Optical time delay estimation apparatus and method
Patent Information
- Application Number
- CN202510560749.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2026-10-30
AI Technical Summary
二分光谱探测模块的固定光谱特性限制了其对光源频率变化的适应性，并且实现精确的光谱分割性能通常需要付出较大的成本
[0015]根据本公开的实施例，利用第一光纤光栅实现对第一光束基于第一反射谱的反射，利用第二光纤光栅实现对第二光束基于第二反射谱的反射，根据反射后的第三光束和第四光束的光强信息，得到待测光时延信息，利用探测组件可以实时获取第三光束和第四光束的光强信息，从而实现光时延的高精度实时估计。本公开实施例的光时延估计装置结构简单，第一光纤光栅和第二光纤光栅可以基于第一反射谱和第二反射谱进行设计，制备成本相对较低，使用便利，提高了对光源频率变化的适应性。
Smart Images
Figure CN123007977A_ABST
Abstract
Description
Technical Field
[0001] At least one embodiment of this disclosure relates to the field of weak measurement computation, and more specifically to an optical delay estimation apparatus and method. Background Technology
[0002] Real-time and high-precision optical time delay estimation techniques play a crucial role in many applications, such as distributed fiber optic sensing, inertial navigation systems, and gravitational wave observation. Since changes in optical time delay are typically small, optical interferometry is generally used for estimation. However, since its inception, weak measurement techniques have emerged as a promising alternative in precision measurement due to their significant amplification effect and ability to suppress technical noise. In optical time delay estimation tasks, weak measurement techniques can achieve a three-order-of-magnitude improvement in sensitivity compared to standard optical interferometry. However, spectrometer-based weak measurement optical time delay estimation methods utilize high-precision spectrometers to acquire all spectral information, thereby extracting necessary information from spectral variations.
[0003] In related technologies, methods for estimating the optical delay of weak measurements based on spectrometers require long integration times, limiting their applicability to detecting time-varying signals. Furthermore, weak measurement methods based on bisecting spectral detection modules use the center wavelength of the light source as the boundary spectrum, calculating the offset by collecting the optical power on the left and right sides, and extracting necessary information from spectral changes. However, the fixed spectral characteristics of bisecting spectral detection modules limit their adaptability to changes in light source frequency, and achieving accurate spectral segmentation performance typically requires significant costs. Summary of the Invention
[0004] In view of the above problems, this disclosure provides a real-time and high-precision optical delay estimation device and method that can improve applicability.
[0005] According to a first aspect of this disclosure, an optical delay estimation apparatus is provided, comprising: a weak measurement component for outputting a first beam and a second beam containing optical delay information to be measured based on a probe light; a first fiber grating for reflecting the first beam based on a first reflection spectrum to obtain a third beam; a second fiber grating for reflecting the second beam based on a second reflection spectrum to obtain a fourth beam; wherein the center angular frequencies of the first reflection spectrum and the second reflection spectrum are symmetrical about the center angular frequency of the probe light spectrum; and a detection component for detecting the light intensity of the third beam and the fourth beam, and obtaining the optical delay information to be measured based on the light intensity of the third beam and the fourth beam.
[0006] According to embodiments of this disclosure, the first fiber grating and the second fiber grating have the same reflectivity; the first reflection spectrum and the second reflection spectrum have the same bandwidth.
[0007] According to an embodiment of this disclosure, the detection component obtains the light intensity ratio based on the light intensity of the third beam and the fourth beam; and obtains the light delay information of the light to be measured based on the light intensity ratio, the spectral information of the detection light, the spectral information of the first reflection spectrum and the second reflection spectrum.
[0008] According to an embodiment of this disclosure, the first fiber optic grating includes: a first grating for reflecting the first light beam based on a first reflection spectrum; a first circulator for receiving the first light beam from the weak measurement component, transmitting the first light beam to the first grating, and transmitting the third light beam reflected by the first grating to the detection component; the second fiber optic grating includes: a second grating for reflecting the second light beam based on a second reflection spectrum; a second circulator for receiving the second light beam from the weak measurement component, transmitting the second light beam to the second grating, and transmitting the fourth light beam reflected by the second grating to the detection component.
[0009] According to an embodiment of this disclosure, the aforementioned weak measurement component includes: a light source for outputting the probe light; a first polarization device for modulating the probe light into a pre-selection state to obtain a probe light in the pre-selection state; a first weak interaction device for weakly interacting an external signal with the probe light in the pre-selection state to introduce the time delay information of the light to be measured into the probe light in the pre-selection state to obtain a first weak interaction light; a second polarization device for modulating the first weak interaction light into a post-selection state to obtain an output light in the post-selection state; wherein the polarization angle between the pre-selection state and the post-selection state is a preset angle; and a beam splitter for proportionally splitting the output light to obtain the first beam and the second beam, respectively.
[0010] According to an embodiment of this disclosure, the weak measurement component further includes: a second weak action device, used to obtain a second weak action light by introducing a reference time delay signal into the first weak action light, so as to adjust the detection area of the light time delay information to be measured from the first interval to the second interval; wherein the second interval has a higher detection sensitivity than the first interval; and a second polarization device, used to modulate the second weak action light into the post-selection state to obtain the output light.
[0011] According to an embodiment of this disclosure, the first polarization device includes a first polarizer for modulating the polarization state of the probe light to obtain the preselection state.
[0012] According to an embodiment of this disclosure, the second polarizing device includes a second polarizer for modulating the polarization state of the first weakly acting light to obtain the post-selected state.
[0013] According to an embodiment of this disclosure, the detection component includes: a balanced detector for receiving the third beam and the fourth beam, and outputting the light intensity of the third beam and the fourth beam.
[0014] Another aspect of this disclosure provides an optical delay estimation method applied to the aforementioned optical delay estimation apparatus. The method includes: using a weak measurement component to output a first beam and a second beam containing optical delay information to be measured based on a probe light; using a first fiber grating to reflect the first beam based on a first reflection spectrum to obtain a third beam; using a second fiber grating to reflect the second beam based on a second reflection spectrum to obtain a fourth beam; wherein the center angular frequencies of the first and second reflection spectra are symmetrical about the center angular frequency of the probe light spectrum; using a detection component to detect the light intensity of the third and fourth beams, and obtaining the optical delay information to be measured based on the light intensity of the third and fourth beams.
[0015] According to embodiments of this disclosure, a first fiber optic grating is used to reflect a first light beam based on a first reflection spectrum, and a second fiber optic grating is used to reflect a second light beam based on a second reflection spectrum. Based on the intensity information of the reflected third and fourth light beams, the optical delay information to be measured is obtained. A detection component can be used to acquire the intensity information of the third and fourth light beams in real time, thereby achieving high-precision real-time estimation of the optical delay. The optical delay estimation device of this disclosure has a simple structure; the first and second fiber optic gratings can be designed based on the first and second reflection spectra, resulting in relatively low manufacturing costs, ease of use, and improved adaptability to changes in light source frequency. Attached Figure Description
[0016] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:
[0017] Figure 1 This schematic diagram illustrates the principle of an optical delay estimation apparatus according to an embodiment of the present disclosure;
[0018] Figure 2 This schematic diagram illustrates the principle of an optical delay estimation apparatus according to an embodiment of the present disclosure;
[0019] Figure 3 A schematic diagram illustrating the principle of an optical delay estimation apparatus according to another embodiment of the present disclosure is shown; and
[0020] Figure 4 The schematic diagram illustrates the principle of an optical delay estimation apparatus according to another embodiment of the present disclosure. Detailed Implementation
[0021] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.
[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.
[0023] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.
[0024] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).
[0025] Optical time-delay signals refer to the time delay phenomenon that occurs during the propagation of optical signals due to the finite speed of light. The phase of an optical signal is a physical quantity describing the changes in light waves in space and time. Optical time-delay signals cause changes in the phase of the optical signal. The amount of phase change is proportional to the frequency of the optical signal and the optical time delay. The relationship between the phase change and the optical time delay is described by angular frequency; the phase change is equal to the product of the angular frequency and the optical time delay.
[0026] This disclosure provides an optical delay estimation device and method, which aims to solve at least one of the above-mentioned technical problems.
[0027] Figure 1 The schematic diagram illustrates the principle of an optical delay estimation apparatus according to an embodiment of the present disclosure.
[0028] like Figure 1 As shown, the optical delay estimation device includes a weak measurement component 110, a first fiber grating 120, a second fiber grating 130, and a detection component 140.
[0029] According to embodiments of this disclosure, a weak measurement component 110 is used to output a first beam and a second beam containing time delay information of the light to be measured based on a probe light. A first fiber grating 120 is used to reflect the first beam based on a first reflection spectrum to obtain a third beam. A second fiber grating 130 is used to reflect the second beam based on a second reflection spectrum to obtain a fourth beam; wherein the center angular frequencies of the first and second reflection spectra are symmetrical about the center angular frequency of the probe light spectrum. A detection component 140 is used to detect the light intensity of the third and fourth beams, and obtain the time delay information of the light to be measured based on the light intensity of the third and fourth beams.
[0030] According to embodiments of this disclosure, the weak measurement component 110, based on the spectral information of the probe light, introduces the time delay information of the light to be measured according to the weak action principle, thereby obtaining a first beam and a second beam containing the time delay information of the light to be measured. The first beam and the second beam originate from the same beam and have the same spectral information. The spectral information of the first beam and the second beam output by the weak measurement component 110 through the weak measurement principle evolves according to the change of the light time delay information over time.
[0031] In one example, the first reflection spectrum can be a distribution of the intensity of the reflected light from the first fiber grating as a function of angular frequency. The center angular frequency of the first reflection spectrum can be the angular frequency corresponding to the maximum reflection intensity (or a specific feature point) in the first reflection spectrum. The second reflection spectrum can be a distribution of the intensity of the reflected light from the second fiber grating as a function of angular frequency. The center angular frequency of the second reflection spectrum can be the angular frequency corresponding to the maximum reflection intensity (or a specific feature point) in the second reflection spectrum. Based on the light intensities of the reflected third and fourth beams, the time delay information of the light under test is calculated.
[0032] According to embodiments of this disclosure, a first fiber optic grating is used to reflect a first light beam based on a first reflection spectrum, and a second fiber optic grating is used to reflect a second light beam based on a second reflection spectrum. Based on the intensity information of the reflected third and fourth light beams, the optical delay information to be measured is obtained. A detection component can be used to acquire the intensity information of the third and fourth light beams in real time, thereby achieving high-precision real-time estimation of the optical delay. The optical delay estimation device of this disclosure has a simple structure; the first and second fiber optic gratings can be designed based on the first and second reflection spectra, resulting in relatively low manufacturing costs, ease of use, and improved adaptability to changes in light source frequency.
[0033] According to embodiments of this disclosure, the first fiber grating and the second fiber grating have the same reflectivity; the first reflection spectrum and the second reflection spectrum have the same bandwidth.
[0034] According to embodiments of this disclosure, a first fiber optic grating can achieve the reflection characteristics of a first reflection spectrum through proper design and parameter optimization. A second fiber optic grating can achieve the reflection characteristics of a second reflection spectrum through proper design and parameter optimization.
[0035] The first beam, after being reflected by the first fiber grating based on the first reflection spectrum, yields the third beam. The first reflection spectrum can be expressed as:
[0036] (1);
[0037] in, This represents the reflectivity of the first fiber grating; Indicates the center angular frequency of the first reflection spectrum; This represents the bandwidth of the first reflection spectrum.
[0038] The second beam, after being reflected by the second fiber grating based on the second reflection spectrum, yields the fourth beam. The second reflection spectrum can be expressed as:
[0039] (2);
[0040] in, This indicates the reflectivity of the second fiber grating; Indicates the center angular frequency of the second reflection spectrum; This indicates the bandwidth of the second reflection spectrum.
[0041] According to embodiments of this disclosure, the detection component obtains the light intensity ratio based on the light intensities of the third beam and the fourth beam.
[0042] Calculate the intensity ratio of the third and fourth beams. .
[0043] (3);
[0044] in, Indicates the light intensity of the third beam; This indicates the intensity of the fourth beam.
[0045] Figure 2 The schematic diagram illustrates the principle of an optical delay estimation device according to an embodiment of the present disclosure.
[0046] like Figure 2 As shown, according to an embodiment of this disclosure, the first fiber Bragg grating 120 includes a first grating 121 and a first circulator 122. The second fiber Bragg grating 130 includes a second grating 131 and a second circulator 132.
[0047] According to embodiments of this disclosure, a first grating 121 is used to reflect a first light beam based on a first reflection spectrum. A first circulator 122 is used to receive the first light beam from the weak measurement component 110, transmit the first light beam to the first grating 121, and transmit a third light beam reflected by the first grating 121 to the detection component 140. A second grating 131 is used to reflect a second light beam based on a second reflection spectrum. A second circulator 132 is used to receive the second light beam from the weak measurement component 110, transmit the second light beam to the second grating 131, and transmit a fourth light beam reflected by the second grating 131 to the detection component 140.
[0048] Figure 3 The schematic diagram illustrates the principle of an optical delay estimation apparatus according to another embodiment of the present disclosure.
[0049] like Figure 3 As shown, according to an embodiment of the present disclosure, the weak measurement component 110 includes a light source 111, a first polarizing device 112, a first weak-acting device 113, a second polarizing device 114, and a beam splitter 115.
[0050] According to embodiments of this disclosure, light source 111 is used to output probe light. First polarization device 112 is used to modulate the probe light into a pre-selected state, obtaining probe light in the pre-selected state. First weak interaction device 113 is used to weakly interact an external signal with the probe light in the pre-selected state to introduce the time delay information of the light to be measured into the probe light in the pre-selected state, obtaining first weak interaction light. Second polarization device 114 is used to modulate the first weak interaction light into a post-selected state, obtaining output light in the post-selected state; wherein the polarization angle between the pre-selected state and the post-selected state is a preset angle. Beam splitter 115 is used to proportionally split the output light into a first beam and a second beam, respectively.
[0051] In one example, the first weakly acting device 113 may be a phase compensator.
[0052] The spectrum of the probe light can serve as an indicator of weak measurement processes, allowing for the measurement of minute changes in physical quantities. By selecting appropriate pre-selection and post-selection states, the spectrum of the probe light can be significantly amplified.
[0053] Detecting the quantum states of the light spectrum It can be represented as:
[0054] (4);
[0055] (5);
[0056] in, It is the wave function for detecting light, describing the Gaussian distribution of the angular frequency of the quantum state; To detect the spectral angular frequency variation of light, Indicates angular frequency as quantum state, To detect the angular frequency of the center of the light spectrum, To detect the spectral bandwidth of light.
[0057] Adjust the polarization state of the probe light to modulate it into a pre-selection state. .
[0058] Pre-selection state It can be represented as:
[0059] (6);
[0060] in, Indicates the horizontal polarization state. The vertical polarization state is represented by formula (6), which represents linearly polarized light with a polarization angle of 45°.
[0061] The external signal interacts weakly with the pre-selected state, introducing the time delay information of the light under test. The first weak interaction operator It can be represented as:
[0062] (7);
[0063] in, The observable measurement of the first weakly acting device 113 is represented. It is the imaginary unit.
[0064] The joint quantum state of the first weakly interacting light It can be represented as:
[0065] (8);
[0066] Adjust the polarization state of the first weakly interacting light to modulate it into a post-selective state. .
[0067] Post-selection state It can be represented as:
[0068] (9);
[0069] in, The post-selection angle represents the angle between the polarizer in the pre-modulation selected state and the polarizer in the post-modulation selected state.
[0070] Joint quantum state of the output light projected onto the post-selected state It can be represented as:
[0071] (10);
[0072] in, This indicates that the quantum state Projection to the post-selection state operation.
[0073] The output light is coupled into the optical fiber and split into a first beam and a second beam proportionally by a beam splitter.
[0074] The spectrum of the first or second beam It can be represented as:
[0075] (11);
[0076] in, This indicates the operation of obtaining the angular frequency probability distribution of the output light.
[0077] According to embodiments of this disclosure, the time delay information of the light to be measured is obtained based on the light intensity ratio, the spectral information of the probe light, and the spectral information of the first reflection spectrum and the second reflection spectrum.
[0078] When the first and second fiber gratings have the same reflectivity, the first and second reflection spectra have the same bandwidth, and the center angular frequencies of the first and second reflection spectra are symmetrical about the center angular frequency of the probe light, the intensity ratio is... It can be represented as:
[0079] (12);
[0080] (13);
[0081] (14);
[0082] (15);
[0083] (16).
[0084] When the weak measurement condition is met, i.e., the light intensity ratio can be approximately equal to the light intensity ratio (18) as shown in the following formula (17), thereby realizing the light time delay estimation.
[0085] (17);
[0086] (18);
[0087] Where n is an integer.
[0088] like Figure 3As shown, in one example, the weak measurement component 110 also includes an optical fiber coupler 116 and an optical fiber collimator 117. The optical fiber coupler 116 is used to couple the probe light from the optical fiber link connected to the light source 111 to the spatial optical path. The optical fiber collimator 117 is used to collimate and couple the output light of the post-selected state of the spatial optical path to the optical fiber link. The beam splitter 115 may be an optical fiber beam splitter.
[0089] Figure 4 The schematic diagram illustrates the principle of an optical delay estimation apparatus according to another embodiment of the present disclosure.
[0090] like Figure 4 As shown, according to an embodiment of the present disclosure, the weak measurement component 110 further includes a second weak action device 118.
[0091] According to embodiments of this disclosure, the second weak-acting device 118 is used to obtain a second weak-acting light by introducing a reference time delay signal into the first weak-acting light, so as to adjust the detection area of the light time delay information to be measured from the first interval to the second interval; wherein, the detection sensitivity of the second interval is higher than that of the first interval. The second polarization device 114 is used to modulate the second weak-acting light into a post-selection state to obtain output light.
[0092] In one example, the second weak-acting device 118 can be a phase compensator. The introduction of a reference delay signal adjusts the optical delay information under test to the second interval, which is within the weak measurement range of the partial linear dynamic measurement. In addition, the measurement curve of the optical delay information under test periodically shows the first interval and the second interval as the optical delay information under test increases. The detection sensitivity of the first interval is very small, while the second interval is the partial linear dynamic measurement range, and the detection sensitivity of the second interval is higher. Therefore, the introduction of a reference delay signal can achieve adjustable detection sensitivity.
[0093] According to embodiments of this disclosure, an external signal carrying reference delay information weakly interacts with a first weakly interacting light, thereby affecting the reference delay signal. A first weakly interacting light is introduced to obtain a second weakly interacting light, which is used to obtain the time delay information of the light under test. The detection area was adjusted from the first interval to the second interval.
[0094] Second weak interaction operator It can be represented as:
[0095] (19).
[0096] The joint quantum state of the second weak interaction light It can be represented as:
[0097] (20).
[0098] Introducing a reference delay signal The light intensity ratio after It can be represented as:
[0099] (twenty one);
[0100] (twenty two);
[0101] (twenty three).
[0102] When the weak measurement condition is met, i.e., the light intensity ratio can be approximately equal to the light intensity ratio (25) as shown in the following formula (24), thereby realizing the light time delay estimation.
[0103] (twenty four);
[0104] (25).
[0105] According to embodiments of this disclosure, the first polarizing device 112 may be a first polarizer used to modulate the polarization state of the probe light to obtain a preselected state.
[0106] According to embodiments of this disclosure, the second polarization device 114 includes a second polarizer for modulating the polarization state of the first weakly acting light to obtain a post-selected state. The second polarization device 114 also includes a quarter-wave plate to convert the time delay information of the light under test into spectral change information of the output light.
[0107] like Figure 4 As shown, according to an embodiment of the present disclosure, the detection component 140 includes a balanced detector 141.
[0108] According to embodiments of this disclosure, the balanced detector 141 is used to receive the third beam and the fourth beam, and output the light intensity of the third beam and the fourth beam. The readout rate of the balanced detector 141 can reach GHz or higher, and the minimum detection optical power can be as low as pW.
[0109] like Figure 4 As shown, in one example, the probe component 140 also includes a processor 142.
[0110] This disclosure also provides an optical delay estimation method, which includes: using a weak measurement component to output a first beam and a second beam containing optical delay information to be measured based on a probe light; using a first fiber grating to reflect the first beam based on a first reflection spectrum to obtain a third beam; using a second fiber grating to reflect the second beam based on a second reflection spectrum to obtain a fourth beam; wherein the center angular frequencies of the first and second reflection spectra are symmetrical about the center angular frequency of the probe light spectrum; using a detection component to detect the light intensity of the third and fourth beams, and obtaining the optical delay information to be measured based on the light intensity of the third and fourth beams.
[0111] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.
[0112] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.
Claims
1. An optical time delay estimation device, characterized in that, include: A weak measurement component is used to output a first beam and a second beam containing time delay information of the light under test based on the probe light output; A first fiber grating is used to reflect the first beam based on a first reflection spectrum to obtain a third beam. A second fiber grating is used to reflect the second beam based on a second reflection spectrum to obtain a fourth beam; wherein the center angular frequencies of the first reflection spectrum and the second reflection spectrum are symmetrical about the center angular frequency of the probe light spectrum. A detection component is used to detect the light intensity of the third beam and the fourth beam, and to obtain the light delay information of the light under test based on the light intensity of the third beam and the fourth beam.
2. The optical delay estimation device according to claim 1, characterized in that: The first fiber grating and the second fiber grating have the same reflectivity; the first reflection spectrum and the second reflection spectrum have the same bandwidth.
3. The optical delay estimation device according to claim 2, characterized in that: The detection component obtains the light intensity ratio based on the light intensity of the third beam and the fourth beam; and obtains the time delay information of the light to be measured based on the light intensity ratio, the spectral information of the detection light, the spectral information of the first reflection spectrum and the second reflection spectrum.
4. The optical delay estimation device according to claim 1, characterized in that: The first fiber grating includes: A first grating is used to reflect the first light beam based on a first reflection spectrum; A first circulator is configured to receive the first beam from the weak measurement component, transmit the first beam to the first grating, and transmit the third beam reflected by the first grating to the detection component; The second fiber grating includes: A second grating is used to reflect the second beam based on a second reflection spectrum; A second circulator is used to receive the second beam from the weak measurement component, transmit the second beam to the second grating, and transmit the fourth beam reflected by the second grating to the detection component.
5. The optical delay estimation device according to claim 1, characterized in that, The weak measurement component includes: A light source, used to output the detection light; A first polarization device is used to modulate the probe light into a pre-selected state to obtain probe light in the pre-selected state; The first weak-interaction device is used to weakly interact an external signal with the probe light in the pre-selection state, so as to introduce the time delay information of the light to be measured into the probe light in the pre-selection state to obtain the first weak-interaction light. The second polarization device is used to modulate the first weak light into a post-selection state to obtain output light in the post-selection state; wherein the polarization angle between the pre-selection state and the post-selection state is a preset angle; A beam splitter is used to split the output light into two beams at equal proportions, resulting in the first beam and the second beam.
6. The optical delay estimation device according to claim 5, characterized in that, The weak measurement component also includes: The second weak-action device is used to obtain a second weak-action light by introducing a reference time delay signal into the first weak-action light, so as to adjust the detection area of the light time delay information to be measured from the first interval to the second interval; wherein the detection sensitivity of the second interval is higher than that of the first interval; The second polarization device is used to modulate the second weakly acting light into the post-selected state to obtain the output light.
7. The optical delay estimation device according to claim 5, characterized in that, The first polarization device includes: A first polarizer is used to modulate the polarization state of the probe light to obtain the preselected state.
8. The optical delay estimation device according to claim 5, characterized in that, The second polarization device includes: The second polarizer is used to modulate the polarization state of the first weakly acting light to obtain the post-selected state.
9. The optical delay estimation device according to claim 1, characterized in that, The detection component includes: A balanced detector is used to receive the third beam and the fourth beam, and to output the light intensity of the third beam and the fourth beam.
10. An optical delay estimation method, applied to the optical delay estimation apparatus as described in any one of claims 1-9, characterized in that, The method includes: A weak measurement component is used to output a first beam and a second beam containing time delay information of the light to be measured based on the probe light; The first beam is reflected based on the first reflection spectrum using the first fiber grating to obtain the third beam; A fourth beam is obtained by reflecting the second beam based on the second reflection spectrum using a second fiber grating; wherein the center angular frequencies of the first reflection spectrum and the second reflection spectrum are symmetrical about the center angular frequency of the probe light spectrum. The light intensity of the third beam and the fourth beam is detected using a detection component, and the light delay information of the light to be measured is obtained based on the light intensity of the third beam and the fourth beam.