Abstract

Millimeter-wave (mm-wave) fiber-radio systems are being proposed for the implementation of future ultra broadband networks to deliver high data-rate services to the user. Recently the application of optical networking concepts such as wavelength division multiplexing (WDM) to such systems has been proposed.¹ In these networks the mm-wave radio signals are superimposed onto optical carriers, multiplexed to form a WDM signal, and distributed by an optical fiber network from a central office to remote antenna base-stations. The performance of such links however can be severely limited by fiber chromatic dispersion.² The use of optical single-sideband with carrier (OSSB + C) modulation has been shown to reduce these effects although a WDM channel spacing in excess of 50 GHz is required leading to poor spectral efficiency in the optical domain.¹ Recently a novel wavelength-interleaving technique was proposed and demonstrated to improve the optical spectral efficiency of mm-wave WDM fiber-radio systems.³ This technique used multiple fiber Bragg gratings (FBGs) to provide the wavelength add/drop functionality required for this type of WDM fiber-radio network. This scheme however suffered from high insertion loss as well as unstable power fluctuations in the dropped channel most likely due to the performance of the individual gratings used. In this paper we overcome these drawbacks to demonstrate for the first time, a wavelength-interleaved optical add/drop multiplexer (OADM) architecture for mm-wave fiber-radio that incorporates a single custom-designed FBG.

© 2002 Optical Society of America