Contrast improvement of autofluorescent vitamins by using shaped laser pulses after a kagome fiber

Abstract

An improved two-photon excited fluorescence contrast difference between autofluorescent vitamins is reported by using shaped laser pulses after a kagome fiber. Specifically phasetailored laser pulses are applied for two-photon excited fluorescence of retinol and riboflavin in solution at the distal end of the fiber. The pulse distortions due to the fiber properties are precompensated to achieve predefined tailored pulses after the kagome fiber. A clear twophoton excited fluorescence contrast difference is received between vitamin A and B 2 for various third order phase parameters. Moreover, selective excitation is observed for retinal versus retinol, although they differ only in a side chain. The presented approach of guiding shaped pulses through kagome fibers has large perspectives for endoscopic applications.