[OPTICAL REVIEW Vol. 6, No. 4 (1999) 334-338]

Reflectivity Characteristics of Resonant Four Wave Mixing Generated in Erbium-Doped Optical Fibers

Yoh IMAI, Hidenori INOUE and Kenzo TAN

Department of Computer Science and Electronics, Kyushu Institute of Technology, 680-4, Kawazu, Iizuka, Fukuoka, 820-8502 Japan

(Received February 19, 1999; Accepted March 23, 1999)

Resonant four-wave mixing (RFWM) based on the photo-induced refractive index change in erbium-doped optical fibers is demonstrated experimentally. The erbium-doped fibers act as a saturable absorber at 1.536 μm pump wavelength. Dependence of efficiency of RFWM on the pump power, the dopant concentration, the fiber length, and the signal modulation frequency are analyzed using three types of erbium-doped fibers differing in dopant concentration. It is found that a signal modulation frequency higher than 10 kHz is required for the correct measurement. The RFWM efficiency is improved with an increase in the input pump power in a range up to 1.5 mW and the highest reflectivity of 5.1% is attained. The highest RFWM efficiency is achieved at αGSL~5 dB, which is in good agreement with the theory.

Key words : resonant four wave mixing, transition absorption, photo-induced refractive index change