A method and device for probe position modulation of a four-pulse cold atom interferometer gyroscope

Abstract

The application relates to a detection position modulation method and device of a four-pulse cold atom interference gyroscope, which comprises the following steps: determining the four-time Raman pulse interval time of the four-pulse cold atom interference gyroscope; determining a plurality of working states of the four-pulse cold atom interference gyroscope according to the four-time Raman pulse interval time; and selecting states of Raman light in different relative directions based on the plurality of working states of the four-pulse cold atom interference gyroscope. The application sets two working states in the state selection stage of the four-pulse cold atom interference gyroscope, realizes the state selection of Raman light in different effective Raman wave vectors, and makes the detection positions of atom groups close, so that the detection error caused by the period change of the detection positions and the limitation on the space size of the detection area are reduced.

Description

Technical Field

[0001] This invention belongs to the field of atomic interferometric gyroscope technology, and specifically relates to a method and apparatus for modulating the detection position of a four-pulse cold atomic interferometric gyroscope. Background Technology

[0002] In the past decade, atomic interferometry has developed rapidly and been widely applied. Due to its high sensitivity and quantum properties, it has potential applications in the field of high-precision inertial navigation.

[0003] An atomic interferometer is a Mach-Zehnder-type interferometer constructed by propagating a cold beam of Rb (or Cs) atoms along two different topological paths to measure the phase difference caused by the different paths taken by the two atomic beams. In this interferometer, atomic optical elements, such as spectrometers and mirrors similar to those in optics, have already achieved the splitting and reflection of the propagation of two photons to measure the phase change of the atomic wavefunction caused by inertial forces, and then measure the amount of this phase change. When an atom absorbs or emits a photon, the momentum of the atom and the light field should be conserved. With the realization of atomic optical elements such as atomic beam splitters and atomic mirrors, appropriate methods to manipulate atoms must be considered; in fact, the interaction between light and matter is a major means to achieve this. This process can be understood as the coherent exchange of photons and the exchange of photon momentum. The principle is as follows: In an atomic system, an atom at a certain energy level is split into two different energy levels due to the action of a laser. The state of the atom depends on the following parameters: laser energy, interaction time, and laser frequency.

[0004] Cold atom interferometric gyroscopes based on the four-pulse interferometry technique offer advantages such as high measurement accuracy and low long-term drift, making them the most accurate cold atom interferometric gyroscopes currently available. These gyroscopes typically employ a vertically thrown cold atom cluster, which is subjected to four Raman pulses during its ascent and descent, forming a Sagnac interference loop. When the cluster falls into the detection region, a probe light is used to detect the internal state information of the atoms. The Raman two-photon transition process generated by the Raman pulses causes the cluster to acquire a transverse velocity with twice the photon momentum in the effective Raman wave vector direction. This causes the detection position of the atom to deviate from the vertical throw line, requiring sufficient space to be reserved in the detection region. Furthermore, with the application of effective Raman wave vector reversal technology, the deviation point of the detection position changes periodically with the reversal of the positive and negative effective Raman wave vectors, further increasing the non-uniform detection error and the required space in the atom detection region.

[0005] To solve the problem of probe position variation in a four-pulse cold atom interferometer gyroscope, one option is to not use positive and negative k, but this will affect the long-term stability of the gyroscope and reduce its performance; another option is to design a detection and imaging system with sufficient space and good consistency, but this places extremely high demands on the design of technical solutions, materials, and processing technology, and its feasibility is poor. Summary of the Invention

[0006] To address the problem of detector position deviation in a four-pulse cold atom interferometric gyroscope, a method for modulating the detector position of a four-pulse cold atom interferometric gyroscope is provided in a first aspect of the present invention. The method includes: determining the interval between the four Raman pulses of the four-pulse cold atom interferometric gyroscope; determining multiple operating states of the four-pulse cold atom interferometric gyroscope based on the interval between the four Raman pulses; and performing state selection on Raman light in different relative directions based on the multiple operating states of the four-pulse cold atom interferometric gyroscope.

[0007] In some embodiments of the present invention, the multiple operating states of the four-pulse cold atom interferometer gyroscope include: positive effective Raman wave vector and negative effective Raman wave vector.

[0008] Furthermore, the selection of Raman light in different relative directions based on the multiple operating states of the four-pulse cold atom interferometer gyroscope includes: using co-directional Raman light to select the state of the four-pulse cold atom interferometer gyroscope when the effective Raman wave vector is positive; and using opposing Raman light to select the state of the four-pulse cold atom interferometer gyroscope when the effective Raman wave vector is negative.

[0009] Furthermore, when the effective Raman wave vector is positive, the detection position of the four-pulse cold atom interferometer gyroscope is represented as:

[0010] D + =v·(t) detection -t raman1 ),

[0011] Where D + The detector position is indicated by the effective Raman wave vector, v represents the two-photon recoil velocity, and t represents the two-photon recoil velocity. detection Indicates the detection time, t raman1 This indicates the moment when the first Raman pulse is applied.

[0012] Furthermore, when the effective Raman wave vector is negative, the detection position of the four-pulse cold atom interferometer gyroscope is represented as follows:

[0013] D - =v·(t) detection -t raman1 )+v·(t raman1 -t selection ),

[0014] Where D - The detector position is indicated by the negative effective Raman wave vector, v represents the two-photon recoil velocity, and t represents the two-photon recoil velocity. detection Indicates the detection time, t raman1 t represents the time of the first Raman pulse application. selection This indicates the selected state moment of the negative effective Raman wave vector.

[0015] In the above embodiments, the intervals between the four Raman pulses are T, 2T, and T, respectively, where T is the minimum positive period of the Raman pulse.

[0016] A second aspect of the present invention provides a detection position modulation device for a four-pulse cold atom interferometric gyroscope, comprising: a first determining module for determining the interval time between the four Raman pulses of the four-pulse cold atom interferometric gyroscope; a second determining module for determining multiple operating states of the four-pulse cold atom interferometric gyroscope based on the interval time between the four Raman pulses; and a third determining module for selecting the state of Raman light in different relative directions based on the multiple operating states of the four-pulse cold atom interferometric gyroscope.

[0017] Furthermore, the third determining module includes: a first state selection unit, used to select the state of the four-pulse cold atom interferometer gyroscope using co-directional Raman light when the effective Raman wave vector is positive; and a second state selection unit, used to select the state of the four-pulse cold atom interferometer gyroscope using counter-directional Raman light when the effective Raman wave vector is negative.

[0018] A third aspect of the present invention provides an electronic device comprising: one or more processors; and a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the detection position modulation method of the four-pulse cold atom interferometer gyroscope provided in the first aspect of the present invention.

[0019] In a fourth aspect, the present invention provides a computer-readable medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the detection position modulation method of the four-pulse cold atom interferometer gyroscope provided in the first aspect of the present invention.

[0020] The beneficial effects of this invention are:

[0021] This invention proposes a method for modulating the detection position of a four-pulse cold atom interferometric gyroscope. During the state selection phase of the four-pulse cold atom interferometric gyroscope, two operating states are set: when the effective Raman wave vector is positive, co-directional Raman light is used for state selection; when the effective Raman wave vector is negative, target Raman light is used for state selection. This ensures that the detection positions of atomic clusters are as close as possible, reducing detection errors caused by periodic changes in the detection position and limiting the spatial size of the detection area. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the basic process of the detection position modulation method of a four-pulse cold atom interferometer gyroscope in some embodiments of the present invention;

[0023] Figure 2 This is a schematic diagram illustrating the changes in the detection position of atomic clusters in some embodiments of the present invention;

[0024] Figure 3 This is a schematic diagram illustrating the reduction of differences in the detection positions of atomic clusters in some embodiments of the present invention;

[0025] Figure 4 This is a schematic diagram of the detection position modulation device of a four-pulse cold atom interferometer gyroscope in some embodiments of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of an electronic device in some embodiments of the present invention. Detailed Implementation

[0027] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0028] refer to Figure 1 and Figure 2 In a first aspect of the present invention, a method for modulating the detection position of a four-pulse cold atom interferometric gyroscope is provided, comprising: S100. determining the interval time between the four Raman pulses of the four-pulse cold atom interferometric gyroscope; S200. determining multiple operating states of the four-pulse cold atom interferometric gyroscope based on the interval time between the four Raman pulses; and S300. selecting the state of Raman light in different relative directions based on the multiple operating states of the four-pulse cold atom interferometric gyroscope.

[0029] It is understandable that a single measurement cycle of a four-pulse cold atom interferometric gyroscope mainly includes processes such as atomic cluster trapping, preparation of magnetically insensitive states, interaction of four Raman pulses with the atomic clusters, and interference phase detection. The interval between the four Raman pulses is T-2T-T, and they interact with the atomic clusters in π / 2-π-π-π / 2 phases, respectively. Within the 4T interference time, the inertial rotation of the carrier changes the phase difference between the atoms on the two paths, causing a phase shift in the atomic interference. By detecting the number of atoms in different states, rotational phase information can be obtained, and further, the rotation of the carrier relative to the inertial reference frame can be calculated. Although this measurement process has high precision, many problems still need to be solved before it can be applied in engineering. One of these problems is that the detection position changes with the direction of the effective Raman wave vector.

[0030] In view of this, in step S200 of some embodiments of the present invention, the multiple operating states of the four-pulse cold atom interferometer gyroscope selection state include: positive effective Raman wave vector and negative effective Raman wave vector.

[0031] Furthermore, the selection of Raman light in different relative directions based on the multiple operating states of the four-pulse cold atom interferometer gyroscope includes: using co-directional Raman light to select the state of the four-pulse cold atom interferometer gyroscope when the effective Raman wave vector is positive; and using opposing Raman light to select the state of the four-pulse cold atom interferometer gyroscope when the effective Raman wave vector is negative.

[0032] Furthermore, in the positive effective Raman wave vector (+k) eff When ), the detection position of the four-pulse cold atom interferometer gyroscope is represented as:

[0033] D + =v·(t) detection -t raman1 ),

[0034] Where D + The detector position is indicated by the effective Raman wave vector, v represents the two-photon recoil velocity, and t represents the two-photon recoil velocity. detection Indicates the detection time, t raman1 This indicates the moment when the first Raman pulse is applied.

[0035] Furthermore, in the negative effective Raman wave vector (-k) eff When ), the detection position of the four-pulse cold atom interferometer gyroscope is represented as:

[0036] D - =v·(t) detection -t raman1 )+v·(t raman1 -t selection ),

[0037] Where D - The detector position is indicated by the negative effective Raman wave vector, v represents the two-photon recoil velocity, and t represents the two-photon recoil velocity. detection Indicates the detection time, t raman1 t represents the time of the first Raman pulse application. selection This indicates the selected state moment of the negative effective Raman wave vector.

[0038] refer to Figure 2 and Figure 3In a specific embodiment of the present invention, taking an initial ejection velocity of 5 m / s on the atomic cluster as an example, the time to reach the selected state is 84 ms, the time to reach the first Raman pulse is 114 ms, the time to reach the second Raman pulse is 314 ms, the time to reach the third Raman pulse is 714 ms, the time to reach the fourth Raman pulse is 914 ms, and the time to reach the detector is 982 ms. The two-photon recoil velocity is 7.04 mm / s.

[0039] Before the improvement, the difference in detection location was:

[0040] 2v·(t detection -t raman1 ) = 2 × 7.04 × 10 -3 ×(0.982-0.114)=12.2mm

[0041] After the improvement, the difference in detection position is as follows:

[0042] v·(t raman1 -t selection ) = 7.04 × 10 -3 ×(0.114-0.084)=0.21mm

[0043] It can be seen that the difference in detection location has been reduced by 98.3%, which can greatly reduce the spatial size limitation of the detection area and the inconsistency detection error.

[0044] Example 2

[0045] refer to Figure 4 In a second aspect, the present invention provides a detection position modulation device 1 for a four-pulse cold atom interferometric gyroscope, comprising: a first determining module 11 for determining the interval time between the four Raman pulses of the four-pulse cold atom interferometric gyroscope; a second determining module 12 for determining multiple operating states of the four-pulse cold atom interferometric gyroscope based on the interval time between the four Raman pulses; and a third determining module 13 for selecting the state of Raman light in different relative directions based on the multiple operating states of the four-pulse cold atom interferometric gyroscope.

[0046] Furthermore, the third determining module 13 includes: a first state selection unit, used to select the state of the four-pulse cold atom interferometer gyroscope using co-directional Raman light when the effective Raman wave vector is positive; and a second state selection unit, used to select the state of the four-pulse cold atom interferometer gyroscope using opposing Raman light when the effective Raman wave vector is negative.

[0047] Example 3

[0048] refer to Figure 5In a third aspect, the present invention provides an electronic device comprising: one or more processors; and a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the detection position modulation method of the four-pulse cold atom interferometer gyroscope of the first aspect of the present invention.

[0049] Electronic device 500 may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 502 or a program loaded from storage device 508 into random access memory (RAM) 503. The RAM 503 also stores various programs and data required for the operation of electronic device 500. The processing unit 501, ROM 502, and RAM 503 are interconnected via bus 504. An input / output (I / O) interface 505 is also connected to bus 504.

[0050] Typically, the following devices can be connected to I / O interface 505: input devices 506 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 507 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 508 including, for example, hard disks; and communication devices 509. Communication device 509 allows electronic device 500 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 5 An electronic device 500 with various devices is shown; however, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively. Figure 5 Each box shown can represent a device or multiple devices as needed.

[0051] Specifically, according to embodiments of this disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 509, or installed from a storage device 508, or installed from a ROM 502. When the computer program is executed by a processing device 501, it performs the functions defined in the methods of embodiments of this disclosure. It should be noted that the computer-readable medium described in embodiments of this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In embodiments of this disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in connection with an instruction execution system, apparatus, or device. In embodiments of this disclosure, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0052] The aforementioned computer-readable medium may be included in the aforementioned electronic device; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable medium carries one or more computer programs, which, when executed by the electronic device, cause the electronic device to:

[0053] Computer program code for performing the operations of embodiments of this disclosure can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages—such as Java, Smalltalk, C++, and Python—and conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0054] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for modulating the detection position of a four-pulse cold atom interferometric gyroscope, characterized in that, include: Determine the interval between the four Raman pulses of a four-pulse cold atom interferometer gyroscope; The various operating states of the four-pulse cold atom interferometer gyroscope are determined based on the interval between the four Raman pulses; the various operating states of the four-pulse cold atom interferometer gyroscope include: positive effective Raman wave vector and negative effective Raman wave vector; Based on the various operating states of the four-pulse cold atom interferometric gyroscope, state selection is performed for Raman light in different relative directions: when the Raman wave vector is positive, the state selection of the four-pulse cold atom interferometric gyroscope is performed using Raman light in the same direction; when the Raman wave vector is positive, the detection position of the four-pulse cold atom interferometric gyroscope is represented as: ,in This indicates the detection position when the Raman wave vector is effective. Indicates the recoil velocity of two photons. Indicates the detection time. The time of the first Raman pulse application is indicated; at the time of the negative effective Raman wave vector, the four-pulse cold atom interferometer gyroscope is selected using opposing Raman light; at the time of the negative effective Raman wave vector, the detection position of the four-pulse cold atom interferometer gyroscope is represented as: ,in This indicates the detection position when the effective Raman wave vector is negative. Indicates the recoil velocity of two photons. Indicates the detection time. This indicates the moment when the first Raman pulse is applied. This indicates the selected state moment of the negative effective Raman wave vector.

2. The detection position modulation method for a four-pulse cold atom interferometric gyroscope according to claim 1, characterized in that, The intervals between the four Raman pulses are T, 2T, and T, respectively, where T is the minimum positive period of the Raman pulse.

3. A detection position modulation device for a four-pulse cold atom interferometric gyroscope, characterized in that, include: The first determining module is used to determine the interval time between the four Raman pulses of the four-pulse cold atom interferometer gyroscope; The second determining module is used to determine multiple operating states of the four-pulse cold atom interferometer gyroscope based on the interval time of the four Raman pulses; the multiple operating states of the four-pulse cold atom interferometer gyroscope include: positive effective Raman wave vector and negative effective Raman wave vector; The third determining module is used to select the state of Raman light in different relative directions based on the various operating states of the four-pulse cold atom interferometric gyroscope: when the Raman wave vector is positive, the unidirectional Raman light is used to select the state of the four-pulse cold atom interferometric gyroscope; when the Raman wave vector is positive, the detection position of the four-pulse cold atom interferometric gyroscope is represented as: ,in This indicates the detection position when the Raman wave vector is effective. Indicates the recoil velocity of two photons. Indicates the detection time. The time of the first Raman pulse application is indicated; at the time of the negative effective Raman wave vector, the four-pulse cold atom interferometer gyroscope is selected using opposing Raman light; at the time of the negative effective Raman wave vector, the detection position of the four-pulse cold atom interferometer gyroscope is represented as: ,in This indicates the detection position when the effective Raman wave vector is negative. Indicates the recoil velocity of two photons. Indicates the detection time. This indicates the moment when the first Raman pulse is applied. This indicates the selected state moment of the negative effective Raman wave vector.

4. An electronic device, comprising: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the detection position modulation method of a four-pulse cold atom interferometer gyroscope as described in any one of claims 1 to 2.

5. A computer-readable medium having a computer program stored thereon, wherein, When the computer program is executed by the processor, it implements the detection position modulation method of the four-pulse cold atom interferometer gyroscope as described in any one of claims 1 to 2.

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