An optical integrated atomic chip and a manufacturing method thereof

Abstract

The application discloses a kind of optical integrated atomic chip, it includes transparent material cuboid, two ends of transparent material cuboid are equipped with diffraction light splitting micro device respectively, and it is equipped with atomic gas chamber in the middle, and it is equipped with three-dimensional waveguide between 2 diffraction light splitting micro devices and atomic gas chamber;The diffraction light splitting micro device of left end has two diffraction light splitting regions, and each diffraction light splitting region corresponds a laser beam;The diffraction light splitting micro device of right end has a diffraction light splitting region;Laser beam forms beam splitting laser after diffraction light splitting micro device, then it is corrected beam direction by three-dimensional waveguide, so that beam splitting laser is parallelly injected into atomic gas chamber;Two sides of parallel beam splitting laser meet in atomic gas chamber and are shot.This application also provides the manufacturing method of the above-mentioned optical integrated atomic chip.The application has simple structure, small volume, and can integrate spatial optical path system, beam splitting device and atomic gas chamber into one.

Description

Technical Field

[0001] This invention relates to the field of atomic chip technology, specifically to an optically integrated atomic chip and its fabrication method. Background Technology

[0002] Currently, atomic chips mainly consist of discrete spatial optical path systems, beam splitters, and atomic gas cells, resulting in large and complex systems, such as patent CN1805650A, entitled "A Method and Apparatus for Generating Atomic Beams for Atomic Chips." Existing atomic chips cannot effectively transport and load atomic beams onto the chip. The beam suffers energy loss and stray light interference during transmission through the spatial optical path, and is susceptible to external factors such as temperature, vibration, and humidity under harsh conditions. To overcome the difficulties in engineering and application, reducing the size of the physical components and achieving high stability are key to the miniaturization of atomic chips. Summary of the Invention

[0003] The purpose of this invention is to provide an integrated optical atomic chip and its fabrication method. The atomic chip and fabrication method have a simple structure and small size, and can integrate a spatial optical path system, a beam splitting device and an atomic gas chamber into one unit.

[0004] The technical solution adopted in this invention is:

[0005] An integrated optical atomic chip includes a transparent material cuboid, with diffraction and beam-splitting micro-devices at both ends of the transparent material cuboid; an atomic gas cell is located in the middle of the transparent material cuboid, and three-dimensional waveguides are respectively provided between the two diffraction and beam-splitting micro-devices and the atomic gas cell;

[0006] The diffraction-splitting microdevice on the left has two diffraction-splitting regions, each corresponding to a laser beam, which are coupled beams with wavelengths of 509 nm and 510 nm, respectively; the diffraction-splitting microdevice on the right has one diffraction-splitting region, which corresponds to a probe beam of 852 nm.

[0007] The laser beam is split into a beam (divergent beam) after passing through a diffraction and beam splitting micro-device. Then, the beam direction is corrected by a three-dimensional waveguide so that the split laser beam enters the atomic gas cell in parallel. The parallel split laser beams on both sides meet and shoot against each other in the atomic gas cell.

[0008] A further option is that the diffraction-dispersive microdevice and the transparent material cuboid are an integral structure; or, the diffraction-dispersive microdevice and the transparent material cuboid are a separate structure. The advantage of the separate structure is that it is easier to process and fabricate the micro-nano structure of the diffraction-dispersive microdevice.

[0009] A further proposed approach is to use 16-step micro / nano structures for both the left and right diffraction-splitting microdevices.

[0010] A further proposed approach is to have two diffraction and beam-splitting regions in the left-end diffraction and beam-splitting microdevice that are both one-dimensional 16-step structures, while the diffraction and beam-splitting region in the right-end diffraction and beam-splitting microdevice is a three-dimensional 16-step structure.

[0011] A further proposed solution involves the diffraction beam splitting microdevices at both the left and right ends each having 16 laser beams. Specifically, the two diffraction beam splitting regions of the left-end microdevice each have 1×8 beams, achieving 1×8 laser beam splitting; while the diffraction beam splitting region of the right-end microdevice has 2×8 beams, achieving 2×8 laser beam splitting. Furthermore, both sides feature 16 beams illuminating each other.

[0012] A further proposed solution is to have the thickness of the diffraction-splitting microdevices on both the left and right ends be 1-3 mm, with the thicknesses being identical.

[0013] A further proposed approach involves using a diffraction-splitting microdevice on both the left and right ends. Based on optical wave diffraction theory, wafer-level micro / nano fabrication technology is employed to etch a relief structure with two or more step depths onto the substrate, forming a pure phase coaxial reproduction. This transforms a single laser beam carrying information into multiple laser beams carrying the same information, fully leveraging the advantages of high-speed parallel transmission of optical information. The three-dimensional waveguide is fabricated using femtosecond laser direct writing of the spatial waveguide. The transparent material includes, but is not limited to, fused silica (JGS1).

[0014] A further proposed approach is to have the two diffraction-splitting regions of the left-end diffraction-splitting microdevice have equal areas; and the total area of ​​the two diffraction-splitting regions of the left-end diffraction-splitting microdevice is equal to the area of ​​the diffraction-splitting region of the right-end diffraction-splitting microdevice.

[0015] A further proposed solution is that the volume of the optically integrated atomic chip is ≥15cm². 3 Its length × width × height is ≥ (20 × 1.5 × 0.5) cm; the size of the atomic gas chamber is ≥ (1 × 1 × 0.3) mm. 3 .

[0016] This invention provides a method for fabricating an optically integrated atomic chip, which includes the following steps:

[0017] 1) The volume of the product should be ≥15cm 3 A transparent rectangular prism;

[0018] 2) Create an atomic gas chamber in the middle part of a transparent rectangular prism. The size of the atomic gas chamber is ≥ (1×1×0.3). 3 mm;

[0019] 3) Diffraction beam splitting microdevices with a thickness of 1-3 mm are fabricated at both ends of a transparent material cuboid for beam splitting. The beam spacing of the beam splitting microdevices is 1.5 mm to 2 mm. The left-end diffraction beam splitting microdevice has two diffraction beam splitting regions, each corresponding to a laser beam with wavelengths of 509 nm and 510 nm, respectively. The number of beam splitting in each diffraction beam splitting region is 1×8, achieving 1×8 laser beam splitting. The right-end diffraction beam splitting microdevice has one diffraction beam splitting region, which corresponds to a laser beam with wavelengths of 852 nm. The number of beam splitting in this diffraction beam splitting region is 2×8, achieving 2×8 laser beam splitting.

[0020] Alternatively, cut small transparent material cuboids with a thickness of 1-3 mm from both ends of the transparent material cuboid, ensuring that the two small transparent material cuboids have the same thickness; then fabricate diffraction and spectral dispersive microdevices on the small transparent material cuboids; after fabrication, low-temperature bond the two small transparent material cuboids and the remaining transparent material cuboids according to the previously divided situation;

[0021] 4) Between the diffraction-splitting microdevice and the atomic gas cell, behind the laser beam splitting, a three-dimensional waveguide is fabricated inside the transparent cuboid at the tilt position of the diverging beam using a femtosecond laser, so that the diverging beam emitted by the diffraction-splitting microdevice can enter the atomic gas cell in parallel after encountering the three-dimensional waveguide.

[0022] Since the laser beam needs to travel a certain distance after passing through the diffraction and beam splitting micro-device to achieve the beam splitting effect, but the split beam is a divergent beam, the direction of the split beam needs to be calibrated. Therefore, after the beam splitting, a femtosecond laser is used inside the material to directly write the spatial waveguide to form a three-dimensional waveguide. This causes the transparent material at the three-dimensional waveguide to undergo material deformation, thereby changing the refractive index of the three-dimensional waveguide and enabling the split beam to become a parallel beam after propagating a certain distance.

[0023] The beneficial effects of this invention are as follows:

[0024] Simple structure, ingenious design, and easy implementation;

[0025] The main function of diffraction beam splitting microdevices is to split laser beams;

[0026] After the three different wavelengths are split by the diffraction beam splitting micro-device, the divergent beam is calibrated into parallel light output using a three-dimensional waveguide;

[0027] The micro-nano structure design of the diffraction beam splitting microdevice of the present invention can realize laser beam splitting on the surface of an atomic chip, which not only meets the high-precision beam splitting requirements of atomic chips, but also allows for controllable processing.

[0028] The diffraction-splitting microdevice, atomic gas cell, three-dimensional waveguide and substrate (transparent cuboid) are integrated into one, which has the advantages of miniaturization, integration, high reliability and is not affected by environmental factors such as temperature and humidity, providing a feasible technical route for subsequent applications such as quantum inertial sensors;

[0029] The micro-nano structure of the diffraction and beam-splitting micro-device of the present invention can be mass-produced, which can save costs.

[0030] It can integrate and realize the functions of diffraction and beam splitting micro-devices, atomic gas cells, and three-dimensional waveguides on the surface and inside of a cube made of the same material, and has the advantages of small size and high stability. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of the three-dimensional structure of an integrated optical atomic chip;

[0033] Figure 2 This is a top view of the structure of an integrated optical atomic chip.

[0034] Figure 3 This is a schematic diagram of the beam splitting of a diffraction-based microdevice.

[0035] In the figure: A, diffraction-splitting microdevice at the left end; B, transparent material cuboid; C, diffraction-splitting microdevice at the right end; D, atomic gas cell; 1-8, left three-dimensional waveguide; 1'-8', right three-dimensional waveguide. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] See Figures 1-3 An integrated optical atomic chip includes a transparent material cuboid B, with diffraction and beam-splitting microdevices (diffraction and beam-splitting microdevice A at the left end and diffraction and beam-splitting microdevice C at the right end) respectively at both ends of the transparent material cuboid B; an atomic gas chamber D is provided in the middle of the transparent material cuboid B, and three-dimensional waveguides (left three-dimensional waveguide 1-8 and right three-dimensional waveguide 1'-8') are respectively provided between the two diffraction and beam-splitting microdevices and the atomic gas chamber D.

[0038] The left-end diffraction beam splitter A has two diffraction beam splitting regions, each corresponding to a laser beam, namely coupling light with wavelengths of 509 nm and 510 nm. The right-end diffraction beam splitter C has one diffraction beam splitting region, corresponding to a probe light with a wavelength of 852 nm. Both the left-end and right-end diffraction beam splitter A and C are 16-step micro / nano structures, meaning that each of them can split 16 laser beams. Specifically, the two diffraction beam splitting regions of the left-end diffraction beam splitter A each have a splitting number of 1×8, achieving 1×8 laser beam splitting; the diffraction beam splitting region of the right-end diffraction beam splitter C has a splitting number of 2×8, achieving 2×8 laser beam splitting.

[0039] In this invention, to ensure the stability of the integrated optical atomic chip, the thickness of the left-end diffraction-splitting microdevice A and the right-end diffraction-splitting microdevice C is 1-3 mm, and the thickness of the two diffraction-splitting microdevices is the same. The two diffraction-splitting regions of the left-end diffraction-splitting microdevice A have equal areas; the total area of ​​the two diffraction-splitting regions of the left-end diffraction-splitting microdevice A is equal to the area of ​​the diffraction-splitting region of the right-end diffraction-splitting microdevice C.

[0040] In this invention, the diffraction-splitting microdevice A on the left and the diffraction-splitting microdevice C on the right are based on optical diffraction theory and employ wafer-level micro / nano fabrication technology to etch relief structures with two or more step depths onto a substrate, forming a pure phase coaxial reproduction, thus transforming a single laser beam carrying information into multiple laser beams carrying the same information. The three-dimensional waveguides (left three-dimensional waveguides 1-8, right three-dimensional waveguides 1'-8') are fabricated using femtosecond laser direct writing of the spatial waveguides. The transparent material is fused silica (JGS1).

[0041] In this invention, the diffraction-splitting microdevice A at the left end and the diffraction-splitting microdevice C at the right end, along with the transparent material cuboid, are an integral structure; or, the diffraction-splitting microdevice A at the left end and the diffraction-splitting microdevice C at the right end, along with the transparent material cuboid, are separate structures.

[0042] In this invention, the volume of the optically integrated atomic chip is ≥15cm². 3 Its length × width × height is ≥ (20 × 1.5 × 0.5) cm 3 The size of the atomic gas chamber D is ≥ (1 × 1 × 0.3) mm. 3 .

[0043] The theories used for efficient diffraction-based optical microdevices with different periodic structure sizes are not entirely the same. For example, when the periodic structure size is much larger than the incident wavelength, scalar diffraction theory can be used for calculation without losing too much accuracy. However, when the diffraction element structure size is close to or smaller than the incident wavelength, the coupling effect between electromagnetic vectors must be considered, and vector diffraction theory is required to obtain the correct solution.

[0044] The incident lasers in the optically integrated atomic chip are divided into two categories: coupling light at 509nm and 510nm, and probe light at 852nm. The two laser wavelengths (coupling light 509nm and 510nm) are incident on... Figure 1 The diffraction beam splitter A at the left-hand end achieves 1×8 laser beam splitting for each laser. Another laser wavelength (probe light 852nm) is used from... Figure 1 The diffraction beam splitting microdevice C at the right end achieves 2×8 laser beam splitting. Both sides are 1×16 beams facing each other. After passing through the diffraction beam splitting microdevices A and C at the left and right ends respectively, the three laser beams propagate a certain distance and achieve beam splitting, forming split laser beams. Then, the beam direction is corrected by three-dimensional waveguides (left three-dimensional waveguide 1-8, right three-dimensional waveguide 1'-8'), so that the diverging split laser beams are parallel and enter the atomic gas cell D. The parallel split beams are spaced 1.5 mm apart. The parallel split laser beams on both sides meet and face each other within the atomic gas cell D.

[0045] A method for fabricating an optically integrated atomic chip includes the following steps:

[0046] 1) The volume of the product should be ≥15cm 3 A transparent rectangular prism B has a length × width × height of ≥ (20 × 1.5 × 0.5) cm. 3 ;

[0047] 2) Fabricate an atomic gas chamber D in the middle part of a transparent material cuboid B. The dimensions of the atomic gas chamber D are ≥ (1 × 1 × 0.3) mm. 3 ;

[0048] 3) Diffraction beam splitting microdevices (diffraction beam splitting microdevice A on the left and diffraction beam splitting microdevice C on the right) with a thickness of 1-3 mm are fabricated at both ends of the transparent material cuboid B (two surfaces opposite to the width and height of the transparent material cuboid B) for beam splitting. The left diffraction beam splitting microdevice A has two diffraction beam splitting regions, each corresponding to a laser beam with wavelengths of 509 nm and 510 nm, respectively. The number of beam splitting in each diffraction beam splitting region is 1×8, realizing 1×8 laser beam splitting. The right diffraction beam splitting microdevice C has one diffraction beam splitting region, which corresponds to a laser beam with wavelengths of 852 nm. The number of beam splitting in this diffraction beam splitting region is 2×8, realizing 2×8 laser beam splitting.

[0049] Alternatively, cut small transparent material cuboids with a thickness of 1-3 mm from both ends of the transparent material cuboid B, and the two small transparent material cuboids have the same thickness; then fabricate diffraction and spectral dispersive micro-devices on the small transparent material cuboids; after fabrication, low-temperature bond the two small transparent material cuboids and the remaining transparent material cuboids according to the previous division.

[0050] 4) Between the diffraction beam splitting micro-devices (diffraction beam splitting micro-devices A at the left end and C at the right end) and the atomic gas cell D, behind the laser beam splitting, a three-dimensional waveguide is fabricated inside the transparent cuboid B at the tilt position of the diverging beam, using a femtosecond laser to write the beam. This allows the diverging beams from the diffraction beam splitting micro-devices (diffraction beam splitting micro-devices A at the left end and C at the right end) to enter the atomic gas cell D in parallel after encountering the three-dimensional waveguide.

[0051] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A light-integrated atomic chip, characterized in that: The device includes a transparent material cuboid, with diffraction and beam-splitting micro-devices at both ends; an atomic gas cell is located in the middle of the transparent material cuboid, and three-dimensional waveguides are respectively provided between the two diffraction and beam-splitting micro-devices and the atomic gas cell; The diffraction-splitting microdevice on the left has two diffraction-splitting regions, each corresponding to a laser beam, which are coupled beams with wavelengths of 509 nm and 510 nm, respectively; the diffraction-splitting microdevice on the right has one diffraction-splitting region, which corresponds to a probe beam of 852 nm. The three-dimensional waveguide is fabricated inside a transparent cuboid using femtosecond laser inscription. By changing the refractive index of the material, the direction of the diverging beam is corrected, making it a parallel beam that is precisely injected into the atomic gas cell. The laser beam is split into a beam after passing through a diffraction and beam splitting micro-device. Then, the beam direction is corrected by a three-dimensional waveguide so that the split laser beam enters the atomic gas cell in parallel. The parallel split laser beams on both sides meet and shoot against each other in the atomic gas cell. The size of the atomic gas chamber is ≥ (1 × 1 × 0.3) mm. 3 .

2. The optically integrated atomic chip according to claim 1, characterized in that: The diffraction-dispersive microdevice and the transparent material cuboid are an integral structure; or, the diffraction-dispersive microdevice and the transparent material cuboid are separate structures.

3. The optically integrated atomic chip according to claim 1, characterized in that: Both the diffraction-splitting microdevices on the left and right ends are 16-step micro / nano structures.

4. The optically integrated atomic chip according to claim 3, characterized in that: The two diffraction and beam-splitting regions in the diffraction and beam-splitting microdevice at the left end are both one-dimensional 16-step structures, while the diffraction and beam-splitting region in the diffraction and beam-splitting microdevice at the right end is a three-dimensional 16-step structure.

5. The optically integrated atomic chip according to claim 4, characterized in that: The number of laser beams split by the diffraction beam splitting microdevice at the left end and the diffraction beam splitting microdevice at the right end is 16 each; among them, the number of beams split by the two diffraction beam splitting regions of the diffraction beam splitting microdevice at the left end is 1×8 respectively; the number of beams split by the diffraction beam splitting region of the diffraction beam splitting microdevice at the right end is 2×8.

6. The optically integrated atomic chip according to claim 3, characterized in that: The thickness of the diffraction-splitting microdevices at the left and right ends is 1-3 mm, and the thickness of the diffraction-splitting microdevices at the left and right ends is the same.

7. The optically integrated atomic chip according to claim 1 or 4, characterized in that: Both the diffraction-splitting microdevices on the left and right ends employ wafer-level micro / nano processing technology to etch relief structures with two or more step depths onto the substrate, forming a pure phase coaxial reproduction that transforms a single laser beam carrying information into multiple laser beams carrying the same information. The three-dimensional waveguide is fabricated using femtosecond laser direct writing of the spatial waveguide. The transparent material includes, but is not limited to, fused silica.

8. The optically integrated atomic chip according to claim 1, characterized in that: The two diffraction regions of the left-end diffraction microdevice have equal areas; the total area of ​​the two diffraction regions of the left-end diffraction microdevice is equal to the area of ​​the diffraction region of the right-end diffraction microdevice.

9. The optically integrated atomic chip according to claim 1, characterized in that: The volume of the optically integrated atomic chip is ≥15cm². 3 .

10. The method for fabricating the optically integrated atomic chip according to any one of claims 1-9, characterized in that, Includes the following steps: 1) The volume of the product should be ≥15cm 3 A transparent rectangular prism; 2) Create an atomic gas chamber in the middle part of a transparent rectangular prism. The size of the atomic gas chamber is ≥ (1×1×0.3) mm. 3 ; 3) Diffraction beam splitting microdevices with a thickness of 1-3 mm are fabricated at both ends of a transparent rectangular prism for beam splitting. The left-end diffraction beam splitting microdevice has two diffraction beam splitting regions, each corresponding to a laser beam with wavelengths of 509 nm and 510 nm, respectively. The number of beam splitting in each diffraction beam splitting region is 1×8, achieving 1×8 laser beam splitting. The right-end diffraction beam splitting microdevice has one diffraction beam splitting region, which corresponds to a laser beam of 852 nm as the probe beam. The number of beam splitting in this diffraction beam splitting region is 2×8, achieving 2×8 laser beam splitting. Alternatively, cut small transparent material cuboids with a thickness of 1-3 mm from both ends of the transparent material cuboid, ensuring that the two small transparent material cuboids have the same thickness; then fabricate diffraction and spectral dispersive microdevices on the small transparent material cuboids; after fabrication, low-temperature bond the two small transparent material cuboids and the remaining transparent material cuboids according to the previously divided situation; 4) Between the diffraction-splitting microdevice and the atomic gas cell, behind the laser beam splitting, a three-dimensional waveguide is fabricated inside the transparent cuboid at the tilt position of the diverging beam using a femtosecond laser, so that the diverging beam emitted by the diffraction-splitting microdevice can enter the atomic gas cell in parallel after encountering the three-dimensional waveguide.

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