Ultrafast laser spectroscopy is a versatile tool for studying the fundamental electronic interactions taking place in the microcosmos and are the origin for the manifestation of the macroscopic properties of novel materials. These properties can be manipulated to serve a particular purpose. For example: increase the catalytic activity of nanocatalysts,  expedite the optical switching of photonic materials, or increase the efficiency of energy harvesting and storage from nanotextured materials, and many more. Thus, the use of ultrafast lasers and laser spectroscopy acquires a dual purpose: to study these processes and to control them.

In this seminar I will discuss the past and the current status of the research activity for the study of ultrafast process in solid state using ultrashort laser pulses with an outlook for the foreseeable future.

For centuries optical microscopy constitutes one of the most fundamental paradigms in biological and medical imaging, offering new avenues for exploration of biological function, detection and treatment of disease in living organisms and systems. It is indeed only recently that the Nobel Prize was awarded for the invention of Nanoscopy enabling us to observe and quantify biology with resolutions down to the nanometer scale. However, optical microscopy is significantly challenged by light diffusion in tissue, limiting its applicability to superficial depths (<0.5mm), reducing resolution with imaging depth. For imaging larger samples methods that provide three dimensional microscopic images such as Optical Projection Tomography (OPT) and Light Sheet Fluorescence Microcopy (LSFM) have been widely used. Furthermore, advances in optoacoustic and multimodality imaging have allowed to image in so far non-accessible regimes with unprecedented resolutions, based on the use of light for the production of ultrasonic waves. To significantly advance the resolution to penetration depth ratio and counteract the diffusive transport of light in biological tissues, radically new technologies are being developed for the production, manipulation and delivery of light radiation, based on adaptive wavefront control. These very exciting discoveries and advances in biophotonic technologies have now started to revolutionize the way biological research is performed, providing the ability to perform in vivo imaging in scales ranging from microscopy to macroscopy at depths from a few micrometers to several centimeters.

Manipulating the properties of interfaces using nanoparticles has attracted widespread attention due to both scientific interest as well as use in practical applications including food, pharma, energy production and environmental remediation.  For example, the assembly of nanoparticles at interfaces stabilizes emulsions (so called Pickering emulsions) and offers the possibility to synthesize materials with controlled interfacial properties.  By varying the chemistry and dimensionality of the nanoparticles, the adsorption energy and thus the interfacial properties can be modulated and controlled.  In some cases, interfacial assembly of nanoparticles leads to a solid-like behavior or jamming with interfaces behaving like an elastic membrane with high modulus.   Surface functionalization of nanoparticles is a necessary and critical step to fine-tune their inter- and intramolecular interactions and thus their interfacial assembly.  In this talk, I will present a newly developed family of nanoparticles and discuss their assembly as a means to fine-tune the properties of emulsions especially under harsh environmental conditions.