DELAY TIME MODULATION FEMTOSECOND TIME-RESOLVED SCANNING PROBE MICROSCOPE APPARATUS

摘要

An apparatus for measuring a physical phenomenon caused by light excitation having an extreme resolution in both time and space domains, particularly a delay time modulation time-resolved probe scanning microscope. The apparatus comprises an ultra-short light laser pulse generator (2), a delay modulation circuit (6) for splitting an ultra-short light laser pulse (3) generated by the ultra-short light laser pulse generator (2) into two pulses and frequency-modulating (omega) the delay time td between the two ultra-short light laser pulses (4, 5), a scanning probe microscope (17), and a lock-in detector (8) for detecting lock-in of a probe signal of the microscope (17) with a modulation frequency (omega) of the delay time. The delay-time dependence of the probe signal (11) on the delay time is determined as a change of rate without being influenced by the fluctuation of the intensity of the ultra-short light laser pulse (3) and without thermal expansion and thermal contraction of the chip of the probe (19) caused by the application of the ultra-short light laser pulse (3). With a femtosecond-order time resolution and an angstrom-order space resolution, a light excitation physical phenomenon depending on the delay time between ultra-short light pulses can be measured.