The invention is concerned with a bushing for high voltage applications and a bushing arrangement including such a bushing. The bushing includes a conductor defining a longitudinal axis (A) through the bushing where the bushing has a central section and a first and a second peripheral section on opposite sides of the central section along the longitudinal axis (A) and includes an optical fibre with a first part (P1) stretching through the central section, the fibre being adapted to detect physical properties being influenced or caused by the operation of the bushing. The sections are sections of a solid condenser core and the bushing further includes an enclosure for a length of fibre that is to exit the bushing, the enclosure being buried in the central section adjacent the surface of the condenser core and having an interior volume.

A pair of acousto-optic deflectors (AODs) is used to steer a pair of laser beams to address individual atoms of an array of atoms so that the beams can conditionally induce a 2-photon transition between the atom's quantum energy levels. The first beam is deflected into a +1 diffraction order, resulting in an AOD output beam with a frequency greater than that of the respective AOD input beam. The second beam is deflected into a −1 diffraction order so that the AOD output beam has a frequency less than that of the respective AOD input beam. The equal and opposite frequency changes compensate it other so that the sum of the output frequencies remains constant.

Methods and apparatus for sensing or measuring an electromagnetic field. The method entails excitation into a distribution of Rydberg states of atoms of a gas occupying a test volume coextensive with the electromagnetic field. Transmission along a path traversing the test volume of at least one probe beam of electromagnetic radiation is measured at one or more frequencies overlapping a spectral feature, and a physical characteristic of the electromagnetic field is derived on the basis of variation of the spectral feature. In various embodiments, the electromagnetic field may be place in interferometric relation with another electromagnetic field. Time-varying electric field amplitude, frequency, phase and noise spectral distribution may be measured, and thus AM and FM modulated fields, as well as magnetic fields of about 1 Tesla. The apparatus for measuring the electromagnetic field may be unilaterally coupled to a probe field and detector or array of detectors.

Sensing the electric or strain field experienced by a sample containing a crystal host comprising of solid state defects under a zero-bias magnetic field can yield a very sensitive measurement. Sensing is based on the spin states of the solid-state defects. Upon absorption of suitable microwave (and optical) radiation, the solid-state defects emit fluorescence associated with hyperfine transitions. The fluorescence is sensitive to electric and/or strain fields and is used to determine the magnitude and/or direction of the field of interest. The present apparatus is configured to control and modulate the assembly of individual components to maintain a zero-bias magnetic field, generate an Optically Detected Magnetic Resonance (ODMR) spectrum (with or without optical excitation) using appropriate microwave radiation, detect signals based on the hyperfine state transitions that are sensitive to electric/strain fields, and to quantify the magnitude and direction of the field of interest.

An optical waveguide 1, an optical waveguide 2 are formed on a substrate 3 to be crossed with each other, modulator electrodes 11, 12, 13 and 14 are arranged along the optical waveguides 1, 2, and antennas 21, 22, 23, 24 (i.e., square patch antennas having an approximately same shape) are arranged around four corners of the square shape. The modulator electrode 11 is energized from the antenna 21 and the antenna 22, the modulator electrode 12 is energized from the antenna 24 and the antenna 23, the modulator electrode 13 is energized from the antenna 21 and the antenna 24, and the modulator electrode 14 is energized from the antenna 22 and the antenna 23. The light wave propagating through the optical waveguide 1 is modulated by an electric field of Y-direction, and the light wave propagating through the optical waveguide 2 is modulated by an electric field of X-direction.

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.

In a general aspect, a vapor cell includes a body defined by a stack of layers bonded to each other. The stack of layers includes a first end layer disposed at a first end of the body and a second end layer disposed at a second, opposite end of the body. Intermediate layers extend between the first and second end layers and define an internal cavity extending through the body between the first end layer and the second end layer. The stack of layers also includes first and second sets of tabs. The first set of tabs extends outward from the intermediate layers on a first exterior side of the body, and the second set of tabs extends outward from the intermediate layers on a second exterior side of the body. The vapor cell also includes a vapor or a source of the vapor disposed in the internal cavity.

A Faraday enclosure for substantially attenuating microwave-frequency fields outside the Faraday enclosure. Information to and from the circuitry inside the Faraday enclosure is accessible by input pinholes and output pinholes, respectively. A sensor positioned outside of the Faraday enclosure and aligned with the first input pinhole senses microwave-frequency fields. A receiver inside the Faraday enclosure aligned with the input pinhole and the sensor responds to the sensor.

A SI-traceable Rydberg atom radiofrequency power meter determines power of reference radiofrequency radiation and includes: a reference radiofrequency source that provides reference radiofrequency radiation; a vapor cell including: a pair of parallel-plate waveguides; a vapor cell wall including parallel opposing faces of the parallel-plate waveguides; and the vapor space physically bounded by the vapor cell wall to contain gas atoms in an optical overlap volume; and a transmission detector that receives the output light from the vapor cell and produces a transmission signal from the transmission detector for determination of power of the reference radiofrequency radiation, wherein the SI-traceable Rydberg atom radiofrequency power meter determines power of the reference radiofrequency radiation by electromagnetically induced transparency of the gas atoms in a Rydberg electronic state, the determination of power being traceable to the International System of Units (SI).

A sensor system comprises a laser source that emits a pump beam at a first wavelength and a probe beam at a second wavelength, and an optical means for receiving the pump and probe beams. The optical means is operative to generate a plurality of light beams, each having a different frequency, from the pump and probe beams. One or more cells receive the light beams from the optical means and allow passage of the light beams therethrough, with the cells containing alkali atoms. A dichroic filter is configured to receive the light beams from the cells. The dichroic filter separates pump beam light and probe beam light from the light beams. A detector array receives the probe beam light from the dichroic filter. The detector array includes a two-dimensional array of photosensors that map out transmission of respective light beams corresponding to the probe beam light through the cells.