CN-121995278-A - Four-channel polarization decoupling detection method of optical atomic magnetic sensor based on super surface

CN121995278ACN 121995278 ACN121995278 ACN 121995278ACN-121995278-A

Abstract

The four-channel polarization decoupling detection method of the optical atomic magnetic sensor based on the super surface aims to solve the problems that a detection end of a single-beam atomic magnetometer is huge in size and is easy to be interfered by pump light ellipticity fluctuation. The technical scheme of the invention is that a four-channel focusing super-surface device integrated with a sub-aperture pseudo-random spatial multiplexing nano-pillar array is utilized to replace discrete components in a traditional detection light path, single-beam detection light carrying magnetic field information is directly separated in space and focused into four independent light spots of left rotation, right rotation, 45 degrees and 135 degrees at the same time, common caliber uniform sampling of a Gaussian beam section is realized through pseudo-random arrangement, a signal processing system utilizes a circular polarization channel to invert the ellipticity of pump light in real time, utilizes a linear polarization channel to extract magnetic field signals, and dynamically corrects the magnetic field signals through a full polarization state decoupling algorithm. The invention is convenient for chip-level integration of the magnetometer and realizes high-sensitivity and high-stability anti-interference measurement.

Inventors

LI JIN
LI JIAWEI
SUN SHUO
CHENG TIANSHI
FU WANMING
DU PENGCHENG

Assignees

北京航空航天大学

Dates

Publication Date: 20260508
Application Date: 20260228

Claims (9)

1. The four-channel polarization decoupling detection method of the optical atomic magnetic sensor based on the super surface is characterized by comprising the following steps of: Step 1, arranging four-channel focusing super-surface devices between a photoelectric detection array and a detection light emitting side of an alkali metal gas chamber in a magnetic probe assembly; Step 2, the four-channel focusing super-surface device is utilized to directly separate the light-emitting side detection light carrying magnetic field information in space and focus the light-emitting side detection light into 4 independent light spots simultaneously, namely a left-handed circular polarization focusing light spot, a right-handed circular polarization focusing light spot, a 45-degree linear polarization focusing light spot and a 135-degree linear polarization focusing light spot; Step 3, synchronously acquiring the following 4 parameters by using the photoelectric detection array: , , , , Is the light intensity of the left-hand circularly polarized focused light spot, Is the light intensity of the right-hand circularly polarized focused light spot, Is the light intensity of the 45 degree linearly polarized focused spot, Is the light intensity of the 135-degree linearly polarized focused light spot; Step 4, according to the light polarization principle, utilizing , , A kind of electronic device Respectively calculate And , Is a monitoring signal representing the real-time ellipticity of the pump light, Is an original signal representing magnetic field information; step 5, utilize For a pair of Decoupling correction is carried out, the interference of ellipticity is eliminated, and inversion is carried out to obtain , Is the magnetic field rotation angle.
2. The four-channel polarization decoupling detection method for a super-surface-based optical atomic magnetic sensor according to claim 1, wherein the following expression is included in step 4: Wherein the method comprises the steps of Is the ellipticity of the pump light.
3. The four-channel polarization decoupling detection method for a super-surface-based optical atomic magnetic sensor according to claim 1, wherein the following expression is included in step 5: the above expression is obtained by eliminating ellipticity terms Is capable of obtaining an accurate modulation effect The value of the sum of the values, Is proportional to the strength of the magnetic field to be measured.
4. The four-channel polarization decoupling detection method for the optical atomic magnetic sensor based on the super surface according to claim 1 is characterized in that the four-channel focusing super surface device in the step 1 adopts a sub-aperture pseudo-random spatial multiplexing design method to ensure uniform sampling of Gaussian beam sections, and specifically comprises the steps of logically dividing the super surface aperture into a plurality of tiny sub-aperture units, setting nano-column focusing units respectively responding to left-handed circular polarization, right-handed circular polarization and linear polarization in each sub-aperture unit according to a preset proportion, and determining the positions of nano-columns in the sub-aperture units by a pseudo-random algorithm so that all functional units are uniformly mixed and distributed on a macroscopic aperture.
5. The method for four-channel polarization decoupling detection of a super-surface-based optical atomic magnetic sensor according to claim 4, wherein the preset ratio is 1:1:1, i.e. the number of nano-pillars responding to left-handed circular polarization, right-handed circular polarization and linear polarization is equal in each sub-aperture unit.
6. The four-channel polarization decoupling detection method for the optical atomic magnetic sensor based on the super surface as claimed in claim 4, wherein the nano-pillar focusing unit responding to the left-handed circular polarization and the right-handed circular polarization performs wavefront regulation based on a geometric phase principle, wherein the nano-pillar has a fixed length and width and is configured as a half-wave plate structure under an operating wavelength to maximize polarization conversion efficiency, and the rotation angle of the nano-pillar in a plane is changed by changing To introduce the required focus phase And meet the following , A sign factor related to the handedness) to achieve independent focusing of left-handed circularly polarized light and right-handed circularly polarized light, respectively.
7. The method for four-channel polarization decoupling detection of a super surface based optical atomic magnetic sensor according to claim 4, wherein the nanopillar focusing unit responsive to linear polarization is a dual-function multiplexing unit configured to have a dual-phase response of generating a focusing phase directed to a 45 ° channel focus when the incident light is 45 ° linear polarization, generating a focusing phase directed to a 135 ° channel focus when the incident light is 135 ° linear polarization, thereby simultaneously realizing detection of two orthogonal linear polarization channels using a single nanopillar.
8. The four-channel polarization decoupling detection device for the optical atomic magnetic sensor based on the super surface is characterized by adopting the four-channel polarization decoupling detection method for the optical atomic magnetic sensor based on the super surface according to one of claims 1 to 7.
9. The four-channel polarization decoupling detection device for the optical atomic magnetic sensor based on the super surface according to claim 8, comprising a four-channel focusing super surface device with an anisotropic nano-pillar array integrated on the surface, wherein a photoelectric detection array is positioned on the focal plane of the four-channel focusing super surface device and comprises four independent photosensitive units, the positions of the four focusing channels are respectively corresponding to the photoelectric detection array, the photoelectric detection array is sequentially connected with a TIA transimpedance amplifier, an LIA phase-locked amplifier and a PC computer end, the LIA phase-locked amplifier is connected with a coil in a magnetic probe assembly, and the light inlet side of an alkali metal air chamber in the magnetic probe assembly is connected with a laser light source assembly through a collimation and polarization state preparation lens group.

Description

Four-channel polarization decoupling detection method of optical atomic magnetic sensor based on super surface Technical Field The invention relates to the technical fields of quantum precision measurement, micro-nano optics and signal processing, in particular to a four-channel polarization decoupling detection method of an optical atomic magnetic sensor based on a super surface. Background The optical atomic magnetic sensor has become a core sensor in the field of extremely weak magnetic field measurement by exceeding the theoretical sensitivity of a superconducting quantum interference device (SQUID), and has great application potential in the fields of biomagnetic imaging such as a Magnetoencephalography (MEG), a Magnetocardiography (MCG) and the like, deep space detection, geomagnetic navigation and the like. Along with the expansion of application scenes, urgent demands are put forward for miniaturization, integration and array of the optical atomic magnetic sensor. Among the numerous magnetometer configurations, a single-beam ellipsometric optical atomic magnetic sensor (SB-EPAM) is an ideal solution for achieving miniaturization because its optical path structure is relatively simple (only one beam is needed to complete pumping and detection at the same time). However, in the practical engineering of SB-EPAM, the integration of the probe optical path becomes one of the core bottlenecks that restricts the further reduction of its volume. In order to accurately extract the magnetic field signal and suppress the optical path noise, the conventional SB-EPAM probe end generally needs to perform complete analysis on the polarization state of the outgoing light. This in conventional optical architectures has to rely on a complex set of discrete optical element combinations, typically including a Quarter Wave Plate (QWP) for converting the circularly polarized component, a polarizing beam splitter Prism (PBS) or a wollaston prism for separating the linearly polarized component, and a focusing lens for coupling the beam to the detector. These conventional optical elements suffer from the following significant drawbacks: 1. Bulky and difficult to integrate, waveplates, prisms and lenses typically have large physical dimensions (in the order of millimeters to centimeters) and require long optical paths for beam splitting, resulting in a probe that is difficult to compact. 2. The assembly is complex, the stability is poor, a plurality of discrete components need extremely high precision mechanical alignment and assembly, and any tiny mechanical vibration or thermal deformation can lead to optical path misalignment to influence the measurement stability. 3. The function of the traditional element is single, and synchronous control and collection of multiple polarization states of the light field are difficult to realize through a single element. Therefore, how to eliminate the heavy traditional discrete optical element and to realize the efficient separation and focusing of the full polarization state of the detection light by using a single integrated device, thereby breaking through the miniaturization bottleneck of the optical atomic magnetic sensor is a technical problem to be solved currently. Disclosure of Invention The invention aims to solve the technical problems that the existing single-beam optical atomic magnetic sensor detection end has a large number of optical elements and large volume, and chip-level integration is difficult to realize, and provides a four-channel polarization decoupling detection method for an optical atomic magnetic sensor based on a super surface. The technical scheme of the invention is as follows: The four-channel polarization decoupling detection method of the optical atomic magnetic sensor based on the super surface is characterized by comprising the following steps of: Step 1, arranging four-channel focusing super-surface devices between a photoelectric detection array and a detection light emitting side of an alkali metal gas chamber in a magnetic probe assembly; Step 2, the four-channel focusing super-surface device is utilized to directly separate the light-emitting side detection light carrying magnetic field information in space and focus the light-emitting side detection light into 4 independent light spots simultaneously, namely a left-handed circular polarization focusing light spot, a right-handed circular polarization focusing light spot, a 45-degree linear polarization focusing light spot and a 135-degree linear polarization focusing light spot; Step 3, synchronously acquiring the following 4 parameters by using the photoelectric detection array: ,,,, Is the light intensity of the left-hand circularly polarized focused light spot, Is the light intensity of the right-hand circularly polarized focused light spot,Is the light intensity of the 45 degree linearly polarized focused spot,Is the light intensity of the 135-degree linearly polarized focused light spot; S