CN108802841B

CN108802841B - Light path adjusting device and method and gravity meter

Info

Publication number: CN108802841B
Application number: CN201810632473.1A
Authority: CN
Inventors: 赵阳; 王少凯; 庄伟�; 李天初
Original assignee: National Institute of Metrology
Current assignee: National Institute of Metrology
Priority date: 2018-06-20
Filing date: 2018-06-20
Publication date: 2020-02-07
Anticipated expiration: 2038-06-20
Also published as: CN108802841A

Abstract

The disclosure provides a light path adjusting device, a light path adjusting method and a gravimeter, and relates to the field of gravimeters. The device includes: a fiber optic device configured to transmit incident light to the collimator and extract the measurement beam reflected back from the gravity meter optical assembly; a collimator configured to convert incident light into collimated light; a gravity meter optical assembly configured to assemble collimated light into a measurement beam and reflect the measurement beam back to the fiber optic device; and a detector configured to detect the reflected measuring beam extracted by the optical fiber device and output a detection signal so that the measuring beam angle is adjusted to be perpendicular to the horizontal reference plane according to the detection signal. The method and the device can avoid the problems of poor reproducibility and the like caused by human factors, and improve the sensitivity and accuracy of light path verticality adjustment.

Description

Light path adjusting device and method and gravity meter

Technical Field

The disclosure relates to the field of gravimeters, in particular to a light path adjusting device, a light path adjusting method and a gravimeter.

Background

The gravitational acceleration is one of important parameters of a geophysical field, is caused by factors such as the gravity and the autorotation of the earth and changes along with the change of time and space, and has timeliness and regionality. The high-precision gravity measurement has very important significance in the aspects of geophysics, geodetic measurement and the like, and has important influence on the research fields of basic physics and the like.

At present, absolute gravimeters are generally divided into an optical gravimeter and an atomic gravimeter, a free-falling pyramid prism and a cold atomic group are respectively adopted as a measured mass, and in the free-falling process, an optical interference fringe and an atomic interference fringe are respectively formed through a laser beam along the gravity acceleration direction, so that the gravity acceleration is measured.

When the laser and the gravity acceleration have a certain angle, the actual measurement result is the component of the gravity acceleration along the laser direction, that is, the measurement result of the atomic interference gravimeter is the component along the direction of the Raman (Raman) light effective wave vector, which causes the measurement accuracy to be reduced. Although the optical gravimeter and atomic gravimeter measurement principles are different, the verticality requirements for the laser are the same. The gravity acceleration deviation introduced by the vertical deflection angle of the laser is expressed as Δ g ═ g Δ θ²/2, thereforeWhen the inclination angle is 45 μ rad, the corresponding gravitational acceleration measurement deviation is 1 μ Gal, and when the sensitivity reaches 0.1 μ Gal, the angular deviation is required to be less than 14.3 μ rad. Laser perpendicularity therefore becomes a non-negligible term in the accuracy of gravity measurements.

Disclosure of Invention

The technical problem to be solved by the present disclosure is to provide an optical path adjusting device, method and gravimeter, which can improve the sensitivity and accuracy of optical path verticality adjustment.

According to an aspect of the present disclosure, there is provided an optical path adjusting apparatus including: a fiber optic device configured to transmit incident light to the collimator and extract the measurement beam reflected back from the gravity meter optical assembly; a collimator configured to convert incident light into collimated light; a gravity meter optical assembly configured to assemble collimated light into a measurement beam and reflect the measurement beam back to the fiber optic device; and a detector configured to detect the reflected measuring beam extracted by the optical fiber device and output a detection signal so that the measuring beam angle is adjusted to be perpendicular to the horizontal reference plane according to the detection signal.

Optionally, the optical fiber device is a fiber optic circulator; the system comprises an optical fiber circulator, a collimator, a first output end and a second output end, wherein incident light enters the optical fiber circulator through the input end of the optical fiber circulator and is output to the collimator through the first output end; and the reflected measuring beam extracted by the optical fiber circulator is output to the detector through a second output end.

Optionally, the optical fiber device is an optical fiber splitter; the system comprises an optical fiber beam splitter, a collimator, a first beam splitting end, a second beam splitting end, a beam combining end and a first beam splitting end, wherein incident light enters the optical fiber beam splitter through the first beam splitting end of the optical fiber beam splitter and is output to the collimator through the beam combining end; and the reflected measuring beam extracted by the optical fiber beam splitter is output to the detector through the second beam splitting end.

Optionally, in a case where the voltage value of the detection signal is a maximum value, the measuring beam is perpendicular to the horizontal reference plane; and/or the measuring beam is perpendicular to the horizontal reference plane in case the optical power value of the detection signal is at a maximum.

Optionally, the optical path adjusting apparatus further includes: a servo control system configured to generate an error signal from the detection signal, generate a servo control signal based on the error signal, and control the controllable mirror mount according to the servo control signal such that the measuring beam is perpendicular to the horizontal reference plane; the controllable mirror bracket is used for clamping a mirror surface of the optical assembly of the gravimeter.

Optionally, the servo control system comprises: a power divider configured to divide the detection signal into a first-dimension detection signal and a second-dimension detection signal; a first servo configured to generate a first error signal from the first dimension detection signal; a second servo configured to generate a second error signal from the second dimension detection signal; a first controller configured to generate a first servo control signal based on the first error signal; a second controller configured to generate a second servo control signal based on the second error signal; a first drive configured to control a first dimension of the controllable mirror mount according to a first servo control signal; a second drive configured to control a second dimension of the controllable mirror mount according to a second servo control signal.

Optionally, the gravimeter optical assembly is an optical gravimeter optical assembly comprising: the semi-transmitting semi-reflecting mirror forms a preset angle with the horizontal reference surface; the pyramid prism is positioned above the semi-transparent semi-reflecting mirror; wherein, collimated light is reflected to the pyramid prism by half mirror, and the pyramid prism reflects collimated light parallel back half mirror in order to form measuring beam, and measuring beam transmits horizontal reference face through half mirror, and horizontal reference face reflects measuring beam to half mirror back, and measuring beam is transmitted to the pyramid prism, and the pyramid prism reflects measuring beam parallel back half mirror, and half mirror reflects measuring beam to the optical fiber device.

Optionally, the controllable mirror frame clamps the half-transmitting and half-reflecting mirror; the servo control system controls the controllable mirror holder according to the servo control signal so as to adjust the angle of the half mirror, thereby enabling the measuring beam to be perpendicular to the horizontal reference plane.

Optionally, the measuring beam comprises a downward measuring beam and an upward measuring beam, and the gravimeter optical assembly is an atomic gravimeter optical assembly comprising: the first reflector forms a preset angle with the horizontal reference surface; a second mirror configured to be placed below the first mirror when forming the upward measuring beam; the collimated light is reflected to the horizontal reference surface by the first reflector to form a downward measuring beam, the downward measuring beam is reflected to the first reflector by the horizontal reference surface, and the downward measuring beam is reflected to the optical fiber device by the first reflector; and replacing the horizontal reference surface with a second mirror, the collimated light being reflected to the second mirror by the first mirror, the second mirror reflecting the collimated light to the first mirror to form an upward measuring beam, the upward measuring beam being reflected to the optical fiber device by the first mirror.

Optionally, the controllable mirror holder holds the first mirror, and the servo control system controls the controllable mirror holder according to the servo control signal so as to adjust the angle of the first mirror, so that the downward measuring beam is perpendicular to the horizontal reference plane; and a controllable mirror bracket clamping the second reflecting mirror, wherein the servo control system controls the controllable mirror bracket according to the servo control signal so as to adjust the angle of the second reflecting mirror, so that the upward measuring beam is perpendicular to the horizontal reference plane.

According to another aspect of the present disclosure, a gravimeter is also provided, which includes the above-mentioned optical path adjusting device.

According to another aspect of the present disclosure, there is also provided an optical path adjusting method, including: the optical fiber device transmits the received input light to the collimator; the collimator converts incident light into collimated light; the collimated light forms a measuring beam through the gravity meter optical assembly, and the measuring beam is reflected back to the optical fiber device through the gravity meter optical assembly; the optical fiber device extracts the measuring beam reflected by the optical assembly of the gravimeter; the detector detects the reflected measuring beam extracted by the optical fiber device and outputs a detection signal so that the angle of the measuring beam is adjusted to be perpendicular to the horizontal reference plane in accordance with the detection signal.

Optionally, the optical fiber device is an optical fiber splitter; the system comprises an optical fiber beam splitter, a collimator, a light source and a light source, wherein incident light enters the optical fiber beam splitter through a first beam splitting end of the optical fiber beam splitter and is output to the collimator; and the reflected measuring beam extracted by the optical fiber beam splitter is output to the detector through the second beam splitting end.

Optionally, the optical path adjusting method further includes: the servo control system generates an error signal according to the detection signal; generating a servo control signal based on the error signal; controlling the controllable mirror bracket according to the servo control signal so that the measuring light beam is perpendicular to the horizontal reference surface; the controllable mirror bracket is used for clamping a mirror surface of the optical assembly of the gravimeter.

Optionally, the servo control system divides the detection signal into a first dimension detection signal and a second dimension detection signal; generating a first error signal according to the first dimension detection signal, generating a first servo control signal based on the first error signal, and controlling the first dimension of the controllable mirror bracket according to the first servo control signal; and generating a second error signal according to the second dimension detection signal, generating a second servo control signal based on the second error signal, and controlling the second dimension of the controllable mirror frame according to the second servo control signal.

Optionally, the gravimeter optical assembly is an optical gravimeter optical assembly, and the controllable lens frame clamps a half-transmitting and half-reflecting lens of the optical gravimeter optical assembly; wherein the servo control system controls the controllable mirror frame according to the servo control signal so as to adjust the angle of the half-mirror, thereby enabling the measuring beam to be vertical to the horizontal reference plane.

Optionally, the measuring beam comprises a downward measuring beam and an upward measuring beam, the gravimeter optical assembly is an atomic gravimeter optical assembly; the controllable mirror frame clamps the first reflecting mirror, and the servo control system controls the controllable mirror frame according to a servo control signal so as to adjust the angle of the first reflecting mirror, so that the downward measuring light beam is perpendicular to the horizontal reference surface; and a controllable mirror bracket clamping the second reflecting mirror, wherein the servo control system controls the controllable mirror bracket according to the servo control signal so as to adjust the angle of the second reflecting mirror, so that the upward measuring beam is perpendicular to the horizontal reference plane.

Compared with the prior art, the optical fiber device is used for inputting incident light into the collimator, collimated light is output to the gravimeter optical assembly through the collimator, the gravimeter optical assembly forms the collimated light into the measuring beam, the measuring beam is reflected back to the optical fiber device, the detector detects the returned measuring beam and then outputs the detection signal, the angle of the measuring beam can be adjusted according to the detection signal, the measuring beam is perpendicular to the horizontal reference surface, and the sensitivity and the accuracy of light path verticality adjustment are improved.

Other features of the present disclosure and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

fig. 1 is a schematic structural diagram of an embodiment of an optical path adjusting device according to the present disclosure.

Fig. 2 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 3 is a schematic structural diagram of a further embodiment of the optical path adjusting device of the present disclosure.

Fig. 4 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 5 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 6 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 7 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 8 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 9 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 10 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 11 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure.

Fig. 12 is a schematic structural diagram of another embodiment of the optical path adjustment device of the present disclosure.

Fig. 13 is a schematic structural diagram of another embodiment of the optical path adjustment device of the present disclosure.

Fig. 14 is a schematic structural diagram of another embodiment of the optical path adjustment device of the present disclosure.

Fig. 15 is a schematic flow chart of an embodiment of the optical path adjusting method of the present disclosure.

Fig. 16 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure.

Fig. 17 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure.

Fig. 18 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure.

Fig. 19 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure.

Fig. 20 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present disclosure unless specifically stated otherwise.

Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic structural diagram of an embodiment of an optical path adjusting device according to the present disclosure. The optical path adjusting device comprises an optical fiber device 1, a collimator 2, a gravity meter optical component 3 and a detector 4.

The fiber optic device 1 is configured to transmit incident light to the collimator 2 and to extract the measurement beam reflected back by the gravimeter optical assembly 3. The incident light may be Raman light, and the optical fiber device 1 may be an optical fiber circulator or an optical fiber splitter.

The collimator 2 is configured to convert incident light into collimated light. The collimator 2 can also be an optical fiber coupler, and the Raman light can be expanded and collimated by the collimator 2 to form collimated space light which is incident to the gravity meter optical component 3.

The gravity meter optical assembly 3 is configured to assemble collimated light into a measuring beam and reflect the measuring beam back to the fiber optic device 1. The optical component 3 of the gravimeter can be an optical gravimeter optical component, and can also be an atomic gravimeter optical component. Wherein the measuring beam is a beam to be adjusted to be parallel to the gravitational acceleration.

The detector 4 is configured to detect the reflected measuring beam extracted by the optical fiber device 1 and output a detection signal so that the measuring beam angle is adjusted to be perpendicular to the horizontal reference plane in accordance with the detection signal. The liquid level of water, mercury, alcohol, or the like may be used as the horizontal reference level. The detector 4 can detect the reflected light beam, and the detection signal can be a voltage signal or an optical power signal. When the voltage value of the voltage signal is the maximum value or the optical power value of the optical power signal is the maximum value, the measuring light beam is vertical to the horizontal reference surface. The mirror surface in the optical component 3 of the gravimeter can be adjusted manually or through a servo control system or the overall structure of the gravimeter can be adjusted, so that the voltage value or the optical power value of the detection signal is the maximum, and the measuring light beam is perpendicular to the horizontal reference surface.

In the embodiment, the optical fiber device is used for inputting incident light into the collimator, collimated light is output to the gravimeter optical assembly through the collimator, the gravimeter optical assembly forms the collimated light into a measuring beam and reflects the measuring beam back to the optical fiber device, and the detector outputs a detection signal after detecting the returned measuring beam, so that the angle of the measuring beam can be adjusted according to the detection signal, the measuring beam is perpendicular to the horizontal reference plane, and the sensitivity and the accuracy of light path verticality adjustment are improved.

Fig. 2 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure. In this embodiment, the optical fiber device 1 is exemplified by a fiber circulator 11, and the gravimeter optical assembly 3 is exemplified by an optical gravimeter optical assembly 31, wherein the fiber circulator 11 includes an input end 111, a first output end 112, and a second output end 113, and the optical gravimeter optical assembly 31 includes a half mirror 311 and a corner cube 312.

The incident light enters the optical fiber circulator 11 through the input end 111 of the optical fiber circulator and is output to the collimator 2 through the first output end 112, and the collimator 2 converts the incident light into collimated light. The collimated light is incident on the half mirror 311, wherein the half mirror 311 forms a predetermined angle with the horizontal reference plane 33.

The collimated light is reflected by the half mirror 311 to the corner cube 312, wherein the corner cube 312 is located above the half mirror 311. The cube-corner prism 312 reflects the collimated light back to the half mirror 311 in parallel to form a measuring beam, the measuring beam is transmitted to the horizontal reference plane 33 through the half mirror 311, the horizontal reference plane 33 reflects the measuring beam to the half mirror 311, the measuring beam is transmitted to the cube-corner prism 312, the cube-corner prism 312 reflects the measuring beam back to the half mirror 311 in parallel, and the half mirror 311 reflects the measuring beam to the fiber circulator 11.

The fiber circulator 11 extracts the reflected measuring beam and outputs the measuring beam to the detector 4 through the second output end 113, and the detector 4 outputs a detection signal. An operator can adjust the half mirror 311 or the entire structure of the gravimeter to adjust the transmission direction of the measuring beam and return the reflected light to the optical fiber circulator, so that the optical power value or the voltage value of the detection signal is maximized, and the measuring beam is perpendicular to the horizontal reference plane.

In this embodiment, the optical fiber circulator is used to extract the measurement signal reflected by the optical component of the optical gravimeter, and the transmission direction of the measurement beam is adjusted to maximize the optical power value or the voltage value of the detection signal output by the detector, which means that the measurement beam is perpendicular to the horizontal reference plane, so that the accuracy of adjusting the verticality of the optical path can be improved, and the problems of poor reproducibility and the like caused by human factors can be reduced.

Fig. 3 is a schematic structural diagram of a further embodiment of the optical path adjusting device of the present disclosure. In this embodiment, the optical fiber device 1 is exemplified by an optical fiber beam splitter 12, and the gravimeter optical assembly 3 is exemplified by an optical gravimeter optical assembly 31, wherein the optical fiber circulator 12 includes a first splitting end 121, a combining end 122, and a second splitting end 123, and the optical gravimeter optical assembly 31 includes a half-mirror 311 and a cube-corner prism 312.

The incident light enters the fiber beam splitter 12 through the first splitting end 121 of the fiber beam splitter, and is output to the collimator 2 through the beam combining end 122, and the collimator 2 converts the incident light into collimated light. The collimated light is incident on the half mirror 311, wherein the half mirror 311 forms a predetermined angle with the horizontal reference plane 33.

The collimated light is reflected by the half mirror 311 to the corner cube 312, wherein the corner cube 312 is located above the half mirror 311. The cube-corner prism 312 reflects the collimated light back to the half mirror 311 in parallel to form a measuring beam, the measuring beam is transmitted to the horizontal reference plane 33 through the half mirror 311, the horizontal reference plane 33 reflects the measuring beam to the half mirror 311, the measuring beam is transmitted to the cube-corner prism 312, the cube-corner prism 312 reflects the measuring beam back to the half mirror 311 in parallel, and the half mirror 311 reflects the measuring beam to the fiber beam splitter 12.

The fiber splitter 12 extracts the reflected measuring beam and outputs the measuring beam to the detector 4 through the second splitting end 123, and the detector 4 outputs a detection signal. An operator can adjust the overall structure of the half-mirror 311 or the gravimeter, adjust the transmission direction of the measuring beam, and return the reflected light to the optical fiber beam splitter, so that the optical power value or the voltage signal of the detection signal is maximized, and the measuring beam is perpendicular to the horizontal reference plane.

In this embodiment, the optical fiber beam splitter is used to extract the measurement signal reflected by the optical component of the optical gravimeter, and the transmission direction of the measurement beam is adjusted to maximize the optical power value or the voltage signal of the detection signal output by the detector, which means that the measurement beam is perpendicular to the horizontal reference plane, thereby reducing the problem of poor consistency caused by human factors and improving the accuracy of adjusting the verticality of the optical path.

Fig. 4 and 5 are schematic structural diagrams of still another embodiment of the optical path adjusting device of the present disclosure. In this embodiment, the optical fiber device 1 is exemplified by a fiber circulator 11, and the gravimeter optical assembly 3 is exemplified by an atomic gravimeter optical assembly 32, wherein the fiber circulator 11 includes an input end 111, a first output end 112, and a second output end 113, and the atomic gravimeter optical assembly 32 includes a first mirror 321 and a second mirror 322.

The principle of interference fringes formed by atomic gravimeters is different from that of optical gravimeters. The atomic gravimeter needs two beams of opposite-emitting laser with certain frequency difference and phase correlation to interact with atoms to form atomic groups for controlling in the gravity measurement process, so the atomic interferometer generally adopts the setting mode as follows: the two beams of light are incident into a physical system, and then the combined beam of light is reflected by the reflector light and returns along the original path, so that a pair of opposite light is obtained to interact with atoms. The measuring beam thus comprises a downward measuring beam and an upward measuring beam.

As shown in fig. 4, the incident light enters the fiber circulator 11 through the input end 111 of the fiber circulator and is output to the collimator 2 through the first output end 112, and the collimator 2 expands and collimates the incident light and converts the expanded and collimated incident light into collimated light. The collimated light is incident to the first reflecting mirror 321, wherein the first reflecting mirror 321 makes a predetermined angle with the horizontal reference plane 33.

The collimated light is reflected by the first mirror 321 to the horizontal reference plane 33 to form a downward measuring beam, the downward measuring beam is reflected by the horizontal reference plane 33 to the first mirror 321, and the first mirror 321 reflects the downward measuring beam to the fiber optic circulator 11.

The fiber optic circulator 11 extracts the reflected downward measuring beam and outputs the downward measuring beam to the detector 4 through the second output terminal 113, and the detector 4 outputs a first detection signal. An operator can adjust the first reflecting mirror 321 or the overall structure of the gravimeter, adjust the transmission direction of the downward measuring beam, and return the reflected light to the optical fiber circulator 11, so that the optical power value of the first detection signal is the maximum or the voltage signal is the maximum, and at this time, the downward measuring beam is perpendicular to the horizontal reference plane.

As shown in fig. 5, the second reflecting mirror 322 is substituted for the horizontal reference surface 33, the collimated light is reflected to the second reflecting mirror 322 by the first reflecting mirror 321, the second reflecting mirror 322 reflects the collimated light to the first reflecting mirror 321 to form an upward measuring beam, and the upward measuring beam is reflected to the fiber circulator 11 by the first reflecting mirror 321.

The fiber circulator 11 extracts the reflected upward measuring beam and outputs the upward measuring beam to the detector 4 through the second output terminal 113, and the detector 4 outputs a second detection signal. The operator can adjust the second reflecting mirror 322 to adjust the transmission direction of the upward measuring beam, and return the reflected beam to the optical fiber circulator 11, so that the optical power value of the second detection signal is maximized or the voltage signal is maximized, and the upward measuring beam is perpendicular to the horizontal reference plane.

In order to reduce atomic interference phase shift caused by Raman optical wave front distortion in an atomic gravimeter, large-spot beam expansion is generally carried out on the atomic gravimeter, so that the optical power density is very low, and in addition, the reflectivity is very low when a water surface or an alcohol surface is used as a reference surface, so that the judgment of the Raman optical gradient is difficult. Especially for a small atomic gravimeter, the whole height of a physical system is low, the optical path of Raman light is short, the light spot deviation of return light and emergent light is small under the same deviation angle, and the requirement for judging and adjusting when the coincidence of the light spots is observed through human eyes is high. In this embodiment, the optical fiber circulator is used to extract the measurement signal reflected by the optical component of the atomic gravimeter, and the transmission direction of the measurement beam is adjusted to maximize the optical power value or the voltage signal of the detection signal output by the detector, which indicates that the measurement beam is perpendicular to the horizontal reference plane, thereby improving the accuracy of adjusting the verticality of the optical path.

Fig. 6 and 7 are schematic structural diagrams of still another embodiment of the optical path adjusting device of the present disclosure. In this embodiment, the optical fiber device 1 is exemplified by a fiber splitter 12, and the gravimeter optical assembly 3 is exemplified by an atomic gravimeter optical assembly 32, wherein the fiber circulator 12 includes a first splitting end 121, a combining end 122, and a second splitting end 123, and the atomic gravimeter optical assembly 32 includes a first mirror 321 and a second mirror 322.

As shown in fig. 6, the incident light enters the optical fiber beam splitter 12 through the first splitting end 121 of the optical fiber beam splitter, and is output to the collimator 2 through the beam combining end 122, and the collimator 2 expands and collimates the incident light and converts the incident light into collimated light. The collimated light is incident to the first reflecting mirror 321, wherein the first reflecting mirror 321 makes a predetermined angle with the horizontal reference plane 33.

The collimated light is reflected by the first mirror 321 to the horizontal reference plane 33 to form a downward measuring beam, the downward measuring beam is reflected by the horizontal reference plane 33 to the first mirror 321, and the first mirror 321 reflects the downward measuring beam to the fiber beam splitter 12.

The fiber splitter 12 extracts the reflected downward measuring beam and outputs the downward measuring beam to the detector 4 through the second splitting end 123, and the detector 4 outputs a first detection signal. An operator can adjust the first reflecting mirror 321 or the overall structure of the gravimeter, adjust the transmission direction of the downward measuring beam, and return the reflected light to the optical fiber beam splitter 12, so that the optical power value or the voltage signal of the first detection signal is the maximum, and at this time, the downward measuring beam is perpendicular to the horizontal reference plane.

As shown in fig. 7, the second reflecting mirror 322 is substituted for the horizontal reference surface 33, the collimated light is reflected to the second reflecting mirror 322 by the first reflecting mirror 321, the second reflecting mirror 322 reflects the collimated light to the first reflecting mirror 321 to form an upward measuring beam, and the upward measuring beam is reflected to the optical fiber beam splitter 12 by the first reflecting mirror 321.

The fiber splitter 12 extracts the reflected upward measuring beam and outputs the upward measuring beam to the detector 4 through the second splitting end 123, and the detector 4 outputs a second detection signal. The operator can adjust the second reflecting mirror 322 to adjust the transmission direction of the upward measuring beam, so that the reflected beam is returned to the optical splitter 12, and the optical power value or the voltage signal of the second detection signal is maximized, and the upward measuring beam is perpendicular to the horizontal reference plane.

In this embodiment, the optical fiber beam splitter is used to extract the measurement signal reflected by the optical component of the optical gravimeter, and the transmission direction of the measurement beam is adjusted to maximize the optical power value or the voltage signal of the detection signal output by the detector, which indicates that the measurement beam is perpendicular to the horizontal reference plane, thereby improving the accuracy of adjusting the verticality of the optical path.

In addition, in the prior art, a polarization splitting prism is usually arranged in an external optical path of a Raman light fiber inlet end to extract laser reflected back when the Raman light polarization is arranged in the same way, but the method cannot be applied to the situation that the Raman light adopts a polarization vertical arrangement mode, and in the embodiment, the return light is extracted in a non-polarization mode through an optical fiber circulator or an optical fiber beam splitter, so that the method has good universality in two different arrangement modes of polarization vertical and polarization same direction adopted by the Raman light.

Fig. 8 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure. In addition to the fiber optic device 1, collimator 2, gravimeter optical assembly 3 and detector 4 of fig. 1, this embodiment also includes a servo control system 5. Wherein the mirror surface in the gravimeter optical assembly 3 is held by the controllable mirror mount.

The servo control system 5 is configured to generate an error signal from the detection signal, generate a servo control signal based on the error signal, and control the controllable mirror mount according to the servo control signal such that the measuring beam is perpendicular to the horizontal reference plane. The servo control system 5 may include a driving device, which may be a piezoelectric ceramic or a stepping motor, and the driving device controls the controllable mirror holder according to the servo control signal, so as to adjust the angle of the mirror surface, and make the measuring beam perpendicular to the horizontal reference surface.

In the embodiment, the servo control system can realize active servo for adjusting the verticality of the optical path, and inhibit slow angle drift caused by external environment, temperature and airflow change.

Fig. 9 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure. In this embodiment, a servo control system 5 is further included on the basis of fig. 2, and the servo control system 5 includes a power divider 51, a first servo Pl1, a second servo Pl2, a first controller C1, a second controller C2, a first driving device 52, and a second driving device 53.

After the detector 4 detects the reflection measurement beam extracted by the optical fiber circulator 11, an AC (alternating current) signal is extracted as a radio frequency signal, and the radio frequency signal is mixed with a local oscillation signal by a mixer to obtain an intermediate frequency signal. The power divider 51 divides the intermediate frequency signal into two parts, i.e., a first dimension detection signal and a second dimension detection signal, which are respectively used for two-dimensional locking of the half mirror 311.

The first servo Pl1 generates a first error signal according to the first dimension detection signal, the first controller C1 generates a first servo control signal according to the first error signal, and the first driving device 52 controls the first dimension of the controllable mirror holder according to the first servo control signal, so as to adjust the first dimension angle of the half mirror 311, and make the half mirror 311 in the optimal position. Then, the second servo Pl2 generates a second error signal according to the second dimension detection signal, the second controller C2 generates a second servo control signal based on the second error signal, and the second driving device 53 controls the second dimension of the controllable mirror holder according to the second servo control signal so as to adjust the second dimension angle of the half mirror 311, and finally, the measuring beam is perpendicular to the horizontal reference plane.

In the embodiment, the accuracy and the sensitivity of the light path verticality adjustment are improved, the problems of poor reproducibility and the like caused by human factors are avoided, and the angular deviation caused by the external environment, mechanical aging and the like is inhibited.

Fig. 10 is a schematic structural diagram of another embodiment of the optical path adjusting device of the present disclosure. In this embodiment, a servo control system 5 is further included on the basis of fig. 3, and the servo control system 5 includes a power divider 51, a first servo Pl1, a second servo Pl2, a first controller C1, a second controller C2, a first driving device 52, and a second driving device 53. The manner of adjusting the angle of the half mirror 311 is similar to that shown in fig. 9, and this embodiment will not be further described.

Fig. 11 and 12 are schematic structural diagrams of still another embodiment of the optical path adjusting device of the present disclosure. In this embodiment, a servo control system 5 is further included on the basis of fig. 4 and 5, and the servo control system 5 includes a power divider 51, a first servo Pl1, a second servo Pl2, a first controller C1, a second controller C2, a first driving device 52, and a second driving device 53.

As shown in fig. 11, the detector 4 generates a first detection signal after detecting the reflected downward measuring beam extracted by the fiber circulator 11. The power divider 51 divides the first detection signal into two parts, that is, a first dimension detection signal of the downward measuring beam and a second dimension detection signal of the downward measuring beam, which are respectively used for two-dimensional locking of the first mirror 321, wherein the controllable mirror bracket first clamps the first mirror 321.

The first servo Pl1 generates a first error signal according to the first dimension detection signal of the downward measuring beam, the first controller C1 generates a first servo control signal based on the first error signal, and the first driving device 52 controls the first dimension of the controllable mirror holder holding the first mirror 321 so as to adjust the first dimension angle of the first mirror 321 to make the first mirror 321 in the optimal position. Then, the second servo Pl2 generates a second error signal according to the second dimension detection signal of the downward measuring beam, the second controller C2 generates a second servo control signal based on the second error signal, and the second driving device 53 controls the second dimension of the controllable mirror holder holding the first mirror 321 so as to adjust the second dimension angle of the first mirror 321, and finally makes the downward measuring beam perpendicular to the horizontal reference plane.

As shown in fig. 12, the second mirror 322 is displaced from the horizontal reference plane, and the detector 4 generates a second detection signal when detecting the reflected upward measurement beam extracted by the fiber circulator 11. The power divider 51 divides the second detection signal into two parts, i.e. a first dimension detection signal of the upward measuring beam and a second dimension detection signal of the upward measuring beam, which are respectively used for two-dimensional locking of the second reflecting mirror 322, wherein the controllable mirror bracket holds the second reflecting mirror 322.

The first servo Pl1 generates a third error signal according to the first dimension detection signal of the upward measuring beam, the first controller C1 generates a third servo control signal according to the third error signal, and the second driving device 53 controls the first dimension of the controllable mirror holder holding the second mirror 322 so as to adjust the first dimension angle of the second mirror 322 to make the second mirror 322 be at the optimum position. Then, the second servo Pl2 generates a fourth error signal according to the second dimension detection signal of the upward measuring beam, the second controller C2 generates a fourth servo control signal based on the fourth error signal, and the second driving device 53 controls the second dimension of the controllable mirror holder holding the second mirror 322 so as to adjust the second dimension angle of the second mirror 322, and finally makes the upward measuring beam perpendicular to the horizontal reference plane. It will be understood by those skilled in the art that the first, second, third and fourth are used to denote different signals.

In the embodiment, the accuracy and the sensitivity of the light path verticality adjustment are improved, the problems of poor reproducibility and the like caused by human factors are avoided, and the angular deviation caused by the external environment, mechanical aging and the like is inhibited. In addition, in the atomic gravimeter, different Raman light configurations can be adopted, for example, the polarization states of the two combined beams of light are parallel or perpendicular, and the perpendicular adjustment control mode in the embodiment has no requirement on the polarization state of the return light, so that the atomic gravimeter has high universality.

Fig. 13 and 14 are schematic structural diagrams of still another embodiment of the optical path adjusting device of the present disclosure. In this embodiment, a servo control system 5 is further included on the basis of fig. 6 and 7, and the servo control system 5 includes a power divider 51, a first servo Pl1, a second servo Pl2, a first controller C1, a second controller C2, a first driving device 52, and a second driving device 53. The angle of the first reflector 321 is adjusted in a manner similar to that of fig. 11, and the angle of the second reflector 322 is adjusted in a manner similar to that of fig. 12, and this embodiment will not be further described.

In an embodiment of the present disclosure, a gravimeter is further included, and the gravimeter includes the optical path adjusting device described in the above embodiment. The gravimeter can measure the gravity acceleration more accurately.

At step 110, the fiber optic device transmits the received input light to a collimator. The incident light can be Raman light, and the optical fiber device can be an optical fiber circulator or an optical fiber beam splitter.

At step 120, the collimator converts the incident light into collimated light. The collimator can expand and collimate incident light so that the incident light becomes collimated space light.

At step 130, the collimated light is assembled by the gravimeter optics to form a measurement beam that is reflected back through the gravimeter optics to the fiber optic device. The optical component of the gravimeter can be an optical gravimeter optical component or an atomic gravimeter optical component. Wherein the measuring beam is a beam parallel to the gravitational acceleration.

At step 140, the fiber optic device extracts the measurement beam reflected back from the gravimeter optical assembly.

In step 150, the detector detects the reflected measuring beam extracted by the fiber optic device and outputs a detection signal to adjust the measuring beam angle based on the detection signal to make the measuring beam perpendicular to the horizontal reference plane. Among them, the liquid surface of water, mercury, alcohol or the like can be used as the horizontal reference surface. The detector can detect the reflected light beam, and the detection signal can be a voltage signal or an optical power signal. And when the voltage signal is the maximum voltage value or the optical power signal is the maximum optical power value, the measuring light beam is vertical to the horizontal reference surface. The mirror surface in the optical assembly of the gravity meter can be manually or automatically adjusted or the overall structure of the gravity meter can be adjusted, so that the voltage signal is maximum or the optical power value is maximum, and the measuring light beam is perpendicular to the horizontal reference surface.

In the embodiment, the optical fiber device is used for inputting incident light into the collimator, collimated light is output to the gravimeter optical assembly through the collimator, the collimated light is constructed through the gravimeter optical assembly to form measuring light beams, the measuring light beams are reflected back to the optical fiber device through the gravimeter optical assembly, the detector outputs detection signals after detecting the returned measuring light beams, and therefore the angle of the measuring light beams can be adjusted according to the detection signals, the measuring light beams are perpendicular to the horizontal reference surface, the problems of poor reproducibility and the like caused by human factors are solved, and the sensitivity and accuracy of light path verticality adjustment are improved.

In another embodiment of the present disclosure, as shown in fig. 16, the method further includes step 160-180 after detecting the reflected measuring beam extracted by the fiber optic device by the detector at step 150 and outputting the detection signal.

In step 160, the servo control system generates an error signal based on the detection signal.

At step 170, a servo control signal is generated based on the error signal.

In step 180, the controllable mirror mount is controlled according to the servo control signal so that the measuring beam is perpendicular to the horizontal reference plane; the controllable mirror bracket is used for clamping a mirror surface of the optical assembly of the gravimeter.

In one embodiment, the servo control system divides the detection signal into a first dimension detection signal and a second dimension detection signal; generating a first error signal according to the first dimension detection signal, generating a first servo control signal based on the first error signal, and controlling the first dimension of the controllable mirror bracket according to the first servo control signal; and generating a second error signal according to the second dimension detection signal, generating a second servo control signal based on the second error signal, and controlling the second dimension of the controllable mirror frame according to the second servo control signal.

In the embodiment, the servo control system can realize active servo for adjusting the verticality of the optical path, and inhibit slow angle drift caused by external environment, temperature and airflow changes.

Fig. 17 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure. In this embodiment, the optical fiber device is exemplified by an optical fiber circulator, and the optical gravity meter optical assembly is exemplified by an optical gravity meter optical assembly, wherein the optical fiber circulator includes an input end, a first output end and a second output end, and the optical gravity meter optical assembly includes a half-mirror and a pyramid prism.

In step 210, incident light is incident on the fiber circulator through the input end of the fiber circulator and is output to the collimator through the first output end.

At step 220, the collimator converts the incident light into collimated light.

At step 230, the collimated light is assembled by the optical gravimeter optics to form a measurement beam that is reflected back to the fiber optic circulator by the optical gravimeter optics. Wherein, collimated light is reflected to the pyramid prism by half mirror, and the pyramid prism reflects collimated light parallel back half mirror in order to form measuring beam, and measuring beam transmits horizontal reference face through half mirror, and horizontal reference face reflects measuring beam to half mirror back, and measuring beam is transmitted to the pyramid prism, and the pyramid prism reflects measuring beam parallel back half mirror, and half mirror reflects measuring beam to the optical fiber circulator.

At step 240, the fiber optic circulator extracts the reflected measuring beam and outputs it to the detector through the second output terminal.

In step 250, the detector detects the reflected measuring beam extracted by the fiber optic circulator and outputs a detection signal. The operator can adjust the whole structure of the semi-transparent semi-reflecting mirror or the gravimeter, adjust the transmission direction of the measuring beam, and return the reflected light to the optical fiber circulator, so that the optical power value of the detection signal is the maximum or the voltage signal is the maximum, and the measuring beam is perpendicular to the horizontal reference surface at the moment.

Additionally, the embodiment can further include the following step 260 and 280, wherein the controllable frame holds the half mirror of the optical gravimeter optical assembly.

In step 260, the servo control system generates an error signal based on the probing signal.

In step 270, the servo control system generates a servo control signal based on the error signal.

In step 280, the servo control system controls the controllable mirror mount according to the servo control signal to adjust the angle of the half mirror so that the measuring beam is perpendicular to the horizontal reference plane.

In this embodiment, the optical fiber circulator is used to extract the measurement signal reflected by the optical component of the optical gravimeter, and the transmission direction of the measurement beam is adjusted to maximize the optical power value or the voltage signal of the detection signal output by the detector, which means that the measurement beam is perpendicular to the horizontal reference plane, so that the accuracy of adjusting the verticality of the optical path can be improved, and the angular deviation caused by the external environment, mechanical aging, and the like can be suppressed.

Fig. 18 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure. In this embodiment, the optical fiber device is described by taking an optical fiber beam splitter as an example, and the gravimeter optical assembly is described by taking an optical gravimeter optical assembly as an example, where the optical fiber beam splitter includes a first splitting end, a combining end, and a second splitting end, and the optical gravimeter optical assembly includes a half-mirror and a cube-corner prism.

In step 310, the incident light enters the fiber splitter through the first splitting end of the fiber splitter and is output to the collimator through the beam combining end.

At step 320, the collimator converts incident light into collimated light.

At step 330, the collimated light is assembled by the optical gravimeter optics into a measurement beam that is reflected back to the fiber optic splitter by the optical gravimeter optics. Wherein, collimated light is reflected to the pyramid prism by half mirror, and the pyramid prism reflects collimated light parallel back half mirror in order to form measuring beam, and measuring beam transmits horizontal reference face through half mirror, and horizontal reference face reflects measuring beam to half mirror back, and measuring beam is transmitted to the pyramid prism, and the pyramid prism reflects measuring beam parallel back half mirror, and half mirror reflects measuring beam to fiber beam splitter.

In step 340, the reflected measuring beam extracted by the fiber optic splitter is output to the detector through the second output terminal. The operator can adjust the whole structure of the semi-transparent semi-reflecting mirror or the gravimeter, adjust the transmission direction of the measuring beam, return the reflected light to the optical fiber beam splitter in the original path, maximize the optical power value or the voltage signal of the detection signal, and at the moment, the measuring beam is vertical to the horizontal reference surface.

In step 350, the detector detects the reflected measuring beam extracted by the fiber optic splitter and outputs a detection signal.

In addition, the embodiment may further include the following steps 360-380, wherein the steps 360-380 are similar to the steps 260-280, and will not be further described herein.

In this embodiment, the optical fiber beam splitter is used to extract the measurement signal reflected by the optical component of the optical gravimeter, and the transmission direction of the measurement beam is adjusted to maximize the optical power value or the voltage signal of the detection signal output by the detector, which means that the measurement beam is perpendicular to the horizontal reference plane, so that the accuracy of adjusting the verticality of the optical path can be improved, and the angular deviation caused by external environment, mechanical aging, and the like can be suppressed.

Fig. 19 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure. In this embodiment, the optical fiber device is exemplified by a fiber optic circulator, and the gravimeter optical assembly is exemplified by an atomic gravimeter optical assembly, wherein the fiber optic circulator includes an input end, a first output end and a second output end, and the atomic gravimeter optical assembly includes a first mirror and a second mirror.

In step 410, incident light is incident on the fiber optic circulator through an input end of the fiber optic circulator and is output to the collimator through a first output end.

At step 420, the collimator converts the incident light into collimated light.

At step 430, collimated light is constructed by the atomic gravimeter optical assembly to form a downward measuring beam that is reflected back to the fiber optic circulator by the atomic gravimeter optical assembly. In one embodiment, the collimated light is reflected by a first mirror to a horizontal reference surface to form a downward measuring beam, the downward measuring beam is reflected by the horizontal reference surface to the first mirror, and the first mirror reflects the downward measuring beam to the fiber optic circulator.

At step 440, the fiber optic circulator extracts the reflected downward measuring beam and outputs the downward measuring beam to the detector through the second output terminal, and the detector outputs the first detection signal. The operator can adjust the overall structure of the first reflector or the gravimeter, adjust the transmission direction of the downward measuring beam, and return the reflected light to the optical fiber circulator, so that the optical power value or the voltage signal of the first detection signal is the maximum, and at this time, the downward measuring beam is perpendicular to the horizontal reference surface.

At step 450, the second mirror is substituted for the horizontal reference plane, and the atomic gravimeter optical assembly forms an upward measuring beam by reflecting the collimated light and reflects the upward measuring beam back to the fiber optic circulator. In one embodiment, the collimated light is reflected by a first mirror to a second mirror, which reflects the collimated light to the first mirror to form an upward measuring beam, which is reflected by the first mirror to the fiber optic circulator.

At step 460, the fiber optic circulator extracts the reflected upward measuring beam and outputs the upward measuring beam to the detector through the second output terminal, and the detector outputs a second detection signal. The operator may adjust the second mirror to adjust the direction of transmission of the upward measuring beam to return the reflected beam to the optical fiber circulator so that the optical power value or the voltage signal of the second detection signal is maximized, where the upward measuring beam is perpendicular to the horizontal reference plane.

In addition, the embodiment may further include steps 441-443 and 461-463, in which the controllable frame first holds the first mirror.

At step 441, the servo control system generates a first error signal based on the first detection signal.

At step 442, the servo control system generates a first servo control signal based on the first error signal.

In step 443, the servo control system controls the controllable mirror mount according to the first servo control signal to adjust the angle of the first mirror so that the downward measuring beam is perpendicular to the horizontal reference plane.

The controllable mirror holder holds the second reflecting mirror.

In step 461, the servo control system generates a second error signal based on the second detection signal.

In step 462, the servo control system generates a second servo control signal based on the second error signal.

In step 463, the servo control system controls the controllable mirror mount based on the second servo control signal to adjust the angle of the second mirror so that the upward measuring beam is perpendicular to the horizontal reference plane.

In this embodiment, the optical fiber circulator is used to extract the measurement signal reflected by the optical component of the atomic gravimeter, and the transmission direction of the measurement beam is adjusted to maximize the optical power value or the voltage signal of the detection signal output by the detector, which means that the measurement beam is perpendicular to the horizontal reference plane, so that the accuracy of adjusting the verticality of the optical path can be improved, and the angular deviation caused by the external environment, mechanical aging, and the like can be suppressed.

Fig. 20 is a schematic flow chart of another embodiment of the optical path adjusting method of the present disclosure. In this embodiment, the optical fiber device is exemplified by an optical fiber beam splitter, and the gravimeter optical assembly is exemplified by an atomic gravimeter optical assembly, where the optical fiber beam splitter includes a first splitting end, a combining end, and a second splitting end, and the atomic gravimeter optical assembly includes a first mirror and a second mirror.

In step 510, the incident light enters the fiber splitter through the first splitting end of the fiber splitter and is output to the collimator through the beam combining end.

At step 520, the collimator converts incident light into collimated light.

At step 530, the collimated light is assembled by the atomic gravimeter optical assembly to form a downward measuring beam that is reflected back to the fiber optic splitter by the atomic gravimeter optical assembly. In one embodiment, the collimated light is reflected by a first mirror to a horizontal reference surface to form a downward measuring beam, the downward measuring beam is reflected by the horizontal reference surface to the first mirror, and the first mirror reflects the downward measuring beam to the fiber optic beam splitter.

In step 540, the fiber optic splitter extracts the reflected downward measuring beam and outputs the downward measuring beam to the detector through the second output terminal, and the detector outputs the first detection signal. The operator can adjust the overall structure of the first reflector or the gravimeter, adjust the transmission direction of the downward measuring beam, and return the reflected light to the optical fiber beam splitter, so that the optical power value of the first detection signal is the maximum or the voltage signal is the maximum, and at this time, the downward measuring beam is perpendicular to the horizontal reference plane.

At step 550, the second mirror is replaced with a horizontal reference surface, and the atomic gravimeter optical assembly forms an upward measuring beam by reflecting the collimated light and reflects the upward measuring beam back to the fiber optic splitter. Wherein the collimated light is reflected by the first mirror to the second mirror, the second mirror reflects the collimated light to the first mirror to form an upward measuring beam, and the upward measuring beam is reflected by the first mirror to the fiber beam splitter.

At step 560, the fiber optic splitter extracts the reflected upward measuring beam and outputs the reflected upward measuring beam to the detector through the second output terminal, and the detector outputs a second detection signal. The operator may adjust the second mirror to adjust the transmission direction of the upward measuring beam to return the reflected beam to the optical splitter in the original path, so that the optical power value of the second detection signal is maximized or the voltage signal is maximized, and the upward measuring beam is perpendicular to the horizontal reference plane.

In addition, the embodiment may further include steps 541-.

Thus far, the present disclosure has been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

The methods and apparatus of the present disclosure may be implemented in a number of ways. For example, the methods and apparatus of the present disclosure may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order for the steps of the method is for illustration only, and the steps of the method of the present disclosure are not limited to the order specifically described above unless specifically stated otherwise. Further, in some embodiments, the present disclosure may also be embodied as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present disclosure. Thus, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An optical path adjusting apparatus comprising:

a fiber optic device configured to transmit incident light to the collimator and extract the measurement beam reflected back from the gravity meter optical assembly;

a collimator configured to convert incident light into collimated light;

a gravity meter optical assembly configured to assemble collimated light into a measurement beam and reflect the measurement beam back to the fiber optic device; wherein, the gravity appearance optical assembly is optics gravity appearance optical assembly, includes:

the semi-transmitting semi-reflecting mirror forms a preset angle with the horizontal reference surface;

the pyramid prism is positioned above the semi-transparent semi-reflecting mirror;

wherein, collimated light is reflected to the pyramid prism by the half mirror, the pyramid prism reflects the collimated light back to the half mirror in parallel to form a measuring beam, the measuring beam is transmitted to a horizontal reference surface through the half mirror, the measuring beam is transmitted to the pyramid prism after the horizontal reference surface reflects the measuring beam to the half mirror, the pyramid prism reflects the measuring beam back to the half mirror in parallel, and the half mirror reflects the measuring beam to the optical fiber device;

a detector configured to detect the reflected measuring beam extracted by the optical fiber device and output a detection signal so as to adjust a measuring beam angle to make the measuring beam perpendicular to a horizontal reference plane according to the detection signal.

2. The optical path adjustment device according to claim 1, wherein the optical fiber device is a fiber circulator;

the input end of the optical fiber circulator transmits incident light to the optical fiber circulator, and the incident light is output to the collimator through the first output end; and the reflected measuring beam extracted by the optical fiber circulator is output to the detector through a second output end.

3. The optical path adjustment device according to claim 1, wherein the optical fiber device is an optical fiber splitter;

incident light enters the optical fiber beam splitter through a first beam splitting end of the optical fiber beam splitter and is output to the collimator through a beam combining end; and the reflected measuring beam extracted by the optical fiber beam splitter is output to the detector through a second beam splitting end.

4. The optical path adjustment device according to claim 1,

under the condition that the voltage value of the detection signal is the maximum value, the measuring light beam is vertical to a horizontal reference plane; and/or

And under the condition that the optical power value of the detection signal is the maximum value, the measuring light beam is vertical to the horizontal reference plane.

5. The optical path adjusting apparatus according to any one of claims 1 to 4, further comprising:

a servo control system configured to generate an error signal from the detection signal, generate a servo control signal based on the error signal, and control the controllable mirror mount according to the servo control signal such that the measuring beam is perpendicular to the horizontal reference plane; wherein the controllable mirror holder is used for clamping the mirror surface of the optical assembly of the gravimeter.

6. The optical path adjusting apparatus according to claim 5, wherein the servo control system comprises:

a power divider configured to divide the detection signal into a first-dimension detection signal and a second-dimension detection signal;

a first servo configured to generate a first error signal from the first dimension detection signal;

a second servo configured to generate a second error signal from the second dimension detection signal;

a first controller configured to generate a first servo control signal based on the first error signal;

a second controller configured to generate a second servo control signal based on the second error signal;

a first drive configured to control a first dimension of the controllable mirror mount according to the first servo control signal;

a second drive configured to control a second dimension of the controllable mirror mount according to the second servo control signal.

7. The optical path adjusting device according to claim 5, wherein the controllable mirror holder holds the half mirror;

the servo control system controls the controllable mirror frame according to the servo control signal so as to adjust the angle of the half-transmitting and half-reflecting mirror, and therefore the measuring light beam is perpendicular to the horizontal reference plane.

8. An optical path adjusting apparatus comprising:

a collimator configured to convert incident light into collimated light;

a gravity meter optical assembly configured to assemble collimated light into a measurement beam and reflect the measurement beam back to the fiber optic device; wherein the measuring beam comprises a downward measuring beam and an upward measuring beam, and the gravimeter optical assembly is an atomic gravimeter optical assembly comprising:

the first reflector forms a preset angle with the horizontal reference surface;

a second mirror configured to be placed below the first mirror when forming an upward measuring beam;

wherein the collimated light is reflected by the first mirror to a horizontal reference surface to form a downward measuring beam, the downward measuring beam is reflected by the horizontal reference surface to the first mirror, and the first mirror reflects the downward measuring beam to the optical fiber device; and

replacing a horizontal reference surface with the second mirror, collimated light being reflected by the first mirror to the second mirror, the second mirror reflecting collimated light to the first mirror to form an upward measuring beam, the upward measuring beam being reflected by the first mirror to the fiber optic device;

9. The optical path adjustment device according to claim 8, wherein the optical fiber device is a fiber circulator;

10. The optical path adjustment device according to claim 8, wherein the optical fiber device is an optical fiber splitter;

11. The optical path adjustment device according to claim 8,

12. The optical path adjusting apparatus according to any one of claims 8 to 11, further comprising:

13. The optical path adjusting apparatus according to claim 12, wherein the servo control system comprises:

14. The optical path adjustment device according to claim 12,

the controllable mirror frame clamps the first reflecting mirror, and the servo control system controls the controllable mirror frame according to a servo control signal so as to adjust the angle of the first reflecting mirror, so that the downward measuring light beam is perpendicular to a horizontal reference plane; and

the controllable mirror frame clamps the second reflecting mirror, and the servo control system controls the controllable mirror frame according to a servo control signal so as to adjust the angle of the second reflecting mirror, so that the upward measuring beam is perpendicular to the horizontal reference plane.

15. A gravimeter comprising the optical path adjusting device according to any one of claims 1 to 14.

16. An optical path adjusting method comprising:

the optical fiber device transmits the received input light to the collimator;

the collimator converts incident light into collimated light;

the collimated light is assembled through a gravimeter optical assembly to form a measuring beam, and the measuring beam is reflected back to the optical fiber device through the gravimeter optical assembly; wherein, when the gravity appearance optical assembly is optical gravity appearance optical assembly, include: the semi-transmitting semi-reflecting mirror forms a preset angle with the horizontal reference surface; the pyramid prism is positioned above the semi-transparent semi-reflecting mirror; wherein, collimated light is reflected to the pyramid prism by the half mirror, the pyramid prism reflects the collimated light back to the half mirror in parallel to form a measuring beam, the measuring beam is transmitted to a horizontal reference surface through the half mirror, the measuring beam is transmitted to the pyramid prism after the horizontal reference surface reflects the measuring beam to the half mirror, the pyramid prism reflects the measuring beam back to the half mirror in parallel, and the half mirror reflects the measuring beam to the optical fiber device; when the gravity appearance optical assembly is atomic gravity appearance optical assembly, include: the first reflector forms a preset angle with the horizontal reference surface; a second mirror configured to be positioned below the first mirror when forming an upward measuring beam, wherein the measuring beam includes a downward measuring beam and an upward measuring beam; the collimated light is reflected by the first mirror to a horizontal reference surface to form a downward measuring beam, the downward measuring beam is reflected by the horizontal reference surface to the first mirror, and the first mirror reflects the downward measuring beam to the optical fiber device; and replacing the second mirror with a horizontal reference surface, collimated light being reflected by the first mirror to the second mirror, the second mirror reflecting collimated light to the first mirror to form an upward measuring beam, the upward measuring beam being reflected by the first mirror to the fiber optic device;

the optical fiber device extracts the measuring light beam reflected by the optical assembly of the gravimeter;

the detector detects the reflected measuring beam extracted by the optical fiber device and outputs a detection signal so as to adjust the angle of the measuring beam according to the detection signal to make the measuring beam perpendicular to the horizontal reference plane.

17. The optical path adjusting method according to claim 16, wherein the optical fiber device is a fiber circulator;

the input end of the optical fiber circulator transmits incident light to the optical fiber circulator, and the incident light is output to the collimator through the first output end; and

and the reflected measuring beam extracted by the optical fiber circulator is output to the detector through a second output end.

18. The optical path adjusting method according to claim 16, wherein the optical fiber device is an optical fiber splitter;

incident light enters the optical fiber beam splitter through a first beam splitting end of the optical fiber beam splitter and is output to the collimator through a beam combining end; and

and the reflected measuring beam extracted by the optical fiber beam splitter is output to the detector through a second beam splitting end.

19. The optical path adjusting method according to claim 16,

under the condition that the voltage value of the detection signal is the maximum value, the measuring light beam is vertical to a horizontal reference plane;

and/or

20. The optical path adjusting method according to any one of claims 16 to 19, further comprising:

the servo control system generates an error signal according to the detection signal;

generating a servo control signal based on the error signal;

controlling the controllable mirror bracket according to the servo control signal so that the measuring light beam is perpendicular to the horizontal reference surface; wherein the controllable mirror holder is used for clamping the mirror surface of the optical assembly of the gravimeter.

21. The optical path adjusting method according to claim 20,

the servo control system divides the detection signal into a first dimension detection signal and a second dimension detection signal;

generating a first error signal according to the first dimension detection signal, generating a first servo control signal based on the first error signal, and controlling the first dimension of the controllable mirror bracket according to the first servo control signal;

and generating a second error signal according to the second dimension detection signal, generating a second servo control signal based on the second error signal, and controlling the second dimension of the controllable mirror frame according to the second servo control signal.

22. The optical path adjustment method according to claim 20, wherein the controllable mirror holder holds a half mirror of the optical gravimeter optical assembly;

the servo control system controls the controllable mirror frame according to the servo control signal so as to adjust the angle of the half-mirror, and therefore the measuring beam is perpendicular to the horizontal reference plane.

23. The optical path adjusting method according to claim 20,

the controllable mirror frame clamps the first reflecting mirror, and the servo control system controls the controllable mirror frame according to a servo control signal so as to adjust the angle of the first reflecting mirror, so that the downward measuring light beam is perpendicular to the horizontal reference plane; and

the controllable mirror frame holds the second mirror, and the servo control system controls the controllable mirror frame according to a servo control signal so as to adjust the angle of the second mirror, so that the upward measuring beam is perpendicular to the horizontal reference plane.