Simultaneous optical label erasure and insertion in a single wavelength conversion stage of combined FSK/IM modulated signals

We report on optical label swapping of combined frequency-shift keying/intensity modulation (FSK/IM) modulated signals by using a single wavelength conversion stage based on a semiconductor optical amplifier Mach-Zehnder interferometer. Simultaneous FSK label erasure and insertion at a bit rate of 156 Mb/s is successfully achieved for a 10-Gb/s IM payload with transmission over two spans of 40-km standard single-mode fiber.

I. Introduction

Optical label swapping (OLS) is a technique that enables the implementation of packet routing and forwarding functions in IP over wavelength-division multiplexing [1]. Fig. 1. Core router architecture in a combined FSK/IM modulation format scheme. OLS supports high bit rates for payload data transmission while employing low-speed electronics in the core nodes for label processing. Several approaches have been studied for labeling optical packets [2], among those the combined frequency-shift keying/intensity modulation (FSK/IM) is one of the promising methods due to its in-band characteristics and simplicity of implementation [3].