A physical package is provided with: a MOT device; an optical chamber which constitutes an optical lattice formation portion; and a vacuum chamber which surrounds these components and has a substantially cylindrical shape. The MOT device is arranged along the beam axis of an atomic beam and traps an atom cluster. The optical lattice formation portion uses optical lattice light that enters therein to form an optical lattice in a cavity, confines the atom cluster trapped by the MOT device in the optical lattice, and transfers, along the X-axis which is a movement axis perpendicular to the beam axis, the atom cluster to a clock transition space which facilitates clock transition. The central axis of the cylinder of the main body of the vacuum chamber passes through the clock transition space, and is set to be substantially parallel with the beam axis.

A physical package is provided with: a MOT device; an optical chamber which constitutes an optical lattice formation portion; and a vacuum chamber which surrounds these components and has a substantially cylindrical shape. The MOT device is arranged along the beam axis of an atomic beam and traps an atom cluster. The optical lattice formation portion uses optical lattice light that enters therein to form an optical lattice in a cavity, confines the atom cluster trapped by the MOT device in the optical lattice, and transfers, along the X-axis which is a movement axis perpendicular to the beam axis, the atom cluster to a clock transition space which facilitates clock transition. The central axis of the cylinder of the main body of the vacuum chamber passes through the clock transition space, and is set to be substantially parallel with the beam axis.

In a general aspect, a communication system comprises a first station and a second station. The first station includes a photonic crystal maser, a laser subsystem, and a tracking subsystem. A photonic crystal structure of the photonic crystal maser is formed of dielectric material and has an array of cavities and an elongated slot. The elongated slot is disposed in a defect region of the array of cavities. The photonic crystal maser also includes a vapor disposed in the elongated slot and operable to emit a target RF electromagnetic radiation in response to receiving an optical signal. The array of cavities and the elongated slot define a waveguide configured to form the target RF electromagnetic radiation, when emitted, into a beam. The second station includes a receiver configured to couple to the beam of target RF electromagnetic radiation.

In a general aspect, a communication system comprises a first station and a second station. The first station includes a photonic crystal maser, a laser subsystem, and a tracking subsystem. A photonic crystal structure of the photonic crystal maser is formed of dielectric material and has an array of cavities and an elongated slot. The elongated slot is disposed in a defect region of the array of cavities. The photonic crystal maser also includes a vapor disposed in the elongated slot and operable to emit a target RF electromagnetic radiation in response to receiving an optical signal. The array of cavities and the elongated slot define a waveguide configured to form the target RF electromagnetic radiation, when emitted, into a beam. The second station includes a receiver configured to couple to the beam of target RF electromagnetic radiation.

In a general aspect, a photonic crystal maser includes a dielectric body having an array of cavities ordered periodically to define a photonic crystal structure in the dielectric body. The dielectric body also includes a region in the array of cavities defining a defect in the photonic crystal structure. An elongated slot through the region extends from a slot opening in a surface of the dielectric body at least partially through the dielectric body. The elongated slot and the array of cavities define a waveguide of the dielectric body. The dielectric body additionally includes an input coupler aligned with an end of the elongated slot and configured to couple a reference radiofrequency (RF) electromagnetic radiation to the waveguide. The photonic crystal maser also includes a vapor or source of the vapor in the elongated slot and an optical window covering the elongated slot.

In a general aspect, a photonic crystal maser includes a dielectric body having an array of cavities ordered periodically to define a photonic crystal structure in the dielectric body. The dielectric body also includes a region in the array of cavities defining a defect in the photonic crystal structure. An elongated slot through the region extends from a slot opening in a surface of the dielectric body at least partially through the dielectric body. The elongated slot and the array of cavities define a waveguide of the dielectric body. The dielectric body additionally includes an input coupler aligned with an end of the elongated slot and configured to couple a reference radiofrequency (RF) electromagnetic radiation to the waveguide. The photonic crystal maser also includes a vapor or source of the vapor in the elongated slot and an optical window covering the elongated slot.

An atomic clock including an ion trap assembly, a C-field coil positioned for generating a first magnetic field in the interrogation region of the ion trap assembly, a compensation coil positioned for generating a second magnetic field in the interrogation region, wherein the combination of the first and second magnetic fields produces an ion number-dependent second order Zeeman shift (Zeeman shift) in the resonance frequency that is opposite in sign to an ion number-dependent second order Doppler shift (Doppler shift) in the resonance frequency, the C-field coil has a radius selected using data indicating how changes in the radius affect an ion-number-dependent shift in the resonance frequency, such that a difference in magnitude between the Doppler shift and the Zeeman shift is controlled or reduced, and the resonance frequency, including the adjustment by the Zeeman shift, is used to obtain the frequency standard.

An atomic clock including an ion trap assembly, a C-field coil positioned for generating a first magnetic field in the interrogation region of the ion trap assembly, a compensation coil positioned for generating a second magnetic field in the interrogation region, wherein the combination of the first and second magnetic fields produces an ion number-dependent second order Zeeman shift (Zeeman shift) in the resonance frequency that is opposite in sign to an ion number-dependent second order Doppler shift (Doppler shift) in the resonance frequency, the C-field coil has a radius selected using data indicating how changes in the radius affect an ion-number-dependent shift in the resonance frequency, such that a difference in magnitude between the Doppler shift and the Zeeman shift is controlled or reduced, and the resonance frequency, including the adjustment by the Zeeman shift, is used to obtain the frequency standard.

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.

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.