source based on the local oscillator light source distribution.
[0087] In the above implementation, the target signal light is obtained by controlling the propagation path of the initial signal light through the scientific observation light, and the optical path difference of the propagation path is obtained by processing the target signal light. Since this scheme allows adjustment of the initial signal light source according to actual needs, it is unaffected by the state parameters of the scientific observation light, resulting in more accurate measurement results.
[0088] In an optional embodiment, the target optical path difference is determined based on the first optical path difference and the second optical path difference, specifically including the following steps: Determine the positional deviation of the light observed in scientific studies; The third optical path difference is obtained by deblurring the first optical path difference based on the second optical path difference. The target optical path difference is determined based on the positional deviation, the third optical path difference, and the second optical path difference for the propagation path of the initial signal light source.
[0089] In embodiments of this disclosure, it is possible to... Figure 2 The navigation camera shown takes pictures of the LED target on the light collector, determines the spacecraft's position deviation on the xy plane perpendicular to the baseline z direction, with an accuracy better than 5 milliarcseconds, and corrects the deviation to the millimeter level.
[0090] After determining the positional deviation, the propagation path of the initial signal source can be constrained by the positional deviation, the second optical path difference, and the third optical path difference to determine the target optical path difference.
[0091] Reference Figure 3 The figure shown is a schematic diagram of the time-position error curve of a femtosecond pulse signal processing device for measuring optical path difference according to an embodiment of this disclosure, wherein: the horizontal axis is time and the vertical axis is position.
[0092] The unit of time is s (seconds), and the unit of position is m (meters). The error curve of the time-position relationship can be determined through simulation calculation.
[0093] Reference Figure 4 The figure shown is a schematic diagram of the time-error curve of a femtosecond pulse signal processing device for measuring optical path difference according to an embodiment of this disclosure, where: the horizontal axis is time and the vertical axis is the difference.
[0094] The unit of time is s (seconds), and the unit of error is m (meters). The above time-position error curve can be determined through simulation calculation.
[0095] Reference Figure 5 The figure shown is a schematic diagram of the time-position error curve of a dual-frequency interferometric signal processing device for measuring optical path difference according to an embodiment of the present disclosure, wherein: the horizontal axis is time and the vertical axis is position.
[0096] The unit of time is s (seconds), and the unit of position is m (meters). The error curve of the time-position relationship can be determined through simulation calculation.
[0097] Reference Figure 6 The figure shown is a schematic diagram of the time-error curve of a dual-frequency interferometric signal processing device for measuring optical path difference according to an embodiment of this disclosure, where: the horizontal axis is time and the vertical axis is the difference.
[0098] The unit of time is s (seconds), and the unit of error is m (meters). The above time-position error curve can be determined through simulation calculation.
[0099] In actual operation, this solution can produce the following technical effects: (1) Throughout the entire on-orbit observation cycle, the optical path difference between sub-telescopes can be accurately measured and controlled without being affected by the brightness of the scientific target, thus ensuring the detection of combined light interferometry imaging.
[0100] (2) By designing the active laser internal metrology optical system and the observation optical system to share the same optical path, the two working modes of metrology and observation are based on the same reference, thus avoiding the increase in load complexity and the introduction of redundant errors caused by multiple coordinate reference transformations.
[0101] (3) The noncoherent time-of-flight ranging technology used can realize dynamic high-frequency measurement of the absolute distance between spacecraft at the hundred-meter level, with measurement accuracy reaching the micrometer level.
[0102] (4) The multi-wavelength coherent measurement method can expand the ambiguity range compared with the single-wavelength coherent measurement method, so that the accuracy of the non-coherent measurement can be connected with its ambiguity range, and realize unambiguous nanometer-level optical path difference high-frequency measurement.
[0103] Based on the same inventive concept, this disclosure also provides an optical path difference calculation device corresponding to the optical path difference calculation method. Since the principle of the device in this disclosure for solving the problem is similar to the optical path difference calculation method described above in this disclosure, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be described again.
[0104] Reference Figure 7 The diagram shown is a schematic of an optical path difference calculation device provided in an embodiment of this disclosure. The device includes: a signal generation module 11, a propagation module 12, a conversion module 13, and a calculation module 14; wherein: The signal generation module 11 is used to determine the propagation path of the scientific observation light of the spacecraft and the initial signal source; wherein, the initial signal source includes: an initial multi-wavelength source and an initial femtosecond source; The propagation module 12 is used to control the initial signal light source to propagate along the propagation path, and the target signal light is obtained after the beam returns; Conversion module 13 is used to convert the target signal light into an electrical signal to obtain a target electrical signal; Calculation module 14 is used to calculate the optical path difference based on the target electrical signal to obtain the target optical path difference of the propagation path.
[0105] This embodiment obtains the target signal light by controlling the propagation path of the initial signal light source through the scientific observation light, and then processes the target signal light to obtain the optical path difference of the propagation path. Because this scheme allows adjustment of the initial signal light source according to actual needs, it is unaffected by the state parameters of the scientific observation light, resulting in more accurate measurement results.
[0106] The processing flow of each module in the device and the interaction flow between each module can be referred to the relevant descriptions in the above method embodiments, and will not be detailed here.
[0107] Corresponding to Figure 1 In addition to the method for determining perceived information, this disclosure also provides an electronic device 800, such as... Figure 8 The diagram shown is a structural schematic of an electronic device 800 provided in an embodiment of this disclosure, including: The system includes a processor 81, a memory 82, and a bus 83. The memory 82 stores execution instructions and includes main memory 821 and external memory 822. The main memory 821, also called internal memory, temporarily stores the computational data in the processor 81, as well as data exchanged with external memory such as a hard disk. The processor 81 exchanges data with the external memory 822 through the main memory 821. When the electronic device 800 is running, the processor 81 communicates with the memory 82 through the bus 83, causing the processor 81 to execute the following instructions: Determine the propagation path of the scientific observation light from the spacecraft and the initial signal source; wherein, the initial signal source includes: an initial multi-wavelength source and an initial femtosecond source; The initial signal light source is controlled to propagate along the propagation path, and the target signal light is obtained after the beam returns; The target signal light is converted into an electrical signal to obtain the target electrical signal; The optical path difference of the propagation path is obtained by calculating the optical path difference based on the target electrical signal.
[0108] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.
[0109] The block diagrams of devices, apparatuses, devices, and systems disclosed herein are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.
[0110] Additionally, as used herein, the "or" used in a list of items beginning with "at least one" indicates a separate list, such that a list of, for example, "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not imply that the described example is preferred or better than other examples.
[0111] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.
[0112] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.
[0113] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.
[0114] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.
Claims
1. A method for measuring optical path difference, characterized in that, include: Determine the propagation path of the scientific observation light from the spacecraft and the initial signal source; wherein, the initial signal source includes: an initial multi-wavelength source and an initial femtosecond source; The initial signal light source is controlled to propagate along the propagation path, and the target signal light is obtained after the beam returns; The target signal light is converted into an electrical signal to obtain the target electrical signal; The optical path difference of the propagation path is obtained by calculating the optical path difference based on the target electrical signal.
2. The method as described in claim 1, characterized in that, The target signal light includes a first target signal light and a second target signal light; The step of converting the target signal light into an electrical signal to obtain the target electrical signal includes: The first target signal light is photoelectrically converted to obtain a first electrical signal; the first target signal light is the signal after the initial multi-wavelength light source has propagated along the propagation path. The second target signal light is photoelectrically converted to obtain a second electrical signal; wherein, the second target electrical signal is the signal after the initial femtosecond light source has propagated along the propagation path; The target electrical signal is determined based on the first electrical signal and the second electrical signal.
3. The method as described in claim 2, characterized in that, The step of photoelectric conversion of the first target signal light to obtain a first electrical signal includes: The first target signal light is subjected to polarization analysis to obtain the polarized target signal light; The polarized target signal light is photoelectrically converted to obtain a first electrical signal.
4. The method as described in claim 2, characterized in that, The step of photoelectric conversion of the second target signal light to obtain a second electrical signal includes: Determine the local oscillator of the initial femtosecond light source; Based on the local oscillator light source, the second target signal light is subjected to signal cross-correlation processing to obtain a cross-correlation signal; The cross-correlation signal is photoelectrically converted to obtain a second electrical signal.
5. The method as described in claim 2, characterized in that, The step of calculating the optical path difference based on the target electrical signal to obtain the target optical path difference of the propagation path includes: Based on the first electrical signal, the first optical path difference corresponding to the initial multi-wavelength light source is determined; Determine the second optical path difference corresponding to the initial femtosecond light source; The target optical path difference is determined based on the first optical path difference and the second optical path difference.
6. The method as described in claim 5, characterized in that, The step of determining the first optical path difference corresponding to the initial multi-wavelength light source based on the first electrical signal includes: The initial multi-wavelength light source is filtered to obtain a filtered multi-wavelength light source; After polarization analysis of the filtered multi-wavelength light source, photoelectric conversion is performed to obtain the control dual-frequency electrical signal; Interference measurement processing is performed based on the reference dual-frequency electrical signal and the first electrical signal to obtain an optical path difference containing multiple ambiguity periods, and the optical path difference containing multiple ambiguity periods is determined as the first optical path difference.
7. The method as described in claim 5, characterized in that, Determining the second optical path difference corresponding to the initial femtosecond light source includes: Determine the first time and the second time, respectively, of the initial signal light source to and from the first and second light collectors in the propagation path; Based on the time-of-flight method, the first time and the second time are processed to obtain the first distance and the second distance between the first light collector and the second light collector and the beam combiner in the propagation path, respectively. The second optical path difference is determined based on the first distance and the second distance.
8. The method as described in claim 5, characterized in that, Determining the target optical path difference based on the first optical path difference and the second optical path difference includes: Determine the positional deviation of the light observed in scientific studies; The first optical path difference is deblurred based on the second optical path difference to obtain the third optical path difference; The target optical path difference is determined based on the positional deviation, the third optical path difference, and the second optical path difference for the propagation path of the initial signal light source.
9. A device for measuring optical path difference, characterized in that, include: The signal generation module is used to determine the propagation path of the scientific observation light of the spacecraft and the initial signal source; wherein, the initial signal source includes: an initial multi-wavelength source and an initial femtosecond source; The propagation module is used to control the initial signal light source to propagate along the propagation path, and the target signal light is obtained after the beam returns; The conversion module is used to convert the target signal light into an electrical signal to obtain the target electrical signal; The calculation module is used to calculate the optical path difference based on the target electrical signal to obtain the target optical path difference of the propagation path.
10. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the optical path difference calculation method according to claims 1 to 8.
11. A computer-readable storage medium having a computer program / instructions stored thereon, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method for calculating the optical path difference as described in claims 1 to 8.
12. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method for calculating the optical path difference as described in claims 1 to 8.