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 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 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 accomplish precise detection of the voltage, a mirror in the form of a thin metal film or a multilayered dielectric film is disposed at the tip of electro-optic material and, at the same time, a transparent electrode is disposed on the side of electro-optic material opposite to the side where the mirror is disposed. As a result, lines of electric force produced by the voltage developing in the object are aligned in the electro-optic material parallel to the center line of the optical probe and the change in refractive index becomes uniform.

Abstract: A voltage detecting device using an electro-optical material with a refractive index which is changed by a voltage at a part of an object comprising a light source, comprises an electro-optical material for changing the optical path of the light beam from the light source in accordance with the refraction index of the electro-optical material and a slit or optical fiber extractor at a predetermined position at the output of the electro-optical material for extracting the quantity of light of the light beam at the predetermined position and a detector detecting a voltage at the part of the object from the quantity of light extracted.

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: 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 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: 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: There is provided a voltage detecting device using an electro-optical material which has its refractive index changed by a voltage provided on an object under test. The voltage detecting device consists of a strip line formed on the upper surface of the electro-optical material and an electrode formed on the bottom surface of the electro-optical material. One or both of the strip line and electrode may be formed of transparent conductive materials. In operation, a light beam is passed either from the top or the bottom of the device through the electro-optical material and the change in the polarization of the light is measured. That change is related to the voltage level of the voltage signal passing through the strip line formed on the material.

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 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 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.