Tokyo University of Agriculture and Technology

Japan Science and Technology Agency

The University of Tokyo

Japan Science and Technology Corporation

Kazuhiko Misawa

Terumasa Ito

Hiroyoshi Lang

Takayuki Suzuki

Yuki Obara

Isao Matsuda

Fumikazu Inuzuka

Takayoshi Kobayashi

Provided is a light detection device having a laser light source, a splitting unit, a first modulation unit, a second modulation unit, a first detection unit and a second detection unit that detect light, and a control unit.

Light detection device and light detection method

An optical pulse pair generator is configured to generate an optical pulse pair including a first pulse beam and a second pulse beam having respective central wavelengths that are separated by a predetermined wavelength difference from each other and having target time waveforms that are substantially the same as each other. The optical pulse pair generator provided includes a splitter section configured to split an incident pulse beam into two, a first shaping section configured to shape one of the pulse beams split by the splitter section by shaping into the target time waveform and setting a central frequency so as to configure the first pulse beam, and a second shaping section configured to shape the other of the pulse beams split by the splitter section by shaping into the target time waveform so as to configure the second pulse beam.

Optical pulse pair generator, light detection device, and light detection method

A phase sensitive detection mechanism that uses electrical processing is realized, and an optical detection device, an optical detection method, and a program that are capable of detecting faint light at high speed and with high sensitivity are provided by a simple configuration. A light source section generates a first pulsed light. A filter section transmits a second pulsed light formed from a portion of a frequency spectrum exhibited by the first pulsed light, and reflects a third pulsed light formed from another portion of the frequency spectrum exhibited by the first pulsed light. A phase modulation section phase modulates the second pulsed light at plural phases. A multiplexing section produces a fourth pulsed light by multiplexing the third pulsed light with the second pulsed light phase modulated by the phase modulation section. A detector spectrally disperses and detects scattered light generated by radiating the fourth pulsed light onto a target object. An extraction section uses specific calculation processing to synchronize with the phase modulation in the phase modulation section, so as to extract a frequency spectrum of scattered light scattered based on the second pulsed light phase modulated by the phase modulation section from the frequency spectrum of the scattered light detected by the detector.

Optical detection device, optical detection method, and program

A time resolved, nonlinear complex susceptibility measuring apparatus () that is capable of measurement unaffected by any distortion of the wave front of a probe light whereby a temporal change in the nonlinear complex susceptibility of a nonlinear optical material that occurs when it is irradiated with a light pulse in a femtosecond range is measured using a pair of polarized lights orthogonal to each other which are formed by splitting a single light pulse into a reference and a probe light () and () in a polarized light splitting Sagnac type interference light path (). A direction of polarization converting mechanism for rotating a direction of polarization of the reference and probe lights by an angle of 90&#xb0; in the polarized light splitting Sagnac type interference light path is included to align the directions of polarization on a test specimen (). A phase difference between the reference and probe lights which are output from the polarized light splitting Sagnac type interference light path is swept by a phase difference sweep mechanism () whereby a time resolved, nonlinear complex susceptibility is found from a phase difference sweep interference waveform obtained by measuring the intensity of interference light between the reference and probe lights for each of such phase differences swept.

Time-resolved nonlinear complex sensitivity measuring apparatus

A linear opto-frequency chirp amount variable apparatus using a dielectric multilayer film mirror, which does not require the optical axis to be realigned each time the amount of a chirp is to be varied includes a pair of opposed, parallel, dielectric, multilayer film mirrors, and a movable mirror between the dielectric multilayer film mirrors. The movable mirror is inclined so that oblique, incident light, projected into the space between the two dielectric multilayer film mirrors, is reflected between them a plurality of times and then is reflected by the movable mirror into a direction parallel to the dielectric multilayer film mirror surfaces and in an incidence plane defined by the incident light and a plane-normal to each dielectric multilayer film mirror and toward the incident light. Moving the movable mirror forwards and backwards, parallel to the multilayer film mirrors changes the amount of a chirp.

Optical frequency linear chirp variable unit

A cyanine pigment and a polyvinylalcohol are dissolved into a water to make a mezzo-J-association body dispersed solution. Then, the mezzo-J-association body dispersed solution is maintained at a high viscosity by holding the solution at a given temperature. Subsequently, the mezzo-J-association body dispersed solution is dropped onto a given substrate and thereafter, rubbed. Thereby, the J-association body oriented dispersion film having the J-association bodies composed of the associated and oriented cyanine pigments in polarization can be obtained.

Growing community of inventors

Tokyo, Japan

Kazuhiko Misawa