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CN-122018105-A - Ultra-low stress ultra-high vacuum optical reference cavity

CN122018105ACN 122018105 ACN122018105 ACN 122018105ACN-122018105-A

Abstract

The invention provides an ultralow-stress ultrahigh-vacuum optical reference cavity, which relates to the technical field of an ultrastable cavity system and comprises a reference cavity substrate, a reflector, a getter component and a vacuumizing sealing component, wherein a resonant channel is arranged in the reference cavity substrate and comprises a first resonant channel and a second resonant channel which are arranged in a crossing way, the first resonant channel and the second resonant channel penetrate through the reference cavity substrate, the two ports of the first resonant channel are respectively provided with the reflector, the getter component is arranged at the first port of the second resonant channel, and the vacuumizing sealing component is arranged at the second port of the second resonant channel. The getter component is used for adsorbing the gas permeated in the resonant channel and maintaining the ultra-high vacuum degree in the resonant channel. The vacuumizing sealing assembly is used for vacuumizing the resonant channel. The inside of the optical reference cavity is made into a closed space, the optical reference cavity can realize long-term ultrahigh vacuum degree, the environment of an external vacuum system is not needed, and the reflector is not polluted by the external environment.

Inventors

  • REN JIEKAI
  • LIU XINGHUA
  • WANG LINHU
  • WANG LIBIN
  • LI ZIXI
  • WANG JIANBO

Assignees

  • 天津集智航宇科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. An ultra-low stress ultra-high vacuum optical reference cavity is characterized by comprising a reference cavity substrate (1), a reflecting mirror (2), a getter component (3) and a vacuumizing sealing component (4); The reference cavity substrate (1) is internally provided with a resonant channel, the resonant channel comprises a first resonant channel (11) and a second resonant channel (12) which are arranged in a crossing way, the first resonant channel (11) and the second resonant channel (12) penetrate through the reference cavity substrate (1), two ports of the first resonant channel (11) are respectively provided with a reflecting mirror (2), the getter component (3) is arranged at a first port (121) of the second resonant channel (12), and the vacuumizing sealing component (4) is arranged at a second port (122) of the second resonant channel (12); The getter assembly (3) comprises a getter flexible base (31) and a getter body (32), the getter flexible base (31) being fixedly connected to the reference cavity base (1) and sealing the first port (121) of the second resonant passage (12); a closed accommodating cavity (33) is formed between the getter flexible base (31) and the reference cavity base (1) in a surrounding manner, and the getter main body (32) is arranged on the getter flexible base (31) and is arranged in the accommodating cavity (33); The getter flexible base (31) comprises a getter base main body (311) and a getter mounting seat (312), wherein the getter base main body (311) is fixedly connected with the reference cavity base body (1), the getter main body (32) is arranged on the getter mounting seat (312), and the getter base main body (311) and the getter mounting seat (312) are flexibly connected through a thin-wall structure; the vacuum pumping sealing assembly (4) comprises a sealing element flexible base (41) and an air pumping sealing element (42), the sealing element flexible base (41) comprises a sealing element base main body (411) and a sealing element mounting seat (412), the sealing element base main body (411) is fixedly connected with the reference cavity base body (1), the air pumping sealing element (42) is mounted on the sealing element mounting seat (412), and the sealing element mounting seat (412) is flexibly connected with the sealing element base main body (411) through a thin-wall structure.
  2. 2. An ultra-low stress ultra-high vacuum optical reference cavity according to claim 1, wherein a connecting hole (413) is formed in the seal mounting seat (412), the connecting hole (413) is communicated with the second port (122) of the reference cavity base body (1), the air extraction seal (42) is fixedly sealed on the seal mounting seat (412), and an air extraction hole (421) communicated with the connecting hole (413) is formed in the air extraction seal (42).
  3. 3. An ultra-low stress ultra-high vacuum optical reference cavity according to claim 2, wherein said pumping seal (42) comprises a mounting chassis (422) and a pumping nozzle (423), said pumping nozzle (423) being arranged on one side of said mounting chassis (422), said pumping hole (421) extending axially through said mounting chassis (422) and said pumping nozzle (423), one end opening being located at an end of said pumping nozzle (423), the other end opening being located on said mounting chassis (422).
  4. 4. An ultra-low stress ultra-high vacuum optical reference cavity according to claim 3, wherein the seal member base body (411) is of a hollow outer frame structure, the seal member mounting seat (412) is arranged in the hollow cavity of the outer frame structure, the seal member mounting seat (412) comprises a side wall and a base, the base is fixedly and hermetically connected with the mounting chassis (422) of the air suction seal member (42), the base is provided with the connecting hole (413), an annular gap is formed between the side wall of the seal member mounting seat (412) and the inner wall of the hollow cavity of the outer frame structure, one end of the side wall is connected with the base, the other end of the side wall extends outwards in a radial direction and is connected with the end face of the seal member base body (411) through the thin-wall structure, and the side wall of the seal member mounting seat (412) is of the thin-wall structure.
  5. 5. The ultra-low stress ultra-high vacuum optical reference cavity according to claim 1, wherein the getter body (32) comprises an annular accommodating shell (321), an annular groove is formed in the surface of the annular accommodating shell (321), and getter active materials (322) are uniformly paved at the bottom of the annular groove; The annular groove opens in an axial direction of the annular accommodating case (321) and towards the first port (121) of the second resonance channel (12), the annular accommodating case (321) being disposed on the getter mount (312).
  6. 6. The ultra-low stress ultra-high vacuum optical reference cavity according to claim 5, wherein the getter mounting base (312) comprises a side plate and a bottom plate, one end of the side plate is flexibly connected with the thin-wall structure of the getter base main body (311), the other end of the side plate is connected with the bottom plate, a fixed column (313) is arranged on the bottom plate, the fixed column (313) extends towards the first port (121) of the second resonant channel (12), and the annular accommodating shell (321) is arranged on the fixed column (313); the side plates, the bottom plate, the getter base body (311), and the reference chamber base (1) of the getter mount (312) collectively surround to form the accommodation chamber (33).
  7. 7. The ultra-low stress ultra-high vacuum optical reference cavity according to claim 6, wherein the getter component (3) further comprises a clamp spring (34), the clamp spring (34) is of a cylindrical structure, one end of the clamp spring (34) is fixed on the fixed column (313), the other end of the clamp spring is fixed on the annular accommodating shell (321), the inner diameter of the clamp spring (34) is larger than the outer diameter of the fixed column (313), the inner diameter of the annular accommodating shell (321) is larger than the outer diameter of the fixed column (313), and the clamp spring (34) and the annular accommodating shell (321) are sleeved on the fixed column (313).
  8. 8. An ultra-low stress ultra-high vacuum optical reference cavity according to any of claims 1-7, wherein said thin-walled structure has a thickness of between 0.2mm and 0.8 mm.
  9. 9. The ultra-low stress ultra-high vacuum optical reference cavity of claim 1, wherein said getter base body (311) and said getter mount (312) are integrally formed, and wherein said seal base body (411) and said seal mount (412) are integrally formed.
  10. 10. The ultra-low stress ultra-high vacuum optical reference cavity according to claim 1, wherein the reference cavity substrate (1) is of a square structure, a cuboid structure, a cylinder structure, an olive structure or a spherical structure, the first resonant channel (11) and the second resonant channel (12) are arranged perpendicular to each other, and an intersection point of the first resonant channel (11) and the second resonant channel (12) is located at the center of the reference cavity substrate (1).

Description

Ultra-low stress ultra-high vacuum optical reference cavity Technical Field The invention relates to the technical field of ultra-stable cavity systems, in particular to an ultra-low stress ultra-high vacuum optical reference cavity. Background In time measurement, gravitational wave detection, navigation positioning and even verification of the forefront of the basic physical laws of universe, scientists have had an endless pursuit of "frequency stability". The ultra stable cavity is used as a novel optical reference system and is moving from a top laboratory to a wider application stage. The device is characterized in that the device is based on unique physical design and revolutionary stability, and becomes a brand new reference for the next generation atomic clock, the ultra-stable laser and even basic physical experiments, and becomes a 'sea-calming nerve needle' supporting a quantum precision measurement scientific building. The core of the ultra-stable cavity system is a high-definition optical reference cavity, and the reference cavity is used for locking the frequency of laser so as to reduce the fluctuation to an extremely low level and provide a nearly 'static' frequency scale for precise measurement. As the heart of an optical clock, the ultrastable laser provided by the optical reference cavity is a future standard defining "seconds", the precision of which is hundreds times higher than that of the current microwave atomic clock, and the time reference is hopeful to be redefined. The core function of the optical reference cavity is to maintain a constant physical length, which must be made of a material having an extremely low coefficient of thermal expansion. In addition, in order to further isolate the environmental disturbance, the optical reference cavity must be placed in a vacuum environment and cooperate with a temperature control system to form a controlled "microclimate". The mirror surface of the optical reference cavity is extremely sensitive to contamination and even if particles of a few nanometres in size adhere to the mirror surface, the light scattering losses increase in the ppm order. Contamination layers of a few nanometers in thickness, such as hydrocarbon contamination layers, can also increase the light absorption losses by ppm levels. Typically, the optical reference cavity is provided with a dedicated vent hole, and the optical reference cavity is disposed in a vacuum maintenance system, and the vacuum maintenance system exhausts the gas in the optical reference cavity. When the optical reference cavity is placed in the ultra-stable cavity system for vacuumizing, the turbulence of the gas in the initial stage of vacuumizing can drive the inner wall of the vacuum system and nano-sized and micro-sized particles adsorbed on the surfaces of various complex supporting structures in the vacuum system to fly upwards, so that the reflecting mirror is polluted. After these particles adhere to the mirror surface, the light scattering loss increases drastically, reducing the finesse. In addition, during long-term operation, residual hydrocarbons in the ultra-stable vacuum system can be volatilized continuously. These volatile contaminants deposit on the reference cavity mirror surface to form a contaminant adsorption layer, which increases drastically the light absorption loss, reducing the finesse and thus degrading the performance of the optical reference cavity. Disclosure of Invention The invention aims to provide an ultra-low stress ultra-high vacuum optical reference cavity, which effectively solves the problems that the traditional optical reference cavity is not sealed, a reflecting mirror is easy to be polluted in an ultra-stable cavity system, and the performance of the optical reference cavity is reduced. In order to solve the problems, the invention discloses an ultra-low stress ultra-high vacuum optical reference cavity which comprises a reference cavity substrate, a reflector, a getter component and a vacuumizing sealing component; The reference cavity substrate is internally provided with a resonant channel, the resonant channel comprises a first resonant channel and a second resonant channel which are arranged in a crossing way, the first resonant channel and the second resonant channel penetrate through the reference cavity substrate, two ports of the first resonant channel are respectively provided with a reflecting mirror, the getter component is arranged at a first port of the second resonant channel, and the vacuumizing sealing component is arranged at a second port of the second resonant channel; The getter assembly comprises a getter flexible base and a getter body, wherein the getter flexible base is fixedly connected with the reference cavity base and seals the first port of the second resonant passage; a closed accommodating cavity is formed between the getter flexible base and the reference cavity base in a surrounding manner, and the getter main body is