The following is an abstract for the selected article. A PDF download of the full text of this article is available here. Members may download full texts at no charge. Non-members may be charged a small fee for certain articles.

Description and Theory of a Fiber-Optic Confocal and Super-Focal Raman Microspectrometer

Volume 50, Number 9 (Sept. 1996) Page 1150-1155

Schrum, Kimberley F.; Ko, Seung Hyeon; Ben-Amotz, Dor

A fiber-optic bundle, placed in the imaging plane of a microspectrometer, functions as a variable-size pinhole. This arrangement allows for conventional confocal measurements to be made by collecting the signal from the central fiber. On the other hand, measurements arising from a larger focal volume are made by integrating the signal from the entire bundle. This new "super-focal" imaging technique yields larger imaging depth without any loss in spectral resolution. The instrument design and performance are described, as well as geometric optics calculations which accurately predict the depth resolution and oscillations in the super-focal depth response. Raman scattering from a three-component layered sample is used to illustrate the extension of this technique to more complicated systems.