Two-beam multiplexed CARS based on a broadband oscillator

A two-beam multiplexed coherentanti-Stokes Raman scattering (CARS) microscopy setup is demonstrated by using a broadband (BB) Ti: sapphire oscillator without using any specialty fibres. A well-defined spectral structure of the source leads to a delay sensitive CARS measurement in two-colour CARS and also provides an efficient means of obtaining three-colour CARS signals combined with the dispersion compensation of the BB pulse. Our result implies that the background suppression is limited by the onset of the spurious signals caused by the different CARS process, qualitatively differing from what is typically observed in the CARS microscopy.