Abstract: A time division multiplexed optical voltage measuring system includes an optical voltage sensing system module including, (i) a plurality of optical sensors where each sensor is responsive to an input interrogation light wave, and (ii) one or more optical outputs affected by sensed electric field thereat. The optical voltage sensing system module includes an optical circuit arrangement having (i) an input for receiving a module specific pulsed light wave derived from a primary pulsed light wave from a remote light source, and (ii) arranged such that each of the plurality of optical sensors receives an interrogation pulsed light wave. The optical circuit arrangement of the optical voltage sensing system module further includes at least one optical wave combiner for combining like-kind of outputs from all of the plurality of optical sensors. The optical circuit is arranged such that the pulsed light waves from the outputs of different optical sensors arrive at the optical wave combiner at differing times.

Abstract: A method for sensing the state of an electrophoretic display includes the steps of applying an electrical signal to a display element, measuring an electrical response for the display element, and deducing the state of the display element from the measured electrical response. Also, the parameters of the display materials are determined using the encapsulated electrophoretic display media as a sensor, either alone or in conjunction with other sensors.

Abstract: An RF power sensor for measuring power for an RF signal using capacitance includes a substrate preferably formed of a semiconductor, such as silicon or of a dielectric substance, a fixture part fixed to the substrate and forming a signal line and ground lines that transmit RF signals, and a bridge connected to the ground lines and floating over the signal line, wherein the bridge is driven by an external driving force, and the external driving force induces capacitance between the bridge and the signal line. Accordingly, power for an RF signal can be measured through the capacitance between the signal line and the bridge. The RF power sensor facilitates matchings, reduces insertion loss, and can be used in a wide bandwidth because it is based on transmission lines having characteristic impedance. Further, high power can be measured depending upon bridge designs.

Abstract: An automatic transfer switch (ATS) system and method of operating an ATS system to switch between first and second powers received from respective first and second power supplies, are disclosed. In one embodiment, the method includes sensing a first phase associated with the first power and a second phase associated with the second power, and determining whether the first and second phases have failed to become synchronized within a first time period. The method further includes providing a control signal at a second output port when it is determined that the first and second phases have failed to become synchronized within the time period, determining that the first and second phases have become synchronized in response to the control signal, and switching between the first and second powers once it is determined that the first and second phases have become synchronized.

Abstract: An electric field sensing system is characterized so that a signal processor may derive an output representative of an electric field intended to be measured, particularly established by high voltage on a power line, with enhanced accuracy. Characterizing parameters may be derived from signals representative of a pair of light waves derived from a light wave exiting an optical electric field sensing element in a electric field sensing head spatially positioned in the high voltage environment.

Abstract: An electric field sensing system is characterized so that a signal processor may derive an output representative of an electric field intended to be measured, particularly established by high voltage on a power line, with enhanced accuracy. Characterizing parameters may be derived from signals representative of a pair of light waves derived from a light wave exiting an optical electric field sensing element in a electric field sensing head spatially positioned in the high voltage environment.

Abstract: Methods and apparatus for remotely controlled illumination of liquids in a variety of environments. In one example, remotely controlled multi-color LED-based light sources are employed to achieve a wide range of enhanced lighting effects in liquids. In another example, a pool or spa is illuminated by one or more remotely controlled multicolor light sources that may be employed as individually and independently controllable devices, or coupled together to form a remotely controlled networked lighting system to provide a variety of programmable and/or coordinated color illumination effects in the pool or spa environment.

Abstract: For measuring an electric voltage in an electro-optic voltage converter, polarized light of two wavelengths is sent through a medium. At the output side, the light is led through a polarizer and the remaining signal is measured. For compensating a temperature dependence of the electro-optic coefficients, the measured results at both wavelengths are compared, and the voltage value consistant with both measurements is used.

Abstract: Precision measurement of optical signal power is provided. In one implementation, a Wilson current mirror senses current through an avalanche photodiode (APD) that has been exposed to the optical signal. The output of this APD may also be used to recover data. By incorporating a high voltage transistor as the buffer, the Wilson current mirror is able to operate in series with the APD at a high bias level.

Abstract: Carbon nanotubes are formed on projections on a substrate. A metal, such as nickel is deposited on the substrate with optional platforms, and heated to form the projections. Carbon nanotubes are formed from the projections by heating in an ethylene, methane or CO atmosphere. A heat sensor is also formed proximate the carbon nanotubes. When exposed to IR radiation, the heat sensor detects changes in temperature representative of the IR radiation. In a gas sensor, a thermally isolated area, such as a pixel is formed on a substrate with an integrated heater. A pair of conductors each have a portion adjacent a portion of the other conductor with projections formed on the adjacent portions of the conductors. Multiple carbon nanotubes are formed between the conductors from one projection to another. IV characteristics of the nanotubes are measured between the conductors in the presence of a gas to be detected.

Abstract: Wiring in new and older aircraft use bundled insulated conductors that are subject to deterioration overtime that can result in on-board fires, loss of in-flight control and eventual crashes of the aircraft. The present invention provides a diagnostic method which permits the on-line and non-destructive diagnosis of the insulation degradation in a portion of the wiring comprising: a) measuring the current flow at locations of the aircraft wiring utilizing an optical current sensor with a bandwidth of dc to 50 kHz; b) determining the current flow within a high frequency bandwidth; and c) analyzing the results of the current flow differential determination and initiate the following: i) detect and locate the point of cable failure; ii) initiate an alarm annunciation; and iii) initiate an on-board sectionalized fire suppression system.

Abstract: An apparatus and method to simultaneously measure electric and thermal fields with a single probe. Using an electrooptic semiconductor probe, the Pockels effect is employed to measure electric field magnitude and phase, and the effect of photon absorption due to bandtail states in the semiconductor is used to measure temperature. Techniques to scale relative electric-field measurements to absolute units (volts/meter), stabilize electric-field phase drift, and calibrate electric-field data that is corrupted when the probe is used in regions where temperature gradients exist are provided.

Abstract: A transparent conductive layer is formed under a glass substrate. A reflection preventing layer and a reflecting layer are formed on the respective surfaces of an electro-optic crystal layer. The reflection preventing layer of the electro-optic liquid crystal layer is attached to the lower surface of the transparent conductive layer by use of an adhesive layer. In this manner, the reflection preventing layer is provided between the adhesive layer and the electro-optic crystal layer.

Abstract: The electra-optical voltage sensor has an electra-optically active medium and a distance medium between two electrodes, between which the voltage V to be measured is present. The media and the thicknesses d1, d2 of the media are chosen in such a way that the measured voltage signal has no temperature dependence. By way of example, the thicknesses d1, d2 are chosen in such a way that the influence of the temperature dependences of critical electra-optical coefficients and dielectric constants of the media on the voltage signal cancel one another out. The two media are advantageously arranged in the form of a rod, comprising an alternating arrangement of cylindrical elements of the two media, between the electrodes. BGO and fused silica may advantageously be used as media. The sensor is preferably cast in silicone.

Abstract: The voltage sensor for measurement of a voltage V, which is present between two electrodes (3, 4) and generates an electric field E, comprises at least two layers (1a, 2a) made of electro-optically active material and being arranged along a light path (5). Through the layers there passes a light beam, the phase and/or state of polarization of which is influenced on account of the electro-optical effect. The orientation of the electro-optically active layers (1a, 2a) relative to the light path and the electric field E is chosen in such a way, that the influencing of the light (5) in the second layer (2a) counteracts the influencing of the light (5) in the first layer (1a). In this way, it is possible to realize a sensor with a high half wave voltage, so that high voltages V can be measured unambiguously. A plurality of first and second electro-optically active layers are advantageously arranged between the electrodes (3, 4).

Abstract: For the multi-source method suitable to measure the photoelectric conversion characteristics of a stacked solar cell, the light-receiving area of the solar cell to be measured is limited to the minimal area of laboratory level, and it is hard to measure a cell, module, or array having an area more than 400 cm2. To cope with this problem, the irradiance of irradiation light is measured or adjusted, the current vs. voltage characteristic of a reference cell is measured, and the current vs. voltage characteristic of a sample cell is measured. Next, the current vs. voltage characteristic of the reference cell in standard test conditions is compared with the measurement result of the current vs. voltage characteristic of the reference cell, thereby obtaining a shift of the measurement result from the standard test condition on the basis of the shift of the irradiation light from the standard test condition. On the basis of the obtained shift of the measurement result, the measurement result of the current vs.

Abstract: An apparatus and method for continuous, passive detection and measurement of tensile and compressional strain in a structure utilizing a shielded optic fiber, the optic fiber having one or more Bragg gratings thereon, the gratings and shield being disposed in a curved path on the structure and a baseline response for the grating is made using an optical source and detector. Changes in tensile or compressional forces on the structure will result in changes in the curve of the grating, resulting in a frequency shift for the returned light.

Abstract: The object of the invention is to provide technique and an apparatus for precisely measuring high frequency current that flows in a transmission line of a small impedance load circuit. A current waveform can be measured in wide bandwidth (at high-time resolution) and at high sensitivity without processing DUT (nondestructive) and without having an effect of the impedance of the apparatus (noninvasive) by installing a magnetooptical device in a magnetic field generated based upon current that flows in the transmission line, applying a bias magnetic field to the magnetooptical device by a magnetic field generator, making polarized light incident under the control of a position so that detection sensitivity is maximum and detecting the variation of polarization included in reflected light from the magnetooptical device.

Abstract: An RF electric field probe device for measuring an RF electric field intensity in a plasma. The device is composed essentially of an electric field sensing unit and an output unit. The electric field sensing unit is composed of a first electro-optical component positionable in the plasma and operable to modulate light as a function of variations of the RF electric field in the plasma at the fundamental frequency and harmonics of the RF electric field, and a first antenna unit electrically coupled to the first component for coupling the first component to the RF electric field. The output unit is coupled to the electric field sensing unit for providing an output signal containing information relating to the magnitude and frequency of the modulation which occurs in the first component. The probe device may be used to map a plasma region by moving the probe device to any selected point in the plasma region.

Abstract: The voltage sensor for measurement of a voltage V, which is present between two electrodes (3, 4) and generates an electric field E, comprises at least two layers (1a, 2a) made of electro-optically active material and being arranged along a light path (5). Through the layers there passes a light beam, the phase and/or state of polarization of which is influenced on account of the electro-optical effect. The orientation of the electro-optically active layers (1a, 2a) relative to the light path and the electric field E is chosen in such a way, that the influencing of the light (5) in the second layer (2a) counteracts the influencing of the light (5) in the first layer (1a). In this way, it is possible to realize a sensor with a high half wave voltage, so that high voltages V can be measured unambiguously. A plurality of first and second electro-optically active layers are advantageously arranged between the electrodes (3, 4).

Abstract: A system for detecting fluids in a microfluidic component having at least one microchannel including a limitation wall which has two surfaces which, facing the microchannel in a transparent area, are inclined towards each other at an acute angle, with the system further including a photo transmitter and a photo receiver which are disposed outside the component and are directed to the inclined surfaces in the transparent area of the limitation wall in such a way that if a gas is waiting in the microchannel on the two surfaces, a light ray emitted by the photo transmitter impinges on the photo receiver following a total reflection on the two surfaces and, if a liquid is waiting in the microchannel, the light ray enters the microchannel on at least one of the two surfaces and, as a result, the incidence of light into the photo receiver is reduced or prohibited.

Abstract: A microwave power sensor and a method for manufacturing the same. The microwave power sensor includes a semiconductor substrate with a nitride or oxide film formed thereon. A membrane which is a portion of the nitride or oxide film is floated by removing a portion of the semiconductor substrate. First and second thermocouple groups are formed to be symmetrically spaced apart from each other on the membrane. An RF input end is formed on the nitride or oxide film. A heating resistor is formed on the membrane to be connected with the RF input end. First and second ground plates are formed on the nitride or oxide film at both sides of the RF input end. A third ground plate is formed on the nitride or oxide film to be connected with the heating resistor and electrically connected with the first and second ground plates. The first and second output terminals are formed on the semiconductor substrate to be connected with the first and second thermocouple groups, respectively.

Abstract: A measuring circuit capable of performing a high-accuracy measurement by eliminating inductive influence from an ambient noise voltage source. An electric circuit including a signal circuit of high impedance, a wiring conductor and a meter is provided with a shielding resistance member having a significantly lower resistance than that of the signal circuit in dependence on an inter-terminal voltage of the high impedance signal circuit and a shield formed of an electrically conductive material disposed in association with the wiring conductor. A voltage distribution function of the shielding resistance member is matched equally to that of an inter-terminal voltage distribution function of the signal circuit. By measuring a line voltage through the medium of the high impedance signal circuit shielded by the shielding resistor, high accuracy measurement can be realized without undergoing adverse influences of parasitic capacitance and induction.

Abstract: An electromagnetic field sensing apparatus includes an optical modulator, a miniature antenna for sensing the electromagnetic field, a light source, a first optical fiber, an optical detector and a second fiber. The optical modulator can vary the amplitude of a light beam propagating therethrough in response to an electric field intensity. The miniature antenna for sensing the electromagnetic field can sense both the electric field intensity and the magnetic field intensity of an electromagnetic field and apply an electric voltage to the optical modulator in response to the sensed electromagnetic field intensity. The light source is used to generate a light beam, the first optical fiber is used for transmitting the light beam to the modulator, and the second fiber is used for transmitting the light beam from the modulator to the optical detector.

Abstract: An optical current sensor having a reflection interferometer (1, 10) has, in its fiber-optic lead (2), a polarization-maintaining first fiber branch (20) for two forward-traveling orthogonally polarized waves and a polarization-maintaining second fiber branch (20′) for two backward-traveling orthogonally polarized waves. In this case, the two fiber branches (20, 20′) are connected to one another via a coupler (8) on the sensor side. The first fiber branch (20) is connected to a light source (4) and the second fiber branch (20′) is connected to the detector (5). A means for phase shifting (7) is funcionally connected to at least one of the fiber branches (20, 20′). It is thus possible to achieve a quasi-static control of the phase shift of the waves, so that less stringent requirements can be made of the means for phase shifting than of the phase modulators that are usually used in current sensors of this type.

Abstract: A method of probing voltage comprises: establishing electrical connectivity between a conductor to be probed and a first terminal of a photoconductive switch; during a sampling interval n, applying a laser pulse to the photoconductive switch while applying a voltage to a second terminal of the photoconductive switch corresponding to a voltage sample taken during a prior sampling interval n−1, such that current flow through the photoconductive switch is dependent on any difference between voltage of the conductor and the applied voltage; converting the current flow to a voltage signal; passing the voltage signal during a gating interval and sampling the passed voltage signal to produce a voltage sample for the sampling interval n. A repetitive test pattern applied to the conductor and the sampling interval is synchronized with the repetitive test pattern.

Abstract: In a fiber optic current sensor having a coiled sensor fiber (1) which encloses a current conductor (S), and at least one phase delay element (4, 5) adjoining the sensor fiber (1), the at least one phase delay element (4, 5) has a phase delay with a temperature dependence such that it at least approximately compensates for a temperature dependence of a Verdet's constant (V) of the sensor fiber (1). It is thereby possible to achieve an at least approximately temperature-independent sensor signal.

Abstract: An opto-electric device for measuring the root mean square value of an alternating current voltage has: a) an electric field-to-light-to-voltage converter having 1) a light source; 2) an electro-optic material: (a) receiving light from the light source; (b) modulating said light; and (c) providing a modulated light output; 3) an electric field applied to the electro-optic crystal to modulate the light from the light source to produce the modulated light output; b) an optical receiver for receiving and converting the modulated output light from the electro-optic material to a first voltage that is proportional to a square of the electric field applied to the electro-optic material; c) an averager circuit receiving the first voltage and providing a second voltage that is proportional to the average of said square of said electric field over a period of time; and d) an inverse ratiometric circuit receiving the second voltage from the averager circuit and returning a third voltage that is an inverse voltage of th

Abstract: An RSSI circuit provides a relatively inexpensive technique for accurately measuring received signal strength over a wide dynamic range. A received signal is processed by a rectifier circuit that generates a series of DC offsets of increasing magnitude. The DC offsets are imposed on a first polarity of the received signal to create a series of outputs that are the first polarity of the received signal with increasing DC offsets. Each of the outputs is coupled to one input of a weighted comparator with the other input of the comparator coupled to a second and opposite polarity of the received signal with no offset. The comparators determine when overlap occurs to indicate particular signal levels.

Abstract: A photo magnetic field sensor includes a Faraday rotator made of a paramagnetic material, a polarizer, an analyzer, a light-irradiating element, and a light-sensing element. The Faraday rotator is made of a paramagnetic garnet single crystal including at least Tb and Al.

Abstract: A measuring method for measuring current-voltage characteristics of a photoelectric conversion device by irradiating light to said photoelectric conversion device and a reference device corresponding to said photoelectric conversion device at the same time while detecting an irradiance of said light using said reference device, characterized in that a light responsive time constant of a irradiance detection circuit in which said reference device is used is adjusted so that said light responsive time constant of said irradiance detection circuit comes closer to a light responsive time constant of said photoelectric conversion device. An apparatus for practicing said measuring method.

Abstract: In order to detect and measure the power of radio or microwave frequency signals it is known to employ thermoelectric devices such as a thermistor or a thermocouple. Such thermoelectric devices can have slow response times and lack sensitivity due to ‘thermal lag’ and poor conduction between a load resistor and the thermoelectric device. The present invention therefore provides an apparatus for the measurement of a power of a radio or microwave frequency signal comprising a resistive element for generating a thermal emission in response to an incident signal and an infra-red photodetector arranged to receive the thermal emission and thereby generate an output signal corresponding to the power of the incident signal. The present invention obviates or at least mitigates the disadvantages associated with known thermoelectric devices.

Abstract: The invention is directed to a Faraday-type current sensor which is less susceptive to effects caused by rotation, acceleration and vibration of the sensor coil. The sensor coil of the invention includes a first coil section which forms the current sensing coil and a second coil section which is optically connected to the first coil section and forms a compensation or “bucking” coil. The optical fiber of the first coil section preferably has an almost zero birefringence and is connected in series with the optical fiber of the second coil section which preferably has a large birefringence. The illuminating radiation propagates through the sensor coil in such a way, as viewed along the coil axis, that the propagation direction of the radiation in the first coil section with respect to the coil axis is opposite from the propagation direction in the second coil section.

Abstract: A site or vehicle which includes a plurality of electromagnetic radiators monitors the radiation by the use of a plurality of broadband sensors spaced about the potential radiation site or vehicle. Each of the sensors produces signals indicative of the sensed power, and process the signals for transmission over a data network. The system also includes a processing system which receives the signals indicative of the sensed power from all of the sensors, and processes the signals to determine whether radiation levels are within the established values. The signals may be processed either at the sensors or at the processing system to form average or peak power determinations. The power levels are continuously compared with threshold levels. When the threshold is exceeded, warnings may be given, or automatic shutdown of the radiator may be instituted (136).

Abstract: An optical/analog/digital pulse detector receives an input signal and drives a Bragg cell illuminated by a collimated light beam. The Bragg cell spatially modulates the collimated light beam and upon exiting the Bragg cell is imaged by lenses of an optics network to the plane of an opaque plate. A binary optical plate replicates the image of the Bragg cell on the opaque plate. The opaque plate contains slits of various lengths located where the images of the Bragg cell are replicated. To obtain the power spectrum of each of the images on the opaque plate an anamorphic lens is positioned in the path of light passing through the opaque plate. Light passing through the anamorphic lens is sensed by a detector array having outputs coupled to a focal plane processor that processes the analog outputs from the detector array into initial tuning commands for detection and characterization of pulses in the input signal.

Abstract: An electro-optic sampling apparatus is provided to enable measurement on potentials of signals on the conductor of coaxial cable with high precision and with ease. Herein, an electric input connector inputs a measured electric signal, which is introduced to a conductive path such as a microstrip line. An electro-optic material (e.g., Bi12SiO20) that provides electro-optic effect such as Pockel's effect is fixed to a bare portion of the conductive path and is varied in birefringence ratio in response to strength of electric field caused by the conductive path through which the measured electric signal transmits. The conductive path is then terminated by a terminal device. Now, a laser beam is radiated toward the electro-optic material, wherein it is varied in polarization in response to variations of the birefringence ratio. Then, the laser beam is reflected by a dielectric mirror and is separated into two beams by a polarization beam splitter.

Abstract: A microwave and millimeter-wave electric-field mapping system based on electro-optic sampling has been developed using micromachined Gallium Arsenide crystals mounted on gradient index lenses and single-mode optical fibers. The probes are able to detect three orthogonal polarizations of electric fields and, due to the flexibility and size of the optical fiber, can be positioned not only from the extreme near-field to the far-field regions of microwave and millimeter-wave structures, but also inside of enclosures such as waveguides and packages. A microwave electric-field-mapping system based on micromachined GaAs electro-optic sampling probes mounted on gradient index lenses and single-mode optical fibers can extract field images from the interior of an enclosed microwave cavity.

Abstract: A method and/or apparatus for measuring current in a high voltage (HV) current carrier generates a low voltage signal proportional to the current in the HV carrier and applies this signal to an integrated-optic voltage sensor located in the HV environment adjacent to the HV current carrier to produce a modulated optical signal representative of the current being measured. The optical signal from the integrated-optic voltage sensor is conducted to a low voltage (LV) environment insulated from said HV environment and processed to provide a second electrical signal. One of the electrical signals is integrated so that an output signal of the required accuracy is available form the system.

Abstract: An apparatus, system, and method are provided for testing an integrated circuit with a probe card having optical fibers. The optical fibers of the probe card are fixed in alignment with test structures in the integrated circuit, and each optical fiber is coupled to an avalanche photo-diode for measuring photoemissions from the test structures. The photoemissions can be analyzed to verify correct circuit behavior. The optical fibers can be alternatives or complements to electrically conductive probes of the probe card.

Abstract: A current sensor which has a rigid metallic link member having two end portions of conductive material and an intermediate portion of resistive material interconnecting the end portions. An integrated circuit analog to digital converter is mounted on the link member. The converter has analog input terminals for connection to respective ones of the two end portions of the link member and digital output terminals for connection to a processing apparatus.

Abstract: Disclosed are methods and apparatus for automatically filtering out physical defects from electrical defects that are found during a voltage contrast inspection of a test structure on a semiconductor device.

Abstract: An optical current transducer configured to sense current in the conductor is disclosed. The optical current transducer includes a light source and a polarizer that generates linearly polarized light received from a the light source. The light is communicated to a magneto-optic garnet that includes, among other elements, bismuth, iron and oxygen and is coupled to the conductor. The magneto-optic garnet is configured to rotate the polarization of the linearly polarized light received from the polarizer. The optical current transducer also includes an analyzer in optical communication with the magneto-optic garnet. The analyzer detects the rotation of the linearly polarized light caused by the magneto-optic garnet.

Abstract: An apparatus and method for imaging a sample, the apparatus comprising: a source for irradiating a sample with a beam of substantially continuous electromagnetic radiation having a frequency in the range 25 GHz to 100 THz; means for subdividing an area of the sample which is to be imaged into a two dimensional array of pixels; means for detecting radiation from each pixel wherein the detector is configured to detect a phase dependent quantity of the detected radiation which is measured relative to the radiation which irradiates the sample.

Abstract: A small sized electro-optic voltage sensor capable of accurate measurement of high voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation. A polarization beam displacer separates the input beam into two beams with orthogonal linear polarizations and causes one linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels effect elliptically polarizes the beam as it travels through the crystal. A reflector redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization. The system may include a detector for converting the output beams into electrical signals and a signal processor for determining the voltage based on an analysis of the output beams.

Abstract: A meter for measuring electricity usage for a given load includes a housing and two light sources disposed in the housing and configured to output light at a predetermined frequency. Two light receivers are disposed in the housing so that a light path is defined between each light source and its respective light receiver. Each light receiver is configured to receive the light from its light source and to output a signal responsively thereto. A rotatable member is disposed in the housing in the light paths and is rotatable responsively to the electricity usage. The member has a first portion and a second portion. The first portion transmits incident light while the second portion blocks light. The first portion and the second portion are defined on the member so that the member modulates the light as it rotates. A filter circuit in communication with the light receiver is configured to receive the output signal from the light receiver and to detect therefrom modulation of the light by the rotatable member.

Abstract: A photonic integrated device includes a waveguide of semiconductor material and a detector for measuring optical power of light traveling along the waveguide. The detector which is monolithically integrated into the device measures a photocurrent on an electrode which has been generated in the waveguide by two photon absorption.

Abstract: The sampling element comprises a DC sampling voltage source, a threshold sampling circuit and a photoconductive switching element. The threshold sampling circuit includes a signal-under-test input, a sampling pulse input and an IF signal output, and has a sampling threshold with respect to sampling pulses received at the sampling pulse input. The photoconductive switching element is connected between the DC sampling voltage source and the sampling pulse input of the threshold sampling circuit. The sampling device comprises a DC sampling voltage source, a threshold sampling circuit, a photoconductive switching element and a light source. The threshold sampling circuit includes a signal-under-test input, a sampling pulse input and an IF signal output, and has a sampling threshold with respect to sampling pulses received at the sampling pulse input. The photoconductive switching element is connected between the DC sampling voltage source and the sampling pulse input of the threshold sampling circuit.

Abstract: A parameter monitoring apparatus for a high voltage chamber in a semiconductor wafer processing system monitors parameters in the high voltage chamber in real time by converting an electrical signal generated from the high voltage chamber into an optical signal using an electro-optical converter. The optical signal is then converted back into an electrical signal again by an opto-electrical converter. The parameters can be monitored in real time without damaging measurement devices, since they are not influenced by the potential difference between the high voltage chamber and the measurement device.

Abstract: An IC testing apparatus has a mainframe that includes a waveform generator, logic comparator, optical signal converter and photodector, and has a test head that includes an optical driver and optical output type voltage sensor. The optical signal converter converts a test pattern signal from the waveform generator into an optical signal that is sent to the test head through an optical waveguide to the optical driver. The optical driver converts the optical signal into an electric signal, which is applied to an IC under test in the test head. The optical output type voltage sensor converts a response signal received from the IC under test into an optical signal that is sent through an optical waveguide to the photodector, which converts it into an electrical signal for the logic comparator to compare so that the IC response can be assessed.

Abstract: An electric field sensing system is characterized so that a signal processor may derive an output representative of an electric field intended to be measured, particularly established by high voltage on a power line, with enhanced accuracy. Characterizing parameters may be derived from signals representative of a pair of light waves derived from a light wave exiting an optical electric field sensing element in a electric field sensing head spatially positioned in the high voltage environment.