Symposium2

Plenary Talk

 

Presenter:

Prof. Takashige Omatsu

Department of Materials Science, Chiba University, Japan
Molecular Chirality Research Center, Chiba University, Japan

Title:

Structured light beams possessing orbital angular momentum

Abstract:

Optical vortices carry annular spatial forms and orbital angular momentum associated with their helical wavefront, and they have been intensively investigated in materials science. In particular, optical vortices can twist the irradiated materials on a nano/microscale to form spiral-shaped structures (chiral structures), being difficult to create even by utilizing advanced chemical processes. We review optical vortices and their physical properties.

Biography:

Professor Omatsu received his B.S. and Ph.D. degrees in applied physics from the University of Tokyo, in 1983 and 1992, and he was appointed as a Professor in Chiba University, in 2007. He has been developing optical vortex light sources and pioneering nanostructures fabrication based on optical vortices illumination. He is currently playing a role as an Editor-in-Chief of OSA Continuum. Also, he is serving as a Visiting Professor of Xinjiang Normal University, China, Ajou University, Korea and Macquarie University, Australia. He was awarded prize for Science and Technology, The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology in 2016. He was also elected as OSA Fellow and JSAP (Japan Society of Applied Physics) Fellow.

Invited Talk

 

Presenter:

Prof. Tomio Petrosky

Department of Physics, Center for Complex Quantum System, University of Texas at Austin, USA
Institute of Industrial Science, The University of Tokyo, Japan

Title:

Classical Radiation Damping and Emission of Optical Vertex as Microscopic Irreversible Processes

Abstract:

Radiation damping process by a charged particle in classical dynamics is discussed in terms of a complex spectral analysis of the Liouville operator in an extended function space outside the Hilbert space. The complex spectral analysis has been introduced to describe irreversible process with a broken time-symmetry on a rigorous dynamical basis starting from the fundamental laws of physics. Thanks to this analysis, we show that the long-standing difficulty of that leads to non-dynamical behaviors such as non-causal behavior and the existence of a runaway solution of the charged particle has been resolved.

Biography:

Tomio Petrosky is currently a Senior Research Scientist at the Center for Complex Quantum Systems at the University of Texas in Austin, and Research Advisor of Institute of Industrial Science in The University of Tokyo. He received his Undergraduate, Masters and Ph.D. degrees from the Department of Physics, Science University of Tokyo. He wrote many papers with late Professor Ilya Prigogine, a Nobel Prize winner in Chemistry. He has received several international scientific awards, including The Special Award of 100 year anniversary of the Solvay International Conference of Physics and Chemistry, and Peter the Great Medal presented by the Russian Academy of the Natural Sciences. His main interest is dynamical origin of the broken-time symmetry.

Invited Talk

 

Presenter:

Prof. Yasunori Toda

Department of Applied Physics, Hokkaido University, Japan

Title:

Vortex mode emissions from large-area vertical-cavity surface-emitting laser with optical feedback

Abstract:

We will present two experimental studies for generating and controlling the vortex mode of the large-area vertical cavity surface emitting laser (VCSEL); optical feedback using external optical injection and external cavity. Single orbital angular momentum (OAM) mode emissions were realized in both experiments, where the spatially modulated optical injection optimized for the transverse mode gain is the key of high efficiency and flexibility, and provides some insights into the mechanism of vortex formation of the VCSEL.

Biography:

Yasunori Toda received the B.E., M.E., and Dr. Eng. degrees from Tokyo Institute of Technology, Japan, in 1991, 1993 and 1996, respectively. From 1996 to 1999, he was a Postdoctoral Researcher and a Research Associate at University of Tokyo, and then moved to Hokkaido University as an Associate Professor. Since 2013, he has been a Professor in the Department of Applied Physics, the Graduate School of Engineering. His current research interests include laser spectroscopy, especially time-resolved spectroscopy, coherent spectroscopy and other advanced spectroscopy using optical vortices, for condensed matter physics.

Tutorial Talk

 

Presenter:

Prof. Kei Sawada

RIKEN SPring-8 Center, Japan

Title:

Berry-phase theory of electromagnetic waves with spin and orbital angular momentum

Abstract:

An effective field theory of electromagnetic wave propagation is studied in terms of Berry’s phase and curvatures. The Berry curvatures are defined as the second derivative of wavefunctions, and behave as effective fields acting on optical wavepacket. This effective field theory describes many interesting phenomena such as enhanced translation of a wavepacket and one-way edge modes caused by topological properties of the wavefunction. We present fundamental ideas of this theoretical approach and its application to light carrying spin and orbital angular momentum with experimental results.

Biography:

Kei Sawada received the B.E., M.E., and Ph. D. degrees from the University of Tokyo in 2002, 2004 and 2007, respectively. He is currently a research scientist in RIKEN SPring-8 Center. His research interests include geometrical effects on propagation of X-rays, visible light and microwaves.