A nanoscale aperture at the end of a scanning probe collects or excites optical signals with sub-wavelength spatial resolution, while simultaneously collecting topographical data in AFM mode.
Scan area is 70 µm x 70 µm with a vertical range of 70 µm. NSOM resolution is ~50 to 200 nm (dependent on aperture size). AFM lateral resolution is ~5 nm to 10 nm; vertical resolution is ~1 nm.
Specialized applications: a) near-field fluorescence imaging using an avalanche photodiode (APD) for low-intensity light detection b) far-field stage-scanned confocal mode using a pinhole placed in front of the APD; c) imaging in fluid; d) tip-enhanced Raman scattering (TERS).
NSOM: Nanonics MV1000 or MV2000 interfaced with an Olympus BXFM focusing unit, configurable as either an upright or inverted microscope, using a 50x long-working distance objective.
Infrared digital cameral for IR laser adjustment and sample or probe positioning.
Excitation lasers: a) Nd:YAG (532 nm); b) multi-line single-mode Ar-ion gas laser (lines from 457 to 514 nm) multi-line single mode Ar-Kr ion gas laser (lines from 476 to 676 nm).