Raman, hyper-Raman, hyper-Rayleigh, two-photon luminescence and morphology-dependent resonance modes in a single optical tweezers system.
We present a setup of optical tweezers combined with linear and nonlinear microspectroscopies that enhances the capabilities of capture and analysis of both techniques. We can use either a continuous-wave (cw) Ti:sapphire laser for Raman measurements or a pulsed femtosecond Ti:sapphire laser that permitted the observation of nonlinear results such as hyper-Raman, hyper-Rayleigh, and two-photon luminescence. Only the high peak intensity of the femtosecond laser allows the observation of all these nonlinear spectroscopies. The sensitivity of our system also permitted the observation of morphology-dependent resonance (MDR) modes of a single stained trapped microsphere of 6 microm. The possibility of performing spectroscopy in a living microorganism optically trapped in any desired neighborhood would mean that one can dynamically observe the chemical reactions and/or mechanical properties changing in real time.
Fontes
A
A
Instituto de Física Gleb Wataghin UNICAMP, Campinas-SP, Brazil.
Ajito
K
K
Neves
A A R
AA
Moreira
W L
WL
de Thomaz
A A
AA
Barbosa
L C
LC
de Paula
A M
AM
Cesar
C L
CL