Abstract: A system including a vacuum cell, an ion pump, and a multi-layer magnetic shield is described. The vacuum cell includes a magnetic field-sensitive section, a pump section, and a channel section providing a vacuum conductance path between the magnetic field-sensitive section and the pump section. The ion pump is in the pump section. The multi-layer magnetic shield surrounds at least a portion of the ion pump. The multi-layer magnetic shield has a first layer and a second layer. The first layer is between the second layer and the ion pump. The first layer has a moderate relative magnetic permeability and a high saturation magnetization. The second layer has a high relative magnetic permeability and a moderate saturation magnetization.

Abstract: An adaptive quantum signal processor (AQSP) includes a signal combiner, a physics station, a measurement system, a machine-learning engine and an output generator. The signal combiner combines incoming signals with control functions to yield recipe functions. For example, the recipe functions can be “shaking” functions used to change the wavefunctions of atoms entrained in an optical lattice. The recipe functions are applied to wavefunctions in initial wavefunction states causing the wavefunctions to transition to signal-impacted states. The measurement system measures the wavefunctions in their signal-impacted quantum states to yield wavefunction characterizations. The machine-learning engine updates control functions based on the wavefunction characterizations. The output generator outputs results based on the wavefunction characterizations and/or control function characterizations. In a matched-filter application, the outputs characterize (e.g., identify, classify, rate) the incoming signals.

Abstract: A microwave sensor determines an electric-field strength of a microwave field populated by quantum particles in an ultra-high vacuum (UHV) cell. A probe laser beam and a coupling laser beam are directed into the UHV cell so that they are generally orthogonal to each other and intersect to define a “Rydberg” intersection, so-called as the quantum particles within the Rydberg intersection transition to a pair of Rydberg states. The frequency of the probe laser beam is swept so that a frequency spectrum of the probe laser beam can be captured. The frequency spectrum is analyzed to determine a frequency difference between Autler-Townes peaks. The electric-field strength of the microwave field within the Rydberg intersection is then determined based on this frequency difference.

Abstract: An atomic clock employs hybrid long/short quantum clock frequency regulation wherein each of a series of regulation cycles includes a relatively long (four Ramsey-cycle) combination error signal (CES) cycle and plural relatively short (two Ramsey-cycle) single error signal (SES) cycles. The CES cycles provide for better long-term stability than can be provided using only SES cycles. However, including the SES cycles between CES cycles improves short term stability with negligible diminishment of long-term stability.

Abstract: 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.

Abstract: A fluorescence detection process begins by localizing rubidium 87 atoms within an optical (all-optical or magneto-optical) trap so that at least most of the atoms in the trap are within a cone defined by an effective angle, e.g., 8°, of a spectral filter. Within the effective angle of incidence, the filter effectively rejects (reflects or absorbs) 778 nanometer (nm) fluorescence and effectively transmits 775.8 nm fluorescence. Any 775.8 nm fluorescence arrive outside the effective angle of incidence. Thus, using an optical trap to localize the atoms within the cone enhances the signal-to-noise ratio of the fluorescence transmitted through the spectral filter and arriving a photomultiplier or other photodetector, resulting fluorescence detection signal with an enhanced S/N.

Abstract: A microwave sensor determines an electric-field strength of a microwave field populated by quantum particles in an ultra-high vacuum (UHV) cell. A probe laser beam and a coupling laser beam are directed into the UHV cell so that they are generally orthogonal to each other and intersect to define a “Rydberg” intersection, so-called as the quantum particles within the Rydberg intersection transition to a pair of Rydberg states. The frequency of the probe laser beam is swept so that a frequency spectrum of the probe laser beam can be captured. The frequency spectrum is analyzed to determine a frequency difference between Autler-Townes peaks. The electric-field strength of the microwave field within the Rydberg intersection is then determined based on this frequency difference.

Abstract: 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.

Abstract: 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.

Abstract: A spectroscopy system is described. The spectroscopy system includes a cell, a photodiode, and mirrors. The cell has walls forming a chamber therein. The chamber is configured to receive laser signal(s) and retaining a vapor therein. The vapor fluoresces in response to the laser signal(s). The mirrors are configured to direct fluorescent light from the vapor toward the photodiode. In some embodiments, the spectroscopy system is incorporated with a photonic integrated circuit.

Abstract: 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.

Abstract: A microwave sensor determines an electric-field strength of a microwave field populated by quantum particles in an ultra-high vacuum (UHV) cell. A probe laser beam and a coupling laser beam are directed into the UHV cell so that they are generally orthogonal to each other and intersect to define a “Rydberg” intersection, so-called as the quantum particles within the Rydberg intersection transition to a pair of Rydberg states. The frequency of the probe laser beam is swept so that a frequency spectrum of the probe laser beam can be captured. The frequency spectrum is analyzed to determine a frequency difference between Autler-Townes peaks. The electric-field strength of the microwave field within the Rydberg intersection is then determined based on this frequency difference.

Abstract: A microwave sensor determines an electric-field strength of a microwave field populated by quantum particles in an ultra-high vacuum (UHV) cell. A probe laser beam and a coupling laser beam are directed into the UHV cell so that they are generally orthogonal to each other and intersect to define a “Rydberg” intersection, so-called as the quantum particles within the Rydberg intersection transition to a pair of Rydberg states. The frequency of the probe laser beam is swept so that a frequency spectrum of the probe laser beam can be captured. The frequency spectrum is analyzed to determine a frequency difference between Autler-Townes peaks. The electric-field strength of the microwave field within the Rydberg intersection is then determined based on this frequency difference.

Abstract: 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.

Abstract: 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.

Abstract: A fluorescence detection process begins by localizing rubidium 87 atoms within an optical (all-optical or magneto-optical) trap so that at least most of the atoms in the trap are within a cone defined by an effective angle, e.g., 8°, of a spectral filter. Within the effective angle of incidence, the filter effectively rejects (reflects or absorbs) 778 nanometer (nm) fluorescence and effectively transmits 775.8 nm fluorescence. Any 775.8 nm fluorescence arrive outside the effective angle of incidence. Thus, using an optical trap to localize the atoms within the cone enhances the signal-to-noise ratio of the fluorescence transmitted through the spectral filter and arriving a photomultiplier or other photodetector, resulting fluorescence detection signal with an enhanced S/N.

Abstract: A 3D microwave sensor includes a cloud of particles, e.g., rubidium 87 atoms. A laser system produces: a first probe beam directed through the particle cloud along a first path; a second probe beam directed through the particle cloud along a second path that intersects the first path to define a Rydberg intersection; a first coupling beam that counterpropagates with respect to the first probe beam along the first path; and a second coupling beam that counterpropagates with respect to the second probe beam along the second path. A spectrum analyzer characterizes the microwave field strength at the Rydberg intersection. The laser beams can be steered to move the Rydberg intersection within the particle cloud to compile a microwave field strength distribution in the particle cloud.

Abstract: A magnetic-field shield is used to shield a magneto-optical trap (MOT) in an ultra-high vacuum (UHV) cell from magnetic fields generated by an ion pump used to maintain the UHV. The magnetic-field shield includes an enclosure of ferro-magnetic material that acts to capture portions of the magnetic field generated by the ion pump. However, as the distance between the ion pump and the MOT is less than 6 centimeters, enough of the magnetic field escapes through the ferro-magnetic material, and this leakage could impair the MOT. A drive magnet attached to the yoke redirects magnetic flux, that would otherwise leak out of the magnetic-field shield, along a path within the ferro-magnetic enclosure and away from the MOT.

Abstract: An atomic clock employs hybrid long/short quantum clock frequency regulation wherein each of a series of regulation cycles includes a relatively long (four Ramsey-cycle) combination error signal (CES) cycle and plural relatively short (two Ramsey-cycle) single error signal (SES) cycles. The CES cycles provide for better long-term stability than can be provided using only SES cycles. However, including the SES cycles between CES cycles improves short term stability with negligible diminishment of long-term stability.

Abstract: An adaptive quantum signal processor (AQSP) includes a signal combiner, a physics station, a measurement system, a machine-learning engine and an output generator. The signal combiner combines incoming signals with control functions to yield recipe functions. For example, the recipe functions can be “shaking” functions used to change the wavefunctions of atoms entrained in an optical lattice. The recipe functions are applied to wavefunctions in initial wavefunction states causing the wavefunctions to transition to signal-impacted states. The measurement system measures the wavefunctions in their signal-impacted quantum states to yield wavefunction characterizations. The machine-learning engine updates control functions based on the wavefunction characterizations. The output generator outputs results based on the wavefunction characterizations and/or control function characterizations. In a matched-filter application, the outputs characterize (e.g., identify, classify, rate) the incoming signals.