Abstract

All-optical wavelength conversion is a key function for future high-speed optical networks. In dense wavelength-division multiplexed (WDM) systems, conversion between close wavelengths within the erbium gain band is necessary. On the other hand, conversion between 1.3- and 1.5-μm wavelength bands is needed for communication between networks or for increased flexibility of a network. This has, to date, been demonstrated only in a semiconductor optical amplifier¹ with limited operation speed, low On-Off ratio, and large wavelength sensitivity. Conversion between 1.5 and 1.3 μm in nonlinear optical-loop mirrors² (NOLM) suffers from a walk-off-limited interaction length due to the large difference in the group velocities of the two wavelength bands. These group velocities can be matched between particular wavelengths by specially designing the fibers,³ with a dramatic increase of the group-velocity mismatch and switching energy away from the design wavelengths. Also, a switching scheme without walk- off suffers from high sensitivity to timing jitter at high bit rates⁴ and from incomplete switching leading to pulse breakup.

© 1995 Optical Society of America