CN213581763U

CN213581763U - Annular space cavity for small laser pumping rubidium clock

Info

Publication number: CN213581763U
Application number: CN202022053468.0U
Authority: CN
Inventors: 张首刚; 郝强; 阮军
Original assignee: National Time Service Center of CAS
Current assignee: National Time Service Center of CAS
Priority date: 2020-09-18
Filing date: 2020-09-18
Publication date: 2021-06-29
Anticipated expiration: 2030-09-18

Abstract

The utility model provides an annular space chamber for small-size laser pumping rubidium clock, fixes the annular electrode in chamber bobbin base portion, and chamber bobbin base portion central point puts and is provided with logical unthreaded hole, fills ceramic ring between chamber bobbin and the annular electrode, and it has the rubidium bubble to paste in the annular electrode, and upper portion is provided with loop antenna in the chamber bobbin, and chamber bobbin top and end cover welding, end cover central point put and have processed logical unthreaded hole, and wherein, the annular electrode comprises 2 independent arc pole pieces of group. The microwave cavity is internally provided with only one glass bulb, and each part fixes parts in modes of pins, welding and the like, so that the use of screws is avoided, and the microwave cavity has the advantages of small volume, low cost, high directional factor and the like, and also has mechanical stretching resistance and impact resistance.

Description

Annular space cavity for small laser pumping rubidium clock

Technical Field

The utility model belongs to the technical field of microwave atomic clock, concretely relates to a ring gap chamber that is used for small-size laser pumping rubidium clock.

Background

Compared with atomic clocks such as hydrogen clocks and cesium clocks, rubidium clocks have the advantages of being small in size, low in power consumption and the like, and are widely applied to communication systems, electric power systems, vehicle-mounted autonomous navigation systems and the like. The rubidium spectrum lamp is used as a light source of a traditional rubidium clock, and has the advantages of high technical maturity, low cost, small size and the like, but due to the fact that spectral components of the rubidium spectrum lamp are complex, an isotope filtering technology is needed in an atomic state preparation process, and a spectral line from a rubidium atomic ground state F to a first excited state is filtered. By using the laser to replace a rubidium spectrum lamp, the line width of the light source can be reduced from a GHz level to a MHz level, and a filter bulb is not needed any more.

The microwave cavity is a core component of the rubidium clock, and on one hand, the microwave cavity plays a role in storing microwaves so as to reduce the loss of microwave energy of the rubidium atomic clock; on the other hand, the microwave field in the microwave cavity can form an ideal resonant mode, with the magnetic field component oriented parallel to the quantization axis, to excite atoms to produce a clock transition signal. The spectrum lamp pumps the microwave cavity of rubidium clock and the laser pumps the difference of rubidium clock. Due to the existence of the filter gun, a spectrum lamp pumping rubidium clock generally places a filter bulb in a microwave cavity; and the laser pumping rubidium clock does not need to use a filter gun, so that the microwave cavity volume can be designed to be smaller. Miniaturization of the microwave cavity has long been a difficulty in designing a compact laser pumping rubidium clock. In 2014, a ring Gap Cavity with a volume of only 1mL and a direction factor of 0.7 is reported in documents (M Violetti, M Pellaton, C Affloderbach, F Merli, The Microloop-Gap reactor: A Novel miniature Microwave Cavity for Double-response radial locks, IEEE Sensors Journal,2014,14(9): 3193:3200), and The Microwave Cavity consists of three layers of ring strip lines and has The problems of difficult debugging, poor mechanical properties and The like.

Disclosure of Invention

The utility model aims to solve the technical problem that overcome above-mentioned prior art not enough, provide a volume only for 2mL, anti-vibration, easily harmonious ring gap chamber that is used for small-size laser pumping rubidium clock.

The technical scheme for solving the technical problems is as follows: an annular space cavity for a mini laser pumping rubidium clock is characterized in that an annular electrode is arranged at the bottom in a cavity cylinder, a light through hole is machined in the center of the bottom of the cavity cylinder, a ceramic ring is arranged between the cavity cylinder and the annular electrode, rubidium bubbles are pasted in the annular electrode, an annular antenna is arranged on the upper portion in the cavity cylinder, an end cover is arranged at the top of the cavity cylinder, and the light through hole is machined in the center of the end cover.

The utility model discloses a chamber section of thick bamboo does: the upper side wall of the cavity cylinder wall is provided with a coaxial line hole, the coaxial line extends into the cavity cylinder wall through the coaxial line hole to feed a signal into the annular antenna, the bottom of the cavity cylinder wall is provided with a light through hole, and pin holes are symmetrically formed in two sides of the light through hole in the bottom of the cavity cylinder wall.

The utility model discloses a ring electrode comprises 2 arc pole pieces of group, and the bottom integrated into one piece of arc pole piece has the pin, and the pin inserts in the pin hole.

The utility model discloses a 2 have 0.4 ~ 1.2 mm's interval between the group's arc pole piece.

The utility model discloses a rubidium bubble is the hollow cylinder structure of alkali-resistant glass preparation, and the up end of rubidium bubble is provided with the bubble tail for the storage⁸⁷Rb Metal, Rb bubble filled with a mixed buffer gas of argon and nitrogen, wherein P_Ar/P_N2＝1.3:1。

The utility model discloses an end cover, a chamber section of thick bamboo, ceramic ring, ring electrode, rubidium bubble set up with one heart.

Compared with the prior art, the utility model has the following advantages:

1. the utility model discloses an annular space chamber that microwave pottery was filled, with the help of microwave pottery's high dielectric constant and the inherent appearance of annular space chamber feel the structure, not only realized the microwave cavity of 2mL volume, the resonant mode in this microwave cavity is class TE moreover₀₁₁And the mode ensures that the magnetic field component of the microwave field has better directional characteristic.

2. The utility model discloses a ring electrode constitute by two mutually independent arc-shaped pole pieces, fix arc-shaped pole piece in chamber section of thick bamboo wall bottom through pin and pinhole, guaranteed that small-size annular space chamber has better mechanical properties, this processing degree of difficulty and the cost that has not only reduced small-size annular space chamber has also avoided the annular space chamber to use the screw in the course of working to the volume of system has further been reduced.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a schematic structural view of the ring electrode 2 in fig. 1.

Fig. 3 is a schematic structural view of the chamber tube 4 in fig. 1.

FIG. 4 shows the simulation result of the field distribution of the microwave magnetic field component in the annular cavity.

In the figure: 1. rubidium bubbles; 2. a ring electrode; 3. a ceramic ring; 4. a chamber cylinder; 5. a coaxial line; 6. a loop antenna; 7. an end cap; 2-1, arc pole pieces; 2-2, pins; 4-1, a cavity cylinder wall; a. a pin hole; b. a light through hole; c. a coaxial aperture.

Detailed Description

The present invention will be described in further detail with reference to the following drawings and examples, but the present invention is not limited to these examples.

Example 1

In fig. 1-3, the utility model relates to a ring gap chamber for small-size laser pumping rubidium clock, install annular electrode 2 in chamber section of thick bamboo 4 bottom, install loop antenna 6 in chamber section of thick bamboo 4 upper portion, further, chamber section of thick bamboo 4 comprises chamber section of thick bamboo wall 4-1, and the height of chamber section of thick bamboo wall 4-1 is 14mm, and the internal diameter is 12mm, and the external diameter is 14mm, and chamber section of thick bamboo wall 4-1 bottom thickness is 2 mm. The bottom of the cavity barrel wall 4-1 is provided with a light through hole a, two sides of the light through hole a on the bottom of the cavity barrel wall 4-1 are symmetrically provided with pin holes b, the annular electrode 2 is composed of 2 groups of arc-shaped pole pieces 2-1, the bottom of the arc-shaped pole pieces 2-1 is integrally provided with pins 2-2, and the pins 2-2 are inserted into the pin holes b. The interval of 0.4-1.2 mm is arranged between the arc-shaped pole pieces 2-1 of the 2 groups, the height of the arc-shaped pole piece 2-1 is 9mm, the height of the pin 2-2 is 2mm, and the arc-shaped pole piece 2-1 and the pin 2-2 are integrally processed to enhance the mechanical impact resistance of the system.

A coaxial line hole c is processed on the upper side wall of the cavity cylinder wall 4-1, a coaxial line 6 extends into the cavity cylinder wall 4-1 through the coaxial line hole c to feed microwave signals into the annular antenna 6, and the microwave signals enter the annular space cavity under the action of the annular antenna 6. A ceramic ring 3 is arranged between the cavity tube 4 and the annular electrode 2, the inner diameter of the ceramic ring is 10mm, the outer diameter of the ceramic ring is 12mm, and the height of the ceramic ring is 9 mm. The annular space cavity filled with the microwave ceramic has smaller volume, better field directionality and stronger mechanical impact resistance. The annular electrode 2 is internally stuck withRubidium bubble 1, rubidium bubble 1 is hollow cylindrical structure made of alkali-resistant glass, and has outer diameter of 8mm, bubble wall thickness of 0.6mm, outer height of 7mm, and inner part filled with mixed buffer gas of argon and nitrogen, wherein P_Ar/P_N21.3: 1. The upper end surface of the rubidium bulb 1 is provided with a bulb tail with the height of 1.5mm and is used for storage⁸⁷Rb Metal. An end cover 7 is welded and fixed on the top of the cavity barrel 4, the thickness of the end cover is 2mm, the outer diameter of the end cover is 14mm, and a light through hole with the diameter of 5mm is machined in the center of the end cover 7.

In order to ensure the accuracy of the whole device, the end cover 7, the cavity tube 4, the ceramic ring 3, the ring electrode 2 and the rubidium bubble 1 are concentrically arranged, and the ring electrode 2, the cavity tube 4 and the end cover 7 are all made of brass materials.

As can be seen from the simulation result of the field distribution of the microwave magnetic field component in the annular cavity in FIG. 4, the magnetic field component has better directivity, and the resonant mode of the microwave cavity at 6.835GHz is TE₀₁₁Mode(s). Further, by software, the field direction factor is calculated to be 0.7, so that the utilization rate of rubidium atoms in the rubidium bulb 1 is improved, and the performance of a laser pumping rubidium clock is improved.

Claims

1. An annular gap cavity for a compact laser pumped rubidium clock, characterized by: the annular electrode (2) is arranged at the bottom in the cavity barrel (4), the light through hole (a) is formed in the center of the bottom of the cavity barrel (4), the ceramic ring (3) is arranged between the cavity barrel (4) and the annular electrode (2), the rubidium bubble (1) is adhered in the annular electrode (2), the annular antenna (6) is arranged on the upper portion in the cavity barrel (4), the end cover (7) is arranged at the top of the cavity barrel (4), and the light through hole is formed in the center of the end cover (7).

2. An annular gap cavity for a compact laser pumping rubidium clock according to claim 1, characterized in that the cavity tube (4) is: a coaxial line hole (c) is machined in the side wall of the upper portion of the cavity cylinder wall (4-1), a coaxial line (5) extends into the cavity cylinder wall (4-1) through the coaxial line hole (c) to feed a signal into the annular antenna (6), a light through hole (a) is machined in the bottom of the cavity cylinder wall (4-1), and pin holes (b) are symmetrically machined in the two sides of the light through hole (a) in the bottom of the cavity cylinder wall (4-1).

3. The ring gap cavity for a compact laser pumping rubidium clock of claim 2, wherein: the annular electrode (2) is composed of 2 groups of arc-shaped pole pieces (2-1), pins (2-2) are integrally machined at the bottoms of the arc-shaped pole pieces (2-1), and the pins (2-2) are inserted into the pin holes (b).

4. The annular gap cavity for the compact laser pumping rubidium clock as claimed in claim 3, wherein the 2 groups of arc-shaped pole pieces (2-1) are spaced by 0.4-1.2 mm.

5. The ring gap cavity for a compact laser pumping rubidium clock of claim 1, wherein: the rubidium bubble (1) is of a hollow cylindrical structure made of alkali-resistant glass, and the upper end face of the rubidium bubble is provided with a bubble tail for storage⁸⁷Rb Metal, Rb bubble filled with a mixed buffer gas of argon and nitrogen, wherein P_Ar/P_N2=1.3:1。

6. The ring gap cavity for a compact laser pumping rubidium clock of claim 1, wherein: the end cover (7), the cavity barrel (4), the ceramic ring (3), the annular electrode (2) and the rubidium bubble (1) are arranged concentrically.