A frequency-modulated spectrometry (FMS) output is used to stabilize an atomic clock by serving as an error signal to regulate the clock's oscillator frequency. Rubidium 87 atoms are localized within a hermetically sealed cell using an optical (e.g., magneto-optical) trap. The oscillator output is modulated by a sinusoidal radio frequency signal and the modulated signal is then frequency doubled to provide a modulated 788 nm probe signal. The probe signal excites the atoms, so they emit 775.8 nm fluorescence. A spectral filter is used to block 788 nm scatter from reaching a photodetector, but also blocks 775.8 nm fluorescence with an angle of incidence larger than 8° relative to a perpendicular to the spectral filter. The localized atoms lie within a conical volume defined by the 8° effective angle of incidence so an FMS output with a high signal-to-noise ratio is obtained.

A frequency-modulated spectrometry (FMS) output is used to stabilize an atomic clock by serving as an error signal to regulate the clock's oscillator frequency. Rubidium 87 atoms are localized within a hermetically sealed cell using an optical (e.g., magneto-optical) trap. The oscillator output is modulated by a sinusoidal radio frequency signal and the modulated signal is then frequency doubled to provide a modulated 788 nm probe signal. The probe signal excites the atoms, so they emit 775.8 nm fluorescence. A spectral filter is used to block 788 nm scatter from reaching a photodetector, but also blocks 775.8 nm fluorescence with an angle of incidence larger than 8° relative to a perpendicular to the spectral filter. The localized atoms lie within a conical volume defined by the 8° effective angle of incidence so an FMS output with a high signal-to-noise ratio is obtained.

An ensemble of spin defect centers or other atom-like quantum systems in a solid-state host can be used as a compact alternative for an atomic clock thanks to an architecture that overcomes magnetic and temperature-induced systematics. A polariton-stabilized solid-state spin clock hybridizes a microwave resonator with a magnetic-field-insensitive spin transition within the ground state of a spin defect center (e.g., a nitrogen vacancy center in diamond). Detailed numerical and analytical modeling of this polariton-stabilized solid-state spin clock indicates a potential fractional frequency instability below 10.sup.−13 over a 1-second measurement time, assuming present-day experimental parameters. This stability is a significant improvement over the state-of-the-art in miniaturized atomic vapor clocks.

An ensemble of spin defect centers or other atom-like quantum systems in a solid-state host can be used as a compact alternative for an atomic clock thanks to an architecture that overcomes magnetic and temperature-induced systematics. A polariton-stabilized solid-state spin clock hybridizes a microwave resonator with a magnetic-field-insensitive spin transition within the ground state of a spin defect center (e.g., a nitrogen vacancy center in diamond). Detailed numerical and analytical modeling of this polariton-stabilized solid-state spin clock indicates a potential fractional frequency instability below 10.sup.−13 over a 1-second measurement time, assuming present-day experimental parameters. This stability is a significant improvement over the state-of-the-art in miniaturized atomic vapor clocks.

Provided according to an embodiment of the present disclosure is a radiation shield 10 including a shield wall surrounding a hollow region capable of accommodating therein atoms for an optical lattice clock 100, the shield wall having, provided therein, at least two apertures communicating with outside. A geometrical shape of an inner wall surface of the shield wall is configured such that a difference between BBR shifts found under two conditions does not exceed a predetermined value over a range of position of atoms, the BBR shifts being caused in atoms 2 by emitted radiation emitted by the inner wall surface, incoming radiation leaking in from the outside through the apertures, and a reflection component of the emitted radiation and incoming radiation at the inner wall surface, the two conditions being a condition where the inner wall surface exhibits mirror reflection and a condition where the inner wall surface exhibits diffuse reflection, the range being where clock transition operation is carried out in the optical lattice clock, the inner wall surface facing the hollow region. Provided according to other embodiments of the present disclosure also are the optical lattice clock 100 including such a radiation shield, and a design method for the radiation shield.

Provided according to an embodiment of the present disclosure is a radiation shield 10 including a shield wall surrounding a hollow region capable of accommodating therein atoms for an optical lattice clock 100, the shield wall having, provided therein, at least two apertures communicating with outside. A geometrical shape of an inner wall surface of the shield wall is configured such that a difference between BBR shifts found under two conditions does not exceed a predetermined value over a range of position of atoms, the BBR shifts being caused in atoms 2 by emitted radiation emitted by the inner wall surface, incoming radiation leaking in from the outside through the apertures, and a reflection component of the emitted radiation and incoming radiation at the inner wall surface, the two conditions being a condition where the inner wall surface exhibits mirror reflection and a condition where the inner wall surface exhibits diffuse reflection, the range being where clock transition operation is carried out in the optical lattice clock, the inner wall surface facing the hollow region. Provided according to other embodiments of the present disclosure also are the optical lattice clock 100 including such a radiation shield, and a design method for the radiation shield.

An oscillation device, such as a frequency standard or “atomic clock”, is disclosed. The device comprises: a system capable of undergoing transitions between different energy states, the transitions defining at least a first resonance frequency and a second resonance frequency; an excitation device arranged to induce the system to undergo such transitions; a detection device arranged to detect a response of the system caused by the excitation device, to produce an output; and a controller arranged to receive the output, to control the excitation device to stimulate said transitions, and to obtain signals corresponding to at least the first and second resonance frequencies; wherein the controller is also arranged to process the obtained signals to produce a corrected output signal that is compensated against at least one influence on the resonance frequencies of the system.

An oscillation device, such as a frequency standard or “atomic clock”, is disclosed. The device comprises: a system capable of undergoing transitions between different energy states, the transitions defining at least a first resonance frequency and a second resonance frequency; an excitation device arranged to induce the system to undergo such transitions; a detection device arranged to detect a response of the system caused by the excitation device, to produce an output; and a controller arranged to receive the output, to control the excitation device to stimulate said transitions, and to obtain signals corresponding to at least the first and second resonance frequencies; wherein the controller is also arranged to process the obtained signals to produce a corrected output signal that is compensated against at least one influence on the resonance frequencies of the system.

A stackable molecular spectroscopy cell includes a hollow body, a first cap affixed to a first surface of the hollow body, covering a first opening in the hollow body, and a second cap affixed to a second surface of the hollow body, covering a second opening in the hollow body, and forming a sealed cavity within the hollow body. The sealed cavity contains a dipolar gas having a pressure of less than 0.5 mbar. The stackable molecular spectroscopy cell also includes a metal layer covering an inner surface of the hollow body and an inner surface of the first and second caps, including a first aperture in the metal layer covering the inner surface of the first cap and a second aperture in the metal layer covering the inner surface of the second cap.

Smart electric meters configured to perform fast, time-synchronized electrical energy measurements at the consumer-level are disclosed herein. In some embodiments, a smart electric meter includes circuitry configured to measure an electrical value at a location of an end user in a power system. The smart electric meter can further include an atomic clock configured to output a timing signal, and a controller configured to receive (a) the measured electrical value from the circuitry and (b) the timing signal from the atomic clock. The controller can further (a) process the electrical value to generate meter data and (b) generate a time tag based on the timing signal. Then, the controller can associate the time tag with the meter data to generate time-tagged meter data.