Abstract: A voltage measuring apparatus comprises an optical probe furnished with an electro-optic material whose refractive index is changed in accordance with a voltage developing in a given part of an object and an auxiliary electrode for terminating electric lines of force coming from the given part, a light source for producing light to be inputted to the electro-optic material, a light polarization detector for detecting a polarization state of output light from the electro-optic material, and a power source for applying a variable voltage to the auxiliary electrode. An absolute value of the voltage in the given part can be determined as a specific value of the variable voltage obtained when no change is detected in the polarization state of the output light.

Abstract: The electrical signal observing device measures the electrical signal by applying the electrical signal to be measured to an optical amplifier in order to modulate a short pulse light train directed through the electrical amplifier. The electrical signal to be measured acts as a gain control for the optical amplifier. The photodetector detects the output of the optical amplifier and applies a resultant electrical signal to an integrator circuit after which the signal is displayed. The signal may be displayed in a time base fashion using a sweep generated by a delay system of the short pulse light train.

Abstract: A voltage detector for measuring the voltage waveform of an object being measured on the basis of the optical intensity signal corresponding to the voltage of the object, including a light source for generating light, an optical modulator for converting the light from the light source into an optical intensity signal corresponding to the voltage of the object, and a sampling type high-speed photodetector for sampling the optical intensity signal from the optical modulator and measuring the voltage waveform of the object on the basis of the sampled optical intensity signal.

Abstract: A voltage detecting device using an electro-optical material with a refractive index that is changed by a voltage at a part of an object comprising a light source, an electro-optical material for changing the optical path of the light beam from the light source in accordance with the refractive index of the electro-optical material, and a streak camera to display on a Phosphor screen an image of the voltage over time at a part of the object.

Abstract: A voltage detector comprises a light modulator which employs an electro-optic material whose refractive index changes according to the voltage developing in an object to be measured. A transparent anti-reflection film having a refractive index and thickness which are predetermined on the bases of a refractive index of the electro-optic material and a wavelength of incident light is formed on both light entrance and exit surfaces of the electro-optic material.

Abstract: An electrical signal observing device has an optical signal as a probe for converting the voltage or current waveform to be measured into an optical intensity waveform. This optical intensity waveform is converted into a signal which can be used by a signal observation device. A continuous wave light source is used for generating an optical signal which is amplified by an optical amplifier having a gain controlled by the electrical signal to be measured. A photodetector detects light from the optical amplifier and generates an observation signal which is displayed by a display unit.

Abstract: A voltage detector with an optical modulator comprising a pulse light source for outputting light pulses, a pulse train generator for generating a light pulse train having a pulse interval with the aid of light pulses provided by the pulse light source and for applying the light pulse train to an optical modulator, and a detector for detecting the optical intensities of light pulses forming the light pulse train which are modulated by the optical modulator with a voltage waveform to be detected.

Abstract: A light intensity stabilizing apparatus comprises an optical amplifier such as a non-resonant traveling-wave type optical amplifier, whose gain is adjustable by a controlling electrical signal and which amplifies incident light emitted from a light source, a beam splitting means for branching output light of the optical amplifier into stabilized output light and feedback light, a light intensity detector for converting said feedback light into an electrical signal, and a control unit for producing said controlling electrical signal in accordance with said electrical signal from said light intensity detector.

Abstract: A multi-channel voltage detector for converting multi-channel electrical signals into optical signals and simultaneously detecting multi-channel voltages in parallel mode.

Abstract: A voltage detector comprises a pulse light source, a delay means, a dispersing prism made of an electro-optic material and a linear image sensor. The electro-optic material senses a voltage developing in a selected area of an object as a change of its refractive index. An optical path of a pulse light is changed by the dispersing prism according to the change of its refractive index. An output pulse light emerging from the dispersing prism is detected by a linear image sensor. A waveform of the periodic voltage pulses can be detected by gradually delaying a phase of the pulse light emitted from the light source. The voltage developing in one-dimensional positions in the object can be also detected by employing a dispersing prism extending along the positions to be detected and a two-dimensional detector.

Abstract: A voltage detector detects a voltage developing in a selected area of an object such as an integrated circuit by utilizing an electro-optic material equipped in an optical probe. A change in refractive index of an electro-optic material which is caused by the voltage in the object, is detected as a change of polarization of a light beam passing through the electro-optic material. In order to avoid undesired changes of polarization of the light beam when passing through optical fibers, a polarizer, beam splitters, and an analyzer are assembled together and connected to the electro-optic material to form a compact optical probe.

Abstract: An optical heterodyne detector comprising means for causing two light beams to interfere with each other and producing interference light beams thereof, a streak camera for receiving the interference light beams and analyzing means for analyzing an output of the streak camera, thereby to detect a beat frequency of the two light beams.

Abstract: A voltage detecting device for detecting voltages in an object under test including an electro-optic material covering a plurality of parts of the object under test; the refractive index of the electro-optic material being variable according to an applied voltage. A light source emits light through the electro-optic material toward the object under test and a detecting device receives an emergent light beam reflected from within the electro-optic material in order to detect voltages in the object. Further, a scanning device automatically scans the object under test with the light beam in order to detect voltages at a plurality of locations on the object.

Abstract: A voltage detector detects and indicates simultaneously the voltage levels at a plurality of parts of an object to be measured. A probe formed of electrooptic material having a refractive index changed in the presence of a voltage placed near the object and beams of polarized light are transmitted through the probe and reflected by a polarized beam splitter to a detector for indicating the voltage levels at the parts of the object.

Abstract: A voltage detector detects a voltage developing in a selected area of an object such as an integrated circuit by utilizing an electro-optic material equipped in an optical probe. A change in refractive index of the electro-optic material hwich is caused by the voltage in the object, is detected as a change of polarization of a light beam passing through the electro-optic material. In order to simplify the optical system, the electro-optic material itself has a function to change the light-traveling path. In the first aspect, a surface of light-incidence side is worked into a lens shape. In the second aspect, the electro-optic material has a graded refractive index profile as a result of ion diffusion.

Abstract: A highly repetitively pulsed laser stabilizing device which comprises a laser resonator, a feedback system for optically delaying an optical pulse emitted from the laser resonator and returning it in such a manner that it is superposed on an optical pulse in the laser resonator, and a feedback system control section that monitors one of the optical pulses of the laser resonator and feedback system, and controls the optical path length of the feedback system so that the monitored optical pulse is optimum in intensity.

Abstract: A voltage detector detects a voltage developing in a selected area of an object such as an integrated circuit by utilizing an electro-optic material equipped in an optical probe. A change in refractive index of the first electro-optic material which is caused by the voltage in the object, is detected as a change of polarization of a light beam passing through the first electro-optic material. In order to compensating for a polarization change caused by the spontaneous birefringence, the first and second electro-optic materials made of the same material are disposed in such a manner that the first and second electro-optic materials and aligned along a light-traveling direction with their lengths in the light-traveling direction being substantially identical and with their optic axes being perpendicular to each other.

Abstract: In a voltage detector using an electro-optic material whose refractive index is changed by a voltage developing in a selected area of an object under test, a light beam emitted from a light source is applied to a beam splitter, where it is split into a light beam advancing along a reference optical path and a light beam advancing along an optical path extended to an optical path length changing means made of the electro-optic material, and the light beams are returned from the reference optical path and the optical path length changing means after reflection to the beam splitter, where they are caused to interference with each other to provide an output light beam which is applied to a detector. The efficiency of light beam utilization is improved, and the voltage developing in the selected area of the object can be detected with high accuracy.

Abstract: In a voltage detector using an electro-optic material whose refractive index is changed by a voltage developing in a selected area of an object under test, an end portion of the electro-optic material has a corner-cube shape, whereby the detection of the voltage can be accurately achieved substantially being free from the influence of the input light tilt to the optical axis.

Abstract: A highly repetitively pulsed laser device is provided including a feedback system simple in construction which returns a light pulse emitted from a laser resonator to the laser resonator so that the light pulse is superposed on a light pulse in the laser resonator.