A method for atom-based closed-loop control includes exciting atoms of a gas into one or more Rydberg states, applying one or more signal processing functions to the one or more Rydberg states, and regulating a characteristic of the applied one or more signal processing functions based on, at least in part, a response of the one or more Rydberg states to the one or more signal processing functions. A system for internal quantum-state-space interferometry includes an atomic receiver, an interferometric pathway, and a detector. The interferometer includes an atomic vapor with first atomic states and second atomic states. The interferometric pathway from RF phases between the first and second atomic states is closed by a quantum-state-space. The detector is configured to detect a readout of an interferometric signal. Embodiments include atom-based automatic level control, baseband processors, phase-locked loops, voltage transducers, raster RF imagers and waveform analyzers.

The present invention is directed to an electro-optical sensor for high intensity electric field measurement. The electro-optical sensor was used to measure a strong 118 MV/m narrow pulse width (˜33 ns) electric field in the magnetically insulated transmission line (MITL) of a pulsed power accelerator. Accurately measuring these high fields using conventional pulsed power diagnostics is difficult due to the strength of interfering particles and fields. The electro-optical sensor uses a free space laser beam with a dielectric crystal sensor that is highly immune to electromagnetic interference and does not require an external calibration.

A device is suitable for revealing spatial variations in polarization of an electromagnetic radiation, in a form of localized temperature variations. The device includes a surface of a carrier which is electrically and thermally insulating, and includes an array of patterns which each consist of at least one rectilinear segment of a sensitive material, of which the orientation is variable within each pattern or between neighboring patterns. Such device may be used with a thermal camera to reveal, in infrared images, temperature variations which are localized at segments not perpendicular to a local direction of linear polarization of the radiation.

A layer arrangement for a phased array antenna comprises phase shifting units arranged between stacked dielectric layers with a tunable dielectric material sandwiched in-between. Each phase shifting unit comprises a transmission line with phase shifting capabilities that is electrically connected with bias lines to a biasing circuit. A dielectric layer is made from an optically transparent material. An overlapping section of the bias lines of each of the phase shifting units is made from an optically transparent and electroconductive material. The tunable dielectric material affects the transmission or reflection of light that illuminates the tunable dielectric material depending on the respective tuning state. Testing this layer arrangement comprises illuminating the layer arrangement by light while a predetermined electric bias potential is applied to at least some of the phase shifting units, and during which the light emission from the layer arrangement is detected and compared with an expected light emission.

A photonic Rydberg atom radio frequency receiver includes: an integrated photonic chip; an atomic vapor cell; and a receiver member including: a photonic emitter; probe light reflectors disposed on the atomic vapor cell; and coupling light reflectors disposed on the atomic vapor cell such that the pair of coupling light reflectors is optically opposed across the interior vapor space and receives and reflects the coupling laser light so that the coupling laser light is reflected between the coupling light reflectors multiple times in the interior vapor space of the atomic vapor cell.

A sensor receiver includes a Rydberg cell configured to be exposed to a radio frequency (RF) signal, and a probe source configured to generate a plurality of spaced apart pulsed probe beams within the Rydberg cell. The pulsed probe beams are offset in time from one another. A detector is positioned downstream from the Rydberg cell.

Methods and apparatuses for performing optical inspection of varactor diodes in an antenna are disclosed. In some embodiments, the method of testing an antenna having varactor diodes comprises: selecting a plurality of varactor diodes to be placed in a light emitting state; forward biasing the selected varactor diodes to a magnitude at which the selected varactor diodes are to emit light; and detecting one or more faulty varactor diodes of the selected varactor diodes based on their emitted light intensity.

A sensor receiver may include a Rydberg cell configured to be exposed to a radio frequency (RF) signal, and a probe source configured to generate a plurality of spaced apart pulsed probe beams within the Rydberg cell. The pulsed probe beams may be offset in time from one another. A plurality of excitation sources may be coupled to the Rydberg cell. A detector may be positioned downstream from the Rydberg cell.

Nitrogen vacancy (NV) centers in diamond combine exceptional sensitivity with nanoscale spatial resolution by optically detected magnetic resonance (ODMR). Infrared (IR)-absorption-based readout of the NV singlet state transition can increase ODMR contrast and collection efficiency. Here, a resonant diamond metallodielectric metasurface amplifies IR absorption by concentrating the optical field near the diamond surface. This plasmonic quantum sensing metasurface (PQSM) supports plasmonic surface lattice resonances and balances field localization and sensing volume to optimize spin readout sensitivity. Combined electromagnetic and rate-equation modeling suggests a near-spin-projection-noise-limited sensitivity below 1 nT Hz.sup.−1/2 per μm.sup.2 of sensing area using numbers for contemporary NV diamond samples and fabrication techniques. The PQSM enables microscopic ODMR sensing with IR readout near the spin-projection-noise-limited sensitivity, making it appealing for imaging through scattering tissues and spatially resolved chemical NMR detection.

In a method of atomic electrometry, EIT spectroscopy is performed on host atoms of an alkali metal in a vapor cell. The EIT spectroscopy indicates a resonant energy of a probed Rydberg state of the host atoms. The vapor cell is exposed to an ambient electric field. A shift in the resonant energy as indicated by the EIT spectroscopy is observed and interpreted as a measurement of the ambient field. During the measurement of the ambient field, a bias electric field is generated inside the vapor cell by shining light into the vapor cell from a light source situated outside of the cell. The bias field is useful for increasing the sensitivity of the measurement.