Abstract: A fiber optic AC electric field or voltage sensing system is described for applications in high voltage environment, particularly, in the vicinity of a power line. The system is based on diffractive MEMS device. A condenser antenna positioned in the electric field feeds a voltage signal to the diffractive MEMS device, which then modulates the light signal passing through it. In the optical receiver, the electric filed strength is measured from the received optical signal.

Abstract: A solar simulator and a measurement method of the multi-junction photovoltaic device is provided. The measurement method includes following processes. The process that the halogen lamp emits a flash and a top of a light pulse wave shape is controlled to be flat. The process that the xenon lamp once or plural times emits a flash which has the flat top and is shorter pulse than the flat area of the halogen lamp flash while the top of a light pulse shape of the halogen lamp flash is flat. The process that the flashes from the halogen lamp and the xenon lamp is irradiated to the photovoltaic device as the measurement object, and during the emission of the flash from the xenon lamp, the load of the photovoltaic device is controlled and the current and the voltage generating therefrom are measured at single point or plural points.

Abstract: A method and a system are provided for fixing a Faraday optical current sensor in a suitable measurement position for measuring the current in a 3-phase cable that includes 3 individual section-shaped phase conductors insulated in relation to one another and encapsulated inside an insulator. The method includes providing a Faraday optical current sensor arrangement having 3 Faraday optical current sensors, each of which is fixed in a specific position outside the insulator; and providing a processing unit for calculating a current value from a magnetic field value. The method is performed by measuring 3 magnetic field values using each of the 3 sensors and calculating the current in each of the section-shaped phase conductors using the processing unit and the 3 magnetic field values.

Abstract: In an integrated optical circuit, light from a light source is polarized and coupled to a first and second strip waveguide. A waveguide coupling element couples the two optical signals from the two strip waveguides to different polarization modes of an optical fiber line. The optical fiber line is connected to a measuring head, which reflects the optical signal and in which a phase difference between the two optical partial signals is modulated in a magnetic field. In the waveguide coupling element, the reflected signal is split into two optical partial signals having the same polarization and the phase difference between the two partial signals is determined. A phase modulator device provides for closed-loop operation. Compared to fiber-optical concepts, the number of splices is reduced.

Abstract: A Faraday optical current sensor arrangement for measuring the current through a power line comprises a Faraday optical current sensor (38) having an elongated and substantially cylindrical shape defining a first end and a second end opposite the first end. The Faraday optical current sensor has a first optical conduit (48) extending from the first end and a second optical conduit (48) extending from the second end. Furthermore, the Faraday optical current sensor arrangement comprises a hollow housing (12,14) enveloping the Faraday optical current sensor and fixating the Faraday optical current sensor in a specific measurement position relative to the hollow housing. The hollow housing defines a channel for accommodating the Faraday optical current sensor and the first and second optical conduits and an opening (15) for communicating with the channel.

Abstract: A system monitors alternating current and includes a magneto-optical current transducer (MOCT) adapted to modulate an optical signal corresponding to magnitude of the alternating current. Beam splitters are in communication with the MOCT which are in turn connected to respective channels. Each channel includes an LED that is powered by a constant current source.

Abstract: A current measuring device for circuit breakers with an improved electronic circuit arrangement by way of arrangement and method for displaying electrical line current by a circuit breaker wherein measurements are made by at least one current transformer. Indications of the magnitude of electrical current are displayed by at least one LED and by the intensity of illumination by each LED. The current measuring device is placed onto a circuit breaker wherein at least one LED of the improved circuit is made accessible by sight at the front face of the current measuring device attached to the circuit breaker. A current transformer is located inside the current measuring device attached to the circuit breaker for measuring the current flowing through the conductor applied to the circuit breaker.

Abstract: In a measurement of a time-domain waveform of a terahertz wave based on time-domain spectroscopy, a current signal including a component originating from the terahertz wave is detected using a photoconductive device, and a voltage signal corresponding to the detected current signal is detected. At a pre-processing stage before the voltage signal detection, an offset current included in the detected current signal and having no relation to the terahertz wave is drawn. The offset current is monitored and the magnitude of the drawn offset current is adjusted according to a result of the monitoring. A time-domain waveform of the terahertz wave is acquired based on the voltage signal detected while drawing the offset current. The monitoring of the offset current and the adjusting of the offset current are performed in a waiting state in which measurement of the time-domain waveform of the terahertz wave is not performed.

Abstract: A radio frequency (RF) testing apparatus, for testing device under test (DUT) comprising a receiving antenna, includes a pair of transmitting antennas transmitting wireless communication signals to the receiving antenna, a shielding box, a first filter and a second filter. The shielding box includes a transmitting box, a receiving box for receiving the DUT, a connecting box connecting between the transmitting box and the receiving box and a pair of transmitting antennas fixed on the transmitting box and suspending towards the connecting box. The connecting box includes a microwave absorption medium on the connecting box and communicates with the receiving box. The first filter is mounted on the connecting box and the transmitting box to electrically connect with the transmitting antenna. The second filter is mounted on the receiving box to electrically connect with the DUT.

Abstract: A system for monitoring a plurality of components distributed in different space locations, includes: at least one optical fiber path; an optical radiation source adapted to inject optical radiation into the at least one optical fiber path; at least one first and at least one second optical branches branching from the at least one optical fiber path and adapted to spill respective portions of the optical radiation, the first and second optical branches being adapted to be operatively associated with a respective component to be monitored.

Abstract: A monitoring circuit of the present invention provides a monitor signal with which a magnitude of a current flowing across a photodetector, such as a photodiode, can be calculated accurately over a wide temperature range on the basis of a value of the monitor signal. The monitoring circuit of the present invention includes: a current mirror circuit for outputting a monitor current proportional to an input current, the current mirror circuit having an input point for receiving the input current, the input point being connected to a photodetector and a load resistor, which are connected thereto in parallel; and an output circuit for outputting a monitor signal indicating a difference between a monitor electric potential proportional to the monitor current, and an offset electric potential proportional to an offset current which flows across the load resistor concurrently with the monitor current.

Abstract: A bi-directional current limiter may be configured to receive an AC signal and bi-directionally limit the loop current to a predetermined current value. A first and second zone may be configured in series with the AC signal and bi-directional current limiter. The first and second zone may include unidirectional current limiters to limit a unidirectional current that is proportionately less than the bi-directionally limited current. A first opto-coupler circuit (ISO1) may be configured to detect both high and low current states in the current loop circuit. Second and third opto-coupler circuits (ISO2 and ISO3) associated with the first and second zones may be configured to detect only high current states in the current loop circuit. The status of the first and second zones may then be determined by an analysis of the current level in the current loop circuit during two half cycles as determined by the various current limiters.

Abstract: A fiber optic current or magnetic field sensor uses a sensing fiber in a coil for measuring a current or a magnetic field and has a retarder for converting between linearly polarized light and elliptically polarized light. The retardation of the retarder, its temperature dependence as well as its azimuth angle in respect to the plane of the fiber coil are optimized in dependence of the birefringence in the sensing fiber in order to minimize the influence of temperature variations and manufacturing tolerances on the overall scale factor of the sensor.

Abstract: Two transversely poled fibers are disclosed which can be wound around a holder with their poling directions being anti-parallel. A coupling exchanges the polarization directions of the modes of the fibers. Thermally and mechanically caused birefringence changes can thereby be substantially cancelled, while electrical field induced birefringence changes can be added, to provide a more robust high voltage measuring device.

Abstract: The invention relates to a method and device for measuring the location of a particle beam (10) present in packets in a linear accelerator comprising a hollow chamber structure (4) in which an electromagnetic wave oscillating at a base frequency (f0) is generated in order to accelerate the particles, wherein an electrical measurement signal (M) generated by the particle beam (10) by means of electromagnetic interaction with the measurement recorder (16) is recorded by at least one measurement recorder (16) disposed in the hollow chamber structure (4), said signal being a function of the distance between the measurement recorder (16) and the particle beam (10). According to the invention, the measurement signal (M) is analyzed in a frequency range different from the base frequency (f0) and higher natural frequencies of the hollow chamber structure (4), comprising a whole multiple of the base frequency (f0).

Abstract: A method and system for determining the Vcom for a liquid crystal display by using a light diffusing unit.

Abstract: A time-stretched enhanced recording scope (TiSER) is described using time stretch analog-to-digital conversion in a real-time burst mode. A chirped optical signal is modulated in response to receiving segments of an input signal. The optical signal with its modulated input signal, is stretched through an optical medium and digitized to represent the waveform segment. TiSER provides ultra-fast real-time sampling within short segment bursts of the original input signal while providing an ability to detect non-repetitive events. Methods and apparatus are also described for providing real-time information about inter-symbol information (ISI), rapidly determining bit-error rates (BER), performing time-domain reflectometry (TDR), generating eye diagrams for serial data, facilitating digital correction of data, clock recovery, optical carrier phase recovery, and otherwise increasing the speed and/or accuracy of a diverse range of high-speed signal measurement and processing activities.

Abstract: A voltage sensor includes an insulator with mutually insulated electrodes embedded therein. The electrodes are coaxial and cylindrical and overlap axially along part of their lengths. They are mutually staggered and control the surfaces of electric equipotential such that there is a substantially homogeneous electric field outside the insulator and a substantially homogeneous but higher field within a sensing cavity within the insulator. A field sensor is arranged within the sensing cavity to measure the field. This design allows for the production of compact voltage sensors for high voltage applications.

Abstract: At least one conductor is disposed in sealed vessel, which is filled with insulating gas, an hand hole is provided to a part of sealed vessel and is closed by a sealed cover, and optical fibers are disposed that form a closed loop surrounding conductor in sealed vessel. Optical fibers are hermetically led out of sealed vessel from sealed cover and are provided with at least a light source unit and an optical signal processor unit at the lead-out end. An airtight hollow tube disposed looping around leaving a predefined distance of separation is provided to conductor in sealed vessel, the end of tube is hermetically connected to sealed cover by sealing/bonding means, and optical fibers can be inserted in sealing/bonding means.

Abstract: A voltage sensor includes an insulator with mutually insulated electrodes embedded therein. The electrodes are coaxial and cylindrical and overlap axially along part of their lengths. They are mutually staggered and control the surfaces of electric equipotential such that there is a substantially homogeneous electric field outside the insulator and a substantially homogeneous but higher field within a sensing cavity within the insulator. A field sensor is arranged within the sensing cavity to locally measure the field. This design allows for the production of compact voltage sensors for high voltage applications.

Abstract: An electro-optic effect based optical voltage transformer comprises an optical voltage sensor head and an electrical unit, wherein the electrical unit comprises an optical closed-loop feedback control unit and a signal processing unit, the optical closed-loop feedback control unit is connected to the optical voltage sensor head and the optical voltage sensor head is connected to the signal processing unit. In this invention, the light source output power is more stable, the light source center wavelength drift is effectively controlled and the output power coastdown caused by light source aging is prevented; the optical power fluctuation of the optical polarization caused by factors such as temperature, optical fiber vibration, etc., is eliminated, which is conductive to stability and reliability of the optical system; the accuracy of data is improved.

Abstract: A detection apparatus and an imaging apparatus are capable of accurately conducting non-destructive observation of a target by using an incoherent electromagnetic wave. The detection apparatus has a generating section, a first coupler section, a delaying section, a second coupler section and a signal processing section. The generating section 101 includes a coherent electromagnetic wave source 102 and a diffusing section 103 for generating a pseudoincoherent electromagnetic wave by changing a propagation state of the coherent electromagnetic wave in accordance with a code pattern. The incoherent electromagnetic wave is split into first and second waves and the first wave is affected by the target of observation while the second wave is delayed by the delaying section. The first and second waves are then coupled to produce a coupled wave having a correlation signal of them and the signal is utilized to acquire information on the inside of the target of observation.

Abstract: Disclosed is an optical fibre birefringence compensation mirror. Also disclosed is a current sensor wherein vibration resistance has been increased due to the optical connection of the optical fibre birefringence compensation mirror. The optical fibre birefringence compensation mirror includes: an optical fibre, a birefringence element, a lens, a magnet, a Faraday rotator, and a mirror. From the light incidence/emission end surface of the optical fibre, the birefringence element, Faraday rotator, and mirror are arranged in said order. Light comes in from the optical fibre, and is separated into two linearly polarised lights by the birefringence element. The polarisation planes of the two linearly polarised lights are rotated by the Faraday rotator, and the two linearly polarised lights are point-symmetrically reflected at one point by the mirror, then again rotated by the Faraday rotator, then re-combined into one light by the birefringence element and made to enter the optical fibre.

Abstract: The invention relates to a method for determining the maximum open circuit voltage and the power that can be output by a photoconverter material subject to a measurement light intensity, the method including the following steps: measuring the photoluminescent intensity of the material, measuring the absorption rate of the photoconverter material at a second wavelength substantially equal to the photoluminescent wavelength of the photoconverter material, determining the maximum open circuit voltage of the photoconverter material with the measurement light intensity by means of the absorption rate and the photoluminescent intensity measured at substantially the same wavelength; said invention being characterised in that the light source and the photoconverter material are arranged such that the angular distributions of the rays incident on and emitted by the lit surface of the material and collected by the detector are substantially identical.

Abstract: Provided is a technique for mass-producing a conductor to which is fixed a current detection head that detects the value of current flowing in the conductor, and in which the relationship between the detection value and the current value is stabilized. The head comprises a lens, a magneto-optical element, a conductor, and a fixing member, and the lens, the magneto-optical element, and the conductor are respectively fixed to the fixing member. An optical system is formed using the current detection head such that light is guided through the lens to the magneto-optical element, and light affected by a magneto-optical effect due to the magneto-optical element is guided to the lens. All of the members contributing to current detection are fixed to the fixing member, and therefore the relative positional relationships of all the members contributing to current detection are uniquely determined, enabling conductors with little variation in current detection characteristics to be mass-produced.

Abstract: A method of measuring a current of a current carrying cable teaches the first step of providing an optical sensor assembly comprising a base unit, and an optical current sensor mounted on the base unit for transmitting a beam of polarized electromagnetic radiation to an optical fiber. A light detector is also provided having a first channel that operably connecting the light detector to an analog to digital converter through a programmable gain amplifier, a second channel that operably connects the light detector directly to the analog to digital converter, and a processor operably connected to the analog to digital converter. The optical sensor assembly is mounted adjacent the current carrying cable, and the fiber optic is operably connected to a light detector. A plurality of factors are then evaluated from rotation information from the light detector, by using the first and second channels for analog to digital conversion operably connected with the processor.

Abstract: The present invention relates to an apparatus and a method for inspecting quantum efficiency homogeneity of a solar cell using a spatial light modulating device. The apparatus includes a light emitting device configured to radiate predetermined light; a spatial light modulating device configured to change a light path of rays emitted from the light emitting device according to individual control of a plurality of pixels; a spatial light modulating device controller configured to individually control the states of the plurality of pixels; a solar cell which the rays passing through or reflected from the spatial light modulating device irradiate; and a calculation controller configured to calculate quantum efficiency of the solar cell based on a photocurrent signal generated from the solar cell.

Abstract: Processes and systems for use in reverse engineering integrated circuits determine functionality through analysis of junctions responding to external radiation. Semiconductor devices include a number of p-n junctions grouped according to interconnected functional cells. A surface of the semiconductor device is illuminated by radiation, e.g., by a laser or an electron beam, producing electron-hole pairs. Such pairs give rise to detectable currents that can be used to determine locations of irradiated junctions. By scanning a surface of the device in such a manner, a layout of at least some of the junctions can be obtained. The layout can be used to identify functional cells according to a lookup process. By selectively providing input test vectors to the device and repeating the scanning process, first level functional cells can be identified. A netlist of interconnected functional cells can thus be determined and expanded by repeating the process with different test vectors.

Abstract: An adapter device for applying a fiber-optic monitoring system to a component to be monitored includes a shell adapted to surround the component to be monitored, the shell having a rounded exposed surface onto which a first optical fiber of the fiber-optic monitoring system can be wrapped.

Abstract: Photo-field-effect transistor devices and associated methods are disclosed in which a photogate, consisting of a quantum dot sensitizing layer, transfers photoelectrons to a semiconductor channel across a charge-separating (type-II) heterointerface, producing a sustained primary and secondary flow of carriers between source and drain electrodes. The light-absorbing photogate thus modulates the flow of current along the channel, forming a photo-field effect transistor.

Abstract: A solar simulator which uses a honeycomb structure for providing highly collimated light for testing one or more photovoltaic cells.

Abstract: An apparatus, for measuring an applied electrical field and for reducing perturbation to the electrical field being measured, includes a laser integrated into an electro optic crystal sensor head prior to the output fiber. A probe beam is passed along the crystal direction of low birefringence of nearly circular optical indicatrix, rather than one of high EO modulation. The EO crystal is placed between two crossed polarizers and oriented such that a small tilt angle is subtended between its optic axis and the path of the probe beam. Improved optical coupling is achieved by using a large core multimode fiber at the output, to reduce optical insertion losses. A collimating lens emits the intensity modulated laser beam back to a photodetector, where the intensity modulated laser beam is converted to an electrical signal representing both field strength and phase of the electrical field applied to the sensor head.

Abstract: The invention relates to a method for analyzing an integrated circuit, including a step for applying laser radiation at a point on the surface of the circuit, a step for exciting the circuit thus subjected to laser radiation by applying an electrical excitation signal, a step for collecting the response of the circuit to the excitation, the circuit being subjected to laser radiation, and a step for measuring the phase difference between the response to the excitation of the circuit subjected to laser radiation and a reference response of the circuit in the absence of laser radiation applied to the circuit. The invention also relates to an associated observation method and installation.

Abstract: A method is provided for tuning the fiber optic retarder of a fiber optic current sensor towards a desired temperature dependence, the sensing fiber is exposed to a magnetic field or corresponding electric current and the sensor signal as well as the signal's dependence on the retarder temperature are measured. From this initial sensor signal and its temperature dependence, a target sensor signal can be determined, at which the dependence on the retarder temperature equals a desired value. Then, the retarder is thermally treated until the sensor signal reaches the target value. The method obviates the need for repetitively measuring the temperature dependence during the tuning process.

Abstract: A Fiber-optic current sensor for sensing electric current carried in an electric conductor (18). Its optical section comprises: a light source (1); a directional coupler (2) with two ports (2A, 2B) of two arms each; a radiation polarizer (3); a polarization modulator (4); a fiber line (17) coupled to a current-sensing fiber loop (11); a mirror (10); and a photodetector (22). The first port of the coupler (2) is coupled to the light source (1) and to the photodetector (22). Its second port is coupled via the radiation polarizer (3) to the polarization modulator (4). The polarization modulator comprises a magneto-sensitive element (5), around which a solenoid (6) is wound. The fiber loop (11) comprises a magneto-sensitive optical fiber with embedded linear birefringence. An electronic section comprises a signal generator (21) which drives the solenoid (6); and a signal processing unit which receives the optical signal from the photodetector (22).

Abstract: The present invention provides an optoelectronic memory device, the method for manufacturing and evaluating the same. The optoelectronic memory device according to the present invention includes a substrate, an insulation layer, an active layer, source electrode and drain electrode. The substrate includes a gate, and the insulation layer is formed on the substrate. The active layer is formed on the insulation layer, and more particularly, the active layer is formed of a composite material comprising conjugated conductive polymers and quantum dots. Moreover, both of the source and the drain are formed on the insulation layer, and electrically connected to the active layer.

Abstract: A voltage measuring circuit includes a voltage measuring port, a voltage reference unit, a first voltage comparing unit and a light emitting diode. The voltage measuring port is for receiving an external voltage to be measured. The voltage reference unit includes a port providing a reference voltage. The first voltage comparing unit includes a reference port connected to the voltage reference unit, a measuring port connected to the voltage measuring port, and an output port for outputting a high/low level voltage when the external voltage is lower/higher than the reference voltage. The light emitting diode includes a cathode connected to the output port of the first voltage comparing unit and an anode connected to an external voltage port.

Abstract: An installation base is secured to part of outer peripheral surface of cylindrical container 1 which has electric conductor 2 arranged thereinside, and a case which stores a Faraday-effect element is detachably secured to the installation base. Faraday-effect element 10 having two optical fibers 24A, 24B of prescribed dimensions, to provide first and second optical paths 11A, 11B maintained in parallel with a predetermined interval therebetween and placed so as to intersect axial direction of electric conductor 2, and having mirror 12 which reflects linearly polarized light at one end surface of each optical fiber. Linearly polarized light from the same light source injected into each of the optical paths 11A, 11B, and current flowing in electric conductor 2 is measured base on the Faraday rotation angle of the linearly polarized light reflected and returned from mirror 12.

Abstract: Apparatus and methods of use thereof for the measurement of photocurrents are provided.

Abstract: A master-slave current sensor system for measuring, for example, differential current on a transmission line is described. The slave current sensor can be periodically recalibrated (or have a compensation value re-calculated) based on the master sensor's average output, and the slave sensor can be unpowered and remote from an electronics box which receives its measurements. Health monitoring and fault location can also be performed using the master-slave optical current sensor system, optionally in conjunction with one or more voltage sensors.

Abstract: A test apparatus for a power supply unit is provided, which includes a body unit configured to define a space to receive a light emitting diode (LED) and to provide a test environment to test a supply state of power applied to the LED; and a test unit mounted in the body unit to face the LED and configured to detect flicker of the LED occurring when a power supply is abnormal. According to the foregoing structure, power supply with respect to the LED may be regularly detected and analyzed, thereby increasing quality of power supply with respect to the LED.

Abstract: A voltage detection circuit used to detect a voltage source includes a Zener diode, a thyristor, a first resistor, a second resistor, a first light-emitting diode (LED), and a second LED. A cathode of the Zener diode is connected to the voltage source. An anode of the Zener diode is connected to a control terminal of the thyristor through a first resistor. An anode of the thyristor is connected to the voltage source through a second resistor. The anode of the thyristor is connected to an anode of the first LED. A cathode of the thyristor is connected to a cathode of the first LED. The cathode of the thyristor is connected to an anode of the second LED, and a cathode of the second LED is grounded.

Abstract: Processes and systems for use in reverse engineering integrated circuits determine functionality through analysis of junctions responding to external radiation. Semiconductor devices include a number of p-n junctions grouped according to interconnected functional cells. A surface of the semiconductor device is illuminated by radiation, e.g., by a laser or an electron beam, producing electron-hole pairs. Such pairs give rise to detectable currents that can be used to determine locations of irradiated junctions. By scanning a surface of the device in such a manner, a layout of at least some of the junctions can be obtained. The layout can be used to identify functional cells according to a lookup process. By selectively providing input test vectors to the device and repeating the scanning process, first level functional cells can be identified. A netlist of interconnected functional cells can thus be determined and expanded by repeating the process with different test vectors.

Abstract: A novel electronic device is described herein that can be manufactured for a cost of less than $10.00, and that can be used by an inexperienced person to measure the TDS in an aqueous solution such as tap water and the conductivity/resistivity of a variety of other substances, materials, and liquids. A phono plug connected to the device is connected to a power source and is immersed in the aqueous solution and causes an LED (in one embodiment) to illuminate to an intensity directly proportional to the TDS in the solution. A rheostat connected to a second LED and power source is then adjusted until the second LED visually is equal in illumination intensity to the first LED. A number is then read from the dial of the rheostat, which number is directly proportional to the TDS of the aqueous solution (or material) and is used as data to compare to future or past readings or to determine the actual TDS using a chart or graph.

Abstract: Broadband isotropic (omnidirectional) antenna typically comprising three orthogonal small size monopole antennas protruding through the centers of three adjacent sides of the small metal cube. Each antenna has the frequency correcting network and RF amplifier. Signals from all three antennas are commutated by the RF switch (multiplexer) and the output can be applied to any RF spectrum analyzer. It is shown that if spectrum analyzer sweeps at relatively slow rate or is used in max/hold mode, the resulting display is proportional to the magnitude of the electromagnetic field vector independent of the orientation of the monopole antennas with respect to the E-field direction. Another embodiment improves the circuit accuracy in case when one dominant RF signal is present.

Abstract: An optical voltage transformer is connected with an external electric device and includes a primary electrode to which a measured voltage is applied by the external electric device, a first secondary electrode provided oppositely to the primary electrode, an insulation layer provided between the primary and first secondary electrodes and constituting an insulation cylinder integrally formed with the primary and first secondary electrodes, a ground layer provided on an outer circumference of the insulation cylinder and around the first secondary electrode for securing a capacitance by interposing the insulation layer between the ground layer and the first secondary electrode, and an electro-optic element for measuring a voltage between the first secondary electrode and the ground layer.

Abstract: A device, apparatus and method for trapping metal ions and detecting metal ion contamination in a solution provide a semiconductor device formed on a semiconductor substrate and including an N-well formed over a P-type substrate and at least a contact portion of the N-well in electrical contact with the solution. When the semiconductor device is optically illuminated, a P/N junction is formed as a result of photovoltaic phenomena. Metal ions from the solution migrate to the contact area due to the voltage created at the P/N junction. The semiconductor device includes a conductive structure with conductive features separated by a gap and therefore in an initially electrically open state. When the ions migrate to the contact area, they precipitate, at least partially bridging the gap and creating conductance through the conductive structure. The conductance may be measured to determine the amount of metal ion contamination.

Abstract: A sensor head assembly is provided, comprising a quarter wave device having shape-induced-birefringence and a sensing coil coupled to the quarter wave device and operable to wind around a current conductor. The quarter wave device converts linearly polarized light from a polarization maintaining fiber to circularly polarized light.

Abstract: In a measurement of a time-domain waveform of a terahertz wave based on time-domain spectroscopy, a current signal including a component originating from the terahertz wave is detected using a photoconductive device, and a voltage signal corresponding to the detected current signal is detected. At a pre-processing stage before the voltage signal detection, an offset current included in the detected current signal and having no relation to the terahertz wave is drawn. The offset current is monitored and the magnitude of the drawn offset current is adjusted according to a result of the monitoring. A time-domain waveform of the terahertz wave is acquired based on the voltage signal detected while drawing the offset current. The monitoring of the offset current and the adjusting of the offset current are performed in a waiting state in which measurement of the time-domain waveform of the terahertz wave is not performed.

Abstract: There is provided a test apparatus for testing a device under test, including a test signal generator that generates a test signal to test the device under test, an electric-photo converter that converts the test signal into an optical test signal, an optical interface that (i) transmits the optical test signal generated by the electric-photo converter to an optical receiver of the device under test and (ii) receives and outputs an optical response signal output from the device under test, a photo-electric converter that converts the optical response signal output from the optical interface into an electrical response signal and transmits the electrical response signal, and a signal receiver that receives the response signal transmitted from the photo-electric converter and a test method.