Variable temperature near-field optical microscope

摘要

An apparatus for optically imaging surfaces at low temperature is disclosed. The apparatus places a probe within the near-field distance of a sample. Both the sample and probe are placed in a low-temperature environment. The probe and sample are movable relative to each other to enable the entire surface of the sample to be imaged. The probe dithers with a certain amplitude and is positioned within the near-field distance by observing the change in the dither amplitude as the probe is placed in proximity to the sample surface. The sample is imaged by spectroscopically evaluating the light emitted from the surface of the sample. The low temperature environment is provided by a cryostat which is adapted to receive the sample and probe. The cryostat enables the sample to be imaged at temperatures as low as 1.5 K., thereby reducing some of the light loss associated with spectroscopic imaging techniques.