Expanding Multiphoton Microscopy Beyond One-Color Calcium Imaging

Multiphoton microscopy is expanding beyond one-color calcium imaging to enable simultaneous measurements of electrical activity, neuromodulator signaling, and optically controlled neural responses.

This webinar will examine how two-color excitation at 920 and 1064 nm can support complementary green and red indicators for calcium, voltage, and neuromodulators, as well as experiments combining optogenetic stimulation and functional imaging. By exciting each indicator with a more favorable wavelength and controlling both channels independently, two-color architectures can improve excitation efficiency, reduce spectral compromises, and preserve the relationship between interacting biological signals. These emerging applications require efficient two-photon generation, particularly when imaging fast or weak fluorescence changes.

Bégin will discuss how a 40 MHz repetition rate and pulse durations below 80 fs, or even 60 fs, increase pulse energy and peak power, improving nonlinear excitation efficiency at lower average power. Because ultrashort pulses broaden rapidly through dispersive microscope optics, the presentation will also explain the importance of adjustable dispersion pre-compensation for preserving short pulses at the sample.

Finally, multimodal results will demonstrate how high peak power and low laser noise can support label-free two- and three-photon autofluorescence, second-harmonic generation, and third-harmonic generation, revealing complementary structural and metabolic information from unstained biological tissue.

About the presenter
Michel Bégin, M.Sc.A., is a seasoned product management professional with more than two decades of experience in high-technology industries. Currently serving as product line manager for Fiber Lasers at indie, he specializes in bringing innovative fiber laser technologies to market.