Towards all-optical circuit technology - Tampere University of Technology

Towards all-optical circuit technology


Gaetano Assanto finds TUT to be an inspiring working environment. During his four-year FiDiPro term, he hopes to create a permanent body of expertise and knowledge in his specialist field at TUT.

Optics and photonics are included in TUT’s leading edge fields, and research in these fields is now enhanced by FiDiPro Professor Gaetano Assanto. He is one of the world’s leading researchers in the field of nonlinear beams of light in liquid crystals. 

Funded by the Academy of Finland, the FiDiPro project involves looking into some  basic optical properties of liquid crystals, adjusting their characteristics using other materials and seeking new applications for them in photonics equipment.

Professor of Optoelectronics at the Roma Tre University in Rome, Gaetano Assanto’s primary research interests include the spatial solitons launched in nematic liquid crystals. They are wavepackets of light that do not spread as ordinary beams do; instead, they maintain their shape and size when traveling in a nonlinear substance. G. Assanto has dubbed these solitons nematicons.

“Solitons can be generated by illuminating liquid crystals with intense light beams. The electromagnetic radiation causes the elongated liquid crystal molecules to redirect, and this changes the optical properties of the material and gives rise to waveguides.”

“The solitons create themselves a light-induced optical fibre that enables them to guide, route and transmit optical information. They could contribute to the foundation of next generation photonic circuits in which light could play the role of electricity in today’s electronics.”

Enormous potential for a range of uses

Assanto has founded a research group at the TUT Department of Physics. The group works in cooperation with the current researchers working at the Optics Laboratory and expands the department’s nonlinear optics research into a new direction.

Professor Gaetano Assanto 

  • FiDiPro Professor at the TUT Department of Physics 2014–2018.
  • Professor of Optoelectronics at the Roma Tre University in Rome, Italy since 1992.
  • Education: PhD in EE (Optical Sciences) from University of Palermo and University of Arizona, 1987.
  • Research interests: Nonlinear optics, all-optical switching, nonlinear integrated optics, parametric effects, spatial solitons, Ge-on-Si photodetectors. 
  • Family: Wife and daughter (5), another daughter (29) living in Italy.
  • Hobbies: hiking, BBQing, travelling, motorcycling.
  • Wow: Physics was always Assanto’s dream field, but his parents hoped that he would study “something more concrete.” He tried out electrical engineering , nuclear engineering and philosophy before deciding to devote himself to optical physics after all – upon advice from his professor of experimental psychology!

“We are currently starting with laboratory tests that aim at improving the optical response of liquid crystal materials with polymers and building a technologic platform for the research of light-defined integrated optics.

“The research is also expected to increase our understanding of basic physical phenomena, such as nonlocal effects, rogue waves and long-range interactions.”

At present, liquid crystals are most typically used in the display technology of televisions and computer screens, for example. They also enable adjusting the properties of light in other ways and, for example, realizing modulators, sensors and optical communications components.

“The objective of the research is to find new photonics applications that are based on liquid crystals.”

Applications that are based on light control can be used to an unlimited extent in various fields. In fact, photonics is one of the fastest growing industries around the world and in Finland. In the field of information technology alone, light could multiply the speed of data transfer and processing and significantly increase energy efficiency.

“Liquid crystals could help in enabling all-optical signal processing in the future,” Assanto explains.

Updated by: Merja Jaaksi, 21.12.2015 14:14.
Content owner: Laukkanen Tuuli
Keywords: science and research, fidipro