In-Fiber Wavelength-Selective Modulation of WDM Channels With Performance Analysis

An in-fiber wavelength-selective optical intensity modulator has been developed to superimpose low-rate overhead (OH) data on the transit high-speed payload signals. The tunable fiber Bragg grating, as the heart of a wavelength-selective modulator (WSM), is designed and properly biased to implement the desired modulation specification. Potential performance limitations of WSM are investigated and described in terms of eye opening penalty and crosstalk between wavelength-division-multiplexing channels. A simple OH/label erasing technique is also provided and used for modifying the labels through cascaded WSMs. The performance of such cascaded systems is calculated both with and without considering the optical loss compensation. The results confirm the ability of WSMs for low-speed applications such as QoS management and service level agreement for differentiated services.