Hamamatsu-photonics K.k.

Hamamatsu Photonics Kabushiki Kaisha

Hitachi, Ltd.

Research Development Corporation of Japan

Tsuneyuki Urakami

Shinichiro Aoshima

Yutaka Tsuchiya

Hironori Takahashi

Isuke Hirano

Yoshihiro Takiguchi

Takuya Nakamura

Motohiro Suyama

Mitsuharu Miwa

Tamiki Takemori

Yutaka Yamashita

Hiroshi Tsuchiya

Teruo Hiruma

Junji Endo

Nobuyuki Osakabe

Kazuyoshi Ohta

Shinji Ohsuka

Tetsuji Kodama

A concentration measuring apparatus for an absorption component in a scattering medium includes a light source ( ) for generating at least two light rays having predetermined wavelengths, the light rays having different transport scattering coefficients for a scattering medium ( ) as an object to be measured, and a known ratio of the transport scattering coefficients; light incidence means ( ) for making the light rays incident from a light incident position into the scattering medium ( ); photodetection means ( ), ( ) for detecting the light ray which has propagated inside the scattering medium ( ) at at least one photodetection position different from the light incident position to acquire at least one photodetection signal; parameter detection means ( ) for detecting, on the basis of the photodetection signal, a light intensity and a mean flight pathlength at the light detection position for each of the at least two light rays having predetermined wavelengths; and arithmetic processing means ( ) for calculating a concentration of an absorption component on the basis of a predetermined relationship between the ratio of the transport scattering coefficients, the light intensity, the mean flight pathlength, and a difference between absorption coefficients per unit concentration of the absorption component for the at least two light rays having predetermined wavelengths.

Concentration measuring method and apparatus for absorption component in scattering medium

An electron-microscope image viewing apparatus capable of measuring of a moving speed or a vibration frequency of an atomic structure, a magnetic structure, an electric structure or the like of a specimen even when the structure changes at a high rate. The apparatus includes a charged particle source for emitting charged particles, an illuminating electron lens system for illuminating a specimen with a beam of the charged particles, an image magnifying/projecting lens system for magnifying an image of the specimen formed by charged particles scattered upon transmission through the specimen and projecting the magnified image onto an image forming plane, at least one charged particle extracting means provided on the image forming plane of the image magnifying/projecting lens system for taking out the charged particles from a predetermined portion of the charged particle beam projected onto the image forming plane, at least one charged particle detector for detecting the charged particles taken out through the charged particle extracting means, and a signal processing means for processing a signal outputted from the charged particle detector.

Charged particle guide apparatus and image viewing apparatus for charged

An optical measuring method and an optical measuring apparatus are capable of obtaining the true mean time delay of a light waveform within a short time for the purpose of obtaining information on the internal structure of an object. Calculations include a first mean time delay when the light path includes the object, a second mean time delay when the light path does not include the object, and a subtraction of the second mean time delay from the first mean time delay to obtain a true mean time delay.

Optical measuring method and an optical measuring apparatus for

This invention has as its object to provide a voltage measurement apparatus which has a compact probe unit, and which can perform a measurement in a non-contact manner. The voltage measurement apparatus includes detection means for detecting an electric field generated in a space by a voltage applied to the surface of a device to be measured, light-emitting means for modulating output light by superposing a detected signal obtained from the detection means on a bias current which is supplied to inductively radiate the output light, a constant current source for supplying the bias current to the light-emitting means, extraction means for extracting a signal component of the output light from the light-emitting means, and light-transmission means for guiding the output light from the light-emitting means to the extraction means, and measures the applied voltage to the surface of the device to be measured by bringing the detection means close to the device to be measured in a non-contact manner.

Voltage detection apparatus

Light having a predetermined wavelength and various incident angle components to be incident on a surface of a scattering medium to generate an equivalent point light source or a group of equivalent point light sources near or on the surface of the scattering medium, and light diffused during propagation in the scattering medium is detected outside, and considering isotropic light from the equivalent light sources is immediately diffused, the optically detected signal is processed to detect a predetermined parameter which is primary information and this predetermined parameter is processed to measure internal information which is secondary information in the scattering medium with high accuracy.

Method for measuring internal information in a scattering medium and

A system for measuring timing relationship between two signals for accurately measuring a timing relationship between signals includes an electro-optic measuring unit and a waveform storage and processing unit. The electro-optic measuring unit samples electrical signals from a device under measurement via a strobe light so as to measure the signal waveform. The electro-optic unit uses a laser diode as a light source. The waveform storage and processing unit stores the electrical signal waveforms measured by the electro-optic measuring unit in digital form. The waveform storage and processing unit also calculates a correlation between two stored electrical signal waveforms via a correlation calculation unit, and also detects a peak of the correlation to detect a timing relationship between the signals.

System for measuring timing relationship between two signals

Light the intensity of which is modulated to the initial intensity by a modulating signal having an ac component with a predetermined frequency and which is from the intensity tuneable light irradiating unit irradiates the scattering and absorption medium which is an object to be measured. The modulated light incident on the scattering and absorption medium propagates in the scattering and absorption medium, emerges therefrom and is incident to the photodetecting unit, and the photodetecting unit converts the incident light into an electric signal corresponding to the intensity of the incident light, and thereafter, outputs the electric signal as an optically detected signal. The feedback unit extracts the ac component from the input optically detected signal, and the intensity of the ac electric signal and the adjusting value are compared and the variation of the quantity of generating light is sent to the intensity tuneable light irradiating unit. Then, the phase difference detection is performed as the gain of the photodetecting means is fixed and the intensity of the ac component having a modulation frequency emitted from the photodetecting means is maintained so as to substantially match with the preset adjusting value.

Photodetecting apparatus having intensity tuneable light irradiating unit

A change in voltage can be sensitively detected at a local part of a measured object. A set of laser medium and E-O probe are disposed between a pair of mirrors, a first one and a second one, forming a laser resonator. A linearly polarized light is emitted from the laser medium. The polarized light enters the E-O probe, and returns after being reflected by the second mirror. When a voltage is given to the E-O probe from the measured object, depending on the voltage, a refractive index of the E-O probe is changed, the light emitted from the E-O probe is ovally polarized, and a resonance status of the laser resonator then varies. Therefore, the light intensity emitted through the partially penetrating first mirror to the outside of the laser resonator corresponds to the voltage at the measured object in the proximity of the E-O probe. Consequently, a voltage distribution on the measured object such as IC with fine structures can be two-dimensionally detected.

Voltage measuring apparatus having an electro-optic member

Polarized light is input to an optical modulator typically consisting of an electrooptic crystal. The polarization state of the input light is changed in accordance with a voltage being applied to the optical modulator. Receiving the light output from the optical modulator, a polarization interferometer produces an interference fringe on the input surface of a photodetector such as a streak camera and a CCD line sensor. Based on an output signal of the photodetector, an analyzing device calculates a pitch and a movement distance of the interference fringe to determine the voltage being applied to the optical modulator.

Polarization interferometer optical voltage detector utilizing movement

Polarized light pulses are applied to an optical modulator including an electrooptic crystal. A polarization state of the applied light is changed in accordance with a voltage of an electrical signal applied to the optical modulator. A polarization interferometer receives the light output from the optical modulator, and generates an interference fringe on the input surface of a photodetector such as a one-dimensional CCD. A processing device calculates a pitch and a movement distance of the interference fringe, based on an output signal of the photodetector, to determine the voltage. A waveform of the electrical signal is determined by sampling the electrical signal with multiple light pulses, while varying a phase relationship between the electrical signal and the light pulses.

Sampling-type optical voltage detector utilizing movement of

An optical converter is so arranged that light to be measured and probe light are made to interact with each other on a nonlinear element and that mixed light produced by the interaction is detected, which is characterized in that an energy amount of interacting signal light is kept as high as possible without spatial expansion of signal light, which could lower the SN ratio. For this, the time-space conversion function is achieved by a method for producing the probe light. Namely, the optical converter comprises (a) a nonlinear element for making two types of light interact with each other to cause the nonlinear optical effect, (b) a device for guiding light to be measured to the nonlinear element, and (c) a device for producing probe light crossing the light to be measured on the nonlinear element and changing a traveling direction of probe light with change of crossing time. A light waveform measuring apparatus or an optical serial-parallel converter may be attained by adding to the optical converter (d) a device for detecting mixed light produced by the interaction between the signal light and the probe light on the nonlinear element.

Apparatus for affecting time-space conversion on a light signal changing

An object of this invention is to provide a pulsed laser beam source device which is easy to handle and is operative stably. Pumping light is irradiated to a laser medium from a light source for optical pumping. The stimulated laser medium pumps radiation of a set wavelength. This radiation is stimulated to be amplified while reciprocating between resonator mirrors. A multi layer film is inserted in an optical path of the radiation. Feeble light of the radiation from the laser medium is absorbed by the multi-layer to be weaker, and that part of the radiation having intensities above a set intensity is compressed in terms of time to be emitted outside. The emitted radiation has a very short pulse duration.

Pulsed laser beam source device

An optical wavelength shifter shifts a wavelength of light over a wide range without need for using a large peak pump pulse. A nonlinear optical medium having a nonlinear refractive index is disposed interiorly of a laser resonator. A pump pulse and a light to be modulated are incident on a nonlinear optical medium to phase shift the light. With the provision of a timing delay unit, the timing at which the light to be modulated is incident on the nonlinear optical medium is delayed with respect to the timing at which the pump pulse is incident thereon.

Optical wavelength shifter using nonlinear refractive medium disposed

The optical apparatus includes first and second deflection members, a mask, a pumping light source, and a controller. The first and second deflection members are formed of nonlinear optical material whose refractive index is changed upon light radiation. The mask is arranged on an optical path extending from a front side of the first deflection member to a rear side of a second deflection member. The mask has a predetermined transmission pattern. The pumping light source radiates first and second beams on predetermined regions of the first and second deflection members. This changes the refractive indices of the predetermined regions to bend the optical path. The controller variably controls the intensity of the first and second beams.

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Hamamatsu, Japan

Tsuneyuki Urakami