Patent classifications
G04F5/14
OPTICAL LOCAL OSCILLATOR FOR ALL-OPTICAL TIME SCALES, AND ASSOCIATED TIMEKEEPING METHODS
The frequency stability of an optical local oscillator is improved by locking a laser to a silicon Fabry-Perot cavity operating at a temperature near 124 K, where the coefficient of thermal expansion of silicon is near zero. The cavity is mounted inside a cryostat housed in a temperature-stabilized vacuum system that is surrounded by an isolating enclosure and supported by an active vibration platform. Laser light is steered with a superpolished mirror toward a superpolished focusing optic that couples the laser light into the cavity. Light reflected from the cavity is used to stabilize the laser via the Pound-Drever-Hall technique, while light transmitted through the cavity is used to stabilize the laser power. A resonant transimpedance amplifier allows the laser power to be reduced, which reduces heating of the cavity caused by residual absorption of the light.
OPTICAL LOCAL OSCILLATOR FOR ALL-OPTICAL TIME SCALES, AND ASSOCIATED TIMEKEEPING METHODS
The frequency stability of an optical local oscillator is improved by locking a laser to a silicon Fabry-Perot cavity operating at a temperature near 124 K, where the coefficient of thermal expansion of silicon is near zero. The cavity is mounted inside a cryostat housed in a temperature-stabilized vacuum system that is surrounded by an isolating enclosure and supported by an active vibration platform. Laser light is steered with a superpolished mirror toward a superpolished focusing optic that couples the laser light into the cavity. Light reflected from the cavity is used to stabilize the laser via the Pound-Drever-Hall technique, while light transmitted through the cavity is used to stabilize the laser power. A resonant transimpedance amplifier allows the laser power to be reduced, which reduces heating of the cavity caused by residual absorption of the light.
Atomic Cell, Method For Manufacturing Atomic Cell, And Quantum Interference Device
An atomic cell filled with an alkali metal includes: a substrate; a first coating layer provided on an inner wall of the substrate and derived from a first molecule; a second coating layer provided on the first coating layer, and derived from a second molecule having a non-polar group and a reactive group that undergoes a desorption reaction with the first molecule; and a third coating layer provided on the second coating layer and derived from a non-polar third molecule. The third coating layer has a degree of crystallinity of 70% or more.
Collimated atomic beam source having a source tube with an openable seal
Various disclosed embodiments include collimated beam atomic ovens, collimated atomic beam sources, methods of loading a source of atoms into an atomic oven, and methods of forming a collimated atomic beam. In some embodiments, an illustrative collimated beam atomic oven includes: a tube having a first portion and a second portion; a source of atoms disposed in the first portion of the tube; an aperture disposed in the second portion of the tube; a heater assembly disposable in thermal communication with the tube; and an openable seal disposed in the tube intermediate the source of atoms and the aperture.
Frequency modulation spectroscopy with localized fluorescence
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.
Frequency modulation spectroscopy with localized fluorescence
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.
Millimeter Wave Magnetic Sensor
In described examples, a magnetic sensor includes a waveguide that encapsulates dipolar molecules. A mm-wave electromagnetic field is launched into the waveguide, travels through the dipolar molecules, and is then received after passing through the dipolar molecules. The frequency of the mm-wave electromagnetic signal is swept across a range that includes an intrinsic quantum rotational state transition frequency (Fr) for the dipolar molecules. Absorption peaks in accordance with the Zeeman effect are determined. A strength of a magnetic field affecting the magnetic sensor is proportional to a difference in the frequencies of the absorption peaks.
Quantum NV-diamond atomic clock
The invention is related to a novel atomic clock developed by taking into basis Quantum mechanics and the spin-spin status of the electrodes that have been trapped. The disadvantages such as radioactivity perceived in atomic clocks, half life and shelf life are prevented by means of the invention.
Quantum NV-diamond atomic clock
The invention is related to a novel atomic clock developed by taking into basis Quantum mechanics and the spin-spin status of the electrodes that have been trapped. The disadvantages such as radioactivity perceived in atomic clocks, half life and shelf life are prevented by means of the invention.
Inorganic passive coatings for atomic vapor cells
Some variations provide an atomic vapor-cell system comprising: a vapor-cell region configured with vapor-cell walls for containing an atomic vapor; and a coating disposed on at least some interior surfaces of the walls, wherein the coating comprises magnesium oxide, a rare earth metal oxide, or a combination thereof. The atomic vapor-cell system may be configured to allow at least one optical path through the vapor-cell region. In some embodiments, the coating comprises or consists essentially of magnesium oxide and/or a rare earth metal oxide. When the coating contains a rare earth metal oxide, it may be a lanthanoid oxide, such as lanthanum oxide. The atomic vapor-cell system preferably further comprises a device to adjust vapor pressure of the atomic vapor within the vapor-cell region. Preferably, the device is a solid-state electrochemical device configured to convey the atomic vapor into or out of the vapor-cell region.