Methods of using vapor cells may involve providing a vapor cell including a body defining a cavity within the body. At least a portion of at least one surface of the vapor cell within the cavity may include at least one pore having an average dimension of about 500 microns or less, as measured in a direction parallel to the at least one surface. A vapor pressure of a subject material within the cavity may be controlled utilizing the at least one pore by inducing an exposed surface of a subject material in a liquid state within the at least one pore to have a shape different than a shape the exposed surface of the subject material in a liquid state would have on a flat, nonporous surface.

Methods of using vapor cells may involve providing a vapor cell including a body defining a cavity within the body. At least a portion of at least one surface of the vapor cell within the cavity may include at least one pore having an average dimension of about 500 microns or less, as measured in a direction parallel to the at least one surface. A vapor pressure of a subject material within the cavity may be controlled utilizing the at least one pore by inducing an exposed surface of a subject material in a liquid state within the at least one pore to have a shape different than a shape the exposed surface of the subject material in a liquid state would have on a flat, nonporous surface.

A rubidium optical atomic clock uses a modulated 778 nanometer (nm) probe beam and its reflection to excite rubidium 87 atoms, some of which emit 758.8 nm fluorescence as they decay back to the ground state. A spectral filter rejects scatter of the 778 nm probe beams while transmitting the 775.8 nm fluorescence so that the latter can be detected with a high signal-to-noise ratio. Since the spectral filter is only acceptably effective at angles of incidence less than 8° from the perpendicular, the atoms are localized by a magneto-optical trap so that most of the atoms lie within a conical volume defined by the 8° angle so that the resulting fluorescence detection signal has a high signal-to-noise ratio. The fluorescence detection signal can be demodulated to provide an error signal from which desired adjustments to the oscillator frequency can be calculated.

A rubidium optical atomic clock uses a modulated 778 nanometer (nm) probe beam and its reflection to excite rubidium 87 atoms, some of which emit 758.8 nm fluorescence as they decay back to the ground state. A spectral filter rejects scatter of the 778 nm probe beams while transmitting the 775.8 nm fluorescence so that the latter can be detected with a high signal-to-noise ratio. Since the spectral filter is only acceptably effective at angles of incidence less than 8° from the perpendicular, the atoms are localized by a magneto-optical trap so that most of the atoms lie within a conical volume defined by the 8° angle so that the resulting fluorescence detection signal has a high signal-to-noise ratio. The fluorescence detection signal can be demodulated to provide an error signal from which desired adjustments to the oscillator frequency can be calculated.

Disclosed embodiments include laser systems. An illustrative laser system includes a tunable laser. A beam splitter is operatively couplable to an output of the laser and is configured to split light output from the laser into a first path and a second path. A first modulator is disposed in the first path and is configured to generate first set of sidebands. A bandpass filter circuit includes a fiber Bragg grating filter and is operatively couplable to receive output from the first modulator and to pass a selected sideband of the first set of sidebands. A lock circuit is disposed in the second path, is configured to determine and stabilize wavelength of the laser, and is further configured to cooperate with the fiber Bragg grating filter to maintain a static lock point for the laser while allowing output of the first path to be tunable with respect to the lock point.

In a clock apparatus, a signal waveguide includes: a gas cell having a sealed interior; and a dipolar gas inside the sealed interior. A first apparatus is configured to provide a first electromagnetic wave through the sealed interior along a first direction. A second apparatus is configured to provide a second electromagnetic wave through the sealed interior along a second direction, in which the second direction is opposite the first direction. Also, the clock apparatus includes receiving apparatus coupled to the signal waveguide and configured to detect an amount of energy in the second electromagnetic wave passing through the dipolar gas.

In a clock apparatus, a signal waveguide includes: a gas cell having a sealed interior; and a dipolar gas inside the sealed interior. A first apparatus is configured to provide a first electromagnetic wave through the sealed interior along a first direction. A second apparatus is configured to provide a second electromagnetic wave through the sealed interior along a second direction, in which the second direction is opposite the first direction. Also, the clock apparatus includes receiving apparatus coupled to the signal waveguide and configured to detect an amount of energy in the second electromagnetic wave passing through the dipolar gas.

A magneto-optical trap apparatus includes a vacuum vessel for encapsulating an atom to be trapped, an anti-Helmholtz coil for applying a magnetic field to an inside of the vacuum vessel, a laser device for generating a laser beam, and an irradiation device for irradiating the generated laser beam from a plurality of directions. The laser beam includes a first laser beam detuned from a first resonance frequency when the atom transits from a total angular momentum quantum number F in a ground state to a total angular momentum quantum number F′=F+1 in an excited state, and a second laser beam detuned from a second resonance frequency when the atom transits from the total angular momentum quantum number F in the ground state to a total angular momentum quantum number F′=F−1 in the excited state, among transitions from J=0 in a ground state to J′=1 in an excited state.

A method for implementing an atomic clock based on NV-.sup.15N coupling spin system in diamond and a device are provided. The method includes: applying a pulse sequence to jointly initialize NV electron spins and .sup.15N nuclear spins; performing a Ramsey interferometry to compare a RF frequency and a .sup.15N hyperfine coupling; entangling the NV electron spin and the nuclear spin, reading out a state of nuclear spins by collecting a fluorescence signal; calculating a frequency difference between the RF frequency and the .sup.15N hyperfine coupling according to the fluorescence signal, thereby locking the RF frequency to the .sup.15N hyperfine coupling; and outputting the RF frequency as a frequency standard. This system is located in a stable solid environment and is not affected by environmental conditions such as an external magnetic field, electric field, and temperature, and therefore it has an excellent robustness. Various components of the device may be integrated into several chips to miniaturize a diamond atomic clock.

A method for implementing an atomic clock based on NV-.sup.15N coupling spin system in diamond and a device are provided. The method includes: applying a pulse sequence to jointly initialize NV electron spins and .sup.15N nuclear spins; performing a Ramsey interferometry to compare a RF frequency and a .sup.15N hyperfine coupling; entangling the NV electron spin and the nuclear spin, reading out a state of nuclear spins by collecting a fluorescence signal; calculating a frequency difference between the RF frequency and the .sup.15N hyperfine coupling according to the fluorescence signal, thereby locking the RF frequency to the .sup.15N hyperfine coupling; and outputting the RF frequency as a frequency standard. This system is located in a stable solid environment and is not affected by environmental conditions such as an external magnetic field, electric field, and temperature, and therefore it has an excellent robustness. Various components of the device may be integrated into several chips to miniaturize a diamond atomic clock.