[OPTICAL REVIEW Vol. 18, No. 2 (2011) 212-217]
© 2011 The Japan Society of Applied Physics
Grating Formation in Fe:LiNbO3 Photorefractive Crystal by Chirped 800-nm Femtosecond Laser Pulses Operated at 1 kHz
Md. Masudul KABIR, Yu OISHI, and Fumihiko KANNARI*
Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
(Received November 22, 2010; Accepted December 21, 2010)
We demonstrate an extension of forming a photorefractive volume grating in an Fe:LiNbO3 crystal by chirped intense femtosecond laser pulses generated from a Ti:Al2O3 regenerative amplifier at 1 kHz. We confirm that one-photon absorption is still dominant in the Fe:LiNbO3 crystal up to 70 GW/cm2. To generate a photorefractive grating at such a low laser repetition rate within a practical writing time, the laser pulse intensity is increased to >30 GW/cm2. Furthermore, we demonstrate the amplification of femtosecond laser pulses by the chirped volume grating that is written in the Fe:LiNbO3 by two-wave mixing.
Key words: ultrashort laser pulse, photorefractive effect, holographic volume grating, two-wave mixing
*E-mail address: kannari@elec.keio.ac.jp