Resonant optical nonlinearity measurement of Yb3+/Al3+ codoped optical fibers by use of a long-period fiber grating pair

Abstract

A new method of measuring optical nonlinearity for resonant nonlinear optical fibers is proposed. A long-period fiber grating (LPG) pair was used to measure the nonlinear refractive index n(2) of a Yb3+ /Al3+ codoped optical fiber, which was spliced between the two LPGs, as the fiber was pumped with a laser diode. The nonlinear refractive index of the Yb3+ /Al3+ codoped fiber near 1580 nm depended on the pump power. As the pump power increased, the nonlinear refractive index decreased. At launched pump powers of 2-8 mW, the nonlinear refractive index of the Yb3+ /Al3+ codoped fiber near 1580 nm was similar to7.5 x 10(15) m(2)/W. (C) 2002 Optical Society of America.