A research group led by Professor Teruya Ishihara at Department of physics, Tohoku University (the former team leader at Exciton Engineering Laboratory, Frontier Research System, RIKEN, Wako, Japan) has demonstrated that a rotational electromagnetic field is detected as a voltage. Such an electromagnetic field is brought about by a circularly polarized light obliquely incident on 40-nm thick Au film with array of holes with periodicity of 500 nm. The voltage was found to be generated perpendicularly to the incident plane and greatly enhanced when the light excites around a resonance state called a surface plasmon polariton. It flips when the sense of the polarization rotation is reversed.

Rotational state of electromagnetic field in nanostructured artificial material can be now explored with such a simple means as a voltage. With this discovery, basic research in plasmonics and metamaterials, which are the platforms of nano-optics, finds a new direction. The discovery can be also seen as a novel elementary technology that bridges electronics and nano-optics.

The research was initiated when Prof. Ishihara was a laboratory head in RIKEN and continued after his moving to Tohoku University. The theoretical analysis was carried out as a collaboration with Prokhorov General Physics Institute, Russia.

The research results have been published in “Physical Review Letters” (academic journal issued by American Physical Society) on September 4, 2009. The paper’s title is _ Transverse Photo-Voltage Induced by Circularly Polarized Light._

[Contact]

Professor Teruya Ishihara

Department of physics, Tohoku University

TEL: +81-22-795-6420

E-mail: terish@sspp.phys.tohoku.ac.jp