Laser-diode-pumped nonlinear switch in erbium-doped fiber.

We describe a two-mode fiber switch made of a short length of erbium-doped fiber in which switching is accomplished by a nonlinearity that is resonantly enhanced by the dopant. In a 0.95-m fiber pumped with a 1.48-μm laser diode, a 906-nm signal is switched with only 8 mW of absorbed power at a signal absorption loss of 0.25 dB.