Optical system for atomic interference raman laser pointing manipulation

Abstract

The application discloses an optical system for atomic interference Raman laser pointing manipulation, which comprises sequentially arranged deflectable mirrors, lens group I and lens group II and an ultrahigh vacuum cavity, the lens group I is composed of six lenses L1-L6 arranged in sequence from front to back, the lens group II is composed of seven lenses L7-L13 arranged in sequence from front to back, and an incident light beam from a narrow line width laser passes through the deflectable mirrors and then enters the lens group I and the lens group II in sequence and finally irradiates into the ultrahigh vacuum cavity; the application adopts common optical materials and devices, has a low production cost, has a large object side working distance and exit pupil distance, and provides sufficient space allowance for subsequent atomic interference precision measurement equipment design.

Description

Technical Field

[0001] This invention belongs to the field of quantum precision measurement technology, and relates to an atomic interferometer system for precise measurement of physical quantities, specifically to an optical system for pointing and manipulating atomic interferometric Raman lasers. Background Technology

[0002] Atomic interferometry is a technique that manipulates the transformation of atomic quantum states to study and precisely measure the physical properties of atoms. It has applications in quantum communication, atomic clocks, cold atom gravimeters, quantum computing, quantum simulation, and many other fields. Cold atom interferometers use Raman lasers to manipulate the transitions between the ground state energy levels of atoms, achieving matter wave interference from the superposition of two different quantum states. By measuring the phase shift of the interference, target physical quantities can be precisely measured.

[0003] The direction of the physical vector measured by a cold atom interferometer is determined by the propagation direction of the Raman laser beam. However, when the cold atom interferometer is in motion, the shaking of the platform causes the propagation direction of the Raman laser beam to fluctuate, reducing measurement accuracy and even rendering the interferometer unusable.

[0004] Therefore, it is necessary to achieve precise atomic interferometry measurements under dynamic conditions by manipulating Raman laser beams. Summary of the Invention

[0005] The direction of the measurement axis vector of an atomic interferometer is directly related to the direction of the Raman laser. In order to meet the high-precision control requirements of the measurement axis vector in complex outdoor environments, this invention designs an optical system for manipulating the direction of an atomic interferometer Raman laser, thereby achieving high-performance control of the Raman laser direction.

[0006] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is: an optical system for pointing and manipulating atomic interference Raman lasers, comprising a deflectable mirror, lens group I and lens group II arranged in sequence, and an ultra-high vacuum cavity; the deflectable mirror I changes the transmission direction of the incident light by changing the angle of the deflectable mirror, and the incident beam from the narrow linewidth laser is refracted by the deflectable mirror and enters lens group I and lens group II in sequence, and finally irradiates the ultra-high vacuum cavity; the ultra-high vacuum cavity includes a cavity shell and a cavity shell fixed to the side wall of the cavity shell. The optical system has a cavity optical window and an atomic cluster located inside the cavity shell. The aperture of the optical system is located on the deflecting mirror, and the exit pupil is located at the atomic cluster. Lens group I consists of 6 lenses L1 to L6 arranged sequentially from front to back, and lens group II consists of 7 lenses L7 to L13 arranged sequentially from front to back. Among them, lenses L1 to L4, L6, L8 to L9, and L11 to L12 are positive lenses, and lenses L5, L7, L10, and L13 are negative lenses. There is an intermediate image plane between lens group I and lens group II.

[0007] The optical system described herein for pointing and manipulating atomic interference Raman lasers comprises lenses L6, L10, and L13 as meniscus negative lenses, lenses L2 and L3 as biconvex positive lenses, lenses L1, L4, L8, L9, L11, and L12 as meniscus positive lenses, and lenses L5 and L7 as biconcave negative lenses.

[0008] The optical system described herein for pointing and manipulating atomic interference Raman lasers has a total length of lens group I ≤ 100 mm, a distance from the entrance pupil to lens group I ≥ 100 mm, a distance from the exit pupil to lens group II ≥ 80 mm, an object-side working distance ≥ 100 mm, and a total length of the optical system not exceeding 150 mm.

[0009] The optical system described herein is for pointing and manipulating atomic interference Raman lasers. The exit pupil diameter of the optical system is ≥15mm, and the image-side field of view range is ≥+ / -7.5°. The RMS of the full field of view aberration of the optical system is better than 1 / 100λ.

[0010] The optical system described herein is used for pointing and manipulating atomic interference Raman lasers, wherein the conjugate distance between the entrance pupil and the exit pupil of the optical system does not exceed 255.5 mm.

[0011] The beneficial effects of this invention are: 1. Compared with existing optical systems, this invention adopts a transmission optical structure composed of no less than 13 objective lenses to complete an optical system design with a laser beam diameter of no less than 15mm, a beam pointing control range of no less than + / -7.5 degrees, a wavelet aberration RMS better than 1 / 100λ, and the beam position coinciding with the position of the atomic cluster, thus meeting the usage requirements of current advanced atomic interferometry precision measurement devices.

[0012] 2. Compared with the current method of using actuators such as rotating motors to deflect the entire optical system and thus control the Raman laser pointing, the present invention only needs to control the rotation of the reflector through an actuator, which can significantly reduce the actuator load, increase the bandwidth of Raman laser pointing control, and reduce the size and weight of atomic interference precision measurement equipment.

[0013] 3. This invention uses commonly used optical materials and devices, resulting in lower production costs and larger object-side working distance and exit pupil distance, providing ample space margin for the subsequent design of atomic interferometry precision measurement equipment.

[0014] 4. The optical system employs mirror deflection to achieve high-performance control of the pointing of the atomic interference Raman laser. During laser pointing control, the center of the laser beam must coincide with the atomic cluster located in the ultra-high vacuum system, and the Gaussian laser beam diameter transformation process must be completed. In addition to laser pointing control, the optical system must also have the function of keeping the position of the beam and the atomic cluster unchanged during the laser pointing control process, and completing the Gaussian laser beam diameter transformation process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the optical structure of the optical system of the present invention; Figure 2 This is the MTF curve of the optical system of the present invention; Figure 3 This is a waveform aberration curve of the optical system of the present invention; Figures 4-6 This is a wavefront diagram of the optical system of the present invention.

[0016] The labels for each figure are as follows: 1—Deflectable mirror, 2—Ultra-high vacuum cavity, 2-1—Cavity shell, 2-2—Cavity optical window, 2-3—Atomic cluster, L1 / L2 / L3 / L4 / L6 / L8 / L9 / L11 / L12—Positive lens, L5 / L7 / L10 / L13—Negative lens. Detailed Implementation

[0017] This invention aims to provide an optical system for pointing and manipulating atomic interference Raman lasers. The specific implementation measures of this invention are described in detail with reference to the accompanying drawings.

[0018] The optical system shown in this invention is as follows: Figure 1 As shown. The optical system is divided into two parts: lens group I and lens group II. The ultra-high vacuum cavity 2, which is a component of this invention, includes a cavity shell 2-1, a cavity optical window 2-2, and an atomic cluster 2-3. The aperture of the optical system is located on the deflecting mirror 1, and the exit pupil is located at the atomic cluster 2-3. There is an intermediate image plane between lens group I and lens group II. The deflecting mirror 1 changes the transmission direction of the incident light by changing the angle of the deflecting mirror. The incident beam from the narrow linewidth laser is refracted by the deflectable mirror 1 and then enters lens group I and lens group II in sequence, finally illuminating the ultra-high vacuum cavity 2. There is an intermediate image plane between lens group I and lens group II.

[0019] The lens group I and lens group II of the present invention consist of 13 lenses, which are respectively represented by L1 to L13 in front-to-back order. The lens group I consists of 6 lenses L1 to L6 arranged in front-to-back order, and the lens group II consists of 7 lenses L7 to L13 arranged in front-to-back order. The lens group I consists of a meniscus positive lens L1, a biconvex positive lens L2, a biconvex positive lens L3, a meniscus positive lens L4, a biconcave negative lens L5, and a meniscus negative lens L6. The lens group II consists of a biconcave negative lens L7, a meniscus positive lens L8, a meniscus positive lens L9, a meniscus negative lens L10, a meniscus positive lens L11, a meniscus positive lens L12, and a meniscus negative lens L13.

[0020] The optical system of this invention uses a narrow-linewidth laser to operate at its operating wavelength, so the effect of chromatic aberration is negligible. The selected lens material has a refractive index ranging from 1.44 to 1.72 at the operating wavelength. The numerical aperture of the optical system is 0.11, which meets the requirements for the beam diameter and directional control angle range of the Raman laser.

[0021] This invention provides an optical system with laser pointing control capability. The total length of lens group I is ≤100mm, the distance from the entrance pupil to lens group I is ≥100mm, and the distance from the exit pupil to lens group II is ≥80mm. Applied to atomic interferometry precision measurement equipment, the total length of the optical system lens groups does not exceed 150mm; the object-side working distance is not less than 100mm, and the exit pupil distance is not less than 80mm, reserving sufficient design space for the deflector 1 and the ultra-high vacuum cavity 2; the conjugate distance between the entrance and exit pupils of the optical system does not exceed 255.5mm, and the exit pupil diameter is not less than 15mm, providing beam size and collimation that meet the requirements of atomic interferometry; beam pointing angle control of not less than + / -7.5 degrees is achieved through the angle deflection of the deflector; the wavefront aberration across the entire field of view is better than 1 / 100λ, meeting the accuracy requirements of atomic interferometry precision measurement.

[0022] Based on the requirements of the Raman laser in the atomic interferometer, the optical specifications of this embodiment are as follows: working wavelength: 780.2nm + / -2pm; numerical aperture: 0.11; image-side half field of view: 7.5°; object-side working distance: 100mm; image-side working distance: infinity; exit pupil distance: 80mm; total length of the lens group: 150mm; exit pupil diameter: 15mm.

[0023] The specific parameters of each lens are shown in the table below.

[0024] .

[0025] Here, the object plane represents the object plane of the optical system, i.e., the location of the incident optical fiber; the image plane is located at infinity, and the laser emitted from the surface is collimated. INF stands for infinity, indicating that the radius of the sphere is infinite, i.e., a plane.

[0026] Figure 2 The MTF curve of the optical system; Figure 3 The wave aberration curves of the optical system are shown, with wave aberration RMS better than 1 / 100λ and wave aberration PV better than 1 / 20λ. Figures 4-6 These are wavefront diagrams of the optical system at different fields of view.

[0027] Overall, the optical system described in this invention has good outgoing wave aberrations, meeting the requirements for atomic interference Raman laser manipulation.

[0028] The design examples detailed in this invention are only used to illustrate the advantages and rationality of this invention. All examples of projection lenses optimized based on the technical solutions of this invention fall within the scope of this invention. Technologies and principles not described in detail in this invention are within the scope of this invention and are known to those skilled in the art.

Claims

1. An optical system for pointing and manipulating atomic interference Raman lasers, characterized in that: It includes a deflectable mirror (1), lens group I and lens group II arranged in sequence, and an ultra-high vacuum cavity (2); the incident beam from the narrow linewidth laser is refracted by the deflectable mirror (1) and enters the lens group I and lens group II in sequence, irradiating the ultra-high vacuum cavity (2); the ultra-high vacuum cavity (2) includes a cavity shell (2-1), a cavity optical window (2-2) fixed to the side wall of the cavity shell (2-1), and an atomic cluster (2-3) located inside the cavity shell (2-1). The aperture of the optical system is located on the deflecting mirror (1), and the exit pupil is located at the atomic cluster (2-3); the lens group I is composed of lenses L1 to L6 arranged in sequence, and the lens group II is composed of lenses L7 to L13 arranged in sequence, wherein lenses L1 to L4, L6, L8 to L9, and L11 to L12 are positive lenses, and lenses L5, L7, L10, and L13 are negative lenses; there is an intermediate image plane between the lens group I and the lens group II.

2. The optical system for pointing and manipulating atomic interference Raman lasers according to claim 1, characterized in that, Lenses L10 and L13 are meniscus negative lenses, lenses L2 and L3 are biconvex positive lenses, lenses L1, L4, L6, L8, L9, lenses L11 and L12 are meniscus positive lenses, and lenses L5 and L7 are biconcave negative lenses.

3. An optical system for pointing and manipulating atomic interference Raman lasers according to claim 1 or 2, characterized in that, The total length of lens group I is ≤100mm, the distance from the entrance pupil to lens group I is ≥100mm, the distance from the exit pupil to lens group II is ≥80mm, the object-side working distance is ≥100mm, and the total length of the optical system does not exceed 150mm.

4. An optical system for pointing and manipulating atomic interference Raman lasers according to claim 1 or 2, characterized in that, The optical system has an exit pupil diameter ≥15mm and an image-side field of view range ≥+ / -7.5°; the full-field-of-view aberration RMS of the optical system is better than 1 / 100λ.

5. An optical system for pointing and manipulating atomic interference Raman lasers according to claim 1 or 2, characterized in that, The conjugate distance between the entrance pupil and exit pupil of the optical system shall not exceed 255.5 mm.

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