Miniature modulation transfer spectrum rubidium atom optical clock based on light building block structure and implementation method of miniature modulation transfer spectrum rubidium atom optical clock

Abstract

The embodiment of the invention provides a miniature modulation transfer spectrum rubidium atom optical clock based on a light building block structure and an implementation method thereof, and the implementation method comprises the steps: a thumb laser emits narrow linewidth laser, after light spots are expanded through a beam expander, a first half-wave plate and a first polarization splitting prism are matched to adjust the light splitting power, the narrow linewidth laser is divided into two beams, and one beam is used for a laser frequency stabilization light path; one beam used for a laser frequency stabilization light path is divided into two beams with different light intensities by a second half-wave plate and a second polarization splitting prism, and the two beams comprise pump light and probe light; the pump light enters rubidium atoms in the double-layer miniature rubidium atom gas chamber to interact after being subjected to phase modulation by the electro-optical modulator, and the probe light is detected and received by the high-speed photoelectric detector after interacting with the rubidium atoms in the double-layer miniature rubidium atom gas chamber and is converted into an electric signal; the mixer generates an error signal according to the electric signal and the demodulation signal, and the servo feedback control circuit controls the laser driving power supply according to the error signal, thereby achieving the output of high-stability narrow-linewidth laser, and achieving the effect of reducing the overall size.

Description

Technical Field

[0001] This application relates to the field of optical frequency atomic clocks and optical frequency quantum frequency standards, and in particular to a micro-modulation transfer spectrum rubidium atomic optical clock based on an optical building block structure and its implementation method. Background Technology

[0002] Microwave atomic clocks dominate in commercial and civilian frequency standard applications, but optical atomic clocks have attracted widespread attention due to their advantages in stability indicators. With the development of scientific research, the application research of optical atomic clocks has continued to advance, bringing new opportunities for the application of high-precision frequency standards.

[0003] In existing technologies, optical clocks in laboratories are industrially integrated to ensure their stability, thereby enabling the stable application of optical frequency atomic clocks.

[0004] However, optical atomic clocks are large, complex, and expensive, making them difficult to widely promote. Summary of the Invention

[0005] This application provides a micro-modulation transfer spectrum rubidium atomic optical clock based on an optical building block structure and its implementation method, in order to reduce the size of the optical clock.

[0006] In a first aspect, embodiments of this application provide a micro-modulation-transfer spectrum rubidium atomic optical clock based on an optical building block structure, comprising: a thumb laser (1), a beam expander (2), a first half-wave plate (3), a first polarizing beam splitter (4), a second half-wave plate (5), a second polarizing beam splitter (6), a third half-wave plate (7), an electro-optic modulator (8), a first reflector (9), a third polarizing beam splitter (10), a second reflector (11), a double-layer micro-rubidium atomic gas cell (12), a high-speed photodetector (13), a mixer (14), a signal generator (15), a servo feedback control circuit (16), and a laser driving power supply (17); wherein, the thumb laser (1) has a volume smaller than The linewidth is less than 100 kHz; the volume of the double-layer micro rubidium atom gas chamber (12) is less than The thumb laser (1) is connected to the beam expander (2), which is then connected in sequence to the first half-wave plate (3) and the first polarization beam splitter (4) to split the laser signal output by the thumb laser into two beams. One beam is used for the laser frequency stabilization optical path, and the other beam is used for the rubidium atom bubble optical path to obtain the clock transition spectrum. The laser used for the laser frequency stabilization optical path is connected in sequence to the second half-wave plate (5) and the second polarization beam splitter (6) and then split into two beams with different intensities. One beam is used as the pump light and the other beam is used as the probe light. The beam used as the pump light is connected in sequence to the third half-wave plate (7) and the electro-optic modulator (8). The electro-optic modulator (8) is connected to the signal generator (15) and in sequence to the first reflector (9), the third polarization beam splitter (10) and the double-layer micro rubidium atom bubble. The sub-gas chamber (12) is connected in sequence to the second reflector (11) and the double-layer micro rubidium atom gas chamber (12) as a probe beam. The laser emitted from the double-layer micro rubidium atom gas chamber (12) is detected and received by the high-speed photodetector (13) and then connected to the mixer (14), the servo feedback control circuit (16) and the laser drive power supply (17). The high-speed photodetector (13) is used to convert the laser emitted from the double-layer micro rubidium atom gas chamber (12) into an electrical signal. The mixer (14) is used to generate an error signal based on the electrical signal and the demodulated signal generated by the signal generator (15) and send it to the servo feedback control circuit (16). The servo feedback control circuit (16) controls the laser drive power supply (17) according to the error signal to realize the output of a high-stability narrow-linewidth laser.

[0007] In one possible implementation, the double-layer micro rubidium atom gas chamber (12) is designed with inner and outer layers, and is a nested cubic structure; wherein, the inner cubic layer of the double-layer micro rubidium atom gas chamber (12) is filled with rubidium atoms for atomic frequency stabilization, and is wound with heating copper wire and thermistor for controlling the temperature of the gas chamber; the outer cubic layer of the double-layer micro rubidium atom gas chamber (12) is evacuated to isolate the external ambient temperature and noise.

[0008] In one possible implementation, the rubidium atomic optical clock, after assembly, exhibits a second-level stability index of [missing value]. Linewidth less than 30kHz, volume less than .

[0009] In one possible implementation, the volume of the electro-optic modulator (8) is smaller than that of the electro-optic modulator (8). .

[0010] In one possible implementation, the first half-wave plate (3), the first polarizing beam splitter (4), the second half-wave plate (5), the second polarizing beam splitter (6), the third half-wave plate (7), and the third polarizing beam splitter (10) are all mounted on a ceramic base and bonded to the fused silica block with UV adhesive, and their volume is less than [missing information]. .

[0011] In one possible implementation, when the rubidium atomic clock is working, a narrow linewidth laser is emitted by a thumb laser (1). After the narrow linewidth laser is expanded by a beam expander (2), the beam splitting power is matched and adjusted by a first half-wave plate (3) and a first polarizing beam splitter (4) and split into two beams. One beam is used for the laser frequency stabilization optical path, and the other beam is used for the rubidium atomic bubble optical path to obtain the clock transition spectrum.

[0012] In one possible implementation, a beam used for laser frequency stabilization is split into two beams of different intensities by a second half-wave plate (5) and a second polarization beam splitter (6), including a pump beam with a stronger intensity and a probe beam with a weaker intensity. The pump beam enters a third half-wave plate (7), is phase-modulated by an electro-optic modulator (8), and then enters a first reflector (9) and a third polarization beam splitter (10) to interact with rubidium atoms in a double-layer micro rubidium atom gas chamber (12). The modulation signal of the electro-optic modulator (8) is generated by a signal generator (15), and the third half-wave plate (7) is used to adjust the polarization direction of the pump beam so that it is consistent with the main axis direction of the electro-optic modulator (8). The probe beam interacts with rubidium atoms in the double-layer micro rubidium atom gas chamber (12) through a second reflector (11) and is detected and received by a high-speed photodetector (13), and converted into an electrical signal.

[0013] In one possible implementation, the electrical signal is input to the mixer (14), which generates an error signal based on the electrical signal and the demodulated signal, wherein the demodulated signal is generated by the signal generator (15).

[0014] In one possible implementation, the electro-optic modulator (8) employs active temperature control.

[0015] Secondly, embodiments of this application provide a method for implementing a micro-modulation transfer spectrum rubidium atomic optical clock based on an optical building block structure, applied to the rubidium atomic optical clock as described in any one of claims 1 to 9, comprising: emitting a narrow-linewidth laser from a thumb laser; after the narrow-linewidth laser spot is expanded by a beam expander, the beam splitting power is adjusted by a first half-wave plate and a first polarizing beam splitter and split into two beams; one beam is used for a laser frequency stabilization optical path, and the other beam is used for a rubidium atomic bubble optical path to obtain clock transition spectral lines; the beam used for the laser frequency stabilization optical path is split into two beams of different intensities by a second half-wave plate and a second polarizing beam splitter, including a stronger pump light and a weaker pump light. The probe light and pump light enter the third half-wave plate, are phase-modulated by an electro-optic modulator, and then enter the first reflecting mirror and the third polarizing beam splitter to interact with rubidium atoms in the double-layer micro rubidium atom gas chamber. The modulation signal of the electro-optic modulator is generated by a signal generator. The probe light interacts with rubidium atoms in the double-layer micro rubidium atom gas chamber through the second reflecting mirror and is detected and received by a high-speed photodetector, which converts it into an electrical signal. The mixer generates an error signal based on the electrical signal and the demodulated signal. The demodulated signal is generated by the signal generator. The servo feedback control circuit controls the laser drive power supply based on the error signal to achieve the output of a high-stability, narrow-linewidth laser.

[0016] The miniature modulation-transfer spectrum rubidium atomic optical clock and its implementation method based on optical building block structure provided in this application reduce the overall volume of the optical clock by using an optical building block structure, thus eliminating the need for traditional metal structures and reducing weight. At the same time, the core components of the rubidium atomic optical clock, such as the double-layer miniature rubidium atomic gas cell, thumb laser, and electro-optic modulator, also adopt miniaturized design, further reducing the overall volume. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] Figure 1 This is a schematic diagram of the structure of a micro-modulation transfer spectrum rubidium atomic optical clock based on an optical building block structure provided in an embodiment of this application;

[0019] Figure 2 A flowchart illustrating the implementation method of a micro-modulation transfer spectrum rubidium atomic optical clock based on an optical building block structure provided in this application embodiment.

[0020] Figure label:

[0021] 1- Thumb laser; 2- Beam expander; 3- First half-wave plate; 4- First polarizing beam splitter; 5- Second half-wave plate; 6- Second polarizing beam splitter; 7- Third half-wave plate; 8- Electro-optic modulator; 9- First reflector; 10- Third polarizing beam splitter; 11- Second reflector; 12- Double-layer miniature rubidium atom gas cell; 13- High-speed photodetector; 14- Mixer; 15- Signal generator; 16- Servo feedback control circuit; 17- Laser drive power supply.

[0022] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0024] It should be noted that, in the description of this application, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] The technical solution of this application and how it solves the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0026] To clearly understand the technical solution of this application, the existing technical solutions will first be described in detail. Currently, most commercial and civilian frequency standards are microwave atomic clocks. Given the absolute advantage of optical atomic clocks in terms of stability, their applications have been reported after decades of research and development. However, their large size, complex structure, and high price remain obstacles to their widespread adoption. Therefore, how to reduce size and weight while maintaining the advantages of optical atomic clocks in terms of performance has become a hot topic in the industry. Currently, most solutions involve industrially integrating optical clocks from laboratories to ensure their stability and achieve stable application of optical atomic clocks. However, how to further structurally address the field applications of optical atomic clocks remains a challenge that needs to be overcome.

[0027] To address the aforementioned technical problems, the inventors conceived of using a light-block structure to reduce the overall size of the optical clock. At the same time, the core components of this optical frequency atomic clock also adopt a miniaturized design, which can further reduce its overall size.

[0028] refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a micro-modulation transfer spectrum rubidium atomic optical clock based on an optical building block structure, provided in an embodiment of this application. Figure 1 As shown, the rubidium atomic optical clock includes: a thumb laser (1), a beam expander (2), a first half-wave plate (3), a first polarizing beam splitter (4), a second half-wave plate (5), a second polarizing beam splitter (6), a third half-wave plate (7), an electro-optic modulator (8), a first reflector (9), a third polarizing beam splitter (10), a second reflector (11), a double-layer micro rubidium atomic gas cell (12), a high-speed photodetector (13), a mixer (14), a signal generator (15), a servo feedback control circuit (16), and a laser drive power supply (17).

[0029] In this embodiment, the thumb laser (1) has a volume smaller than The linewidth is less than 100kHz.

[0030] The thumb laser is a miniaturized laser consisting of a laser diode, collimating lens, interference filter, partial reflector, piezoelectric ceramic, and temperature control module. The laser diode is the core component that generates the laser beam. The collimating lens collimates the relatively divergent laser beam emitted by the laser diode, making it parallel or near-parallel light for subsequent transmission and application. The interference filter filters the laser beam, selecting laser components that meet specific wavelength requirements. The partial reflector partially reflects and transmits the incoming laser beam. The piezoelectric ceramic plays a role in adjustment or feedback control. The temperature control module is positioned around the laser diode to ensure a stable operating temperature.

[0031] In this embodiment, the thumb laser (1) is connected to the beam expander (2), and the beam expander (2) is then connected in sequence to the first half-wave plate (3) and the first polarization beam splitter (4) to split the laser signal output by the thumb laser into two beams, one beam for the laser frequency stabilization optical path and the other beam for the rubidium atom bubble optical path to obtain the clock transition spectrum.

[0032] The beam expander is used to adjust the divergence angle of the laser so that the expanded laser beam can better adapt to parameters such as numerical aperture and pupil of subsequent optical devices. In addition, the laser needs to interact precisely with atoms, and the beam expander is used to enlarge the laser spot so that the laser can uniformly cover the entire double-layer micro rubidium atom gas cell.

[0033] The first half-wave plate changes the polarization state of the laser to prepare for subsequent beam splitting. The laser, after polarization adjustment, enters the first polarization beam splitter, which can split the laser signal into two beams according to the characteristics of light.

[0034] The laser used for laser frequency stabilization optical path is connected in sequence to the second half-wave plate (5) and the second polarization beam splitter (6) and then split into two beams with different intensities. One beam is used as pump light and the other is used as probe light.

[0035] Specifically, the pump light is used to provide energy for processes such as rubidium atom energy level transitions in the entire laser frequency stabilization optical path, while the probe light is used to detect and provide feedback on various parameters in the laser frequency stabilization process, such as frequency changes and atomic state changes.

[0036] One beam of pump light is connected in sequence to the third half-wave plate (7) and the electro-optic modulator (8). The electro-optic modulator (8) is connected to the signal generator (15) and in sequence to the first reflector (9), the third polarization beam splitter (10) and the double-layer micro rubidium atom gas chamber (12). The other beam of probe light is connected in sequence to the second reflector (11) and the double-layer micro rubidium atom gas chamber (12). The laser emitted from the double-layer micro rubidium atom gas chamber (12) is detected and received by the high-speed photodetector (13) and then connected to the mixer (14), the servo feedback control circuit (16) and the laser drive power supply (17).

[0037] In this embodiment, the double-layer micro rubidium atom gas chamber is designed with inner and outer layers, forming a nested cubic structure. The inner cubic layer of the double-layer micro rubidium atom gas chamber is filled with rubidium atoms for atomic frequency stabilization, and is wrapped with heating copper wire and a thermistor to control the chamber temperature. The outer cubic layer of the double-layer micro rubidium atom gas chamber is evacuated to isolate it from external ambient temperature and noise.

[0038] In this embodiment, the volume of the electro-optic modulator is smaller than that of the electro-optic modulator. .

[0039] A high-speed photodetector (13) is used to convert the laser emitted from the double-layer micro rubidium atom gas chamber (12) into an electrical signal. A mixer (14) is used to generate an error signal based on the electrical signal and the demodulated signal generated by the signal generator (15) and send it to the servo feedback control circuit (16). The servo feedback control circuit (16) controls the laser drive power supply (17) based on the error signal to achieve the output of a high-stability narrow-linewidth laser.

[0040] In this embodiment, the second-level stability index of the rubidium atomic optical clock after assembly is: Linewidth less than 30kHz, volume less than .

[0041] In this embodiment, the first half-wave plate, the first polarizing beam splitter, the second half-wave plate, the second polarizing beam splitter, the third half-wave plate, and the third polarizing beam splitter are all mounted on a ceramic base and bonded to the fused silica block with UV adhesive, and their volume is less than [missing information]. .

[0042] Among them, UV adhesive is a type of adhesive that can cure rapidly under ultraviolet light, allowing optical devices to be tightly bonded to fused silica blocks. Fused silica blocks themselves also possess excellent optical properties, such as high transparency and a low temperature coefficient of refractive index, providing superior medium conditions for light transmission and helping to ensure that light maintains good propagation characteristics when passing through these devices and the connected optical path components.

[0043] In this embodiment, when the micro-modulation transfer spectrum rubidium atomic clock based on the optical building block structure is working, a narrow linewidth laser is emitted by a thumb laser (1). After the narrow linewidth laser is expanded by a beam expander (2), the beam splitting power is matched and adjusted by a first half-wave plate (3) and a polarizing beam splitter (4) and split into two beams. One beam is used for the laser frequency stabilization optical path, and the other beam is used for the rubidium atomic bubble optical path to obtain the clock transition spectrum.

[0044] In this embodiment, the laser frequency stabilization optical path is split into two beams of different intensities by the second half-wave plate (5) and the second polarization beam splitter (6), including a pump light with a stronger intensity and a probe light with a weaker intensity. The pump light enters the third half-wave plate (7), is phase-modulated by the electro-optic modulator (8), and then enters the first reflector (9) and the third polarization beam splitter (10) to interact with the rubidium atoms in the double-layer micro rubidium atom gas chamber (12). The modulation signal of the electro-optic modulator (8) is generated by the signal generator (15). The third half-wave plate (7) is used to adjust the polarization direction of the pump light so that it is consistent with the main axis direction of the electro-optic modulator (8). The probe light interacts with the rubidium atoms in the double-layer micro rubidium atom gas chamber (12) after passing through the second reflector (11) and is detected and received by the high-speed photodetector (13), and converted into an electrical signal.

[0045] In this embodiment, in the electrical signal input mixer (14), the mixer (14) generates an error signal based on the electrical signal and the demodulated signal, wherein the demodulated signal is generated by the signal generator (15).

[0046] In this embodiment, the electro-optic modulator (8) adopts an active temperature control method.

[0047] As can be seen from the above embodiments, by using an optical building block structure on the modulation transfer spectrum rubidium atomic optical clock structure, the overall volume of the optical clock is reduced, the traditional metal structure is eliminated and the weight is reduced. At the same time, the core components of the rubidium atomic optical clock, such as the double-layer micro rubidium atomic gas cell, thumb laser and electro-optic modulator, are also miniaturized, further reducing the overall volume.

[0048] Furthermore, the heating copper wire wound within the inner cube of the double-layered micro-rubidium atom gas chamber actively regulates the temperature within the chamber. It can increase heat as needed to maintain a suitable temperature environment, while the thermistor senses temperature changes within the chamber in real time. Together, they form a highly effective temperature control system. A vacuum is created within the outer cube, successfully isolating the inner chamber from the influence of external ambient temperature and noise. Fluctuations in external temperature and noise are not easily transmitted to the inner layer, allowing the inner rubidium atom gas chamber to operate in a relatively independent and stable environment. This plays a crucial role in maintaining the stable state of rubidium atoms and ensuring the continuous and effective operation of the atom frequency stabilization function.

[0049] refer to Figure 2 , Figure 2 A flowchart illustrating the implementation method of a micro-modulation transfer spectrum rubidium atom optical clock based on an optical building block structure provided in this application embodiment includes steps S201~S205:

[0050] S201: A narrow-linewidth laser is emitted by a thumb laser. After the narrow-linewidth laser spot is expanded by a beam expander, the beam splitting power is adjusted by the first half-wave plate and the first polarizing beam splitter and split into two beams. One beam is used for the laser frequency stabilization optical path, and the other beam is used for the rubidium atom bubble optical path to obtain the clock transition spectrum.

[0051] S202: A beam used in the laser frequency stabilization optical path is split into two beams of different intensities by the second half-wave plate and the second polarization beam splitter, including a pump beam with a stronger intensity and a probe beam with a weaker intensity.

[0052] S203: The pump light enters the third half-wave plate, is phase-modulated by the electro-optic modulator, and then enters the first reflecting mirror and the third polarizing beam splitter to interact with rubidium atoms in the double-layer micro rubidium atom gas chamber. The modulation signal of the electro-optic modulator is generated by the signal generator. The probe light interacts with rubidium atoms in the double-layer micro rubidium atom gas chamber through the second reflecting mirror and is then detected and received by the high-speed photodetector, and converted into an electrical signal.

[0053] S204: The mixer generates an error signal based on the electrical signal and the demodulated signal, wherein the demodulated signal is generated by the signal generator.

[0054] S205: The servo feedback control circuit controls the laser drive power supply according to the error signal to achieve high-stability narrow-linewidth laser output.

[0055] As can be seen from the above embodiments, by using an optical building block structure on the modulation transfer spectrum rubidium atomic optical clock structure, the overall volume of the optical clock is reduced, the traditional metal structure is eliminated and the weight is reduced. At the same time, the core components of the rubidium atomic optical clock, such as the double-layer micro rubidium atomic gas cell, thumb laser and electro-optic modulator, are also miniaturized, further reducing the overall volume.

[0056] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0057] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0058] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A miniature modulation transferred spectrum rubidium atom optical clock based on optical building block structure, characterized in that, The device comprises a thumb laser (1), a beam expander (2), a first half-wave plate (3), a first polarization beam splitter prism (4), a second half-wave plate (5), a second polarization beam splitter prism (6), a third half-wave plate (7), an electro-optical modulator (8), a first mirror (9), a third polarization beam splitter prism (10), a second mirror (11), a double-layer micro-Rb atom cell (12), a high-speed photodetector (13), a frequency mixer (14), a signal generator (15), a servo feedback control circuit (16) and a laser driving power supply (17). The volume of the thumb laser (1) is less than 100 kHz; the volume of the double-layer micro-Rb atomic gas chamber (12) is less than ​ The thumb laser (1) is connected to the beam expander (2), which is then connected to the first half-wave plate (3) and the first polarization beam splitter prism (4) in sequence, for splitting the laser signal output by the thumb laser into two beams, one of which is used for laser frequency stabilization and the other of which is used for obtaining the clock transition spectrum of the Rb atom bubble light path. The laser for the laser frequency stabilization light path is connected to the second half-wave plate (5) and the second polarization beam splitter prism (6) in sequence and then split into two beams with different light intensities, one of which is used as pump light and the other of which is used as probe light. The pump light is connected to the third half-wave plate (7) and the electro-optical modulator (8) in sequence, the electro-optical modulator (8) is connected to the signal generator (15), and the first mirror (9), the third polarization beam splitter prism (10) and the double-layer micro-Rb atom cell (12) are connected in sequence; the probe light is connected to the second mirror (11) and the double-layer micro-Rb atom cell (12) in sequence, and the laser emitted from the double-layer micro-Rb atom cell (12) is detected by the high-speed photodetector (13) and then connected to the frequency mixer (14), the servo feedback control circuit (16) and the laser driving power supply (17). The high-speed photodetector (13) is used to convert the laser emitted from the double-layer micro-Rb atom cell (12) into an electrical signal, the frequency mixer (14) is used to generate an error signal according to the electrical signal and the demodulation signal generated by the signal generator (15) and send it to the servo feedback control circuit (16), the servo feedback control circuit (16) controls the laser driving power supply (17) according to the error signal, and the output of high-stability narrow-linewidth laser is realized.

2. The rubidium atomic optical clock of claim 1, wherein, The double-layer micro-Rb atom cell (12) is designed as an inner and outer double-layer structure, which is a nested structure of a square. The inner layer of the double-layer micro-Rb atom cell (12) is filled with Rb atoms for atomic frequency stabilization, and a heating copper wire and a thermistor are wound for controlling the temperature of the cell. The outer layer of the double-layer micro-Rb atom cell (12) is evacuated to isolate the external environment temperature and noise.

3. The rubidium atomic optical clock of claim 1, wherein, The rubidium atomic optical clock has a post-assembly second-level stability index of , a line width less than 30 kHz, and a volume less than .

4. The rubidium atomic optical clock of claim 1, wherein, The volume of the electro-optical modulator (8) is less than .

5. The rubidium atomic optical clock of claim 1, wherein, The first half-wave plate (3), the first polarization beam splitter prism (4), the second half-wave plate (5), the second polarization beam splitter prism (6), the third half-wave plate (7) and the third polarization beam splitter prism (10) are all mounted on a ceramic base, bonded to a fused quartz block by ultraviolet glue, and have a volume less than .

6. The rubidium atomic optical clock of claim 1, wherein, The rubidium atom optical clock works as follows: narrow linewidth laser is emitted by the thumb laser (1), the spot of the narrow linewidth laser is expanded by the beam expander (2), and then the light power is matched and adjusted by the first half-wave plate (3) and the first polarization beam splitter prism (4) and divided into two beams, one of which is used for laser frequency stabilization light path, and the other is used for obtaining clock transition spectrum line of rubidium atom bubble light path.

7. The rubidium atomic optical clock of claim 2, wherein, The one for laser frequency stabilization light path is divided into two beams with different light intensities by the second half-wave plate (5) and the second polarization beam splitter prism (6), including pump light with relatively strong light intensity and probe light with relatively weak light intensity. The pump light enters the third half-wave plate (7), is phase-modulated by the electro-optical modulator (8), and then is injected into the first mirror (9) and the third polarization beam splitter prism (10) to interact with the rubidium atoms in the double-layer micro rubidium atom gas chamber (12), wherein the modulation signal of the electro-optical modulator (8) is generated by the signal generator (15), and the third half-wave plate (7) is used to adjust the polarization direction of the pump light to be consistent with the direction of the main axis of the electro-optical modulator (8). The probe light interacts with the rubidium atoms in the double-layer micro rubidium atom gas chamber (12) through the second mirror (11), and then is detected and received by the high-speed photodetector (13) to be converted into an electrical signal.

8. The rubidium atomic optical clock of claim 7, wherein, The electrical signal is input into the frequency mixer (14), and the frequency mixer (14) generates an error signal according to the electrical signal and a demodulation signal, wherein the demodulation signal is generated by the signal generator (15).

9. The rubidium atomic optical clock of claim 4, wherein, The electro-optical modulator (8) adopts an active temperature control mode.

10. An implementation method of a miniature modulation transfer spectroscopy rubidium atomic optical clock based on a light-brick structure, characterized in that, The application is applied to the rubidium atom optical clock of any one of claims 1 to 9, and includes: narrow linewidth laser is emitted by the thumb laser, the spot of the narrow linewidth laser is expanded by the beam expander, and then the light power is matched and adjusted by the first half-wave plate and the first polarization beam splitter prism and divided into two beams, one of which is used for laser frequency stabilization light path, and the other is used for obtaining clock transition spectrum line of rubidium atom bubble light path; the one for laser frequency stabilization light path is divided into two beams with different light intensities by the second half-wave plate and the second polarization beam splitter prism, including pump light with relatively strong light intensity and probe light with relatively weak light intensity; the pump light enters the third half-wave plate, is phase-modulated by the electro-optical modulator, and then is injected into the first mirror and the third polarization beam splitter prism to interact with the rubidium atoms in the double-layer micro rubidium atom gas chamber, wherein the modulation signal of the electro-optical modulator is generated by the signal generator; the probe light interacts with the rubidium atoms in the double-layer micro rubidium atom gas chamber through the second mirror, and then is detected and received by the high-speed photodetector to be converted into an electrical signal; the frequency mixer generates an error signal according to the electrical signal and a demodulation signal, wherein the demodulation signal is generated by the signal generator; the servo feedback control circuit controls the laser driving power supply according to the error signal, and realizes the output of high-stability narrow linewidth laser.

Images