摘要:
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.
摘要:
A low noise pulsed light source utilizing a laser diode for generating a short pulsed light of a high repetitive frequency. The low noise pulsed light source includes a laser diode drived by an electric pulse generator for emitting repetitive pulsed light; a current source for supplying a bias current to the laser diode; and a photodetector for detecting the repetitive pulsed light emitted from the laser diode; and control means. The control means modulates at least one of the bias current from the current source and the amplitude of a pulse signal generated from the electric pulse generator in accordance with an output signal from the photodetector such that the intensity of the pulsed light is kept unchanged and any noise involved in the same is reduce. A feedback system including the photodetector and the control means has a peak in its frequency characteristics within a frequency band for light detecting in a light measuring system utilizing the low noise pulsed light source.
摘要:
A first part of input light containing both background light and signal light is extracted by a sampling streak tube and converted to a first electric signal by a photodetector. A second part of the input light containing only background light is extracted by the same sampling streak tube by offsetting the sampling timing and converted to a second electric signal by the photodetector. A signal component corresponding to the signal light is extracted by taking the difference between the first and second electric signals. In one embodiment, the sampling timing is offset by applying a chopping voltage to chopping electrodes provided in the sampling streak tube.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
An method of positioning an E-O probe applied to an apparatus for the measurement of voltage. In the first step, the relative position of the E-O probe against the magnifying optical system in the first condition of being focused the magnifying optical system on the base of the E-O probe, and the focal point difference between the focal plane of the magnifying optical system in the second condition that the E-O probe is substantially out of the optical path for observation of the surface of the device and the focal plane in the first condition are stored. The relative position and the focal point difference are fixed in the apparatus for the measurement of voltage regardless of the device to be measured. Next, in the second step, the focus of the magnifying optical system is adjusted to the observation position of the surface of the device in the second condition, and then in the third step, the magnifying optical system, the E-O probe, and the probe stage are separated from the device by the focal point difference stored in the first step by the Z-axis stage, and in the fourth step, the E-O probe is moved to the relative position of the E-O probe stored in the first step relative to the magnifying optical system by the probe stage.
摘要:
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.
摘要:
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.
摘要:
Young's interferometer consisting of a single slit and a double slit member, and an analyzer are arranged along the axis of light to be measured. Parallel slits of the double slit member are provided with respective polarizers whose paralyzing directions are at .+-.45.degree. to the longitudinal direction of the parallel slits. The polarizing direction of the analyzer is set in parallel with the parallel slits. The incident light passes through Young's interferometer and the analyzer to form an interference fringe, which is detected by an image detector unit. An image analyzer unit produces an intensity profile of the interference fringe and determines the polarization state of the incident light, for instance, by comparing the produced intensity profile with conceivable profiles stored in advance.