Abstract

The demonstrated Raman microprobe uses optical fibers and GRIN lenses to focus an exciting laser and record Raman scattering. Due to the small size of the optical components, the two parts are spatially separated; therefore much specular light or diffused light is removed from the collected light. Five collecting channels are used to increase the collecting efficiency. Experiments show that the stray light is efficiently reduced and the intensity of the Raman signal is more than ten times higher than the intensity of the spectrum obtained with a conventional Raman microscope. An exciting spot of less than 9 μ in diameter is obtained.

MEMS compatible micro-GRIN lenses for fiber to chip coupling of light

Michael Zickar, Wilfried Noell, Cornel Marxer, and Nico de Rooij
Opt. Express 14(10) 4237-4249 (2006)

Raman microprobe analysis of preforms and optical fibers

W. Carvalho, P. Dumas, M. Delhaye, J. Corset, Y. Levy, and C. Imbert
Appl. Opt. 23(23) 4197-4201 (1984)

Coupling efficiency evaluation of multimode fiber devices using GRIN rod lenses

Paola Accordi, Carlo P. Basola, Giam Paolo Bava, Guido Chiaretti, and Ivo Montrosset
Appl. Opt. 29(1) 37-46 (1990)

Fiber-optic thermometric probe utilizing GRIN lenses

Giuliano Conforti, Massimo Brenci, Andrea Mencaglia, and Anna Grazia Mignani
Appl. Opt. 28(3) 577-580 (1989)

Applications of GRIN-rod lenses in optical fiber communication systems

W. J. Tomlinson
Appl. Opt. 19(7) 1127-1138 (1980)