All-fiber laser optical path system applied to 87Rb cold atom interferometer

Abstract

The invention provides an all-fiber laser optical path system applied to an 87Rb cold atom interferometer, which comprises a plurality of optical fiber amplifiers, a plurality of optical fiber acoustic optical modulators, a plurality of optical fiber beam combiners, a plurality of optical fiber beam splitters, an optical fiber frequency multiplication waveguide and a beat frequency phase lock servo module, the all-fiber laser optical path system can generate lasers with different frequencies required by the 87Rb cold atom interferometer, can replace a complex laboratory laser optical path system of the cold atom interferometer, and is smaller in size, higher in environmental adaptability, higher in reliability, simpler in process and more suitable for large-scale production. The laser can meet the requirements of various functional lasers of the 87Rb cold atom interferometer, so that the laser can be used as an important component for miniaturization, integration, modularization and engineering of a laser light path of the 87Rb cold atom interferometer.

Description

Technical Field

[0001] The present invention relates to the field of cold atom interference technology, and more specifically, to a method for 87 All-fiber laser optical path system of Rb cold atom interferometer. Background Art

[0002] Quantum sensors based on cold atom interferometry are new sensors that use matter wave interference as a medium. Due to their extremely high theoretical measurement accuracy and wide application prospects in gravity measurement and inertial sensing, they are currently recognized as important candidates for the next generation of high-precision inertial sensors in the world. Atom interferometry technology has been widely used in the field of precision measurement. Various quantum sensors based on cold atom interferometry technology, such as cold atom interferometry absolute gravimeters, cold atom interferometry gravity gradient meters, and cold atom interferometry gyroscopes, have experienced rapid development.

[0003] After nearly 30 years of development, a variety of quantum sensors based on cold atom interferometry technology, such as cold atom interferometry absolute gravimeter, cold atom interferometry gravity gradient meter, cold atom interferometry gyroscope, etc., have made significant progress. In particular, the cold atom interferometry absolute gravimeter has not only achieved the level of the current mainstream commercial laser interferometry absolute gravimeter FG5 in terms of instrument measurement accuracy and instrument performance, but has also begun to move out of the laboratory and towards commercialization. Quantum sensors based on cold atom interferometry technology are gradually moving out of the laboratory and are beginning to develop in the direction of miniaturization, integration, modularization, and engineering. Summary of the invention

[0004] In view of the needs of the prior art, the present invention provides a 87 The all-fiber laser optical path system of the Rb cold atom interferometer has the advantages of small size, strong environmental adaptability and high reliability.

[0005] The present invention provides a method for applying 87 The all-fiber laser optical path system of the Rb cold atom interferometer includes multiple fiber amplifiers, multiple fiber acousto-optic modulators, multiple fiber combiners, multiple fiber beam splitters, fiber frequency doubling waveguides and beat frequency phase-locked servo modules; The first fiber laser seed source is divided into two beams of fundamental frequency light after passing through the first fiber amplifier and the first fiber beam splitter, the first beam of fundamental frequency light is injected into the first fiber frequency doubling waveguide to obtain the first frequency doubling laser, the first frequency doubling laser is passed through the first fiber acousto-optic modulator to obtain the laser required by the cold atom interferometer; the second beam of fundamental frequency light is divided into two beams of frequency-shifted laser after passing through the second fiber acousto-optic modulator and the second fiber beam splitter, the first beam of frequency-shifted laser is injected into the first fiber beam combiner through the fiber optical switch, and the second beam of frequency-shifted laser is injected into the second fiber beam combiner; The second fiber laser seed source is divided into two beams of fundamental frequency light by the third fiber beam splitter, the third beam of fundamental frequency light is input into the first fiber beam combiner, and after beam combining with the first beam of frequency-shifted laser, it passes through the second fiber amplifier and the second fiber frequency-doubling waveguide to obtain the second frequency-doubled laser, and the second frequency-doubled laser passes through the third fiber acousto-optic modulator to obtain the laser required for the cold atom interferometer; the fourth beam of fundamental frequency light is injected into the second fiber beam combiner, and beam combined with the second beam of frequency-shifted laser to obtain the beat frequency light, which is input into the photodetector to obtain the beat frequency signal required by the beat frequency phase-locked servo module.

[0006] The present invention provides a method for applying 87 The all-fiber laser optical path system of the Rb cold atom interferometer can generate different lasers required by the cold atom interferometer. The all-fiber laser optical path system can not only replace the complex laboratory laser optical path system of the cold atom interferometer, but also has a smaller size, stronger environmental adaptability, higher reliability, and simpler process. It can meet the needs of various functional lasers of the cold atom interferometer. Therefore, it can serve as an important technical path for the miniaturization, integration, modularization, and engineering of the laser optical path of the cold atom interferometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 The present invention provides a method for applying 87 Schematic diagram of the structure of the all-fiber laser optical path system of the Rb cold atom interferometer. DETAILED DESCRIPTION

[0008] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the technical features in the various embodiments or single embodiments provided by the present invention can be arbitrarily combined with each other to form a feasible technical solution. This combination is not subject to the constraints of the sequence of steps and / or the structural composition mode, but must be based on the ability of ordinary technicians in this field to achieve. When the combination of technical solutions is contradictory or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0009] Figure 1 The present invention provides a method for applying 87 All-fiber laser optical path system of Rb cold atom interferometer, such as Figure 1As shown, the all-fiber laser optical path system includes multiple fiber amplifiers, multiple fiber acousto-optic modulators, multiple fiber combiners, multiple fiber splitters, fiber frequency doubling waveguides and beat frequency phase-locked servo modules.

[0010] The working process of the all-fiber laser optical path system is as follows: the first fiber laser seed source is divided into two beams of fundamental frequency light after passing through the first fiber amplifier and the first fiber beam splitter. The first beam of fundamental frequency light is injected into the first fiber frequency doubling waveguide to obtain the first frequency doubling laser. The first frequency doubling laser passes through the first fiber acousto-optic modulator to obtain the laser required for the cold atom interferometer. The second beam of fundamental frequency light passes through the second fiber acousto-optic modulator and the second fiber beam splitter and is divided into two beams of frequency-shifted laser. The first beam of frequency-shifted laser is injected into the first fiber combiner through the fiber optical switch, and the second beam of frequency-shifted laser is injected into the second fiber combiner.

[0011] The second fiber laser seed source is divided into two fundamental frequency lights by the third fiber beam splitter. The third fundamental frequency light is input into the first fiber beam combiner, combined with the first frequency-shifted laser, and then passed through the second fiber amplifier and the second fiber frequency-doubling waveguide to obtain the second frequency-doubled laser. The second frequency-doubled laser passes through the third fiber acousto-optic modulator to obtain the laser required for the cold atom interferometer. The fourth fundamental frequency light is injected into the second fiber beam combiner, combined with the second frequency-shifted laser to obtain the beat frequency light input into the photodetector, and the beat frequency signal required by the beat frequency phase-locked servo module is obtained.

[0012] Wherein, the all-fiber laser optical path system also includes a fourth fiber beam splitter and a fourth fiber acousto-optic modulator; the first frequency-doubled laser is divided into two beams of first frequency-doubled laser by the fourth fiber beam splitter, one beam of the first frequency-doubled laser is passed through the first fiber acousto-optic modulator to obtain cooling light / blowing light / detection light of the cold atom interferometer; the other beam of the first frequency-doubled laser is passed through the fourth fiber acousto-optic modulator to obtain the frequency-stabilized laser of the cold atom interferometer.

[0013] Specifically, the working process of the all-fiber laser optical path system provided by the present invention includes the following steps: Step S1, injecting a first fiber laser seed source (Seed1) into a first fiber amplifier to obtain about 5W of 1560nm fundamental frequency light; Step S2, according to the 1560nm fundamental frequency light of about 5W in step S1, the pigtail is fused with the first optical fiber beam splitter to obtain two beams of 1560nm fundamental frequency light of 10% / 90%; Step S3, 90% of the 1560nm fundamental frequency light in step S2 is fused to the first optical fiber frequency doubling waveguide through the pigtail, and a 780nm frequency doubling laser of about 1W is obtained through the frequency doubling technology, and 10% of the 1560nm fundamental frequency light is fused to the second optical fiber acousto-optic modulator through the pigtail to obtain a 1560nm fundamental frequency light with a frequency shift of -1.2 GHz; Step S4, passing the 780nm frequency-doubled laser in step S3 through the pigtail and the fourth optical fiber beam splitter to obtain two beams of 780nm laser with a ratio of 10% / 90%; Step S5, 10% of the 780nm laser in step S4 is fused to the fourth fiber acousto-optic modulator through the pigtail to obtain the frequency-stabilized laser of the MTS laser frequency stabilization module of the 87Rb cold atom interferometer, and 90% of the 780nm laser is fused to the first fiber acousto-optic modulator through the pigtail to obtain the cooling light / blowing light / detection light of the 87Rb cold atom interferometer; Step S6, splicing the 1560nm fundamental frequency light with a frequency shift of -1.2 GHz in step 3 to the second optical fiber beam splitter through a pigtail to obtain two beams of 1560nm fundamental frequency light with a frequency shift of -1.2 GHz of 10% / 90%; Step S7, 90% of the 1560nm fundamental frequency light with a frequency shift of -1.2 GHz in step 6 is fused to the optical fiber switch through the pigtail to obtain the 1560nm fundamental frequency light with a frequency shift of -1.2 GHz that can be controlled by the switch; Step S8, secondly, the fiber laser seed source (Seed2) is fused with the third fiber beam splitter through the pigtail to obtain two beams of 1560nm fundamental frequency light of 10% / 90%; Step S9, 10% of the 1560nm fundamental frequency light with a frequency shift of -1.2 GHz in step 6 and 10% of the 1560nm fundamental frequency light in step 8 are respectively fused to two input ends of the second optical fiber combiner through pigtails, and the beat frequency light output by the second optical fiber combiner is injected into a fast photodetector to obtain a beat frequency signal required by the beat frequency phase-locked servo module; Step S10, 90% of the 1560nm fundamental frequency light in step 9 and the 1560nm fundamental frequency light with a frequency shift of -1.2GHz that can be controlled by the switch in step 7 are respectively fused to the two input ends of the first optical fiber combiner through the pigtails, and the output light of the first optical fiber combiner is injected into the second optical fiber amplifier to obtain about 5W of 1560nm fundamental frequency light; Step S11, fusing the 1560nm fundamental frequency light of about 5W in step 10 with the second optical fiber frequency doubling waveguide through the pigtail, and obtaining a 780nm frequency doubling laser of about 1W by frequency doubling technology; Step S12, the 780nm light in step 11 is fused with the third fiber acousto-optic modulator through the pigtail to obtain 87 Back pump light and Raman light of Rb cold atom interferometer.

[0014] In a possible implementation manner of the present invention, the central wavelength of the first fiber laser seed source and the second fiber laser seed source is 1560nm, the laser line width is 2kHz, the output power is 40mW, the polarization degree is better than 20dB, the fast frequency tuning bandwidth is 5kHz, and the fast frequency tuning range is 3GHz.

[0015] The central operating wavelength of the first optical fiber amplifier and the second optical fiber amplifier is 1560nm, the incident seed power is 1mW, the maximum output power is 5W, the operating mode is continuous light, and the output relative intensity noise is less than 1%.

[0016] The input light wavelength of the first optical fiber frequency doubling waveguide and the second optical fiber frequency doubling waveguide is 1560nm, the doubled light wavelength is 780nm, the input power is 5W, the maximum output power is 2W, and the temperature tuning range is 20-70°C.

[0017] The first fiber beam splitter is a 1560nm high-power fiber beam splitter with a power damage threshold of 5W, the second fiber beam splitter and the third fiber beam splitter are 1560nm low-power fiber beam splitter with a power damage threshold of 500mW, and the fourth fiber beam splitter is a 780nm high-power fiber beam splitter with a power damage threshold of 2W.

[0018] The first optical fiber combiner and the second optical fiber combiner are 1560nm low-power optical fiber combiners, and the power damage threshold is 500mW.

[0019] The first fiber acousto-optic modulator is a 780nm variable frequency fiber acousto-optic frequency shifter with a shift frequency of 100 to 250MHz; the second fiber acousto-optic modulator is a 1550nm fixed frequency fiber acousto-optic frequency shifter with a shift frequency range of -1200 MHz; the third fiber acousto-optic modulator is a 780nm fixed frequency fiber acousto-optic frequency shifter with a shift frequency of -100 MHz; the fourth fiber acousto-optic modulator is a 780nm fixed frequency fiber acousto-optic frequency shifter with a shift frequency of 200MHz.

[0020] The fiber optical switch is a silicon-based high-speed optical switch with a switching speed of about 0.3uS; the photodetector is a broadband InGaAs photodetector with a bandwidth of 10GHz.

[0021] An all-fiber laser optical path system applied to a cold atom interferometer provided by an embodiment of the present invention has the following beneficial effects: (1) The all-fiber laser optical path system can generate different lasers required for the cold atom interferometer. The all-fiber laser optical path system can not only replace the complex laboratory laser optical path system of the cold atom interferometer, but also has a smaller size, stronger environmental adaptability, higher reliability, and simpler process. It can meet the needs of various functional lasers of the cold atom interferometer. Therefore, it can serve as an important technical path for the miniaturization, integration, modularization, and engineering of the laser optical path of the cold atom interferometer.

[0022] (2) The all-fiber laser optical path system provided has a simple process and is easy to implement. It has a smaller size, stronger environmental adaptability, and higher reliability. It is of great significance to promote the development of cold atom interferometry technology and advance the application of cold atom interferometers.

[0023] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0024] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0025] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for 87 The all-fiber laser optical path system of the Rb cold atom interferometer is characterized by: It includes multiple fiber amplifiers, multiple fiber acousto-optic modulators, multiple fiber combiners, multiple fiber splitters, fiber frequency doubling waveguides and beat frequency phase-locked servo modules; The first fiber laser seed source is divided into two beams of fundamental frequency light after passing through the first fiber amplifier and the first fiber beam splitter, the first beam of fundamental frequency light is injected into the first fiber frequency doubling waveguide to obtain the first frequency doubling laser, the first frequency doubling laser is passed through the first fiber acousto-optic modulator to obtain the laser required by the cold atom interferometer; the second beam of fundamental frequency light is divided into two beams of frequency-shifted laser after passing through the second fiber acousto-optic modulator and the second fiber beam splitter, the first beam of frequency-shifted laser is injected into the first fiber beam combiner through the fiber optical switch, and the second beam of frequency-shifted laser is injected into the second fiber beam combiner; The second fiber laser seed source is divided into two beams of fundamental frequency light by the third fiber beam splitter, the third beam of fundamental frequency light is input into the first fiber beam combiner, and after beam combining with the first beam of frequency-shifted laser, it passes through the second fiber amplifier and the second fiber frequency-doubling waveguide to obtain the second frequency-doubled laser, and the second frequency-doubled laser passes through the third fiber acousto-optic modulator to obtain the laser required for the cold atom interferometer; the fourth beam of fundamental frequency light is injected into the second fiber beam combiner, and beam combined with the second beam of frequency-shifted laser to obtain the beat frequency light, which is input into the photodetector to obtain the beat frequency signal required by the beat frequency phase-locked servo module.

2. The all-fiber laser optical path system according to claim 1, characterized in that: The system also includes a fourth fiber optic beam splitter and a fourth fiber optic acousto-optic modulator; The first frequency-doubled laser is divided into two beams of first frequency-doubled laser by the fourth fiber beam splitter, one of which is passed through the first fiber acousto-optic modulator to obtain cooling light / blowing light / detection light of the cold atom interferometer; the other beam of the first frequency-doubled laser is passed through the fourth fiber acousto-optic modulator to obtain frequency-stabilized laser of the cold atom interferometer.

3. The all-fiber laser optical path system according to claim 2, characterized in that: The first optical fiber beam splitter is used to split the fundamental frequency light into 80-90% of the first fundamental frequency light and 10-20% of the second fundamental frequency light; The second optical fiber beam splitter is used to split the frequency-shifted laser into 80-90% of the first frequency-shifted laser beam and 10-20% of the second frequency-shifted laser beam; The third fiber beam splitter is used to split the fundamental frequency light of the second fiber laser seed source into 80-90% of the third beam of fundamental frequency light and 10-20% of the fourth beam of fundamental frequency light.

4. The all-fiber laser optical path system according to claim 1, characterized in that: The central wavelength of the first fiber laser seed source and the second fiber laser seed source is 1560nm, the laser line width is 2kHz, the output power is 40mW, the polarization degree is better than 20dB, the fast frequency tuning bandwidth is 5kHz, and the fast frequency tuning range is 3GHz.

5. The all-fiber laser optical path system according to claim 1, characterized in that: The central operating wavelength of the first optical fiber amplifier and the second optical fiber amplifier is 1560nm, the incident seed power is 1mW, the maximum output power is 5W, the operating mode is continuous light, and the output relative intensity noise is less than 1%.

6. The all-fiber laser optical path system according to claim 1, characterized in that: The input light wavelength of the first optical fiber frequency doubling waveguide and the second optical fiber frequency doubling waveguide is 1560nm, the doubled light wavelength is 780nm, the input power is 5W, the maximum output power is 2W, and the temperature tuning range is 20-70°C.

7. The all-fiber laser optical path system according to claim 2, characterized in that: The first fiber beam splitter is a 1560nm high-power fiber beam splitter with a power damage threshold of 5W, the second fiber beam splitter and the third fiber beam splitter are 1560nm low-power fiber beam splitter with a power damage threshold of 500mW, and the fourth fiber beam splitter is a 780nm high-power fiber beam splitter with a power damage threshold of 2W.

8. The all-fiber laser optical path system according to claim 1, characterized in that: The first optical fiber combiner and the second optical fiber combiner are 1560nm low-power optical fiber combiners, and the power damage threshold is 500mW.

9. The all-fiber laser optical path system according to claim 2, characterized in that: The first fiber acousto-optic modulator is a 780nm variable frequency fiber acousto-optic frequency shifter with a shift frequency of 100 to 250MHz; the second fiber acousto-optic modulator is a 1550nm fixed frequency fiber acousto-optic frequency shifter with a shift frequency range of -1200 MHz; the third fiber acousto-optic modulator is a 780nm fixed frequency fiber acousto-optic frequency shifter with a shift frequency of -100 MHz; the fourth fiber acousto-optic modulator is a 780nm fixed frequency fiber acousto-optic frequency shifter with a shift frequency of 200MHz.

10. The all-fiber laser optical path system according to claim 1, characterized in that: The fiber optical switch is a silicon-based high-speed optical switch with a switching speed of about 0.3uS; the photodetector is a broadband InGaAs photodetector with a bandwidth of 10GHz.

Images