A quantum interference device (atomic oscillator) includes a light source unit as a coherent light source, a unit that superimposes microwave on the light source unit to generate a side band, an atom cell in which an alkali metal gas is enclosed, and a light receiving unit that detects light transmitted through the atom cell, wherein the light source unit is a surface-emitting laser that outputs a zero-order mode light and a plurality of higher-order mode lights, and a mode filter that cuts the higher-order mode lights is placed between the light source unit and the atom cell.

An atomic oscillator including an oscillator that outputs an oscillation signal, a light emitter to which a signal based on the oscillation signal is inputted, an atomic cell, a light receiver that detects the light passing through the atomic cell and outputs a detection signal, a first temperature controller, and a control circuit, and the control circuit has a first mode including the process of operating the light emitter and the first temperature controller and the process of causing the oscillator to output the oscillation signal, a second mode including the process of causing the light emitter and the first temperature controller to stop operating and the process of causing the oscillator to stop outputting the oscillation signal, and a third mode including the process of causing the light emitter to stop operating, the process of operating the first temperature controller, and the process of causing the oscillator to stop outputting the oscillation signal.

In a described example, an apparatus includes: a package substrate having a device side surface and a board side surface opposite the device side surface; a physics cell mounted on the device side surface having a first end and a second end; a first opening extending through the package substrate and lined with a conductor, aligned with the first end; a second opening extending through the package substrate and lined with the conductor, aligned with the second end; a millimeter wave transmitter module on the board side, having a millimeter wave transfer structure including a transmission line coupled to an antenna aligned with the first opening; and a millimeter wave receiver module mounted on the board side surface of the package substrate and having a millimeter wave transfer structure including a transmission line coupled to an antenna for receiving millimeter wave signals, aligned with the second opening.

The present invention discloses a chip atomic clock microsystem based on a nano Y waveguide, including a magnetic shielding portion, an optical system and a physical system. The optical system and the physical system are arranged in a magnetic shielding layer. The unique nano Y waveguide and nano vertical coupling gratings used in the optical system greatly improve the photoelectric conversion efficiency and a space utilization rate, and reduce the size of the atomic clock. In addition, especially the two-layer magnetic shielding design is adopted, which effectively improves the shielding effect. The chip atomic clock microsystem based on a nano Y waveguide according to the present invention has the advantages of being easy to mount, stable in performance, compact in structure, small in size, low in power consumption, long in service life and high in precision.

This atomic resonator for causing a resonance frequency by CPT resonance includes: a gas cell having alkali metal atoms enclosed; a photodetector configured to detect light having passed through the gas cell and convert the light to an electric signal; a high-frequency oscillator configured to receive the electric signal and output the signal after a frequency thereof is divided by two; and a laser light source configured to modulate and introduce, into the gas cell, light based on the signal output from the high-frequency oscillator. The high-frequency oscillator has an injection-locked frequency divider circuit including an acoustic resonator as an oscillation element.

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.

In a general aspect, a vapor cell is presented that includes a dielectric body. The dielectric body has a surface that defines an opening to a cavity in the dielectric body. The vapor cell also includes a vapor or a source of the vapor in the cavity of the dielectric body. An optical window covers the opening of the cavity and has a surface bonded to the surface of the dielectric body to form a seal around the opening. The seal includes metal-oxygen bonds formed by reacting a first plurality of hydroxyl ligands on the surface of the dielectric body with a second plurality of hydroxyl ligands on the surface of the optical window.

A miniature atomic clock with pulse mode operation. The clock includes: a local oscillator; a dual-frequency laser source; a pulsing element to pulse the output signal from the source according to a Ramsey-type interrogation sequence having pulses with duration T1 separated by intervals with duration T2; an alkaline vapour microcell; a photodiode; a feedback control loop for controlling the microwave frequency of the local oscillator; and a feedback control loop for controlling the optical frequency of the source by using a pulse control block receiving the output signal from the photodiode and the interrogation sequence, and providing a correction signal to the source. During the period T1, the block extracts an error signal from the output signal received from the photodiode and generates the correction signal from the error signal. During the period T2, the block resets the error signal to zero and generates the correction signal by extrapolation.

The invention relates to a coherent population trapping (CPT) phase modulation and demodulation method and a system for implementing the method of this invention. The method comprises the following steps: Generating a coherent bichromatic light, in which the relative phase between the two frequency components is modulated with proper modulation depth. The phase modulated coherent bichromatic light interacts with a quantum resonance system, and prepares it alternately into two inverted CPT states. Detecting the transmitted light with a photodetector, two inverted dispersive CPT signals in two detection windows are observed. With synchronous phase demodulation, a CPT error signal is obtained, which is used for locking the local oscillator to implement a CPT atomic clock.

The invention relates to a differential detection of double-modulation (DM) CPT method and a system for implementing the method of this invention. The method comprises the following steps: Generating a coherent bichromatic light, in which the polarization and the relative phase are synchronously modulated. The DM light interacts with a quantum resonance system and prepares it into a CPT state. Then the polarization of coherent bichromatic light is switched from circular polarization to linear polarization. After interacting with the CPT state prepared in the previous stage, the constructive and destructive quantum interference occur simultaneously. The polarization of the transmitted light from the quantum resonance system is converted and spatially separated. Then two CPT signals, detected by balanced photodetectors, are observed with constructive and destructive interference respectively. Finally, a differential CPT signal with high signal-to-noise ratio is obtained by subtracting the above-mentioned two CPT signals.