Extending Femtosecond Stimulated Raman Microscopy Toward Silent and Fingerprint Region of Biomolecules

• Published in: 2020 22nd International Conference on Transparent Optical Networks (ICTON) pp. 1 - 4
• Main Authors: Ranjan, R., Ferrara, M. A., Sirleto, L.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.07.2020
• Subjects: Integrated optics; label-free imaging; Laser beams; Microscopy; non-linear optical imaging; nonlinear microscopy; Optical harmonic generation; Optical microscopy; Raman scattering; stimulated Raman scattering; Ultrafast optics
• ISSN: 2161-2064
• DOI: 10.1109/ICTON51198.2020.9203024

In this work, the design and the implementation of a femtosecond Stimulated Raman Scattering microscope, equipped with three femtosecond laser sources: a Titanium-Sapphire (Ti:Sa), an optical parametric oscillator (OPO) and a second harmonic generator (SHG) is presented. Our microscope is designed in such a manner which has the capability to cover all the regions of Raman spectra, taking advantage of two possible laser combinations. The first, Ti:Sa and OPO laser beams, which covers the C-H region or O-H region (F > 2800\ \mathrm{cm}^{-1} in stimulated Raman gain (SRG) modality, whereas the second, Ti:Sa and SHG laser beams, covers the C-H region and the fingerprint region ( < 1800\ \mathrm{cm}^{-1} ) and the silent region (1800 - 2800 cm −1 ) in stimulated Raman loss (SRL) modality. In order to demonstrate the successful realization of microscope, SRL and SRG images of polystyrene beads using the two-laser combination has been successfully reported.