Japan Science and Technology Agency

Gtheranostics Co., Ltd.

Hidemi Shigekawa

Osamu Takeuchi

Mikio Yamashita

Ryuji Morita

Zi-han Wang

An optical output system includes: a first laser that outputs first light which is a pulse laser in response to input of a first signal; a second laser that outputs second light which is a pulse laser in response to input of a second signal; and an arithmetic unit that inputs the first signal and the second signal to the first laser and the second laser, wherein the arithmetic unit repeatedly inputs the first signal and the second signal with switching a variable delay value, which is a difference between a timing to input the first signal to the first laser and a timing to input the second signal to the second laser, in a plurality of ways.

Optical output system, measurement system, optical pump-probe scanning tunneling microscope system, computing device, program, and computing method

A scanning probe microscope includes: a pump light output unit that emits pump light having a first specified phase to a specimen and performs emission of the pump light a plurality of number of times to excite the specimen; a probe light output unit that emits probe light having a second specified phase to the specimen once while the specimen is excited by one-time emission of the pump light; and a scanning probe that detects, from the specimen, a probe signal corresponding to each one-time emission of the probe light, wherein the pump light output unit or the probe light output unit includes a delay time adjustment unit that adjusts delay time from a start of the emission of the pump light until a start of the emission of the probe light.

Scanning probe microscope

A pump probe measuring device () comprises: an ultrashort optical pulse laser generator () for generating a first ultrashort optical pulse train which is a pump light (), second and third ultrashort optical pulse trains (), () which are probe lights; an optical shutter unit () to which the second and the third ultrashort pulse trains (), () are introduced; and a detecting unit () including an irradiation optical system () for directing the pump light (), the first probe light () and the second probe light () to a sample (), a sensor () for detecting a probe signal from the sample (), and a phase-sensitive detecting means () connected to the sensor (). An optical shutter control unit () periodically modulates the delay time of the first probe light () and that of the second probe light () with respect to the pump light (), and the modulated first and second probe lights (), () illuminate the sample () alternately to detect the probe signals from the sample () by the phase-sensitive detecting means () in synchronization with the periodic modulation signal of the delay time.

Pump probe measuring device

A pump probe measuring device () includes an ultrashort optical pulse laser generator () for generating a first ultrashort optical pulse train, which becomes a pump light, and a second ultrashort optical pulse train, which becomes a probe light, a delay time adjusting unit () for adjusting a delay time between ultrashort optical pulse trains, a first pulse picker and a second pulse picker () for accepting each of the first and the second ultrashort optical pulse trains and allowing only one pulse to be transmitted at an arbitrary repetition periodicity, thus reducing the effective repetition frequency of the optical pulses, a delay time modulation unit () for periodically changing a position through which pulses are transmitted by the first and the second pulse pickers (), an irradiation optical system () for applying pump light and probe light to a sample (), a measuring unit () for detecting probe signals from a sample (), and a lock-in amplifier ().

Pump probe measuring device and scanning probe microscope apparatus using the device

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.

Growing community of inventors

Tsukuba, Japan

Hidemi Shigekawa