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.

Abstract: In a probe system which enables high sensitivity to be achieved in a differential phase contrast optical or electron microscope, a focused beam is periodically deflected over the surface of an object and resulting phase modulation of the beam (related to the phase structure of the object) is sensed. In one embodiment, the beam (18) is derived from a laser (10) and light reflected from the irradiated object (24) is received by a photodetector (26), where it interferes with a reference beam (28) also derived from the laser (10) but shifted in frequency by means of a Bragg cell (30); the detection system includes a vector voltmeter (40) sensing the amplitude and phase of a signal component at the deflection frequency. Also described are other optical embodiments utilizing different forms of interferometer and/or detection system, and an embodiment using an electron probe instead of a laser probe.

Abstract: An acoustic coupling device for use in a scanning acoustic microscope consists of an acoustic lens which has a concave focusing surface, and an acoustic coupler having a convex surface on which a convergent beam of acoustic radiation is normally incident. The coupler has a coupling surface which conforms to the shape of a test object; the coupler may be disposable. The spacing between the concave and convex surfaces may be varied to give a variable-focus device.

Abstract: A scanning acoustic microscope comprises transducer means (10, 12, 14) to provide a convergent beam of acoustic radiation; means (20, 22) to cause relative movement in the focal plane of the focus of the beam and a sample (16); transducer means (10, 12, 14) to receive acoustic radiation modulated by the sample near the beam focus; and means (30) to supply a pressurized gas to a volume surrounding the transducer means and the sample.