Optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilized laser and preparation method thereof

文档序号:1507717 发布日期:2020-02-07 浏览:15次 中文

阅读说明:本技术 基于调制转移谱稳频激光的光抽运铷原子钟及其制备方法 (Optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilized laser and preparation method thereof ) 是由 陈景标 刘天宇 潘多 于 2019-10-11 设计创作,主要内容包括:本发明公布了一种基于调制转移谱稳频激光的光抽运铷原子钟及其制备方法,包括窄线宽激光器、扩束器、半波片、偏振分光棱镜、相位调制器、用于激光稳频的铷原子泡、高速光电探测器、混频器、高速伺服反馈电路、射频信号源、激光驱动电源、凸透镜、声光调制器、用于获得钟跃迁谱线的铷原子泡、晶振频综和控制电路部分;由射频信号源产生调制信号,输入相位调制器对泵浦激光进行相位调制,同时产生解调信号与来自光电探测器的信号进行混频解调,得到误差信号,再经高速伺服反馈电路控制激光驱动电源,实现基于调制转移谱的高稳定度窄线宽激光。将稳频后的激光作为光抽运铷原子钟的抽运激光,得到高性能的光抽运铷原子钟。(The invention discloses an optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilization laser and a preparation method thereof, wherein the optical pumping rubidium atomic clock comprises a narrow line width laser, a beam expander, a half-wave plate, a polarization beam splitter prism, a phase modulator, a rubidium atomic bubble for laser frequency stabilization, a high-speed photoelectric detector, a frequency mixer, a high-speed servo feedback circuit, a radio frequency signal source, a laser driving power supply, a convex lens, an acousto-optic modulator, a rubidium atomic bubble for obtaining a clock transition spectral line, a crystal oscillator frequency synthesizer and a control circuit part; a radio frequency signal source generates a modulation signal, the modulation signal is input into a phase modulator to carry out phase modulation on pump laser, meanwhile, a demodulation signal is generated to carry out frequency mixing demodulation with a signal from a photoelectric detector to obtain an error signal, and then a high-speed servo feedback circuit controls a laser driving power supply to realize high-stability narrow-linewidth laser based on modulation transfer spectrum. And taking the frequency-stabilized laser as pumping laser of the optical pumping rubidium atomic clock to obtain the high-performance optical pumping rubidium atomic clock.)

1. An optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilized laser is characterized in that,

the optically pumped rubidium atomic clock comprises: the device comprises a narrow-line-width laser, a light spot beam expander, a first half-wave plate, a second half-wave plate, a third half-wave plate, a fourth half-wave plate, a first polarization splitting prism, a second polarization splitting prism, a third polarization splitting prism, a phase modulator, a rubidium atom bubble for laser frequency stabilization, a high-speed photoelectric detector, a frequency mixer, a high-speed servo feedback circuit, a radio frequency signal source, a laser driving power supply, an acousto-optic modulator, a rubidium atom bubble for obtaining a clock transition spectral line, a crystal oscillator frequency synthesizer and a control circuit part; the rubidium atomic bubble for laser frequency stabilization comprises a heat-preservation magnetic shielding material; the rubidium atomic bubble for obtaining the clock transition spectral line comprises a heat-preservation magnetic shielding material and a microwave cavity;

the narrow-linewidth laser is connected with a first light spot beam expander, and the first light spot beam expander is sequentially connected with a first half-wave plate and a first polarization splitting prism; then dividing the optical path into two paths, wherein one path is a laser frequency stabilizing optical path, and the other path is used for obtaining a clock transition spectral line optical path;

after the laser used for the laser frequency stabilization light path is sequentially connected with the second half-wave plate and the second polarization beam splitting prism, the laser is divided into two paths with different light intensities:

the path with stronger light intensity is connected with a third half-wave plate and then connected with a phase modulator, the phase modulator is connected with a radio frequency signal source, then connected with a fourth half-wave plate and a third polarization splitting prism, and then connected with a rubidium atom bubble for laser frequency stabilization; the detection light with weaker light intensity enters the high-speed photoelectric detector through the rubidium atomic bubble for laser frequency stabilization, and the frequency mixer is connected with a radio frequency signal source; the high-speed photoelectric detector is sequentially connected with the frequency mixer, the high-speed servo feedback circuit and the laser driving power supply to complete the laser frequency stabilizing system;

the laser used for obtaining the optical path of the clock transition spectral line is connected with the acousto-optic modulator, enters the rubidium atomic bubble used for obtaining the clock transition spectral line for pumping, and then is detected by the photoelectric detector to obtain the clock transition spectral line, and the rubidium atomic bubble used for obtaining the clock transition spectral line is connected with the crystal oscillation frequency synthesizer and the control circuit part;

the optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser generates a modulation signal by the radio frequency signal source, the modulation signal is input into the phase modulator to perform phase modulation on the pumping laser, meanwhile, a demodulation signal is generated, and the demodulation signal and a signal from the photoelectric detector are subjected to frequency mixing demodulation in the frequency mixer to obtain an error signal, and then a laser driving power supply is controlled by the high-speed servo feedback circuit, so that the high-stability narrow-linewidth pumping laser based on the modulation transfer spectrum frequency stabilization is realized; the frequency-stabilized narrow linewidth laser passes through an acousto-optic modulator and then is driven into a rubidium atom bubble for obtaining a clock transition spectral line for pumping, a microwave signal is fed into a microwave resonant cavity to excite rubidium atoms, a laser signal transmitted from the rubidium atom bubble for obtaining the clock transition spectral line is detected through a photoelectric detector to obtain the clock transition spectral line, the clock transition spectral line is modulated and demodulated, the crystal oscillator frequency is fed back and controlled, and the optical pumping rubidium atom clock based on the modulation transfer spectrum frequency-stabilized laser is realized.

2. The optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser as claimed in claim 1, wherein when the optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser works, the narrow linewidth laser emits the narrow linewidth laser, after the light spot is expanded by the first light spot beam expander, the first half wave plate and the first polarization splitting prism are used for matching and adjusting the splitting power and dividing the laser into two beams, one beam is used for a laser frequency stabilization light path, and the other beam is used for obtaining a rubidium atomic bubble light path of the clock transition spectral line.

3. The optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser as claimed in claim 2, wherein the laser used for the laser frequency stabilization light path is divided into two beams with different light intensity by a second half-wave plate and a second polarization beam splitter prism, and one beam with stronger light intensity is modulated by a phase modulator and then irradiates into a rubidium atomic bubble used for laser frequency stabilization; one beam with weak light intensity interacts with rubidium atoms in a rubidium atom bubble for laser frequency stabilization and then is received by high-speed photoelectric detection, signals of the high-speed photoelectric detector are modulated and demodulated to obtain error signals, and a laser driving power supply is controlled through a high-speed servo feedback circuit, so that high-stability narrow-linewidth laser is realized.

4. The optically pumped rubidium atomic clock based on the modulation transfer spectrum frequency stabilized laser as claimed in claim 3, wherein the laser is frequency shifted through an acousto-optic modulator and is pumped into a rubidium atomic bubble for obtaining clock transition spectral line.

5. The optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilized laser as the claim 4, wherein microwave signals are fed into the microwave resonant cavity to excite rubidium atoms which are subjected to the pumping light action, and clock transition spectral lines are obtained through the microwave signal action; and modulating and demodulating the clock transition spectral line and controlling the crystal oscillator in a feedback manner to obtain the high-stability optical pumping rubidium atomic clock signal output.

6. The optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilized laser as the claim 1, wherein the polarization direction of the pump light is adjusted through a third half-wave plate, so that the polarization direction of the pump light is consistent with the direction of a main shaft of a phase modulation crystal; the fourth half-wave plate is used for adjusting the polarization direction of the pump light, so that the pump light is completely reflected into the atomic bubble through the third polarization splitting prism.

7. The optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilized laser as the claim 1, wherein a radio frequency signal source simultaneously generates a modulation signal and a demodulation signal, the modulation signal is input into a phase modulator, the demodulation signal is input into a frequency mixer to be mixed with a signal from a high-speed photoelectric detector to obtain an error signal, and a high-speed servo feedback circuit feeds back the error signal to a laser driving power supply and a fast feedback port and a slow feedback port of a laser to realize high-speed full-bandwidth locking of laser frequency.

8. The optically pumped rubidium atomic clock based on modulation transfer spectrum frequency stabilized laser as claimed in claim 1, wherein the narrow linewidth laser is a narrow linewidth interference filter external cavity semiconductor laser, or other narrow linewidth laser; and/or the presence of a gas in the gas,

the laser driving power supply, the radio frequency signal source, the rubidium atomic bubble temperature control circuit, the high-speed servo feedback circuit, the crystal oscillator frequency synthesis circuit and the control circuit are respectively discrete circuit devices or integrated circuit devices; and/or the presence of a gas in the gas,

the facula beam expander is a facula beam expander formed by combining discrete concave-convex lenses or a beam expander formed by combining concave-convex lenses.

9. A preparation method of an optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilization laser is characterized by comprising the following steps:

1) the laser device emits narrow-linewidth laser, after a light spot is expanded by the first light spot beam expander, the first half-wave plate and the first polarization beam splitter prism are matched to adjust the beam splitting power and divide the laser into two beams, one beam is used for a laser frequency stabilizing light path, and the other beam is used for obtaining a clock transition spectral line light path;

2) the laser used for the laser frequency stabilization light path is divided into two beams with different light intensities by a second half-wave plate and a second polarization beam splitter prism, one beam with stronger light intensity is used as pumping laser, one beam with weaker light intensity is used as detection laser, the two beams of laser are reversely superposed and interact with rubidium atomic bubbles used for laser frequency stabilization, and a high-speed photoelectric detector receives the detection laser;

3) a radio frequency signal source generates a modulation signal, the modulation signal is input into a phase modulator to carry out phase modulation on the pump laser, and simultaneously, a demodulation signal is generated and is subjected to frequency mixing demodulation in a frequency mixer together with a signal from a photoelectric detector to obtain an error signal;

4) the generated error signal is fed back to a laser driving power supply and a fast feedback port and a slow feedback port of a laser through a high-speed servo feedback circuit, so that high-speed full-bandwidth locking of laser frequency is realized;

5) pumping the frequency stabilized narrow linewidth laser into rubidium atomic bubbles for obtaining clock transition spectral lines after passing through an acousto-optic modulator;

6) microwave signals are fed into a microwave resonant cavity to excite rubidium atoms, laser signals transmitted from rubidium atom bubbles for obtaining clock transition spectral lines are detected through a photoelectric detector, the clock transition spectral lines are obtained, the clock transition spectral lines are modulated and demodulated, and the crystal oscillator frequency is fed back and controlled, so that the optical pumping rubidium atom clock based on modulation transfer spectrum frequency stabilization lasers is realized.

Technical Field

The invention belongs to the technical field of microwave atomic clocks and microwave quantum frequency standards, and adopts high-performance narrow linewidth lasers for modulating, transferring and stabilizing frequency as pumping lasers and detection lasers of an optically pumped rubidium atomic clock so as to realize the optically pumped rubidium atomic clock with high performance.

Background

Although the rubidium atomic frequency standard can only be a secondary frequency standard, the quantum part of the rubidium atomic frequency standard has a very simple structure, is convenient for manufacturing and mass production, is convenient for miniaturization and low in price, and therefore, the rubidium atomic frequency standard can only be used as the secondary frequency standard but has wide application. The frequency stability is the most important index for measuring the performance of the atomic clock, so the frequency stability of the optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser is also one of the most important indexes, wherein the frequency stability of the optical pumping rubidium atomic clock is determined by the performance of the pumping laser and the performance of the detection laser to a great extent, and therefore the indexes of the rubidium atomic clock can be greatly improved by improving the performance of the pumping laser and the performance of the detection laser.

At present, a laser with a wider line width is adopted internationally, and frequency stabilization technologies such as a saturated absorption spectrum or a polarization spectrum are combined, the laser after frequency stabilization is used as pumping laser and detection laser of a laser pumping rubidium atomic clock, but the laser with the wider line width can introduce frequency noise to a clock system, and the improvement of the signal to noise ratio of clock transition spectral lines is restricted. In addition, the saturation spectrum frequency stabilization technique usually needs to perform internal modulation on the laser, which also introduces additional frequency noise, and the stability of the frequency stabilized laser is limited by the bandwidth of the feedback loop; the polarization spectrum frequency stabilization technology has the problem that a locking reference zero point changes along with parameters such as optical power and the like, and is limited by the bandwidth of a feedback loop; therefore, the stability index of the laser pumping rubidium atomic clock is limited to be further improved by the commonly adopted laser and frequency stabilization technology at present.

Disclosure of Invention

In order to break through the bottleneck that the signal-to-noise ratio and stability of a laser pumping rubidium atomic clock are limited by the line width and stability of laser, the invention adopts narrow-line-width laser based on modulation transfer spectrum frequency stabilization as the pumping laser of an optical pumping rubidium atomic clock so as to improve the signal-to-noise ratio of a clock transition spectral line, thereby realizing the optical pumping rubidium atomic clock with high stability and high performance, and further providing a preparation method of the optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser.

The invention provides an optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilized laser. Modulation transfer spectroscopy is an external laser modulation spectroscopy technique that transfers a signal from a modulated beam to another unmodulated beam by four-wave mixing through a nonlinear medium. Because the modulation transfer spectrum has the characteristic of high signal-to-noise ratio, compared with frequency stabilization technologies such as a saturated absorption spectrum or a polarization spectrum, the laser frequency noise can be better reduced. The laser after frequency stabilization is used as the pumping laser of the optical pumping rubidium atomic clock, and the bottleneck that the signal-to-noise ratio and the stability of the optical pumping rubidium atomic clock are limited by the line width and the stability of the laser can be broken through.

In the invention, the pump laser based on the modulation transfer spectrum is realized by generating a modulation signal by a radio frequency signal source, inputting the modulation signal into a phase modulator to perform phase modulation on the pump laser, and simultaneously generating a demodulation signal and performing frequency mixing demodulation on the demodulation signal and a signal from a photoelectric detector in a frequency mixer to obtain an error signal.

The invention provides an optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilized laser, which comprises: the device comprises a narrow line width laser, a light spot beam expander, a first half wave plate, a second half wave plate, a third half wave plate, a fourth half wave plate, a first polarization splitting prism, a second polarization splitting prism, a third polarization splitting prism, a phase modulator, a rubidium atom bubble (containing heat preservation magnetic shielding materials) for laser frequency stabilization, a high-speed photoelectric detector, a frequency mixer, a high-speed servo feedback circuit, a radio frequency signal source, a laser driving power supply, an acousto-optic modulator, a rubidium atom bubble (containing heat preservation magnetic shielding materials and a microwave cavity) for obtaining a clock transition spectral line, a crystal oscillator frequency synthesizer and a control circuit part.

The narrow-linewidth laser is connected with a first light spot beam expander, and the first light spot beam expander is sequentially connected with a first half-wave plate and a first polarization splitting prism; then dividing the optical path into two paths, wherein one path is used as a laser frequency stabilizing optical path, and the other path is used for obtaining a clock transition spectral line optical path. The laser used for the laser frequency stabilization light path is sequentially connected with a second half-wave plate and a second polarization beam splitter prism and is divided into two paths with unequal light intensity, one path with stronger light intensity is connected with a third half-wave plate and then connected with a phase modulator, the phase modulator is connected with a radio frequency signal source, then connected with a fourth half-wave plate and a third polarization beam splitter prism, and then connected with a rubidium atom bubble used for laser frequency stabilization, detection light with weaker light intensity enters a high-speed photoelectric detector through the atom bubble, and a frequency mixer is connected with the radio frequency signal source. Then the high-speed photoelectric detector is sequentially connected with a mixer, a high-speed servo feedback circuit and a laser driving power supply to complete the laser frequency stabilizing system. And the other path of laser used for obtaining the clock transition spectral line is connected with an acousto-optic modulator, enters a rubidium atom bubble (comprising a heat-preservation magnetic shielding material and a microwave cavity) used for obtaining the clock transition spectral line for pumping, is detected by a photoelectric detector to obtain the clock transition spectral line, and is connected with a crystal oscillation frequency synthesizer and a control circuit part.

When the optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser works, the narrow-linewidth laser emits narrow-linewidth laser, light spots are expanded through the first light spot beam expander, the first half wave plate and the first polarization splitting prism are matched to adjust splitting power and divide the laser into two beams, one beam is used for a laser frequency stabilization light path, and the other beam is used for obtaining a rubidium atomic bubble light path of a clock transition spectral line. The laser used for the laser frequency stabilization light path is divided into two beams with unequal light intensity by the second half-wave plate and the second polarization beam splitter prism, one beam with stronger light intensity is modulated by the phase modulator and then irradiates into the rubidium atom bubble for laser frequency stabilization, one beam with weaker light intensity is interacted with the rubidium atom in the rubidium atom bubble for laser frequency stabilization and then is received by high-speed photoelectric detection, the signal of the high-speed photoelectric detector is modulated and demodulated to obtain an error signal, and the laser driving power supply is controlled by the high-speed servo feedback circuit, so that the high-stability narrow-linewidth laser is realized.

And the other laser for obtaining the clock transition spectral line is connected with an acousto-optic modulator to shift frequency, a rubidium atom bubble (comprising a heat-preservation magnetic shielding material and a microwave cavity) for obtaining the clock transition spectral line is driven to pump, a microwave signal is fed into the microwave resonant cavity to excite rubidium atoms under the action of pumping light, the clock transition spectral line is obtained under the action of the microwave signal and is detected by a photoelectric detector, the clock transition spectral line is modulated and demodulated and fed back to control a crystal oscillator, and therefore high-stability clock signal output is obtained, and the optical pumping rubidium atomic clock based on the modulation transition spectrum frequency stabilization laser is realized.

Further, the third half-wave plate is used for adjusting the polarization direction of the pump light to be consistent with the direction of the main axis of the phase modulation crystal so as to reduce the influence of residual amplitude modulation. The fourth half-wave plate is used for adjusting the polarization direction of the pump light, so that the pump light is completely reflected into the atomic bubble through the third polarization splitting prism.

Further, a radio frequency signal source simultaneously generates a modulation signal and a demodulation signal, the modulation signal is input into the phase modulator, the demodulation signal is input into the frequency mixer to be mixed with a signal from the high-speed photoelectric detector to obtain an error signal, and the high-speed servo feedback circuit feeds back the error signal to the laser driving power supply and the fast feedback port and the slow feedback port of the laser to realize high-speed full-bandwidth locking of laser frequency.

The narrow linewidth laser can be a narrow linewidth interference filter external cavity semiconductor laser, and can also be other narrow linewidth lasers.

The laser driving power supply, the radio frequency signal source, the rubidium atomic bubble temperature control circuit, the high-speed servo feedback circuit and the crystal oscillator frequency synthesis and control circuit can be discrete circuit devices and can also be integrated circuit devices.

The facula beam expander can be a facula beam expander formed by combining discrete concave-convex lenses and can also be a beam expander formed by combining concave-convex lenses.

The invention also aims to provide a preparation method of the optically pumped rubidium atomic clock based on the modulated transfer spectrum frequency stabilized laser.

The invention relates to a method for realizing an optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilized laser, which specifically comprises the following steps:

1) the laser emits narrow-linewidth laser, after a light spot is expanded by the first light spot beam expander, the first half-wave plate and the first polarization beam splitter prism are matched to adjust the beam splitting power and divide the laser into two beams, one beam is used for a laser frequency stabilizing light path, and the other beam is used for obtaining a clock transition spectral line light path;

2) the laser used for the laser frequency stabilization light path is divided into two beams with different light intensities by a second half-wave plate and a second polarization beam splitter prism, one beam with stronger light intensity is used as pumping laser, one beam with weaker light intensity is used as detection laser, the two beams of laser are reversely superposed and interact with rubidium atomic bubbles used for laser frequency stabilization, and a high-speed photoelectric detector receives the detection laser;

3) a radio frequency signal source generates a modulation signal, the modulation signal is input into a phase modulator to carry out phase modulation on the pump laser, and simultaneously, a demodulation signal is generated and is subjected to frequency mixing demodulation in a frequency mixer together with a signal from a photoelectric detector to obtain an error signal;

4) the generated error signal is fed back to a laser driving power supply and a fast feedback port and a slow feedback port of a laser through a high-speed servo feedback circuit, so that high-speed full-bandwidth locking of laser frequency is realized;

5) pumping the frequency stabilized narrow linewidth laser into rubidium atomic bubbles for obtaining clock transition spectral lines after passing through an acousto-optic modulator;

6) microwave signals are fed into a microwave resonant cavity to excite rubidium atoms, laser signals transmitted from rubidium atom bubbles for obtaining clock transition spectral lines are detected through a photoelectric detector, the clock transition spectral lines are obtained, the clock transition spectral lines are modulated and demodulated, the crystal oscillator frequency is fed back and controlled, and the optical pumping rubidium atom clock based on modulation transfer spectrum frequency stabilization lasers is achieved;

in step 1), the laser may be a narrow linewidth interference filter external cavity semiconductor laser.

In the step 2), the rubidium atomic bubble is used for laser frequency stabilization and clock transition signal obtaining, the heating material can be a heating sheet, and high-precision temperature control is realized by driving of an external temperature control circuit.

The invention has the advantages of special technology and performance:

the invention innovatively applies narrow linewidth laser for modulating, transferring and stabilizing spectrum frequency to an optical pumping rubidium atomic clock as pumping laser and detection laser, combines the advantages of high stability and narrow linewidth of the modulating, transferring and spectrum stabilizing laser based on narrow linewidth interference filter external cavity semiconductor laser technology, modulating, transferring spectrum frequency stabilizing technology and rapid phase modulation feedback technology, and improves the signal-to-noise ratio of the clock transition spectral line of the optical pumping rubidium atomic clock by several times or even orders of magnitude, thereby improving the clock stability close to the orders of magnitude and being expected to become the laser pumping rubidium atomic clock with the best stability index in the world. The invention can break through the bottleneck that the optical pumping rubidium atomic clock is limited by the line width and the stability of the frequency stabilized laser, and obviously improves the signal-to-noise ratio of the clock transition spectral line and the clock stability, thereby realizing the high-performance optical pumping rubidium atomic clock.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of an optically pumped rubidium atomic clock based on modulation transfer spectrum frequency stabilization according to the present invention;

wherein: 1-narrow line width external cavity semiconductor laser, 2-facula beam expander, 3-first half wave plate, 4-first polarization beam splitter prism, 5-second half wave plate, 6-second polarization beam splitter prism, 7-third half wave plate, 8-phase modulator, 9-fourth half wave plate, 10-rubidium atom bubble (containing heat preservation magnetic shielding material) for laser frequency stabilization, 11-third polarization beam splitter prism, 12-high speed photoelectric detector, 13-mixer, 14-high speed servo feedback circuit, 15-radio frequency signal source, 16-laser driving power supply, 17-acousto-optic modulator, 18-rubidium atom bubble (containing heat preservation magnetic shielding material and microwave cavity) for obtaining clock transition spectral line, 19-photoelectric detector, 20-crystal oscillation frequency comprehensive and control circuit part; wherein the solid line is the light path portion and the dashed line portion is the circuit portion.

Detailed Description

The invention will be further elucidated by means of specific embodiments in the following with reference to the drawing.

Referring to fig. 1, the optical pumping rubidium atomic clock based on modulation transfer spectrum frequency stabilization of the embodiment includes: the device comprises a narrow-line-width laser 1, a light spot beam expander 2, a first half-wave plate 3, a second half-wave plate 5, a third half-wave plate 7, a fourth half-wave plate 9, a first polarization splitting prism 4, a second polarization splitting prism 6, a third polarization splitting prism 11, a phase modulator 8, a rubidium atom bubble (containing heat-preservation magnetic shielding materials) 10 for laser frequency stabilization, a high-speed photoelectric detector 12, a mixer 13, a high-speed servo feedback circuit 14, a radio frequency signal source 15, a laser driving power supply 16, an acousto-optic modulator 17, a rubidium atom bubble (containing heat-preservation magnetic shielding materials and a microwave cavity) 18 for obtaining a clock transition spectral line, a photoelectric detector 19 and a crystal oscillation frequency synthesis and control circuit part 20. Narrow linewidth laser is emitted by a narrow linewidth laser 1, after a light spot is expanded by a first light spot beam expander 2, the light splitting power is adjusted by matching of a first half-wave plate 3 and a first polarization beam splitter prism 4, the laser is divided into two beams, one beam is used for a laser frequency stabilizing light path, and the other beam is used for obtaining rubidium atomic bubbles of a clock transition spectral line. The laser used for the laser frequency stabilization light path is divided into two beams with different light intensities by a second half-wave plate 5 and a second polarization beam splitter prism 6, one beam with stronger light intensity is subjected to phase modulation by a phase modulator 8 and then interacts with rubidium atoms in a rubidium atom bubble (containing a heat preservation magnetic shielding material) 10 used for laser frequency stabilization, a modulation signal is generated by a radio frequency signal source 15, and one beam with weaker light intensity and the rubidium atoms interact and then is received by a high-speed photoelectric detection 12. The third half-wave plate 7 is used for adjusting the polarization direction of the pump light to be consistent with the direction of the main axis of the phase modulator 8, and the fourth half-wave plate 9 is used for adjusting the polarization direction of the pump light to be completely reflected into the rubidium atomic bubble 10 through the third polarization splitting prism 11. The detector signal is input into the mixer 13, the demodulated signal is generated by the radio frequency signal source 15 to obtain an error signal, and the high-speed servo feedback circuit 14 controls the laser driving power supply 16 to realize the high-stability narrow-linewidth laser.

The other path of frequency stabilized laser is connected with an acousto-optic modulator 17 for frequency shift, a rubidium atom bubble (comprising a heat preservation magnetic shielding material and a microwave cavity) 18 for obtaining a clock transition spectral line is injected for pumping rubidium atoms, a microwave signal generated in a crystal oscillation frequency synthesis and control circuit part 20 is fed in through a microwave resonant cavity to excite the rubidium atoms subjected to the action of pumping light, the frequency of the microwave cavity is adjusted to a standard frequency, the obtained clock transition spectral line is detected through a photoelectric detector 19, then modulation and demodulation are carried out on a crystal oscillation frequency synthesis and control circuit part 20, and a high-stability clock signal is obtained and output, so that the optical pumping rubidium atom clock based on the modulation transfer spectrum frequency stabilized laser is realized.

The optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser in the embodiment of the invention specifically adopts a narrow linewidth laser, and combines a modulation transfer frequency stabilization technology and a rapid phase modulation feedback technology, and the optical pumping rubidium atomic clock based on the modulation transfer spectrum frequency stabilization laser has essential difference from the existing laser pumping rubidium atomic clock adopting a wide linewidth laser and a laser frequency stabilization feedback technology under the condition.

Finally, it is noted that the disclosed embodiments are intended to aid in further understanding of the invention, but those skilled in the art will appreciate that: various substitutions and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the invention should not be limited to the embodiments disclosed, but the scope of the invention is defined by the appended claims.

8页详细技术资料下载
上一篇:一种医用注射器针头装配设备
下一篇:一种偏脊结构带有焊线图形的半导体激光器的制备方法

网友询问留言

已有0条留言

还没有人留言评论。精彩留言会获得点赞!

精彩留言,会给你点赞!

技术分类