Optical path delay device and delay method for a high-speed optical fiber

Abstract

The present invention discloses an optical path delay device and an optical path delay method for a high-speed optical fiber. The device includes: a laser, a plurality of corner cube reflectors, a fixed disk, an optical fiber collimator, an optical scanning mover, and a control and analysis component; a plurality of prism mounting points are uniformly arranged along the circumference of the fixed disk, the corner cube reflectors are correspondingly mounted on the prism mounting points, and all the corner cube reflectors are co-circular. The optical scanning mover is arranged at the center of the fixed disk and can rotate circumferentially. The optical fiber collimator is arranged in the direction of the vertical axis of the optical scanning mover, and the control and analysis component receives the signal of the optical scanning mover to analyze the delay data of the optical path. The coaxial incident optical coupling component performs active scanning, and the angle-induced delay optical path is scanned. The structural design of the corner cube reflector with freely changeable configurations such as size and quantity realizes the load lightening, high-precision positioning, and high dynamic stability of the delay system, and expands the delay range and applicable working frequency.

Description

Technical Field

[0001] The present invention belongs to the technical field of terahertz high-speed time-domain spectroscopy and imaging, and particularly relates to an optical path delay device and a delay method for a high-speed optical fiber. Background Technique

[0002] As a core component of a terahertz time-domain spectroscopy (THz-TDS) detection device, the performance of an optical fiber delay line directly affects the detection imaging quality. By changing the optical path, the terahertz wave is cut in the time domain, and then the terahertz wave is drawn through an algorithm. Currently, the commonly used optical fiber delay technologies are based on asynchronous optical sampling technology and mechanical delay line technology.

[0003] The technology based on asynchronous optical sampling is an emerging technology that combines ultrafast spectroscopy and femtosecond lasers. This technology uses two mode-locked lasers, one as the pump light and the other as the probe light. There is a fixed difference in the repetition frequencies of the two laser pulses. The relative time delay between each pulse linearly increases from 0 to the reciprocal of the pump pulse repetition frequency. That is, assuming that at a certain pulse, the THz pulse and the probe light pulse coincide in time. Due to their different repetition frequencies, there is a time difference between the two pulses at the next pulse. Each subsequent pulse increases by a time difference in turn until they coincide again, thereby realizing the sampling measurement of a terahertz pulse by the probe light.

[0004] For example, Patent CN113932729A discloses a terahertz antenna surface detection system and method based on an optical frequency comb. The optical comb light field generation module performs spatial chirping on the test light emitted from one of the optical frequency combs to form a one-dimensional test light field with multiple wavelengths, and then forms an orthogonal test light field through a translation or rotation device. Utilizing the corresponding relationship between the intensity, spatial position, and phase of this light field, high-precision detection of the terahertz antenna surface is achieved. Another optical frequency comb with a small repetition frequency difference from the test light is used to perform asynchronous optical sampling on the test light field, and then the terahertz antenna surface is restored through high-precision three-dimensional structured light field reconstruction. This not only provides a reliable basis for realizing high-precision surface detection of terahertz antennas but also provides technical support for the design and implementation of high-gain spaceborne terahertz antennas.

[0005] The above technologies have solved the efficiency problems brought by the coupling of spatial light and optical waveguides and mechanical inertia, making the THz-TDS have higher spectral resolution, faster spectrum formation, and more compact structure. However, THz-TDS based on optical asynchronous sampling is difficult to implement because it requires two femtosecond lasers with similar but slightly detuned repetition frequencies and a complex and precise circuit feedback control loop, and the cost has been high, which has continued to affect its popularization and development for a long time.

[0006] Based on the fact that mechanical high-speed delay lines are the earliest and most widely used technologies in THz-TDS systems, they are price-friendly and include rotational delay schemes, oscillatory delay schemes, and high-speed linear motor delay schemes. Among them, the rotational delay scheme can achieve a much higher maximum rate than the other two schemes, and the highest delay scanning frequency that can be achieved by this scheme is up to thousands of Hz.

[0007] However, due to mechanical inertia, traditional mechanical high-speed delay systems cannot achieve fast scanning. To achieve fast scanning, it is necessary to increase the number of reflective optical devices on the rotating rotor, which will increase the size and mass of the rotor and at the same time increase the rotational speed of the rotating motor. Therefore, the mechanical inertia of the rotational delay line, the dynamic balance under high load, and the dynamic stability level under high-speed operation of the motor are the fundamental reasons restricting the further speed increase of the rotational delay line scheme.

[0008] Therefore, how to design an optical path delay device and method for high-speed optical fibers to achieve high-precision, high dynamic stability and meet the optical fiber delay requirements in a wide range and multiple scenarios is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0009] Aiming at the defects existing in the above-mentioned prior art, the present invention provides an optical path delay device and a delay method for high-speed optical fibers. By setting an optical scanning rotor, a fixed disk, and corner cube retroreflectors arranged circumferentially along the fixed disk, optical path delay is achieved. The present invention uses the active scanning method of a coaxial incident optical coupling component, and realizes the scanning of the optical path through angle-induced delay, breaking the inherent idea of using reflective optical devices as the rotor in traditional rotational delay lines. Through the structural design of fixed corner cube prisms with freely changeable configurations such as size and quantity, the load of the delay system is lightened, high-precision positioning and high dynamic stability are achieved, and high-speed optical fiber delay lines with different delay ranges and different working frequencies can be obtained, overcoming the problems of mechanical inertia, dynamic balance under high load, and dynamic stability level under high-speed operation of the motor restricted by traditional mechanical delay devices, and thus achieving a scanning rate of up to thousands of Hertz.

[0010] In the first aspect, the present invention provides an optical path delay device for high-speed optical fibers, including: a laser, a plurality of corner cube retroreflectors, a fixed disk, an optical fiber collimator, an optical scanning rotor, and a control and analysis component;

[0011] The fixed disk is uniformly provided with a plurality of prism mounting points along the circumference, the corner cube retroreflectors are correspondingly mounted on the prism mounting points, and all the corner cube retroreflectors are co-circular. The optical scanning rotor is arranged at the center of the fixed disk, and the optical scanning rotor can rotate circumferentially. The optical fiber collimator is arranged in the direction of the vertical axis of the optical scanning rotor, and the control and analysis component receives the signal of the optical scanning rotor and analyzes the optical path delay data;

[0012] The laser emitted by the laser passes through the fiber collimator and outputs vertically parallel light rays, which are perpendicularly incident on the optical scanning rotor. The optical scanning rotor changes the perpendicularly incident light rays into planar light rays for output. The planar light rays propagate along the radius from the center of the fixed disk, are incident on the corner cube reflector, and after three reflections by the corner cube reflector, return to the optical scanning rotor. The optical scanning rotor then changes the planar light rays back into vertically parallel light rays and returns them to the fiber collimator. After the fiber collimator couples and collects them, the optical path delay is completed.

[0013] Further, the optical scanning rotor includes an incident optical rotor mirror, a planar steering mirror, an angle encoder, and a rotating motor. The incident optical rotor mirror, the planar steering mirror, the fixed disk, and each corner cube reflector are all in the same plane. Both the incident optical rotor mirror and the planar steering mirror can rotate circumferentially. The planar steering mirror performs the mutual steering between vertically parallel light rays and planar light rays. The incident optical rotor mirror reflects the light rays reflected by the corner cube reflector back to the corner cube reflector again. The rotating motor provides power for the circumferential rotation of the incident optical rotor mirror and the planar steering mirror. The angle encoder real-time collects the rotation angle of the rotating motor and transmits signals to the control and analysis component.

[0014] Further, the planar steering mirror, the incident optical rotor mirror, the angle encoder, and the rotating motor are arranged in sequence along the vertical axis direction. The incident optical rotor mirror includes a planar structure and a vertical structure. The planar structure fixes the planar steering mirror, and the planar steering mirror is located at the center of the planar structure. The surface for reflection is inclined at 45° to the plane of the fixed disk, changing the light rays perpendicularly incident from the fiber collimator into planar light rays for output. The vertical structure is a sheet-like structure arranged at both ends of the planar structure. A central hole corresponding to the planar steering mirror along the radius of the fixed disk is provided at the center of the vertical structure.

[0015] Further, the incident end face of the corner cube reflector faces the optical scanning rotor along the radius of the fixed disk, and the apex of the corner cube reflector faces away from the optical scanning rotor along the radius of the fixed disk.

[0016] Further, the sizes of the fixed disk and the corner cube reflector are both preset. The relationship between the optical path difference and the size of the preset corner cube reflector is as follows:

[0017]

[0018] Among them, Δd is the optical path difference between the direct incidence and the oblique incidence of the incident light rays, n is the relative refractive index of the corner cube reflector, L1 is the vertical distance from the apex of the corner cube reflector to the incident end face of the corner cube reflector, L2 is the vertical distance from the incident end face of the corner cube reflector to the intersection point of the refracted light ray and the inclined plane of the corner cube reflector, and α is the angle between the incident light ray and the axis of the corner cube reflector.

[0019] In a second aspect, the present invention further provides an optical path delay method for a high-speed optical fiber, which uses the optical path delay device for a high-speed optical fiber as described above, and includes the following steps:

[0020] Turn on the laser, output vertically parallel light through the fiber collimator, and vertically incident on the optical scanning rotor;

[0021] During the circumferential rotation of the optical scanning rotor, the vertically incident light is changed into plane light and output. The plane light propagates along the radius from the center of the fixed disk and is incident on the corner cube retroreflector. Among them, the sizes of the fixed disk and the corner cube retroreflector are preset;

[0022] After the plane light is reflected three times by the corner cube retroreflector, it returns to the optical scanning rotor;

[0023] The optical scanning rotor then changes the plane light into vertically parallel light and returns it to the fiber collimator;

[0024] After the fiber collimator couples and collects it, the light propagation is completed, and the control and analysis component analyzes and completes the optical path delay based on the analysis of the received optical scanning rotor signal.

[0025] Further, the optical scanning rotor includes an incident optical rotor mirror, a plane steering mirror, an angle encoder, and a rotating motor that are sequentially installed in the vertical direction. The incident optical rotor mirror includes a planar structure and a vertical structure. The planar structure fixes the plane steering mirror, and the plane steering mirror is located at the center of the planar structure. The surface for reflection is inclined at 45° to the plane of the fixed disk, and changes the light vertically incident from the fiber collimator into plane light and outputs it. The vertical structure is a sheet-like structure provided at both ends of the planar structure, and a central hole corresponding to the plane steering mirror along the radius of the fixed disk is provided at the center of the vertical structure.

[0026] Further, during the circumferential rotation of the optical scanning rotor, the vertically incident light is changed into plane light and output. The plane light propagates along the radius from the center of the fixed disk and is incident on the corner cube retroreflector. After the plane light is reflected three times by the corner cube retroreflector, it returns to the optical scanning rotor, specifically including:

[0027] The rotating motor drives the incident optical rotor mirror and the plane steering mirror to rotate at a preset speed;

[0028] The vertically parallel light is vertically incident on the plane steering mirror, and the plane steering mirror changes the vertically incident light into plane light and outputs it;

[0029] The plane light passes through the central hole of the vertical structure of the incident optical rotor mirror and then propagates along the radius of the fixed disk and is incident on the corner cube retroreflector;

[0030] After the plane light is reflected three times by the corner cube prism, it returns to the vertical structure of the incident optical rotor mirror and is reflected again to the corner cube prism. After three more reflections by the corner cube prism, it passes through the central hole of the vertical structure of the incident optical rotor mirror and returns to the plane turning mirror.

[0031] The plane turning mirror then changes the plane light into vertically parallel light and returns it to the fiber collimator.

[0032] Furthermore, the control and analysis component analyzes and completes the optical path delay based on the analyzed received optical scanning rotor signal, specifically including:

[0033] The control and analysis component receives the rotation angle signal transmitted by the angle encoder;

[0034] Based on the radius dimension of the fixed disk and the dimension of the corner cube prism, the optical path difference is given;

[0035] The corresponding relationship between the rotation angle and the optical path difference is formed, the data calibration of the rotation angle and the optical path difference is completed, and the optical path delay is completed.

[0036] Furthermore, the relationship between the radius dimension of the fixed disk, the dimension of the corner cube prism and the optical path difference is as follows:

[0037]

[0038] Among them, Δd is the optical path difference when the incident light is normally incident and obliquely incident, n is the relative refractive index of the corner cube prism, L1 is the vertical distance from the apex of the corner cube prism to the incident end face of the corner cube prism, L2 is the vertical distance from the incident end face of the corner cube prism to the intersection point of the refracted light and the inclined plane of the corner cube prism, and α is the angle between the incident light and the axis of the corner cube prism.

[0039] The optical path delay device and delay method of a high-speed optical fiber provided by the present invention at least include the following beneficial effects:

[0040] (1) By using the active scanning method of the coaxial incident optical coupling component, the scanning of the optical path is realized through angle-induced delay, breaking the inherent idea of using traditional rotating delay line reflecting optical devices as rotors. Through the design of a fixed corner cube prism structure with freely changeable configurations such as size and quantity, the load of the delay system is lightened, high-precision positioning and high dynamic stability are achieved, and high-speed optical fiber delay lines with different delay ranges and different working frequencies can be obtained, overcoming the problems of mechanical inertia, dynamic balance under high load, and dynamic stability level under high-speed operation of the motor in traditional mechanical delay devices. Furthermore, a scanning rate of up to thousands of hertz is realized, thus meeting the requirements of more high-speed measurement application scenarios.

[0041] (2) A fixed reflecting optical device and a rotating incident optical device are proposed, which greatly reduce the actual load of the rotating motor and have inherent advantages for achieving the dynamic balance and light weight of the device; the corner cube reflecting prism is changed from the original moving part to a fixed part, and there is no need to consider the problems of large mass, low positioning accuracy and poor dynamic stability caused by a large number of corner cube reflecting prisms, improving the reliability of the device operation.

[0042] (3) The solution of the present invention makes it more convenient to modify or even dynamically adjust the core parameters of the optical path delay device. Only by changing the configuration such as the size and quantity of the corner cube reflecting prisms distributed on the fixed disk, a high-speed optical fiber delay line with different delay ranges and different working frequencies can be realized without having to re-consider the dynamic balance problem of the device. The arrangement among the photon scanning mover, the fixed disk and the corner cube reflecting prism in the optical path delay device can achieve the effect of expanding the optical path delay range by adjusting the sizes of the corner cube reflecting prism and the fixed disk. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Structural diagram of an optical path delay device for a high-speed optical fiber provided by the present invention;

[0044] Figure 2 Schematic diagram of light reflection in an optical path delay device for a high-speed optical fiber provided by the present invention;

[0045] Figure 3 Flowchart of an optical path delay method for a high-speed optical fiber provided by the present invention;

[0046] Figure 4 Corresponding trend diagram of the included angle between the light ray and the corner cube reflecting prism and the optical path difference in a certain embodiment provided by the present invention.

[0047] Description of the reference numerals:

[0048] 1 - Corner cube reflecting prism, 2 - Fixed disk, 3 - Fiber collimator, 4 - Incident optical mover mirror, 5 - Plane turning mirror, 6 - Angle encoder, 7 - Rotating motor, 41 - Plane structure, 42 - Vertical structure, 421 - Central hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0050] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two.

[0051] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, such that a commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the commodity or device comprising said element.

[0052] As Figure 1-2 shown, the present invention provides an optical path delay device for a high-speed optical fiber, comprising: a laser (not shown in the figure), a plurality of corner cube retroreflectors 1, a fixed disk 2, an optical fiber collimator 3, an optical scanning mover and a control and analysis component (not shown in the figure);

[0053] The fixed disk 2 is provided with a plurality of prism mounting points evenly along the circumferential direction. The corner cube retroreflectors 1 are correspondingly mounted on the prism mounting points, and all the corner cube retroreflectors 1 are co-circular. The optical scanning mover is arranged at the center of the fixed disk 2, and the optical scanning mover can rotate circumferentially. The optical scanning mover coincides with the rotation axis of the fixed disk 2. The optical fiber collimator 3 is arranged in the direction of the vertical axis of the optical scanning mover. The direction of the vertical axis represents the direction perpendicular to the rotation plane of the optical scanning mover. The control and analysis component receives the signal of the optical scanning mover and analyzes the optical path delay data;

[0054] The laser emits laser light, which is output as vertically parallel light by the optical fiber collimator 3. The vertically parallel light is in the direction perpendicular to the rotation plane of the optical scanning mover and is incident vertically on the optical scanning mover. The optical scanning mover changes the vertically incident light into plane light and outputs it. The plane light propagates along the radius from the center of the fixed disk 2, is incident on the corner cube retroreflector 1, and after being reflected three times by the corner cube retroreflector 1, returns to the optical scanning mover. The optical scanning mover then changes the plane light back into vertically parallel light and returns it to the optical fiber collimator 3. After the optical fiber collimator 3 couples and collects it, the optical path delay is completed.

[0055] The size of the fixed disk 2 can be preset according to the requirements of the scenario application, and it is mainly used to carry the corner cube retroreflectors 1, and ensures that all the corner cube retroreflectors 1 are co-circular through precise manufacturing.

[0056] The optical scanning mover includes an incident optical mover mirror 4, a planar steering mirror 5, an angle encoder 6, and a rotating motor 7. The incident optical mover mirror 4, the planar steering mirror 5, the fixed disk 2, and each corner cube prism 1 are all in the same plane, and this same plane is the same as the rotation plane of the fixed disk 2. The incident optical mover mirror 4 and the planar steering mirror 5 can both rotate circumferentially, and the rotation axes of the incident optical mover mirror 4 and the planar steering mirror 5 coincide. The planar steering mirror 5 performs mutual steering between perpendicular parallel light and planar light. The incident optical mover mirror 4 reflects the light reflected by the corner cube prism 1 back to the corner cube prism 1 again. The rotating motor 7 provides driving force for the circumferential rotation of the incident optical mover mirror 4 and the planar steering mirror 5. The angle encoder 6 collects the rotation angle of the rotating motor 7 in real time and transmits signals to the control and analysis component.

[0057] The planar steering mirror 5, the incident optical mover mirror 4, the angle encoder 6, and the rotating motor 7 are arranged in sequence along the vertical axis direction. The meaning of this vertical axis is the rotation axis of the fixed disk 2. The incident optical mover mirror 4 includes a planar structure 41 and a vertical structure 42. The planar structure 41 is parallel or coincident with the rotation plane of the fixed disk 2, and the vertical structure 42 is perpendicular to the rotation plane of the fixed disk 2. The planar structure 41 fixes the planar steering mirror 5, and the planar steering mirror 5 is located at the center position of the planar structure 41, and the surface for reflection is inclined at 45° to the plane of the fixed disk 2, changing the light vertically incident from the fiber collimator 3 into planar light for output. The vertical structure 42 is a sheet-like structure provided at both ends of the planar structure 41, and a central hole 421 corresponding to the planar steering mirror 5 along the radius direction of the fixed disk is provided at the center position of the vertical structure 42.

[0058] The incident end face of the corner cube prism 1 faces the optical scanning mover along the radius of the fixed disk, and the apex of the corner cube prism 1 faces away from the optical scanning mover along the radius of the fixed disk.

[0059] The sizes of the fixed disk 2 and the corner cube prism 1 are both preset. The optical path difference and the size relationship of the preset corner cube prism are as follows:

[0060]

[0061] Among them, Δd is the optical path difference between the normal incidence and the oblique incidence of the incident light, n is the relative refractive index of the corner cube prism, L1 is the vertical distance from the apex of the corner cube prism to the incident end face of the corner cube prism, L2 is the vertical distance from the incident end face of the corner cube prism to the intersection point of the refracted light and the inclined plane of the corner cube prism, and α is the angle between the incident light and the axis of the corner cube prism. Among them, the value of n is related to the selected corner cube prism.

[0062] The circumferential rotation of the photon scanning mover can cause changes in the optical path difference in two aspects. Firstly, it causes a change in the included angle α. The specific value of the optical path difference can be calculated through the above relationship. As Figure 4 shown, in a certain embodiment, it is set that L1 = 60mm, L2 = 22mm, and α is set to 10°. Then the corresponding optical path difference Δd will reach approximately 0.3mm. The optical path difference Δd corresponds to a time delay of 1ps. Secondly, it also causes a change in the position of the incident light ray, and this part can be analyzed through Zmax modeling and simulation.

[0063] Using the active scanning method of the coaxial incident optical coupling component, the scanning of the optical path is realized through angle-induced delay, breaking the inherent idea of using the traditional rotating delay line reflection optical device as the mover. Through the design of the fixed corner cube prism structure with freely changeable configurations such as size and quantity, the load of the delay system is lightened, high-precision positioning and high dynamic stability are achieved, and high-speed fiber optic delay lines with different delay ranges and different operating frequencies can be obtained, overcoming the problems of mechanical inertia, dynamic balance under high load, and dynamic stability level limitation under high-speed operation of the motor in the traditional mechanical delay device. Furthermore, a scanning rate of up to several thousand hertz is achieved, thus meeting the requirements of more high-speed measurement application scenarios. Taking the embodiment of evenly placing 20 corner cube reflection prisms on the fixed disc 2 for analysis, when the rotational speed of the rotating motor 7 is set to 3000r / min, a scanning rate of 1000Hz can be satisfied. By increasing or decreasing the number of corner cube reflection prisms 1, the operating rate of the device can be easily changed without readjusting the dynamic balance.

[0064] As Figure 3 shown, the present invention also provides a method for optical path delay of a high-speed optical fiber, adopting the high-speed optical fiber optical path delay device as described above, including the following steps:

[0065] Turn on the laser, and output vertically parallel light through the fiber collimator, which is vertically incident on the optical scanning mover;

[0066] During the circumferential rotation of the optical scanning mover, the vertically incident light is changed into plane light and output. The plane light propagates along the radius from the center of the fixed disc and is incident on the corner cube reflection prism, where the sizes of the fixed disc and the corner cube reflection prism are preset;

[0067] After three reflections of the plane light by the corner cube reflection prism, it returns to the optical scanning mover;

[0068] The optical scanning mover then changes the plane light back into vertically parallel light and returns it to the fiber collimator;

[0069] After the fiber collimator couples and collects it, the light propagation is completed, and the control and analysis component analyzes and completes the optical path delay based on the analysis of the received optical scanning mover signal.

[0070] The optical scanning mover includes an incident optical mover mirror, a planar steering mirror, an angle encoder, and a rotating motor that are sequentially installed in the vertical direction. The incident optical mover mirror includes a planar structure and a vertical structure. The planar structure fixes the planar steering mirror, and the planar steering mirror is located at the center of the planar structure. The surface for reflection is inclined at 45° to the plane of the fixed disk, and the light vertically incident from the fiber collimator is changed into planar light and output. The vertical structure is a sheet-like structure provided at both ends of the planar structure, and a central hole corresponding to the planar steering mirror in the radial direction of the fixed disk is provided at the center of the vertical structure.

[0071] As Figure 2 shown, during the circumferential rotation of the optical scanning mover, the vertically incident light is changed into planar light and output. The planar light propagates along the radius from the center of the fixed disk and is incident on the corner cube prism. After three reflections by the corner cube prism, the planar light returns to the optical scanning mover, specifically including:

[0072] The rotating motor drives the incident optical mover mirror and the planar steering mirror to rotate at a preset speed;

[0073] The vertically parallel light is vertically incident on the planar steering mirror, and the planar steering mirror changes the vertically incident light into planar light and outputs it;

[0074] The planar light passes through the central hole of the vertical structure of the incident optical mover mirror and then propagates along the radius of the fixed disk and is incident on the corner cube prism;

[0075] After three reflections by the corner cube prism, the planar light returns to the vertical structure of the incident optical mover mirror and is reflected again to the corner cube prism. After another three reflections by the corner cube prism, it passes through the central hole of the vertical structure of the incident optical mover mirror and returns to the planar steering mirror;

[0076] The planar steering mirror changes the planar light back into vertically parallel light and returns it to the fiber collimator.

[0077] The control and analysis component analyzes and completes the optical path delay based on the analyzed optical scanning mover signal, specifically including:

[0078] The control and analysis component receives the rotation angle signal transmitted by the angle encoder;

[0079] Based on the radius size of the fixed disk and the size of the corner cube prism, the optical path difference is given;

[0080] The corresponding relationship between the rotation angle and the optical path difference is formed, the data calibration of the rotation angle and the optical path difference is completed, and the optical path delay is completed.

[0081]

[0082] Among them, Δd is the optical path difference when the incident light is normally incident and obliquely incident, n is the relative refractive index of the corner cube retroreflector, L1 is the vertical distance from the apex of the corner cube retroreflector to the incident end face of the corner cube retroreflector, L2 is the vertical distance from the incident end face of the corner cube retroreflector to the intersection point of the refracted light and the inclined plane of the corner cube retroreflector, and α is the angle between the incident light and the axis of the corner cube retroreflector.

[0083] When the physical dimensions of the corner cube retroreflector are determined, the optical path difference Δd has a positive and monotonic relationship with the incident angle (small angle offset). At this time, the rotation of the incident optical mover mirror and the planar steering mirror will introduce a change in the incident position of the light. When rotated by a certain angle, the corresponding optical path changes synchronously, and the corresponding time is delayed. However, this monotonic relationship is not completely linearly correlated. Therefore, in the specific implementation process, it is necessary to calibrate the angle-optical path for each corner cube retroreflector.

[0084] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An optical path delay device for a high-speed optical fiber, characterized in that, Including: A laser, multiple corner cube reflectors, a fixed disk, an optical fiber collimator, an optical scanning mover, and a control and analysis component; The fixed disk is evenly provided with a plurality of prism mounting points along the circumferential direction. The corner cube reflectors are correspondingly mounted on the prism mounting points, and all the corner cube reflectors are co-circular. The optical scanning mover is arranged at the center position of the fixed disk, and the optical scanning mover can rotate circumferentially. The optical fiber collimator is arranged in the direction of the vertical axis of the optical scanning mover. The control and analysis component receives the signal of the optical scanning mover to analyze the optical path delay data; The laser emits laser light, which is output as vertically parallel light through the optical fiber collimator and vertically incident on the optical scanning mover. The optical scanning mover changes the vertically incident light into plane light and outputs it. The plane light propagates along the radius from the center of the fixed disk, is incident on the corner cube reflector, and after three reflections by the corner cube reflector, returns to the optical scanning mover. The optical scanning mover then changes the plane light back into vertically parallel light and returns it to the optical fiber collimator. After the optical fiber collimator couples and collects it, the optical path delay is completed; The optical scanning mover includes an incident optical mover mirror, a plane steering mirror, an angle encoder, and a rotating motor. The incident optical mover mirror, the plane steering mirror, the fixed disk, and each corner cube reflector are all in the same plane. The incident optical mover mirror and the plane steering mirror can both rotate circumferentially; The plane steering mirror, the incident optical mover mirror, the angle encoder, and the rotating motor are arranged in sequence along the vertical axis direction. The incident optical mover mirror includes a planar structure and a vertical structure. The planar structure fixes the plane steering mirror, and the plane steering mirror is located at the center position of the planar structure. The surface for reflection is inclined at 45° to the plane of the fixed disk, and changes the light vertically incident from the optical fiber collimator into plane light and outputs it. The vertical structure is a sheet-like structure provided at both ends of the planar structure. A central hole corresponding to the plane steering mirror along the radius of the fixed disk is provided at the center position of the vertical structure.

2. The optical path delay device according to claim 1, characterized in that, The incident end face of the corner cube reflector faces the optical scanning mover along the radius of the fixed disk, and the apex of the corner cube reflector faces away from the optical scanning mover along the radius of the fixed disk.

3. The optical path delay device according to claim 2, characterized in that, The sizes of the fixed disk and the corner cube reflector are both preset. The relationship between the optical path difference and the size of the preset corner cube reflector is as follows: Where, Δd is the optical path difference between the normal incidence and the oblique incidence of the incident light, n is the relative refractive index of the corner cube reflector, L1 is the vertical distance from the apex of the corner cube reflector to the incident end face of the corner cube reflector, L2 is the vertical distance from the incident end face of the corner cube reflector to the intersection point of the refracted light and the inclined face of the corner cube reflector, and α is the angle between the incident light and the axis of the corner cube reflector.

4. A method for optical path delay of a high-speed optical fiber, which uses the optical path delay device of the high-speed optical fiber as described in any one of claims 1-3, characterized in that, Including the following steps: Turn on the laser, and output vertically parallel light through the optical fiber collimator, which is vertically incident on the optical scanning mover; During the circumferential rotation of the optical scanning mover, the vertically incident light is changed into plane light and output. The plane light propagates along the radius from the center of the fixed disk and is incident on the corner cube reflector. Among them, the sizes of the fixed disk and the corner cube reflector are preset; The plane light returns to the optical scanning mover after three reflections by the corner cube reflector; The optical scanning mover then changes the planar light into vertically parallel light and returns it to the fiber collimator. After the fiber collimator couples and collects it, the light propagation is completed, and the control and analysis component analyzes and completes the optical path delay based on the received optical scanning mover signal.

5. The optical path delay method according to claim 4, wherein The optical scanning mover includes an incident optical mover mirror, a planar steering mirror, an angle encoder, and a rotating motor that are sequentially installed in the vertical direction. The incident optical mover mirror includes a planar structure and a vertical structure. The planar structure fixes the planar steering mirror, and the planar steering mirror is located at the center of the planar structure. The surface for reflection is inclined at 45° to the plane of the fixed disk, and changes the light vertically incident from the fiber collimator into planar light for output. The vertical structure is a sheet-like structure provided at both ends of the planar structure, and a central hole corresponding to the planar steering mirror along the radius direction of the fixed disk is provided at the center position of the vertical structure.

6. The optical path delay method according to claim 5, wherein During the circumferential rotation of the optical scanning mover, the vertically incident light is changed into planar light for output. The planar light propagates along the radius from the center of the fixed disk and is incident on the corner cube prism. After three reflections of the planar light by the corner cube prism, it returns to the optical scanning mover, specifically including: The rotating motor drives the incident optical mover mirror and the planar steering mirror to rotate at a preset speed. The vertically parallel light is vertically incident on the planar steering mirror, and the planar steering mirror changes the vertically incident light into planar light for output. The planar light passes through the central hole of the vertical structure of the incident optical mover mirror and then propagates along the radius direction of the fixed disk and is incident on the corner cube prism. After three reflections of the planar light by the corner cube prism, it returns to the vertical structure of the incident optical mover mirror and is reflected again to the corner cube prism. After another three reflections of the corner cube prism, it passes through the central hole of the vertical structure of the incident optical mover mirror and returns to the planar steering mirror. The planar steering mirror then changes the planar light into vertically parallel light and returns it to the fiber collimator.

7. The optical path delay method according to claim 6, wherein, The control and analysis component analyzes and completes the optical path delay based on the received optical scanning mover signal, specifically including: The control and analysis component receives the rotation angle signal transmitted by the angle encoder. Based on the radius size of the fixed disk and the size of the corner cube prism, the optical path difference is given. The corresponding relationship between the rotation angle and the optical path difference is formed, the data calibration of the rotation angle and the optical path difference is completed, and the optical path delay is completed.

8. The optical path delay method according to claim 7, wherein The relationship between the size of the corner cube prism and the optical path difference is as follows: Among them, Δd is the optical path difference when the incident light is normally incident and obliquely incident, n is the relative refractive index of the corner cube prism, L1 is the vertical distance from the apex of the corner cube prism to the incident end face of the corner cube prism, L2 is the vertical distance from the incident end face of the corner cube prism to the intersection point of the refracted light and the inclined plane of the corner cube prism, and α is the angle between the incident light and the axis of the corner cube prism.

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