Abstract

Since rare-earth doped fibers have resonantly enhanced optical nonlinearity, there have been much research activities to enhance the nonlin-earity for all-optical switching applications.^1,2 It is also important to evaluate the optical nonlinearity with reliability and precision. Several measurement methods such as the Mach-Zehnder interferometer, ³ the two-mode fiber, ⁴ and the twin-core fiber, ⁵ have been suggested and used to determine the nonlinear optical property of the fibers. However, all the methods suffer from uneasiness of the measurement and high cost. The Mach-Zehnder interferometer method needs an expensive phase modulator, and the two-mode fiber method requires a special design of the doped fibers to be single-mode at the pump wavelength and two-mode at the signal wavelength. The twin-core fiber method needs a special twin-core fiber for the test.

© 2002 Optical Society of America