Interferometric measurement of femtosecond optical pulses emitted from a fibre probe

Abstract

An interferometric technique is applied to a temporal analysis of the far-field radiation from a near-field optical fibre probe. A balanced homodyne scheme combined with lock-in detection at dual harmonics allows one to evaluate the temporal form of weak signal pulses, even in the presence of some environmental vibrations that disturb the optical interference. The transmission properties of a small aperture are formulated theoretically. It is shown that the sub-wavelength aperture should not distort the femtosecond optical pulses temporally, which is consistent with the experimental observation.

Femtosecond near‐field scanning optical microscopy study of molecular thin films

“…The resolution in space and time was estimated to be 200 nm and 100 fs, respectively. We have taken an interferometric approach in order to characterize the temporal profile of weak radiation emitted from the fibre tip (Kawashima et al ., 1999).…”

Theoretical study of transient phenomena in near‐field optics

“…(1999) demonstrated near‐field optical photomask repair with a femtosecond laser. The transmission properties of the optical pulse through near‐field optical nano‐probe was experimentally studied by various methods: second harmonic generation (Smith et al ., 1994), absorption saturation (Smith et al ., 1995) and interferometric measurement (Dunn & Xie, 1995; Kawashima et al ., 1999).…”