Polarization-spectrum coupling-based ghosting regulation and control infrared system and ghosting elimination method

Abstract

The invention discloses a polarization-spectrum coupling-based ghosting regulation and control infrared system and a ghosting elimination method, and the system comprises a reflecting layer which reflects the radiation light of an imaged object and generates a ghosting signal; the rotation angle theta of the rotatable polaroid is matched with the black phosphorus crystal axis direction of the black phosphorus spectrum polarization coupling infrared photoelectric detector; according to the black phosphorus spectrum polarization coupling infrared photoelectric detector, a SiO2 / Si substrate serves as an insulating supporting layer, a graphene layer is arranged on the SiO2 / Si substrate, an InSe thin film covers the graphene layer to form an II-type heterojunction interface, a black phosphorus layer serves as a core photosensitive layer on the InSe thin film, Cr / Au metal composite electrodes are deposited on the graphene layer and the black phosphorus layer respectively, and the Cr / Au metal composite electrodes are arranged on the core photosensitive layer. A real signal and a ghosting signal are distinguished according to the characteristic that the anisotropy ratio PER (lambda) in a black phosphorus layer changes along with wave bands and the difference of light response values I-alpha T4 / PER (lambda), and the ghosting elimination system and method which are miniaturized and have self-driving capacity are provided.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic detection, and particularly relates to a ghost control infrared system and a ghost elimination method based on polarization-spectral coupling. Background Art

[0002] With the deep integration of artificial intelligence and optoelectronic sensing technology, the application of infrared imaging systems in fields such as autonomous driving, intelligent security, and environmental monitoring has entered the stage of large-scale deployment. Especially in complex scenarios, the anti-interference ability of infrared detectors is directly related to life safety and public governance efficiency. However, due to ghosts generated by highly reflective surfaces in the environment such as glass, water surfaces, and metals, due to their high similarity to real targets in terms of thermal radiation intensity and morphological characteristics, they have become the core bottleneck restricting high-tech infrared sensing. Research shows that in vehicle-mounted infrared night vision systems, the high false alarm rate of virtual images formed by road water accumulation or reflection from building glass curtain walls causes the autonomous driving system to trigger incorrect braking or obstacle avoidance commands in extreme scenarios, seriously threatening driving safety. In the field of border security, the high false alarm events caused by the reflection of heat sources on the water surface in night infrared monitoring increase the manual verification cost significantly and delay the emergency response efficiency. In addition, in medical infrared diagnosis, the lesion artifacts reflected by the metal surface of medical devices may cause deviations in the positioning of minimally invasive surgeries, directly threatening the safety of clinical operations.

[0003] Current mainstream infrared detection technologies rely on single-dimensional spectra or polarizations and are difficult to separate real target and virtual image signals in complex reflection scenarios. Although traditional algorithms can compensate through multi-frame fusion or deep learning, their limitations in relying on high computing power support and prior data annotation make it difficult to meet the industrial requirements of real-time, lightweight, and universality. The new infrared optoelectronic detector based on spectral polarization coupling, through the collaborative coupling of multi-dimensional optical parameters, reconstructs the target light field characteristics from the physical perception level, providing a subversive technical path for breaking through environmental reflection interference and reducing false alarm rates for high-fidelity imaging, and is expected to reshape the reliability boundary of the intelligent perception system terminal and promote the paradigm upgrade in fields such as unmanned systems, public safety, and precision medicine.

[0004] The existing structures rely relatively on single-dimensional detection, and ghost elimination is carried out through backend algorithm optimization processing.

[0005] Traditional infrared sensing solutions have long been limited by the high false alarm rate under environmental reflection interference; and they rely on high-power consumption computing power and data training, with insufficient generalization ability in unknown reflection scenarios, making it difficult to meet the rigid requirements of edge devices for real-time, lightweight, and low power consumption.

[0006] Therefore, how to solve the problems of high false positive rate, high computing power dependence, and insufficient generalization ability caused by ghost interference in traditional infrared sensing technology in complex reflection environments, and to provide an infrared system for black phosphorus dual-mode ghost detection and elimination based on polarization-spectral coupling and a self-driven ghost elimination method are technical problems that need to be urgently solved by those skilled in the art. Summary of the Invention

[0007] The first object of the present invention is to realize that the object and the ghost of a high-temperature object cannot be distinguished due to their small detection gap. A photodetector based on the spectral polarization coupling effect of black phosphorus is provided to solve the problems in the prior art, and the elimination of ghosts is realized through polarization detection.

[0008] To achieve the above object, the present invention adopts the following technical solutions: An infrared system for ghost control based on polarization-spectral coupling includes a reflection layer, a rotatable polarizer, and a black phosphorus spectral polarization coupling infrared photodetector arranged in sequence along the light transmission direction; The reflection layer directly faces the object to be imaged, and its reflected light radiates backward and generates a ghost signal; A rotatable polarizer, the rotation angle θ of which dynamically matches the black phosphorus crystal axis direction of the black phosphorus spectral polarization coupling infrared photodetector; The black phosphorus spectral polarization coupling infrared photodetector receives the polarization-modulated optical signal, and sequentially includes a SiO 2 / Si substrate, a graphene layer, an InSe film, and a black phosphorus layer from bottom to top. The black phosphorus layer serves as a photosensitive layer to receive the optical signal modulated by the rotatable polarizer. Metal composite electrodes are deposited on the graphene layer and the black phosphorus layer respectively. The light reflected by the reflection layer passes through the polarizer. When the rotatable polarizer rotates to θ = 90°, its transmission axis is aligned with the zigzag direction ZZ of the black phosphorus, and the ghost signal is eliminated; when θ = 0°, its transmission axis is aligned with the armchair direction AC of the black phosphorus, and ghost detection is realized. Through the azimuth modulation θ = 0° / 90° of the rotatable polarizer, the polarization state selective transmission and the spectral coupling of the in-plane anisotropy of the black phosphorus are used to realize the dynamic regulation of the ghost signal.

[0009] While adopting the above technical solutions, the present invention can also adopt or combine the following technical solutions: As a preferred technical solution of the present invention: after the transmission axis of the rotatable polarizer is adjusted to the ZZ direction, the signal I of the object to be imaged 3 ~αT 1 4 / PER(λ 1 ) is retained because PER(λ 1 ) is weak; the ghost signal is suppressed because PER(λ 2 ) is strong, and I 4 ~αT 24 / PER(λ 2 ) → 0 to achieve ghost elimination, where α is the comprehensive efficiency factor of infrared radiation - electrical signal conversion, λ 1 and λ 2 correspond to the radiation spectra of the object to be imaged and the ghost respectively, and T 1 and T 2 are the equivalent radiation temperatures of the object to be imaged and the ghost respectively.

[0010] As a preferred technical solution of the present invention: when there is no polarization regulation, the signal I 1 ~αT 1 4 of the object to be imaged; the ghost signal I 2 ~αT 2 4 , where α is the comprehensive efficiency factor of infrared radiation - electrical signal conversion, and T 1 and T 2 are the equivalent radiation temperatures of the object to be imaged and the ghost respectively. After the transmission axis of the rotatable polarizer is adjusted to the AC direction, black phosphorus has weak light absorption in the AC direction, and the detector receives the complete reflected signal (I 1 +I 2 ). At this time, the ghost signal (I 2 ) and the real signal (I 1 ) are detected simultaneously.

[0011] As a preferred technical solution of the present invention: a filter is provided, and the filter is a band - pass filter, which is arranged at the front end of the incident light path of the polarizer to filter out visible light and near - infrared light with a wavelength < 2.5μm.

[0012] As a preferred technical solution of the present invention: the detector adopts a layered stacked structure with a vertical light path, and the light signal transmission direction is perpendicular to the plane of each material layer.

[0013] As a preferred technical solution of the present invention: the in - plane anisotropy ratio of black phosphorus is PER(λ).

[0014] As a preferred technical solution of the present invention: the size of the black phosphorus spectral polarization - coupled infrared photodetector is 5mm×5mm×1mm.

[0015] The second object of the present invention is to provide a method for ghost elimination.

[0016] To this end, the above object of the present invention is achieved by the following technical solutions: A method for ghost elimination, comprising the following steps: Switch the rotatable polarizer to θ = 90°, align it with the ZZ direction, collect signals, and use the high PER(λ) of black phosphorus in the ZZ direction to suppress the ghost component I 4 / PER(λ 2 ) → 0, the synergistic effect of polarization state - light intensity correlation regulation and the in - plane anisotropy of black phosphorus PER(λ) realizes ghost signal elimination.

[0017] Compared with the prior art, the ghost - regulating infrared system and the ghost - elimination method based on polarization - spectrum coupling of the present invention have the following beneficial effects: By integrating an anisotropic black phosphorus detector and a rotatable polarization filter, the present invention realizes the real - time separation of the target and the ghost at the physical perception level of the detector. Utilizing the dual sensitivity of the low - symmetry in - plane structure of black phosphorus to polarization and spectrum, combined with dynamic polarization modulation and feature extraction algorithms, ghost suppression can be completed at the device level without relying on high - power computing power at the backend. At the same time, it has the characteristics of millimeter - scale miniaturization and zero - power self - driving, and can be widely applied to fields such as autonomous driving, security monitoring, and medical diagnosis, significantly improving the imaging reliability and edge - computing adaptability in complex scenarios.

[0018] Compared with the traditional spectroscopic polarization infrared system, the present invention realizes signal detection relying on the black - body Planck radiation emitted by the object to be imaged and the self - driving characteristics of black phosphorus materials. The size of the detector can be compressed to 9 mm, providing a miniaturized and self - driving ghost - elimination system and method, which has great application prospects in fields such as autonomous driving, security monitoring, and medical diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the ghost - regulating infrared system based on polarization - spectrum coupling of the present invention; Figure 2 It is a schematic structural diagram of the ghost - regulating infrared system based on polarization - spectrum coupling of the present invention; Figure 3 It is the anisotropy ratio of black phosphorus at different wavelengths; Figure 4 It is an image of the object to be imaged through a commercial infrared thermal imager in the ghost - elimination imaging experiment of the ghost - regulating infrared system based on polarization - spectrum coupling of the present invention; Figure 5 It is the actual effect diagram of a ghost - regulating infrared system based on polarization - spectrum coupling of the present invention in the ghost - elimination experiment.

[0020] Among them, the object to be imaged 1; the thermal resistance wire 2; the high - reflection layer 3; the rotatable polarizer 4; the black phosphorus spectral polarization - coupled infrared photodetector 5; the Cr / Au metal composite electrode 6; SiO 2 / Si substrate 10; the graphene layer 9; the InSe thin film 8; the black phosphorus layer 7. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

[0022] As shown Figure 1 in the figure, a ghost control infrared system based on polarization-spectral coupling of the present invention includes a reflective layer 3, a rotatable polarizer 4, and a black phosphorus spectral polarization-coupled infrared photodetector 5. The reflective layer, the rotatable polarizer, and the black phosphorus spectral polarization-coupled infrared photodetector are on the same optical axis and are arranged in sequence according to the light transmission direction.

[0023] The reflective layer 3 directly faces the object to be imaged, reflects the radiation light of the object to be imaged, and generates a ghost signal; The rotatable polarizer 4 has a rotation angle θ that matches the black phosphorus crystal axis direction of the black phosphorus spectral polarization-coupled infrared photodetector 5. When θ = 0°, the polarizer rotates to the armchair direction of black phosphorus to achieve ghost detection. When θ = 90°, the polarizer rotates to the ZZ direction to achieve ghost elimination.

[0024] The black phosphorus spectral polarization-coupled infrared photodetector receives the light signal modulated by polarization and includes SiO 2 / Si substrate 10, graphene layer 9, InSe thin film 8, and black phosphorus layer 7 from bottom to top. The black phosphorus layer serves as the photosensitive layer to receive the light signal modulated by the rotatable polarizer. Metal composite electrodes are deposited on the graphene layer and the black phosphorus layer respectively. The light reflected by the reflective layer passes through the polarizer. When the rotatable polarizer rotates to θ = 90°, its transmission axis aligns with the zigzag direction ZZ of black phosphorus, and the ghost signal is eliminated; when θ = 0°, its transmission axis aligns with the armchair direction AC of black phosphorus to achieve ghost detection. Through the azimuth modulation θ = 0° / 90° of the rotatable polarizer, the polarization state selective transmission and the spectral coupling of the in-plane anisotropy of black phosphorus are used to achieve the dynamic control of the ghost signal.

[0025] As shown Figure 2 in the figure, the black phosphorus spectral polarization-coupled infrared photodetector of the present invention from bottom to top is: SiO 2 / Si substrate 10 as an insulating support layer, graphene layer 9 on the SiO 2 / Si substrate, an InSe thin film 8 is covered on the graphene layer 9 to form a type-II heterojunction interface, and a black phosphorus layer 7 is on the InSe thin film 8 as the core photosensitive layer. Cr / Au metal composite electrodes 6 are deposited on the graphene layer 9 and the black phosphorus layer 7 respectively. The detector adopts a layered stacked structure with a vertical optical path, and the light signal transmission direction is perpendicular to the plane of each material layer. Through the characteristic that the in-plane anisotropy ratio PER(λ) of the black phosphorus layer changes with the wavelength band, the real signal and the ghost signal are distinguished by the difference in the light response value I~αT 4 PER(λ). The in-plane anisotropy ratio PER(λ) of black phosphorus: The graphene layer 9 and the black phosphorus layer 7 do not directly contact. After the transmission axis of the rotatable polarizer is adjusted to the ZZ direction, the signal I of the object to be imaged 3 ~αT 14 / PER(λ 1 ) is retained due to the difference in PER(λ1); the ghost signal is suppressed due to the enhancement of PER(λ2), I 4 ~αT 2 4 / PER(λ 2 ) → 0, realizing ghost elimination, where α is the comprehensive efficiency factor of infrared radiation - electrical signal conversion, λ 1 and λ 2 correspond to the radiation spectra of the object to be imaged and the ghost respectively, and T 1 and T 2 are the equivalent radiation temperatures of the object to be imaged and the ghost respectively.

[0026] When there is no polarization regulation, the signal of the object to be imaged I 1 ~αT 1 4 ; the ghost signal I 2 ~αT 2 4 , where α is the comprehensive efficiency factor of infrared radiation - electrical signal conversion, and T 1 and T 2 are the equivalent radiation temperatures of the object to be imaged and the ghost respectively. After the transmission axis of the rotatable polarizer is adjusted to the AC direction, black phosphorus has weak light absorption in the AC direction, and the detector receives the complete reflected signal (I 1 +I 2 ). At this time, the ghost signal (I 2 ) and the real signal (I 1 ) are detected simultaneously.

[0027] Through the collaborative action of the polarization state regulation with the azimuth angle modulation θ = 0° / 90° of the rotatable polarizer and the spectral anisotropy PER(λ) of black phosphorus, using the response difference of I ∼ αT / PER(λ), the ghost signal is dynamically distinguished and suppressed, while retaining the real target information.

[0028] Based on the dynamic switching of the rotation angle θ of the polarizer, the synergistic action of the armchair / ZZ direction alignment, polarization state - light intensity correlation regulation and the in - plane anisotropy of black phosphorus PER(λ) realizes the programmable suppression of the ghost signal.

[0029] The ghost - controlled infrared system based on polarization - spectrum coupling is also provided with a filter, and the filter is a band - pass filter, which is arranged at the front end of the incident light path of the polarizer and is used to filter out visible light and near - infrared light with wavelengths < 2.5μm.

[0030] The size of the black phosphorus spectral polarization - coupled infrared photodetector is 5mm × 5mm × 1mm.

[0031] Self-driven ghost elimination method for a ghost control infrared system based on polarization-spectral coupling, comprising the following steps: Switch the rotating polarizer to θ = 90°, align it with the ZZ direction, collect signals, and use the high PER(λ) of black phosphorus in the ZZ direction to suppress the ghost component I 4 / PER(λ 2 ) → 0, through the synergistic effect of polarization state-light intensity correlation regulation and the in-plane anisotropy of black phosphorus PER(λ), ghost signal elimination is achieved.

[0032] The ghost control infrared system and ghost elimination method based on polarization-spectral coupling of the present invention have the following beneficial effects: Compactness: Removing the filter can reduce the volume, making it suitable for integrated applications, such as infrared imaging of drones; Dynamic adaptation: Real-time switching of the detection / elimination mode by rotating the polarizer; Multispectral potential: Combining the continuous change of the anisotropy ratio of black phosphorus with the wavelength band, it may be possible to achieve multispectral detection without a filter.

[0033] Embodiment 1 As Figure 1 shown, in the ghost control infrared system and ghost elimination method based on polarization-spectral coupling of the present invention, a schematic diagram of ghost elimination is shown. In this figure, the imaged object 1 is a thermal resistance wire, and there is a high-reflection layer 3 behind the resistance wire. The high-reflection layer 3 is a metal reflection net. Through the metal reflection net, there are the imaged object 1 and the ghost 2 for the resistance wire. In the detection of ghost elimination, a filter is set to eliminate the interference of visible light. Only need to place the polarizer 4 in front of the black phosphorus spectral polarization coupling infrared photodetector 5, and rotate the angle of the polarizer to the ZZ direction of the black phosphorus spectral polarization coupling infrared photodetector 5. The obtained imaging diagram is as Figure 4 shown, and the ghost in the imaged object can be eliminated.

[0034] As Figure 2 shown, for the black phosphorus spectral polarization coupling infrared photodetector of the present invention, due to the anisotropy of black phosphorus itself changing with the wavelength band as Figure 3 shown, the anisotropy ratio corresponding to each wavelength band is different. Therefore, the intensity of polarization detection for different blackbody temperatures will also change. For example, under normal circumstances, for a blackbody at 1000K and a blackbody at 900K, with other conditions unchanged, the light response value I of black phosphorus ~ αT 4 , if the detection is carried out in the ZZ direction, that is, the polarizer is rotated by 90°, then the light response value I of black phosphorus ~ αT 4 / PER (λ), where PER is the device extinction ratio as Figure 3As shown; and the anisotropy ratios at different temperatures of ours have a large gap. The ghost image has a greater anisotropy ratio than the object because of reasons such as refraction and reflection, that is, the radiation band is redshifted. Then, according to the above formula, when PER(λ) is large, the actual light response value is small.

[0035] For a polarizer-added black phosphorus spectral polarization-coupled infrared photodetector, the elimination of the ghost image is achieved by rotating the polarizer to the ZZ direction in the plane of the black phosphorus as Figure 5 , and the in-plane direction of the black phosphorus can be determined by the magnitude of the photocurrent.

[0036] Among them, and the device size ≤ 9 mm.

[0037] The above specific embodiments are used to explain the present invention, which is only the preferred embodiment of the present invention, rather than a limitation to the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and scope of the protection of the claims of the present invention all fall within the protection scope of the present invention.

Claims

1. A ghost control infrared system based on polarization-spectral coupling, characterized by: It includes a reflective layer, a rotatable polarizer and a black phosphorus spectral polarization coupled infrared photodetector arranged in sequence according to the light transmission direction; The reflective layer directly faces the imaged object, and its reflected light radiates back and generates a ghost signal; A rotatable polarizer whose rotation angle θ is dynamically matched with the direction of the black phosphorus crystal axis of the black phosphorus spectral polarization coupled infrared photodetector; The black phosphorus spectral polarization coupled infrared photodetector receives polarization-modulated light signals, which includes SiO2 / Si substrate, graphene layer, InSe film and black phosphorus layer from bottom to top. The black phosphorus layer serves as a photosensitive layer to receive light signals modulated by the rotatable polarizer. Metal composite electrodes are deposited on the graphene layer and the black phosphorus layer, respectively. The reflective layer reflects light through the polarizer. When the rotatable polarizer is rotated to θ=90°, its transmission axis is aligned with the sawtooth direction ZZ of black phosphorus, and the ghost signal is eliminated; when θ=0°, its transmission axis is aligned with the armchair direction AC of black phosphorus, realizing ghost detection. By modulating the azimuth angle of the rotatable polarizer to θ=0° / 90°, the polarization state selective transmission is coupled with the spectral anisotropy of the black phosphorus plane to achieve dynamic regulation of the ghost signal.

2. The ghost control infrared system based on polarization-spectral coupling as claimed in claim 1, characterized in that: After the rotatable polarizer transmittance axis is adjusted to the ZZ direction, the imaged object signal I3~αT1 4 / PER(λ1) is retained due to the difference in PER(λ1); the ghost signal is suppressed due to the enhancement of PER(λ2), I4~αT2 4 / PER(λ2) →0, ghost elimination is achieved, where α is the comprehensive efficiency factor of infrared radiation-electrical signal conversion, λ1 and λ2 correspond to the radiation spectra of the imaged object and the ghost, respectively, and T1 and T2 are the equivalent radiation temperatures of the imaged object and the ghost, respectively.

3. The ghost control infrared system based on polarization-spectral coupling as claimed in claim 1, characterized in that: When polarization control is not performed, the imaged object signal I1~αT1 4 ; Ghost signal I2~αT2 4 , where α is the comprehensive efficiency factor of infrared radiation-electrical signal conversion, T1 and T2 are the equivalent radiation temperatures of the imaged object and the ghost, respectively. After the rotatable polarizer transmission axis is adjusted to the AC direction, black phosphorus has weak absorption of light in the AC direction, and the detector receives the complete reflected signal (I1+I2). At this time, the ghost signal (I2) and the real signal (I1) are detected at the same time.

4. The ghost control infrared system based on polarization-spectral coupling as claimed in claim 1, characterized in that: A filter is provided, which is a bandpass filter and is arranged at the front end of the incident light path of the rotatable polarizer to filter out visible light and near-infrared light with a wavelength of less than 2.5 μm.

5. The ghost control infrared system based on polarization-spectral coupling as claimed in claim 1 is characterized by: The detector adopts a layered stacking structure with a vertical light path, and the light signal transmission direction is perpendicular to the plane of each material layer.

6. The ghost control infrared system based on polarization-spectral coupling as claimed in claim 1, characterized in that: In-plane anisotropy ratio PER(λ) of black phosphorus.

7. The ghost control infrared system based on polarization-spectral coupling as claimed in claim 1, characterized in that: The metal composite electrode is a Cr / Au metal composite electrode.

8. The ghost control infrared system based on polarization-spectral coupling as claimed in claim 1, characterized in that: The black phosphorus spectral polarization coupled infrared photodetector has a size of 5 mm×5 mm×1 mm.

9. The ghost elimination method of the infrared system based on polarization-spectrum coupling ghost control according to any one of claims 1 to 5, characterized in that: The following steps are involved: The rotating polarizer is switched to θ = 90° and aligned with the ZZ direction to collect signals. The high PER(λ) of black phosphorus in the ZZ direction is used to suppress the ghost component I4 / PER(λ2)→0. The ghost signal is eliminated by the synergistic effect of polarization state-intensity correlation regulation and the in-plane anisotropy of black phosphorus PER(λ).

Images