We have used a novel phase-referenced heterodyne dual-beam low-coherence interferometer to perform what we believe are the first noncontact measurements of surface motion in a nerve bundle during the action potential. Nerve displacements of ∼5-nm amplitude and ∼10-ms duration are measured without signal averaging. This interferometer may find general application in measurement of small motion in cells and other weakly scattering samples.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics