Abstract

Optical cross-connect (OXC) devices are essential components for the realization of dense wavelength division multiplexing (WDM) systems and/or optical switching networks [1], Fiber-Bragg-grating (FBG)-based OXC architectures are one of the promising candidates for designing these devices. Several approaches based on FBGs and optical circulators (OCs) were proposed/experimentally studied recently [2-3], In this paper, we propose an NxN OXC device based on strain-tunable FBGs (STFBGs). OXC devices for large-scale NxN (N≥3) switching systems are discussed. Figs. 1 (a)-(d) show the proposed four types 2x2 OXC devices. Each of them contains two 3-port optical circulators (OCs) and several FBGs. The different definitions UT, UR, BT and BR are based on appropriately choosing the corresponding II, I2, O1 and 02 ports of the four ports of these OXC devices. The Bragg wavelength of STFBG_i is designed to match the WDM-channel signals of λ_i, and λ′_i (1≤ 1≤N). Without applying strain to the STFBG_i, the channel signal at λ_i (λ′_i) is reflected by the certain FBG. On the other hand, apply strain to STFBG_i, λ_i (λ′_i) may pass-through the OXC and continue its forward propagation. Where λ_i and λ′_i (1≤ 1 ≤N) are the same wavelengths. The reflection-type OXC device means that any pair of the channel signals (λ_i and λ′_i) may cross-connect to the other link if they are "reflected" by the corresponding STFBG_i. On the other hand, the transmission-type OXC device means that any pair of the channel signals (λ_i and λ′_i) may cross-connect to the other link if they "transmit" the corresponding STFBG_i.

© 2001 IEEE