Differential microscopy for fluorescence-detected nonlinear absorption linear anisotropy based on a staggered two-beam femtosecond Yb:KGW oscillator

Abstract

We present a new laser system and nonlinear microscope, designed for differential nonlinear microscopy. The microscope features time-correlated single photon counting of multiphoton fluorescence generated by an alternating pulse-train of orthogonally polarized pulses. The generated nonlinear signal is separated using home-built electronics. Results are presented on fluorescence-detected nonlinear absorption linear anisotropy (FDNALA) of chloroplasts in Asparagus Sprengerii Regel and of Congo Red-stained cellulose.