Optical cemented endoscopic mirror reflecting multi-path atomic cell and application thereof

Abstract

The present application relates to the technical field of quantum sensing based on atomic cell, in particular to a light glue inner mirror surface reflection multi-optical path atomic cell and application thereof. The light glue inner mirror surface reflection multi-optical path atomic cell of the present application increases the optical path of the probe laser in the atomic cell cavity and amplifies the signal without changing the size of the spectral analysis cell chamber; ultimately, the fundamental sensitivity of the measurement is limited by the quantum shot noise of the atoms, and the limit of such sensitivity is called the standard quantum limit, which is inversely proportional to the square root of the number of atoms simultaneously detected in the chamber. The multi-optical path design of the light glue inner mirror surface reflection multi-optical path atomic cell of the present application can make the probe laser cover the entire cross section of the atomic cell cavity and simultaneously detect almost all the atoms in the atomic cell cavity, thereby greatly improving the signal-to-noise ratio of the measurement and the sensitivity under the standard quantum limit caused by the shot noise.

Description

Technical Field

[0001] This invention relates to the field of optical adhesive endoscope surface reflection multi-optical-path atomic gas chamber technology, and in particular to an optical adhesive endoscope surface reflection multi-optical-path atomic gas chamber and its application. Background Technology

[0002] Atomic gas cells are core components in quantum sensing fields such as atomic magnetometers and atomic gyroscopes. They typically encapsulate atomic vapor within a cavity using a transparent material, enabling precise measurement of external signals such as electromagnetic fields. The signal measured by an atomic gas cell is proportional to the optical path length of the interaction between the probe laser and the atoms within the cell. When the optical path length is sufficiently long, the fundamental sensitivity of the measurement is limited by atomic shot noise, thus becoming inversely proportional to the square root of the number of atoms being measured. Therefore, to improve the fundamental sensitivity of an atomic gas cell, the probe laser should cover as much of the cavity as possible, thereby fully detecting all atoms within the cavity. Thus, multiple optical paths and high atomic coverage become important means to improve the performance of atomic gas cells. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a photogel-coated intra-mirror reflection multi-optical-path atomic gas cell and its applications. This invention's photogel-coated intra-mirror reflection multi-optical-path atomic gas cell increases the optical path length of the probe laser within the atomic gas cell cavity without significantly altering the size of the spectral analysis cell, thus amplifying the signal. Ultimately, the fundamental sensitivity of the measurement is limited by the quantum shot noise of atoms; this sensitivity limit is known as the standard quantum limit, which is inversely proportional to the square root of the number of atoms (molecules) simultaneously detected within the cavity. The multi-optical-path design of this invention's photogel-coated intra-mirror reflection multi-optical-path atomic gas cell allows the probe laser to cover the entire cross-section of the atomic gas cell cavity, simultaneously detecting almost all atoms (molecules) within the cavity, thereby significantly improving the signal-to-noise ratio and enhancing the sensitivity under the standard quantum limit caused by shot noise.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] The first objective of this invention is to provide a photoresistive multi-path atomic gas chamber, comprising an atomic gas chamber cavity and a window plate;

[0006] The atomic gas chamber is a hollow chamber with openings at both ends, and windows are provided at the openings on both sides of the atomic gas chamber. The sealed space formed by the atomic gas chamber and the windows is filled with the gas or liquid to be tested. A high-reflectivity film is provided on the side of the window near the atomic gas chamber. The window is provided with a laser inlet and an outlet.

[0007] The laser enters through the inlet, passes through the atomic gas chamber, and is reflected back into the atomic gas chamber by a high-reflection membrane far from the inlet. It is then reflected by the high-reflection membrane on the opposite side, thus achieving multiple reflections before finally exiting through the outlet.

[0008] In one embodiment of the present invention, the window includes a first window and a second window; the first window is disposed at one side opening of the atomic gas chamber, and the second window is disposed at the other side opening of the atomic gas chamber.

[0009] In one embodiment of the present invention, a first high-reflectivity film is provided on the side of the first window sheet near the atomic gas chamber; and a second high-reflectivity film is provided on the side of the second window sheet near the atomic gas chamber.

[0010] In one embodiment of the present invention, the ends of the first window piece and the two sides of the atomic gas chamber are sealed and connected by molten photoresist; the other ends of the second window piece and the two sides of the atomic gas chamber are sealed and connected by molten photoresist.

[0011] In one embodiment of the invention, the inlet is disposed at one end of the first window plate.

[0012] In one embodiment of the present invention, the outlet is located at the end of the first window plate away from the inlet or at the end of the second window plate away from the inlet.

[0013] In one embodiment of the present invention, when the outlet is located at the end of the first window plate away from the inlet, the length of the first high-reflectivity film is shorter than the length of the second high-reflectivity film and they are aligned at the center along their length direction; when the outlet is located at the end of the second window plate away from the inlet, the lengths of the first high-reflectivity film and the second high-reflectivity film are equal and offset by a distance along their length direction.

[0014] In one embodiment of the present invention, the entrance port is beveled, and the exit port is beveled at the same angle as the entrance port, so that the laser incident and exit directions are perpendicular to the first window plate and the second window plate, respectively.

[0015] In one embodiment of the present invention, the atomic gas chamber is a high borosilicate glass square tube.

[0016] The second objective of this invention is to provide an application of a photopolymer-coated internal mirror surface-reflecting multi-path atomic gas cell, which is applied in the fields of atomic gyroscopes, atomic magnetometers, or gas absorption cells.

[0017] The fabrication of atomic gas chambers requires high sealing performance, and the adhesive layer must not react with alkali metal atoms. Therefore, ordinary adhesives are not suitable for bonding atomic gas chambers. Glossy adhesive is a physical bonding method. When the flatness and smoothness of the bonding surfaces are high, materials can be directly bonded together through van der Waals forces. After baking in an environment close to the material's softening temperature, a non-deforming fusion bond can be achieved.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention provides a photogel-coated intramirror-reflected multi-path atomic gas cell that, without significantly altering the dimensions of the spectral analysis cell, increases the optical path length of the probe laser within the atomic gas cell, thus amplifying the signal. Ultimately, the fundamental measurement sensitivity (i.e., the minimum resolvable signal) is limited by the quantum shot noise of atoms; this sensitivity limit is known as the standard quantum limit, which is inversely proportional to the square root of the number of atoms (molecules) simultaneously detected within the cell. The multi-path design of this photogel-coated intramirror-reflected multi-path atomic gas cell allows the probe laser to cover the entire cross-section of the atomic gas cell, simultaneously detecting almost all atoms (molecules) within the cell, thereby significantly improving the signal-to-noise ratio and enhancing sensitivity under the standard quantum limit caused by shot noise. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a multi-path atomic gas chamber with an internal mirror surface of photoresist.

[0021] The diagram is labeled as follows: 1. Atomic gas chamber; 2. First window; 3. Second window; 4. First high-reflectivity film; 5. Second high-reflectivity film; 6. Inlet; 7. Outlet. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] In the description of this embodiment, the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0026] Example 1

[0027] This embodiment provides a photoresistive multi-path atomic gas chamber with an internal mirror surface, such as... Figure 1 As shown, it includes an atomic gas chamber 1 and a window plate; the window plate includes a first window plate 2 and a second window plate 3. The atomic gas chamber 1 is a hollow chamber with openings at both ends. The openings on both sides of the atomic gas chamber 1 are connected to the first window plate 2 and the second window plate 3 to form a sealed environment. The sealed space is filled with the gas or liquid to be tested. A first high-reflectivity membrane 4 is provided on the side of the first window plate 2 near the atomic gas chamber 1, and a second high-reflectivity membrane 5 is provided on the side of the second window plate 3 near the atomic gas chamber 1. An inlet 6 is provided at one end of the first window plate 2, and an outlet 7 is provided at the other end. The inlet 6 has a chamfered edge, and the outlet 7 has a chamfered edge with the same angle as the inlet 6. In addition, when the outlet 7 is located at the end of the first window 2 away from the inlet 6, the length of the first high-reflectivity film 4 is shorter than the length of the second high-reflectivity film 5 and they are aligned along their length direction. When the outlet 7 is located at the end of the second window 3 away from the inlet 6, the lengths of the first high-reflectivity film 4 and the second high-reflectivity film 5 are equal and they are offset by a distance along their length direction.

[0028] The preparation process includes the following steps:

[0029] (1) High borosilicate glass with a thickness of 2mm and a cross-section of 14*18mm is used as the first window piece 2 and the second window piece 3, and a high borosilicate glass square tube with a cross-section of 14*18mm, a length of 24mm, and a thickness of 2mm is used as the atomic gas chamber 1.

[0030] (2) The two ends of the first window plate 2 are beveled so that the incident light and the outgoing light are perpendicular to the first window plate 2 at the same time, which facilitates the optical path setting; wherein, the bevel angle depends on the wavelength of the incident light;

[0031] (3) Polish the surfaces of the first window 2 and the second window 3 and the two end faces of the atomic gas chamber 1 to a flatness better than λ / 5. Deposit a dielectric reflective film (first high reflective film 4 and second high reflective film 5) corresponding to the wavelength of the probe light on the side of the window 2 and the second window 3 that is close to the atomic gas chamber 1. The size of the first high reflective film 4 is 9*11mm and the size of the second high reflective film 5 is 9*13mm.

[0032] (4) The first window 2 and the second window 3 are surface treated to achieve a flatness of λ / 10@633nm and a smoothness of 20 / 10. Then, the film (first high reflective film 4 and second high reflective film 5) of the window (first window 2 and second window 3) is photo-adhesively bonded to the atomic gas chamber 1 by van der Waals force. The bonded atomic gas chamber 1 is placed in an oven and baked at 600°C to melt it into one piece. Then, alkali metal and buffer gas are filled in.

[0033] In use, a collimated laser with a cross-sectional width of approximately 1.5 mm and a height of approximately 10 mm is incident through the inlet port 6. Due to the chamfering treatment of the inlet port 6, the incident light is perpendicular to the first window plate 2. After passing through the atomic gas chamber, the collimated laser is reflected back to the atomic gas chamber cavity 1 by the second high-reflection film 5, and then reflected by the first high-reflection film 4 on the opposite side, thus achieving multiple reflections, and finally exiting through the outlet port 7. Due to the chamfering treatment of the outlet port 7, the outgoing light is perpendicular to the first window plate 2, and the final optical path is 18 times the longitudinal length of the cavity.

[0034] The measured optical path of the multi-path atomic gas cell with internal mirror reflection is determined by the reflection angle, i.e., the angle of the chamfered edge of the entrance port 6. When the angle between the plane produced by the chamfered edge and the reflecting surface is θ, and the refractive index of the gas cell material is n, the incident angle of the laser at the interface of the reflecting surface in the atomic gas cell is arcsin{nsin[θ-arcsin(sinθ / n)]}.

[0035] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A photoresist-reflective multi-path atomic gas chamber, characterized in that, Includes atomic gas chamber and window plate; The atomic gas chamber is a hollow chamber with openings at both ends, and windows are provided at the openings on both sides of the atomic gas chamber. The sealed space formed by the atomic gas chamber and the windows is filled with the gas or liquid to be tested. A high-reflectivity film is provided on the side of the window near the atomic gas chamber. The window is provided with a laser inlet and an outlet. The laser enters from the inlet, passes through the atomic gas chamber, and is reflected back into the atomic gas chamber by a high-reflection film away from the atomic inlet. It is then reflected by the high-reflection film on the opposite side, thus achieving multiple reflections before finally exiting from the outlet. The window includes a first window and a second window; the first window is disposed at one side opening of the atomic gas chamber, and the second window is disposed at the other side opening of the atomic gas chamber. A first high-reflectivity film is provided on the side of the first window sheet closest to the atomic gas chamber; a second high-reflectivity film is provided on the side of the second window sheet closest to the atomic gas chamber. The ends of the first window piece and the two sides of the atomic gas chamber are sealed and connected by molten photoresist; the other ends of the second window piece and the two sides of the atomic gas chamber are sealed and connected by molten photoresist. Wherein, when the outlet is located at the end of the first window plate away from the inlet, the length of the first high-reflectivity film is shorter than the length of the second high-reflectivity film and they are aligned at the center along their length direction; when the outlet is located at the end of the second window plate away from the inlet, the lengths of the first high-reflectivity film and the second high-reflectivity film are equal and they are offset by a distance along their length direction. The atomic gas chamber is a high borosilicate glass square tube; Both the first and second high-reflectivity films are dielectric reflective films.

2. The photoresistive multi-path atomic gas chamber with internal mirror reflection according to claim 1, characterized in that, The injection port is located at one end of the first window plate.

3. The photoresistive multi-path atomic gas chamber with internal mirror reflection according to claim 2, characterized in that, The outlet is located at the end of the first window that is away from the inlet or at the end of the second window that is away from the inlet.

4. The photoresistive multi-path atomic gas chamber with internal mirror reflection according to claim 1, characterized in that, The entrance port is beveled, and the exit port is beveled at the same angle as the entrance port, so that the laser incident and exit directions are perpendicular to the first window plate and the second window plate, respectively.

5. An application of a photoresist-coated internal mirror surface reflection multi-optical-path atomic gas cell, characterized in that, The optical adhesive inner mirror surface reflection multi-optical-path atomic gas cell is applied in the fields of atomic gyroscopes, atomic magnetometers, or gas absorption cells. The photoresistive multi-path atomic gas chamber is the photoresistive multi-path atomic gas chamber described in any one of claims 1-4.

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