High temporal and spatial resolution and high sensitivity detection system and detection method based on time series coding

Abstract

The present invention provides a high-temporal-spatial resolution and high-sensitivity detection system and method based on time-series coding, comprising: a coupler, an optical fiber, and a high-sensitivity detector; the light beam echo emitted by the object to be measured is incident on the coupler, and the couplers are arranged at equal intervals in space according to the range of the light beam echo emitted by the object to be measured; each coupler is connected to the detector via an optical fiber; the number of couplers is the same as the number of optical fibers, and the optical fiber is provided with an optical fiber delay line, which is used to phase-delay the light beam echo; the optical fiber is also provided with an optical switch, which is used to time-series code different optical fibers, allowing the detector to receive a pulse distribution diagram of the object to be measured under a large field of view; and the distance to the object to be measured is calculated based on the pulse distribution diagram. The system adopts an optical fiber interconnection architecture and collects and transmits photons through optical waveguides, overcoming the shortcomings of large spatial span light input, such as large space occupation and high weight, and achieving high-precision spatial target positioning.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to a high-temporal-spatial resolution and high-sensitivity detection system and detection method based on time series coding. Background Art

[0002] When the space telescope reaches the designated position, its lenses unfold. When the telescope can collect golden light, a fiber optic internet prism system is set up on the same surface. The light points of each lens are tracked one by one. After the position of each light point is obtained, the position of each light point is adjusted to the common focus.

[0003] Large-aperture space-deployable telescopes face the challenge of balancing detection dynamic range and accuracy during their in-orbit deployment. To ensure that the system's output wavefront approaches the ideal wavefront through sparse sampling, it is necessary to suppress the system's common phase error and achieve coherent synthesis. Traditional synthetic aperture systems often use bulk optical elements such as cat's-eye systems to achieve optical path modulation, which is not only bulky but also difficult to assemble and adjust.

[0004] Extremely high angular resolution can be achieved through long-baseline optical and infrared interferometry. However, traditional interferometer arrays are limited by the number of telescopes and the freedom of baseline configuration. Subsequent data processing relies heavily on prior physics and cosmological models. Furthermore, the limited light-collecting area hinders further improvements in back-end instrument sensitivity. Currently, only the CHARA interferometer array at Mount Wilson Observatory in the United States and the VLTI at the European Southern Observatory in Chile are capable of interferometric imaging of four telescopes larger than one meter. Summary of the Invention

[0005] In view of the above problems, the purpose of the present invention is to propose a high temporal and spatial resolution and high sensitivity detection system and detection method based on time coding. By utilizing optical fiber interconnection and aperture rearrangement technology, it can make full use of existing telescopes for flexible baseline configuration, and by improving spatial resolution, it can achieve more precise imaging and geometric measurement.

[0006] To achieve the above objectives, the present invention adopts the following specific technical solutions:

[0007] The present invention provides a high temporal and spatial resolution and high sensitivity detection system based on time sequence coding, comprising: a coupler, an optical fiber and a high sensitivity detector;

[0008] Solid-state detection is achieved by emitting a light beam to illuminate the object to be measured, generating a large number of beam echoes that are incident on the coupler. The couplers are arranged at equal intervals in space according to the reporting range of the beam reflected by the object to be measured; each coupler is connected to a highly sensitive detector via an optical fiber.

[0009] The number of couplers is the same as that of optical fibers, and an optical fiber delay line is provided on the optical fiber to perform phase delay on the light beam echo;

[0010] An optical switch is also provided on the optical fiber, which is used to perform time coding on different optical fibers, so that the highly sensitive detector receives the pulse distribution diagram of the object to be measured under a large field of view; and calculates the distance of the object to be measured based on the pulse distribution diagram.

[0011] Preferably, the lengths of the optical fiber delay lines of different optical fibers are different, that is, the phase delay amounts to the light beam echo are also different; that is, the magnitude of the phase delay amount is determined by the length of the optical fiber delay line.

[0012] Preferably, a delay compensation line is further provided on the optical fiber, and the delay compensation line is used to compensate for the delay amount generated by the optical fiber delay line, so that the phase delay amount is more accurate.

[0013] The present invention also provides a high temporal and spatial resolution and high sensitivity detection method based on time sequence coding, comprising the following steps:

[0014] S1. The light beam emitted by the target to be measured passes through the coupler array, generates different phase delays through different optical fibers, and is time-coded by the optical switch before being incident on a high-sensitivity detector.

[0015] S2. Detecting with a highly sensitive detector to obtain a pulse distribution diagram of photons in different directions of the object to be measured;

[0016] S3, fitting the outer contour of the pulse distribution diagram by a Gaussian function and calculating the vertex position of the outer contour, that is, obtaining the time Δt corresponding to the vertex widening position;

[0017] S4. Calculate the distance ΔL of the object to be measured based on the time Δt. The formula is as follows:

[0018] ΔL≥Δt·c / 2n

[0019] Where c is the speed of light and n is the refractive index of the medium.

[0020] Compared to existing technologies, this invention employs a discrete subaperture sampling method, combining the sampling of multiple subapertures with the eigenmode decomposition of the wavefront to achieve wavefront sensing. It also employs a fiber-optic interconnect architecture, collecting and transmitting photons via optical waveguides, overcoming the drawbacks of large spatial spans, such as the large space occupied and heavy weight of light input. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 3 is a schematic structural diagram of a high temporal and spatial resolution and high sensitivity detection system based on time series coding provided according to an embodiment of the present invention.

[0022] Figure 23 is a flow chart of a high spatiotemporal resolution and high sensitivity detection method based on time series coding provided according to an embodiment of the present invention.

[0023] The reference numerals include: object to be measured 1 , coupler 2 , delay compensation line 3 , optical switch 4 , optical fiber 5 , optical fiber delay line 51 and high-sensitivity detector 6 . DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical modules are denoted by identical reference numerals. In the case of identical reference numerals, their names and functions are also identical. Therefore, their detailed description will not be repeated.

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0026] Figure 1 The structure of a high temporal and spatial resolution and high sensitivity detection system based on time series coding provided according to an embodiment of the present invention is shown.

[0027] like Figure 1 As shown, the structure of the high spatiotemporal resolution and high sensitivity detection system based on timing coding provided by an embodiment of the present invention includes: an object to be measured 1, a coupler 2, a delay compensation line 3, an optical switch 4, an optical fiber 5, an optical fiber delay line 51 and a high sensitivity detector 6.

[0028] By emitting a large number of multi-angle light beams to illuminate the object 1 to be measured, the light beams generate a large range of light beam echoes after irradiating the object 1 to be measured, which are incident on the coupler 2 to achieve solid-state detection. The couplers 2 are arranged at equal intervals according to the range of the light beam echoes reflected by the object 1 to be measured;

[0029] Each coupler 2 is connected to a highly sensitive detector 6 via an optical fiber 5. The highly sensitive detector 6 receives the beam echo and generates a pulse profile. The number of couplers 2 and optical fibers 5 is the same. Utilizing optical fibers to provide phase delay and effectively reduce the dead time of the highly sensitive photon detector further improves the temporal and spatial resolution of detection. By delaying multiple optical fibers 5, the point detector can be expanded, and temporal encoding can be used to achieve the same effect as a surface detector.

[0030] The optical fiber 5 is also provided with a delay compensation line 3, an optical switch 4 and an optical fiber delay line 51 in sequence.

[0031] Stretched optical fiber is used to achieve optical path delay. In order to address the degradation of interference fringe contrast caused by factors such as ambient temperature changes, vibration and bending during the actual detection process, fringe tracking technology is used to perform closed-loop control of the optical path difference to ensure the stability of the wavefront and ultimately achieve coherent synthesis.

[0032] The basic principle of fringe tracking technology is to rely on rapid scanning of the fringe pattern, feed back the position information of the obtained interference fringes to the servo controller, calculate the randomly changing phase delay and group delay of each baseline in real time, and adjust the optical path difference by controlling the optical delay line or actuator to make the fringe jitter much smaller than the fringe interval, thereby stabilizing the fringes.

[0033] The optical fiber delay line 51 is used to delay the optical path difference of the scattered light received by the coupler 2 . The lengths of the optical fiber delay lines 51 of different optical fibers 5 are different, and the delay amounts generated are also different.

[0034] The amount of delay is determined by the length of the optical fiber delay line 51 .

[0035] The delay compensation line 3 is used to compensate for the delay generated by the optical fiber delay line 51 to make it more accurate.

[0036] The optical switch 4 is used to control the opening and closing of the optical fiber path in which it is located. The optical switch 4 is used to perform timing coding to reduce crosstalk between different optical fiber channels and realize large field of view detection of the highly sensitive detector 6.

[0037] The present invention utilizes the optical path adjustment between different optical fibers to achieve the adjustment of the overall optical coupling direction, replacing the traditional deflection measurement method.

[0038] Figure 2 The flowchart of the high spatiotemporal resolution and high sensitivity detection method based on time series coding provided according to an embodiment of the present invention is shown.

[0039] like Figure 2 As shown, the high temporal and spatial resolution and high sensitivity detection method based on time series coding provided by the embodiment of the present invention includes the following steps:

[0040] S1. The light beam emitted by the target to be measured is time-coded through phase delays and optical switches of different optical fibers and then incident on a high-sensitivity detector.

[0041] S2. Detection is performed using a highly sensitive detector to obtain a pulse distribution diagram of photons in different directions of the object to be measured.

[0042] S3. Fit the outer contour of the pulse distribution diagram using a Gaussian function and calculate the vertex position of the outer contour, that is, obtain the time Δt corresponding to the pulse peak broadening position.

[0043] S4. Calculate the distance ΔL from the object to be detected to the detection system provided by the present invention based on the time Δt. The formula is as follows:

[0044] ΔL≥Δt·c / 2n

[0045] Where c is the speed of light and n is the refractive index of the medium;

[0046] Δt=Δt 色散 +Δt 散射 +Δt 几何 ;

[0047] By continuously sending light pulses to the target, and then using the sensor to receive the light returned from the object to be measured, the distance to the target to be measured is obtained by detecting the flight (round-trip) time of the light pulses.

[0048] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0049] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A high-temporal-resolution and high-sensitivity detection method based on time-series coding, implemented using a high-temporal-resolution and high-sensitivity detection system, wherein the high-temporal-resolution and high-sensitivity detection system comprises a coupler, an optical fiber, and a high-sensitivity detector, wherein the number of the couplers is the same as the number of the optical fibers, each coupler is connected to the high-sensitivity detector via the optical fiber, the optical fiber is provided with an optical fiber delay line, and the optical fiber is also provided with an optical switch, characterized in that: The following steps are involved: S1. The light beam emitted by the object to be measured passes through the coupler array, generates different phase delays through different optical fibers, and is time-coded by the optical switch before being incident on a high-sensitivity detector; S2. Detecting with the highly sensitive detector to obtain a pulse distribution diagram of photons of the object to be measured in different directions; S3, fitting the outer contour of the pulse distribution diagram by a Gaussian function and calculating the vertex position of the outer contour, that is, obtaining the time Δt corresponding to the vertex widening position; S4. Calculate the distance ΔL of the object to be measured according to the time Δt, using the following formula: ΔL≥Δt·c / 2n Where c is the speed of light and n is the refractive index of the medium.

2. The high temporal and spatial resolution and high sensitivity detection method based on time series coding according to claim 1 is characterized in that: The lengths of the optical fiber delay lines between different optical fibers are different, that is, the phase delay amounts to the light beam echo are also different; that is, the magnitude of the phase delay amount is determined by the length of the optical fiber delay line.

3. The high temporal and spatial resolution and high sensitivity detection method based on time series coding according to claim 2 is characterized in that: A delay compensation line is also provided on the optical fiber, and the delay compensation line is used to compensate for the delay amount generated by the optical fiber delay line, so that the phase delay amount is more accurate.

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