The field obtained by the interference between the object and reference beams in holography is actually vectorial by nature. However, in order to record all its parameters, a polarization-sensitive media is required. Typically, these are materials with photo-induced anisotropy (birefringence or dichroism) and the azodyes, azopolymers and azo-based nanocomposites are among the most efficient. In this webinar, Lian Nedelchev will discuss some important characteristics of the polarization-sensitive materials.

The spatial modulation of birefringence, obtained by polarization holography, enables numerous advanced applications – polarization-selective holographic optical elements, like bifocal lenses, circular polarization beam-splitters and other diffractive optical elements referred to as 4G optics. Another important area of applications is related to the possibility of controlling optically the surface topography of azopolymers and obtaining surface relief gratings with various structures, even on a sub-micron scale. Upon illumination, with elliptically polarized light an interesting phenomenon is observed – the formation of supramolecular chiral structures, which can be applied for all-optical switching.

Subject Matter Level: Intermediate - Assumes basic knowledge of the topic

What You Will Learn:
• The basic principles of polarization holography and how to select appropriate photoanisotropic material for a given application
• A comprehensive overview of the polarization holography applications: polarization-selective diffractive optical elements, surface relief gratings, chiral structures and others

Who Should Attend:
• Researchers interested in holography, diffractive optical element
• Graduate and PhD students in the field of optics

About the Presenter: Lian Nedelchev from the Institute of Optical Materials and Technologies - Bulgarian Academy of Sciences

Lian Nedelchev received his MSc in Laser Physics from the University of Sofia (1997) and PhD in Physics from the Bulgarian Academy of Sciences (2004). During his PhD, he specialized in the Risø National Laboratory, Denmark and worked as a research assistant for the company Optilink A/S, Denmark. In 2022 he was elected as Professor in IOMT. He is Head of the Laboratory “Holography” and since 2022 he is the Vice Director of IOMT. His research is in the field of polarization holography, photoanisotropic materials (azopolymers, nanocomposites, etc.), photoinduced chiral structures and polarimetry. Prof. Nedelchev is co-author of more than 80 papers, 2 book chapters and a granted utility model, as well as project manager and participant in many projects with national and international funding. He has supervised 2 PhD, 4 MSc and 3 BSc students to their completion.