Seminar: "High-power synchronized dual-channel laser enabling fast 2- and 3-photon in vivo brain imaging"

High-power synchronized dual-channel laser enabling fast 2- and 3-photon in vivo brain imaging

Speakers: Dr. Robert Riedel and Dr. Jan Heye Buss

One of the main frontiers in neuro-science is to capture the functional dynamics of in vivo neuronal circuits in deep brain tissue.

Recently, new techniques in two- and three-photon fluorescence microscopy allow fast imagining of mammalian brain tissue to a depth of 1mm. In particular, two-photon microscopy at 960 nm avoids the effects of scattering from deep tissue and because of its higher order nonlinear excitation and weaker scattering at longer wavelengths at 1300nm, three-photon microscopy reduces further the out-of-focus excitation and has a better signal-to-background ratio at the same depth.

Additionally, the ideal repetition rate is limited by the lifetime of the marker fluorescence and thermal damage of the brain tissue and is found to be between 1 to 10MHz.

To allow further research possibilities within the field of functional biological imaging, the compact, white-light generation seeded (WLG), optical parametric chirped-pulse amplifier (OPCPA)(White Dwarf OPCPA from Class 5 Photonics) was extended to a synchronized dual-channel laser. The customized WLG-module from Class 5 Photonics provides a stable and tunable platform to meet the application needs. In addition, the system can be pumped by a standard industrial Yb-doped solid-state laser, for example, Yb:YAG Innoslab or thin-disk, or a Yb-doped fiber laser system. Depending on the pump, the total footprint on the laser table can be as small as 120 x 80 cm2.