Phase-sensitive detection in Raman tweezers

• Published in: Applied physics letters Vol. 89; no. 26; pp. 261116 - 261116-3
• Main Authors: Rusciano, G., De Luca, A. C., Sasso, A., Pesce, G.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 25-12-2006
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2424674

The authors discuss on a method to acquire the Raman spectrum of a single optically trapped particle. The method makes use of two laser beams: the first laser traps the particle and moves it back and forth in a plane perpendicular to the laser beam propagation; a second laser acts as Raman probe and it is fixed in space. The Raman spectrum is obtained by phase detecting the backscattered Raman photons using a lock-in amplifier. Within this approach, the background due to the scattering of the environment is completely removed. The authors apply this method to
4.25
μ
m
diameter polystyrene beads in aqueous solution.