THz radiation by optically controlled depolarization in BiFeO3

Author

Tonouchi, Masayoshi

Author_Institution

Inst. of Laser Eng., Osaka Univ., Suita, Japan

fYear

2010

fDate

5-10 Sept. 2010

Firstpage

1

Lastpage

2

Abstract

Terahertz (THz) radiation has been observed from BiFeO₃ (BFO) thin films via ultrafast modulation of spontaneous polarization upon carrier excitation with illumination of femtosecond laser pulses. The radiated THz pulses from BFO thin films were clarified to directly reflect the spontaneous polarization state, giving rise to a memory effect in a unique style and enabling THz radiation even at zero-bias electric field. The emission mechanism is explained by the direct modulation of spontaneous polarization. We also find strong photoassist effect on polarization switching of BFO films.

Keywords

bismuth compounds; electric domains; high-speed optical techniques; multiferroics; photoconductivity; thin films; BiFeO₃; BiFeO₃ thin films; carrier excitation; direct modulation; emission mechanism; femtosecond laser pulse illumination; memory effect; optically controlled depolarization; polarization switching; spontaneous polarization state; strong photoassist effect; terahertz radiation; ultrafast modulation; zero-bias electric field; Lighting; Optical films; Optical imaging; Optical polarization; Optical pulses; Optical reflection; Ultrafast optics;

fLanguage

English

Publisher

ieee

Conference_Titel

Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2010 35th International Conference on

Conference_Location

Rome

Print_ISBN

978-1-4244-6655-9

Type

conf

DOI

10.1109/ICIMW.2010.5612742

Filename

5612742