Theoretical and experimental investigations of the nonlinear refractive index in an erbium- doped fiber are reported. We also show that an optical switch based on twin-core erbium- doped fiber can be constructed and operated at low input optical power, in the order of 1 or 2 mW. The transient response of this fiber also is examined. The switching speed can be improved by using a signal power at a wavelength close to the resonant wavelength between the excited state and the ground state.
Pak Lim Chu,
Yan Ling Xue,
"Optical switching in erbium-doped fibers", Proc. SPIE 1979, 1992 International Conference on Lasers and Optoelectronics, (11 May 1993); doi: 10.1117/12.144156; https://doi.org/10.1117/12.144156