Vibrational imaging of a J-aggregate microcrystal using ultrabroadband multiplex coherent anti-Stokes Raman scattering microspectroscopy

Vibrational properties of a porphyrin J-aggregate microcrystal have been investigated by ultrabroadband multiplex coherent anti-Stokes Raman scattering (CARS) microspectroscopy using a supercontinuum generated from a photonic crystal fiber. Owing to a strong resonance effect due to an excitonic transition, clear spectral and spatial profiles of the CARS signal have been successfully obtained. The multiplex CARS image indicates a rod-like microcrystal, which agrees well with the microscopic image and the atomic force microscopy studies.