Abstract:

Lasers are usually made from hard materials, such as glass, crystals and semiconductors. In my laboratory, we make lasers and other light sources from soft and biological materials. These include living cells, liquid crystals, soap bubbles and food. In 2015, we made the first laser inside a living human cell. A laser inside a cell gives the cell a unique optical code, so that the cell can be identified and followed over time. The laser can also act as a sensor for changes inside the cell. I will also show how we print three-dimensional structures inside living cells, and how we make lasers that are completely edible. Lasers made from soap bubbles can measure very small changes in pressure and electric field. In the last part, I will show that soft materials can also produce quantum light. In 2024, we generated entangled photon pairs in a liquid crystal. The properties of these photons can be controlled with an electric field, in a similar way to a liquid crystal display. These results show that soft and biological materials can be the basis for new optical sensors, imaging methods and quantum light sources.

Short biography:

Matjaž Humar leads the Laboratory for Biophotonics, Soft Photonics and Quantum Optics at the Jožef Stefan Institute in Ljubljana, Slovenia, where he is a scientific councillor. He is also an associate professor at the University of Ljubljana. He received his PhD in physics in 2012. From 2013 to 2016, he was a postdoctoral fellow at Harvard Medical School and Massachusetts General Hospital in Boston. There, he made the first laser inside a living human cell. His group makes photonic and quantum devices from soft and biological materials. He has published in journals such as Nature, Nature Photonics, Physical Review X and PNAS. His research is funded by grants from the European Research Council and the Human Frontier Science Program. An asteroid, 17201 Matjazhumar, is named after him.