Patent ID: 7002149

Claim:
A delay time modulated and femtosecond time-resolved scanning probe microscope apparatus, characterized in that it comprises: an ultrashort laser pulse generator; a delay time modulating circuit for splitting an ultrashort laser pulse produced by said ultrashort laser pulse generator into two ultrashort laser pulses interspaced by a delay time while establishing a value for the delay time between the two ultrashort laser pulses and modulating the delay time centering about the established value with a fixed modulation frequency; a scanning probe microscope for scanning a specimen over a surface area thereof with a probe wherein the probe is disposed just above the specimen so that a tunnel junction is formed between a probe apex and a surface of said specimen when irradiated with said two ultrashort laser pulses modulated by said delay time modulating circuit; and a lock-in detection unit for lock-in-detecting a probe signal of the specimen irradiated with said ultrashort laser pulses in said scanning probe microscope using the modulation frequency for the delay time as a reference signal.