Femtosecond resonance enhanced CARS for background-free detection of organic molecules

Single-shot detection of bacterial endospores via coherent Raman spectroscopy

“…A set of femtosecond adaptive spectroscopic techniques for CARS (FAST CARS), including electronicresonance-enhanced coherent Raman scattering (15,16), laser pulse shaping (17), and timing, was proposed and analyzed. The authors showed how to boost the CARS efficiency and discussed possible strategies for real-time bacterial spore detection.…”

Calculation of CARS excitation profile of ZnPc

“…However, let us remind that for ZnPc the excitation spectrum of CARS was not recorded in the standard way but by changing only one of the laser frequencies [2]. Therefore, no CEP of a certain Raman mode was measured (like in Fig.…”

“…However, in this experiment the CARS excitation profile has not been measured in the standard way, where the pump ( p ω ) and the Stokes ( S ω ) beams are scanned together at a fixed difference equal to the Raman frequency: p S j ω ω ω − = (recording the CARS signal from a certain Raman mode). Instead, in [2] the CARS signal intensity was recorded by varying only the pump frequency at a fixed Stokes frequency. Thus more than one Raman mode were involved.…”

“…In [2], a model molecular system, ZnPc in a solid host/thin film, was used and the coherent excitation profile of CARS signal with femtosecond pulses measured. However, in this experiment the CARS excitation profile has not been measured in the standard way, where the pump ( p ω ) and the Stokes ( S ω ) beams are scanned together at a fixed difference equal to the Raman frequency: p S j ω ω ω − = (recording the CARS signal from a certain Raman mode).…”

Contrast in coherent Raman scattering microscopy

“…Generally speaking, CARS microscopy falls into two broad categories: narrowband CARS, where the frequency bandwidth of the driving lasers is on the order of a vibrational natural linewidth [55]; and broadband or multiplex CARS, where the spectral bandwidth of at least one of the driving lasers is significantly larger than a vibrational linewidth [56][57][58][59][60][61][62][63][64][65]. There are two primary experimental advantages to a narrowband approach.…”