Carbon nanotubes can be produced with a variety of shapes and properties and are therefore of much interest for widespread applications in fields as diverse as electronics,photonics, nanomechanics, and quantum optics. Hence it is important to contain a tool at hand that allows to determine these properties in a rapid/fast and precise way. Raman spectroscopy is particularly sensitive for the chemical structure that gives rise to these properties. However,the signals are intrinsically weak and call for enhancement techniques. Now, a team of researchers of the Laser Spectroscopy Division of Prof. Theodor W. Hänsch (Director at the Max Planck Institute of Quantum Optics and Chair of Experimental Physics at the Ludwig-Maximilians-Universität, and Munich) has developed a technique,where an optical microcavity is used to enhance Raman scattering signals, and utilized it for molecular diagnostics by combined Raman and absorption imaging. In contrast to other techniques, and the unique approach only relies on increased vacuum fluctuations of the electromagnetic field inside a cavity,which enables significant enhancement without undesired background, and thereby renders the technique a promising tool for molecular imaging.
Source: phys.org