Polarized multiplex coherent anti-Stokes Raman scattering using a picosecond laser and a fiber supercontinuum

Abstract

We perform multiplex coherent anti-Stokes Raman scattering (CARS) micro-spectroscopy with a picosecond pulsed laser and a broadband supercontinuum (SC) generated in photonic crystal fiber. CARS signal stability is achieved using an active fiber coupler that avoids thermal and mechanical drifts. We obtain multiplex CARS spectra for test liquids in the 600-2000 cm(-1) spectral range. In addition we investigate the polarization dependence of the CARS spectra when rotating the pump beam linear polarization state relative to the linearly polarized broad stokes SC. From these polarization measurements we deduce the Raman depolarization ratio, the resonant versus nonresonant contribution, the Raman resonance frequency, and the linewidth.

Structure and function relationships in alkylammonium lead(ii) iodide solar cells

“…Sample powders were recovered from dimethylformamide solution of the compounds. By comparing the Raman spectra of PAPbI 3 and dimethylformamide, 31 it is clear that dimethylformamide is present in the sample powder of PAPbI 3 . Detected peaks at 667 cm À1 , 866 cm À1 , and 1413 cm À1 are marked by a red arrow in the spectrum of PAPbI 3 .…”

Optimization and characterization of a femtosecond tunable light source based on the soliton self-frequency shift in photonic crystal fiber

“…Note that having used a configuration where a single pulse is frequency shifted is beneficial to prevent soliton-to-soliton interactions and subsequent degradations leading potentially to so-called rogue events. The long-term study is carried out as the fiber injection can suffer from mechanical drift of the launching device 8 . A several tens of minutes long power monitoring is performed with and without a Thorlabs' Nanotrack system (an actuated piezoelectric flexure stage).…”

Numerical evaluation of spectral coverage and spectral resolution in coherent Raman scattering spectroscopy using a broadband fiber laser source

“…These properties make CARS and SRS a powerful intrinsic label-free imaging/spectroscopy tool for chemical identification of a wide variety of compounds. [10][11][12][13][14] Nevertheless, the main drawback of most CRS spectroscopy/imaging systems is their complexity. Both CARS and SRS require a synchronized interaction of the two different laser pulses within the sample (in time, space, and polarization).…”