Abstract

High resolution absorption microscopy, spectroscopy and similar applications are implemented by providing for a measurement tip which is maintained spaced from a sample under investigation sufficiently close so as to equalize thermal levels in the tip and the sample; generally within about 10 Angstroms. Energy is applied to the sample being investigated and either a steady state or dynamic junction potential is measured. The junction potential is representative of local sample temperature. The close separation can be maintained by techniques employed in scanning tunneling microscopy, atomic force microscopy or capacitance microscopy. In the event the close separation is maintained using scanning tunneling microscopy techniques, then a switching arrangement is provided for connecting a conductive film (either of the sample or supported on a sample) to either a suitable potential or ground and simultaneously connecting the STM tip either in a feedback loop or to a device for measuring the junction potential. The feedback loop, in addition to conventional operational amplifier components, includes a sample and hold element to maintain the input voltage to an operational amplifier in the feedback loop during those times that the measurement tip is connected to the junction potential measurement device, as opposed to being connected in the STM feedback loop. The spectroscopy application uses similar architecture, althrough the energy source is tunable.