High-speed optical sampling measurement of electrical wave form using a scanning tunneling microscope

Abstract

The optical sampling measurement of a high-speed electrical wave form using a scanning tunneling microscope (STM) is demonstrated. An optical pulse train from a laser diode (LD) is used to turn on and off a photoconductive switch on a STM probe to measure a signal from a Schottky barrier diode (SBD) in a sampling procedure. A time resolution less than 300 ps has been achieved. This novel method has the potential to create a breakthrough in ultra-high-speed wave form measurement through this unique combination of optical sampling and STM technology.

Advances in ultrafast scanning tunneling microscopy

“…[6][7][8][9][10][11] Many of these attempts have relied on the mixing of two fast signals which spatially overlap at the junction between SPM tip and sample. [6][7][8][9][10][11] Many of these attempts have relied on the mixing of two fast signals which spatially overlap at the junction between SPM tip and sample.…”

Time-resolved scanning tunnelling microscopy for molecular science

“…Another pump-probe approach to ultrafast STM has been by photoconductivity gated STM [109,110]. In an example by Weiss and co-workers [111] a 120 fs laser pulse is split into two, one beam excites the dynamic surface response of interest (pump) and the other, via a delayed line, gates the connection between STM tip and current pre-amplifier (probe).…”

Spatially resolved femtosecond spectroscopy beyond the diffraction limit

“…Therefore, the combination of ultrafast spectroscopic techniques with scanning probe microscopy is a promising approach for simultaneously obtaining outstanding temporal and spatial resolution. Both time-resolved scanning force [10,11] and scanning tunnelling microscopy [12][13][14][15][16][17][18][19] have been known since the early 1990s. However, since these techniques rely either on photoconductive switches [20] as time-gating devices or on electronics, it seems doubtful whether the temporal resolution can be pushed to the 100 fs range.…”