Master Thesis Phy/PoL/ET/MT
Motivation
Background:
Many different optical methods are used for studying biological tissue. The penetration depths of these methods is usually limited to several tens of micrometers by the strongly wavelength-dependent scattering in tissue. Using much less scattered near infrared light, powerful ultrashort pulsed lasers allow for a much deeper tissue penetration and simultaneous micrometer-scale optical sectioning similar to confocal microscopy e.g. by the use of two-photon fluorescence processes.
Scope:
In this work, a femtosecond laser will be used to set up an optical system to realize the cutting edge two-photon excitation method of temporal focusing. Here, femtosecond light pulses are spread out temporally by a grating such that all components only overlap temporally in the desired measurement volume to reach the field strengths necessary for two-photon processes. Adaptive optics will be used to shape illumination patterns in the sample plane. The setup will be characterized optically as well as in its ability to stimulate light-sensitized biological tissue in exemplary measurements.
imaging volume of Ca2+ signaling of neurons in mouse hippocampus [Prevedel, R. et al. Fast volumetric calcium imaging across multiple
cortical layers using sculpted light. Nat Methods 13, 1021–1028 (2016).]
Range of Tasks
- Design and setting up of an optical system for two photon stimulation with temporal focusing
- Optical characterization of the system
- Assessment off suitability for cell stimulation with exemplary measurements
Related Topics
Optics, two-photon microscopy, temporal focusing, ultrashort pulsed laser
Contact
- Felix Schmieder, BAR 28, Tel. 463-33894, E-Mail: felix.schmieder@tu-dresden.de
- Lars Büttner, BAR 28, Tel. 463-35314, E-Mail: lars.buettner@tu-dresden.de