A sensor for detecting an amount of current flowing in a wire wherein displacement of a sensing mirror is used in an interferometer to enable determination of the amount of current. The sensor includes a magnetostrictive element located within a magnetic field formed by the wire. The sensor also includes a position sensor that detects a size increase of the magnetostrictive element. In addition, the sensor includes an amplifying device that amplifies the size increase of the magnetostrictive element by a predetermined amplification factor to provide an amplified size increase. Further, the sensor includes a displacement device that displaces the sensing mirror by an amount corresponding to the amplified size increase.

A sensor for detecting an amount of current flowing in a wire wherein displacement of a sensing mirror is used in an interferometer to enable determination of the amount of current. The sensor includes a magnetostrictive element located within a magnetic field formed by the wire. The sensor also includes a position sensor that detects a size increase of the magnetostrictive element. In addition, the sensor includes an amplifying device that amplifies the size increase of the magnetostrictive element by a predetermined amplification factor to provide an amplified size increase. Further, the sensor includes a displacement device that displaces the sensing mirror by an amount corresponding to the amplified size increase.

An inspection apparatus includes a tester unit that applies a stimulus signal to a semiconductor apparatus, an MO crystal arranged to face a semiconductor apparatus, a light source that outputs light, an optical scanner that irradiates the MO crystal with light output from light source, a light detector that detects light reflected from the MO crystal arranged to face the semiconductor apparatus D and outputs a detection signal, and a computer that generate phase image data based on a phase difference between a reference signal generated based on a stimulus signal and the detection signal, the phase image data including a phase component indicating the phase difference, and generates an image indicating a path of a current from the phase image data.

The disclosure includes an electro-optical sensor. The electro-optical sensor includes a test signal input to receive a test signal from a device under test (DUT). A bias circuit is employed to generate a bias signal. The electro-optical sensor also includes a Mach-Zehnder Modulator (MZM) that employs an optical input, an optical output, and a bias input. The MZM is configured to receive an optical carrier signal via the optical input. The MZM also receives both the test signal and the bias signal on the bias input. The MZM modulates the test signal from the bias input onto the optical carrier to generate an optical signal while operating in a mode selected by the bias signal. The MZM also outputs the optical signal over the optical output.

An optical voltage sensor assembly includes an input fiber-optic collimator positioned and configured to collimate input light beam from a light source. A crystal material is positioned to receive the input light beam from the light source and configured to exhibit the Pockels effect when an electric field is applied through the crystal material. An output fiber-optic collimator is positioned to receive an output light beam from the crystal material and configured to focus the output light beam from the crystal onto a detector. Methods of using the optical voltage sensor assembly are also disclosed.

In an optical modulator capable of modulating incident laser beam L by a compound semiconductor single crystal having a property of generating an electro-optic effect, the attenuation of the signal strength in a low frequency band is prevented without lowering the carrier concentration of the compound semiconductor. The optical modulator 23 comprises: incidence limiting means 25 which is provided on or near an incidence plane 24a, on which the laser beam L can be incident, of the compound semiconductor single crystal 24 so as to limit incidence of light other than the laser beam L on the incidence plane 24a; and a shielding member 26 which is formed from a low-permittivity material having a light blocking effect, and covers a surface 24c of the compound semiconductor single crystal 24 extending along a traveling direction of the laser beam L that entered the compound semiconductor single crystal 24.

An optical voltage sensor assembly includes an input fiber-optic collimator positioned and configured to collimate input light beam from a light source. A crystal material is positioned to receive the input light beam from the light source and configured to exhibit the Pockels effect when an electric field is applied through the crystal material. An output fiber-optic collimator is positioned to receive an output light beam from the crystal material and configured to focus the output light beam from the crystal onto a detector. Methods of using the optical voltage sensor assembly are also disclosed.

The present invention discloses a system and method for measuring an anode current of an aluminum electrolytic cell. The system includes a plurality of electrolytic cell units, where the electrolytic cell units each include: a column bus, two horizontal buses, m anodes, m anode rods, one or a pair of crossover buses, and a plurality of optical fiber current sensors. When one side of the anode rod is adjacent to another anode rod, the horizontal bus between the two anode rods is provided with one of the optical fiber current sensors; and when any side of the anode rod is adjacent to the column bus or the crossover bus, the horizontal bus between the anode rod and the column bus or the crossover bus is provided with one of the optical fiber current sensors. In the present invention, optical fiber current sensors are mounted between two adjacent anode rods and between the anode rod and the column bus or the crossover bus for current measurement, the current of each anode can be measured accurately, and the measurement precision is accurate to be within 1%.

A fiber-optic interferometer is designed to receive and propagate a first single-mode wave along a first optical path and, respectively, a second single-mode wave along a second optical path, the second optical path being the reverse of the first optical path, and to form a first output wave and, respectively, a second output wave, having a modulated phase difference .sub.m(t). According to the invention, the modulated phase difference .sub.m(t) is equal to sum of a first periodic phase difference .sub.(t) having a level equal to , a second periodic phase difference .sub.alpha(t) having a level equal to alpha and a third periodic phase difference .sub.beta(t) having a variable level between beta and +beta, said modulated phase difference .sub.m(t) comprising per modulation period T at least eight modulation levels among twelve modulation levels and said modulated phase difference between such that: .sub.m(t+T/2)=.sub.m(t).

A current sensor for a detection target current using a shunt resistor includes: a resistance value correction circuit having a correction resistor; a signal application unit that applies an alternating current signal to a series circuit of the shunt resistor and the correction resistor; a voltage detection unit that detects terminal voltages of the shunt resistor and the correction resistor; and a correction unit that calculates a resistance value of the shunt resistor and corrects the resistance value for detection; and a power supply circuit having a first power supply generation unit that generates a first power supply of the signal application unit from an input power supply of an outside; and a second power supply generation unit that generates a second power supply of the voltage detection unit.