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JP-2026074662-A - Atomic oscillator

JP2026074662AJP 2026074662 AJP2026074662 AJP 2026074662AJP-2026074662-A

Abstract

[Problem] It is difficult to further improve the stability of the resonance frequency against magnetic field fluctuations in atomic oscillators. [Solution] The atomic oscillator of the present disclosure comprises two gas cells, each containing alkali metal atoms and having bias magnetic fields applied in opposite directions; a light generating unit that irradiates the two gas cells with light having at least two different frequency components; a light detection unit that detects the transmitted light that has passed through the two gas cells; and a control unit that determines a resonance frequency based on detection signals corresponding to the transmitted light detected from the two gas cells and controls the oscillation frequency of an oscillation signal output to the outside based on the determined resonance frequency. [Selection Diagram] Figure 10

Inventors

  • 松本 健太

Assignees

  • 日本電気株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (10)

  1. Two gas cells containing alkali metal atoms, with bias magnetic fields applied in opposite directions to each other, A light generating unit that irradiates each of the two gas cells with irradiation light having at least two different frequency components, A photodetector that detects the transmitted light that has passed through the two gas cells, A control unit that determines the resonance frequency based on detection signals corresponding to the transmitted light detected from each of the two gas cells, and controls the oscillation frequency of the oscillation signal output to the outside based on the determined resonance frequency, An atomic oscillator equipped with [a specific feature/equipment].
  2. The atomic oscillator according to claim 1, The system is configured to apply the same strength of bias magnetic fields in opposite directions to the two gas cells. Atomic oscillator.
  3. The atomic oscillator according to claim 2, The control unit, when the detection signals detected from the two gas cells are different, determines the resonance frequency based on the detection signals detected from the two gas cells and controls the oscillation frequency of the oscillation signal output to the outside based on the determined resonance frequency. Atomic oscillator.
  4. The atomic oscillator according to claim 2, The control unit determines the resonance frequency based on the detection signal detected from the first gas cell, and corrects the oscillation frequency of the oscillation signal based on the resonance frequency based on the detection signal detected from the second gas cell. Atomic oscillator.
  5. The atomic oscillator according to claim 2, The control unit corrects the strength of the bias magnetic field based on the detection signal detected from the second gas cell, and determines the resonance frequency based on the detection signal detected from the first gas cell to control the oscillation frequency of the oscillation signal. Atomic oscillator.
  6. The atomic oscillator according to claim 1, The system is configured to apply bias magnetic fields of different intensities in opposite directions to the two gas cells. Atomic oscillator.
  7. The atomic oscillator according to claim 6, The control unit determines the resonance frequency based on the difference between the detection signals detected from the two gas cells, and controls the oscillation frequency of the oscillation signal output to the outside based on the determined resonance frequency. Atomic oscillator.
  8. Two gas cells containing alkali metal atoms, A light generating unit that irradiates each of the two gas cells with irradiation light having at least two different frequency components, A photodetector that detects the transmitted light that has passed through the two gas cells, A control method for an atomic oscillator equipped with, By applying bias magnetic fields in opposite directions to the two gas cells, Based on the detection signals corresponding to the transmitted light detected from each of the two gas cells, the resonance frequency is determined, and the oscillation frequency of the externally output oscillation signal is controlled based on the determined resonance frequency. Control method.
  9. A control method according to claim 8, Apply the bias magnetic field of the same intensity to the two gas cells in opposite directions. Control method.
  10. A control method according to claim 8, The system is configured to apply bias magnetic fields of different intensities in opposite directions to the two gas cells. Control method.

Description

This disclosure relates to atomic oscillators. As an oscillator with long-term high-precision oscillation characteristics, atomic oscillators that oscillate based on the energy transitions of alkali metal atoms are known. In atomic oscillators, the resonance frequency is determined by detecting the amount of light transmitted through the atom, and the oscillation frequency is controlled based on this. In this case, atomic oscillators are generally operated by applying a bias magnetic field of several tens to several hundred μT to obtain a clear resonance signal. On the other hand, in atomic oscillators, when magnetic field fluctuations occur due to an external magnetic field, the resonance frequency fluctuates, making it difficult to improve the stability of the resonance frequency. Therefore, in atomic oscillators, methods such as shielding or canceling the magnetic field are employed, as described in Patent Document 1. Japanese Patent Publication No. 2023-21719 This diagram shows the configuration of the atomic oscillator in this disclosure.This figure shows the processing performed by the atomic oscillator in this disclosure.This figure shows the processing performed by the atomic oscillator in this disclosure.This flowchart shows the processing operation by the atomic oscillator in this disclosure.This diagram shows the configuration of the atomic oscillator in this disclosure.This flowchart shows the processing operation by the atomic oscillator in this disclosure.This diagram shows the configuration of the atomic oscillator in this disclosure.This figure shows the processing performed by the atomic oscillator in this disclosure.This flowchart shows the processing operation by the atomic oscillator in this disclosure.This diagram shows the configuration of the atomic oscillator in this disclosure. <Embodiment 1> A first embodiment of this disclosure will be described with reference to the drawings. The drawings may be relevant to any of the embodiments. [composition] First, let's explain the basics of atomic oscillators. An atomic oscillator is a device that uses atomic gases, such as alkali metal atoms, to achieve stable frequency oscillation. An atomic oscillator has a gas cell containing an atomic gas, and by irradiating the gas cell with light containing at least two different frequencies and measuring the transmitted light, the quantum interference effect (called CPT (Coherent Population Trapping) resonance) that occurs when the difference frequency of the irradiated light matches the transition frequency between specific quantum states of the atomic gas can be detected as a fluctuation in the amount of transmitted light. For example, if the transmitted light spectrum is measured while sweeping the difference frequency of the irradiated light and detecting the transmitted light of cesium atoms, the amount of transmitted light reaches a peak value when the difference frequency matches the transition frequency between specific quantum states, and CPT resonance is detected. The difference frequency of the irradiated light at this time is called the resonance frequency. By detecting the resonance frequency of CPT resonance and controlling the difference frequency of the irradiated light to match the transition frequency between specific quantum states, a high-precision atomic oscillator utilizing the quantum interference effect can be realized. In the CPT-based atomic oscillator described above, the resonance frequency of the CPT resonance is used as the reference frequency for the oscillation frequency. The transmitted light spectrum is represented as a Lorentz function centered on the transition frequency between quantum states. The point where the transmitted light intensity is maximum is generally used as the resonance frequency of the CPT resonance, and this is used as the reference frequency for the oscillation frequency. As an example, by sweeping the difference frequency of the light emitted during the startup of an atomic oscillator, an error signal of the transmitted light spectrum, as shown in the schematic diagram in Figure 2 (2-1), can be obtained. The zero-crossing point of this error signal can then be used as the resonance frequency, and this can be used as the reference frequency for the oscillation frequency. The error signal of the transmitted light spectrum can be obtained, for example, by modulating the difference frequency with a reference frequency that has a shorter period than the sweep period of the emitted light, and then locking in the detected transmitted light intensity with the reference frequency. Furthermore, the zero-point slope is defined as the amount of change in the error signal at the zero-crossing point, which is the resonance frequency. That is, the ratio of the error signal fluctuation to the deviation between the difference frequency and the resonance frequency. When monitoring the error signal, a larger absolute value of the zero-point slope indicates higher