Hamamatsu-photonics K.k.

Koyo Watanabe

Takashi Inoue

Naoya Matsumoto

Koji Takahashi

Hisanari Takahashi

Kyohei Shigematsu

Hirotoshi Terada

Haruyasu Ito

Hiroshi Satozono

Hironori Takahashi

Yoichi Kawada

A dispersion measuring device includes a pulse forming unit, a light detection unit, a control unit, and an arithmetic operation unit. The control unit selectively outputs a first phase pattern and a second phase pattern. The pulse forming unit forms an optical pulse train from initial pulsed light, the optical pulse train including a plurality of optical pulses having a time difference from each other and having different center wavelengths from each other. The light detection unit detects a temporal waveform of the optical pulse train. The arithmetic operation unit estimates a wavelength dispersion amount of a measurement object based on a feature amount of the temporal waveform of the optical pulse train. When the first phase pattern is output, a pulse having a long center wavelength is generated first. When the second phase pattern is output, a pulse having a short center wavelength is generated first.

Dispersion measurement device and dispersion measurement method

A time response measurement apparatus includes a pulse formation unit, an attenuation unit, a waveform measurement unit, and an analysis unit. The pulse formation unit generates first pulsed light including a wavelength of pump light, second pulsed light including a wavelength of probe light, and third pulsed light including the wavelength of the pump light and the wavelength of the probe light, on a common optical axis. The attenuation unit transmits the first pulsed light, the second pulsed light, and the third pulsed light output from a sample arranged on the optical axis after being incident on the sample. An attenuation rate for the pump light is larger than an attenuation rate for the probe light. The analysis unit obtains a time response of the sample based on temporal waveforms of the first pulsed light, the second pulsed light, and the third pulsed light having passed through the attenuation unit.

Time response measurement apparatus and time response measurement method

An optical property measurement apparatus includes a pulse formation unit, a waveform measurement unit, and an optical system. The pulse formation unit is capable of changing a temporal waveform of pulsed light in accordance with a type of optical property to be measured. The waveform measurement unit measures a temporal waveform of the pulsed light output from a measurement object after being incident on the measurement object. The optical system has an attenuation unit with an attenuation rate with respect to one wavelength component constituting the pulsed light larger than an attenuation rate with respect to another wavelength component constituting the pulsed light. The optical system is capable of switching between a first state in which the attenuation unit is arranged on an optical path of the pulsed light output from the measurement object and a second state in which the attenuation unit is not arranged on the optical path.

Optical property measurement apparatus and optical property measurement method

A dispersion measurement apparatus includes a pulse forming unit, a correlation optical system, a beam splitter, an operation unit, an imaging unit, a spatial filter unit, and a photodetector. The pulse forming unit forms a light pulse train including light pulses having time differences and different center wavelengths. The beam splitter branches the light pulse train passed through a measurement object. The imaging unit disperses one light pulse train and images each light pulse. The spatial filter unit extracts light of a partial region of the other light pulse train. The correlation optical system outputs correlation light including a cross-correlation or an autocorrelation of the extracted light. The photodetector detects a temporal waveform of the correlation light. The operation unit estimates a wavelength dispersion amount in the measurement object based on a feature value of the temporal waveform.

Dispersion measurement apparatus and dispersion measurement method

A dispersion measurement apparatus includes a pulse forming unit, a correlation optical system, a photodetection unit, and an operation unit. The pulse forming unit forms a light pulse train including a plurality of light pulses having time differences and center wavelengths different from each other from a measurement target light pulse output from a pulsed laser light source. The correlation optical system receives the light pulse train output from the pulse forming unit and outputs correlation light including a cross-correlation or an autocorrelation of the light pulse train. The photodetection unit detects a temporal waveform of the correlation light output from the correlation optical system. The operation unit estimates a wavelength dispersion amount of the pulsed laser light source based on a feature value of the temporal waveform of the correlation light.

Dispersion measuring device, pulse light source, dispersion measuring method, and dispersion compensating method

Provided is a light shaping device including: an intensity modulation unit that modulates a spectrum intensity of an optical pulse that is input light, and outputs the optical pulse of which a temporal width is narrowed as output light. The intensity modulation unit modulates the spectrum intensity of the optical pulse with a mask expressed by a starting end wavelength from a central wavelength of the input light and a wavelength width.

Light shaping device and light shaping method

An iterative Fourier transform unit of a modulation pattern calculation apparatus performs a Fourier transform on a waveform function including an intensity spectrum function and a phase spectrum function, performs a replacement of a temporal intensity waveform function based on a desired waveform after the Fourier transform, and then performs an inverse Fourier transform. The iterative Fourier transform unit performs the replacement using a result of multiplying a function representing the desired waveform by a coefficient. The coefficient has a value with which a difference between the function after the multiplication of the coefficient and the temporal intensity waveform function after the Fourier transform is smaller than a difference before the multiplication, and a ratio of the difference is smaller when an intensity is higher at each time of the function before the multiplication.

Data creation apparatus, light control apparatus, data creation method, and data creation program

An intensity spectrum designing unit of a data generating device includes an initial value setting unit that sets a plurality of objects of a first generation of an intensity spectrum function A(ω) and a phase spectrum function Ψ(ω), an evaluation value calculating unit that calculates an evaluation value for each of a plurality of objects of an n-th generation, an object selecting unit that selects two or more objects used for generating a plurality of objects of an (n+1)-th generation among objects of the n-th generation on the basis of superiority of the evaluation value, and a next-generation generating unit that generates a plurality of objects of the (n+1)-th generation on the basis of the selected two or more objects. The evaluation value calculating unit, the object selecting unit, and the next-generation generating unit repeat processes while 1 is added to n until a predetermined condition is satisfied.

Data generating device, light control device, data generating method, and computer-readable recording medium

An imaging system includes a light source for outputting initial pulsed light, a polarization control unit for rotating a polarization plane of the initial pulsed light, an optical pulse shaping unit for inputting the initial pulsed light with the rotated polarization plane, and outputting first pulsed light Lphaving a first polarization direction and second pulsed light Lphaving a second polarization direction different from the first polarization direction with a time, an irradiation optical system for irradiating an imaging object with the pulsed light Lpand the pulsed light Lp, a light separation element for separating the pulsed light Lpand the pulsed light Lpreflected by or transmitted through the imaging object on the basis of the polarization directions, an imaging unit for imaging the pulsed light Lp, and an imaging unit for imaging the pulsed light Lp.

Imaging system and imaging method

A data generating device sets an initial candidate solution of an intensity spectrum function, a phase spectrum function, and an initial temperature and a cooling rate, generates a neighborhood solution, transforms a first waveform function of a frequency domain including the neighborhood solution and the phase spectrum function into a second waveform function of a time domain including a time-intensity waveform function and a time-phase waveform function and calculates an evaluation value representing a degree of difference between the time-intensity waveform function and the desired time-intensity waveform, sets the neighborhood solution as an n-th candidate solution for a certain probability, and lowers the temperature on the basis of the cooling rate. A decrease in the temperature acts in a direction in which the probability P is lowered when the evaluation value of the neighborhood solution is worse than the evaluation value of the candidate solution.

A modulation pattern calculation apparatus includes an iterative Fourier transform unit, a filtering process unit, and a modulation pattern calculation unit. The iterative Fourier transform unit performs a Fourier transform on a waveform function including an intensity spectrum function and a phase spectrum function, performs a replacement of a temporal intensity waveform function based on a desired waveform after the Fourier transform and then performs an inverse Fourier transform, and performs a replacement to constrain the phase spectrum function after the inverse Fourier transform. The filtering process unit performs a filtering process of cutting a part exceeding a cutoff intensity for each wavelength, on the intensity spectrum function in a frequency domain.

Modulation pattern calculation device, light control device, modulation pattern calculation method, modulation pattern calculation program, and storage medium

A Fourier transform is performed on a first waveform function in a frequency domain, and a second waveform function in a time domain including a temporal intensity waveform function and a temporal phase waveform function is generated. A replacement of the temporal intensity waveform function based on a desired waveform is performed for the second waveform function. The second waveform function is modified so as to bring a spectrogram of the second waveform function close to a target spectrogram generated in advance in accordance with a desired wavelength band. An inverse Fourier transform is performed on the modified second waveform function, and a third waveform function in the frequency domain is generated. Data is generated on the basis of an intensity spectrum function or a phase spectrum function of the third waveform function.

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Hamamatsu, Japan

Koyo Watanabe