Interdisciplinary Postgraduate Studies Program "Nanosciences & Nanotechnologies" (N&N)
N&N Seminars – 14 January 2026 at 14:00
School of Physics Assembly Hall – 4th Floor, Department of Sciences Building

Zoom Link: https://authgr.zoom.us/j/98729717972?pwd=Oo5hAqnfuhMJuQzmbimLDCZbENZTPG.1

TITLE
Optical Measurement Techniques for Plant Leaves and Organic Semiconductor Materials

Sandor Lenk, PhD
Associate Professor
Department of Atomic Physics, Institute of Physics
Budapest University of Technology and Economics (BME), Hungary

ABSTRACT

Since the discovery of Hans Kautsky in 1931, it has been known that when plants are illuminated, fluorescence emission occurs simultaneously with photosynthetic activity. By analyzing this emission, the efficiency of photosynthesis can be quantitatively evaluated, enabling early detection of plant stress conditions such as nutrient deficiencies or pathogen-induced biotic stress.

For several decades, physicists and engineers at the Optical Laboratory of the Department of Atomic Physics at BME have been developing fluorometric instruments in collaboration with international plant physiology research groups. These portable instruments have demonstrated high efficiency in early stress detection under real field conditions.

Recently, our research focus has shifted towards short-pulse, low-photon-count optical measurement techniques, which are now being applied to in vivo plant investigations. The same methodology has also been successfully extended to organic semiconductor materials, including OPV thin films provided by the LTFN Nanotechnology Lab / COPE-Nano Center of Excellence (AUTH).

In addition, special optical characterization systems developed in cooperation with glass manufacturing industries for the measurement of haze and angular color of large-area optical glass panels will be briefly introduced.

SHORT CV

Dr. Sándor Lenk is Associate Professor at the Department of Atomic Physics, Budapest University of Technology and Economics (BME).
He received his PhD in Physics in 2013 on the development of fluorescence and reflection techniques for plant physiology and semiconductor materials.

His research focuses on photoluminescence spectroscopy, laser physics, applied optics and optical measurement techniques for both biological and organic electronic systems.
He has published 40 peer-reviewed papers, received more than 630 independent citations (h-index: 12) and is recipient of several national awards including the János Bolyai Research Scholarship of the Hungarian Academy of Sciences.

He teaches laser techniques and spectroscopy at BME and supervises undergraduate, master’s and PhD students.