Other

Japan Science and Technology Agency

Citizen Holdings Company, Ltd.

Ryuji Morita

Mikio Yamashita

Shigeru Morokawa

Osamu Takeuchi

Hidemi Shigekawa

Akira Suguru

Disclosed is a measuring apparatus for a physical phenomenon by photoexcitation, in particular a delay time modulated and time-resolved, scanning probe microscope apparatus providing an ultimate resolution both temporal and spatial. The apparatus comprises an ultrashort laser pulse generator (); a delay time modulating circuit () which splits an ultrashort laser pulse () produced by the ultrashort laser pulse generator () into two and which also modulates a delay time tbetween the two ultrashort laser pulses (and) with a frequency (&#x3c9;); a scanning probe microscope (); and a lock-in detection unit () which performs lock-in detection with the delay time modulation frequency (&#x3c9;) of a probe signal () from the scanning probe microscope (). It can detect the delay time dependency of the probe signal () as its differential coefficient to the delay time, with no substantial influence from fluctuations in the intensity of ultrashort laser pulses () while preventing the probe apex () from thermal expansion and shrinkage by repeated irradiation with ultrashort laser pulses (). A photoexcited physical phenomenon dependent on a delay time between ultrashort laser pulses can thus be measured at a temporal resolution in the order of femtoseconds and at a spatial resolution in the order of angstroms.

Delay time modulation femtosecond time-resolved scanning probe microscope apparatus

An ultra-broadband, variable and multiple wavelength, waveform shaping apparatus is disclosed that excels with the ability to yield light pulses shaped in waveform, variable and multiple in wavelength over an ultra-broad bandwidth, the pulses being as short as in the order of pico-seconds or less, or even in the order of femto-seconds. The apparatus includes a light source ( ) for a light pulse, an ultra-broadband light pulse generating unit ( ) for producing from a light pulse, an ultra-broadband light pulse beam, a beam expander ( ) for spatially expanding the beam in one direction (along the y-axis) in its cross section, and a wavelength dispersive unit ( ) for dispersing wavelengths of light beam pulse while further spatially expanding the expanded beam along the x-axis, a two-dimensional spatial amplitude modulator ( ) for selecting wavelength bands varying in center frequency along the y-axis, a two-dimensional space phase amplifier ( ) for modulating a plurality of lights selected by wavelengths into different phases, and a beam reducing and waveform shaping unit ( ) for reducing so phase modulated light beam pulse components along the x-axis while shaping them into desired waveforms, whereby multiple wavelength light pulses are formed, which have center their wavelengths varying along the y-axis and waveforms shaped independently of each other and as desired.

Ultrabroad-band variable-wavelength wavelength-multiplexed pulse waveform shaping device

Growing community of inventors

Hokkaido, Japan

Ryuji Morita