Abstract: A light source for emitting a pulsed laser beam having an ultrashort pulse width and a voltage detector including the light source therein. The light source includes a laser driving unit for driving the laser source to output the pulsed laser beam while the intensity of the pulsed laser beam is stabilized. A chirp compensator is also included to compensate for a chirp in the pulsed laser beam. A wavelength selector is used to extract light having a desired wavelength from the pulsed laser beam, thereby obtaining a pulsed laser beam having an ultrashort pulse width and a desired narrow spectral band width.

Abstract: 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.

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 low noise pulsed light source using 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 reduced.

Abstract: 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.

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 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 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 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: 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: 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 stably trigger a streak camera, the first reference light split before entering the electro-optic material and the second reference light split after emerging from the electro-optic material are used in the form of the difference in intensity between the two reference light beams for generating a trigger signal supplied to the streak camera.