Photonic crystal WDM cross-connect with reconfigurable OCDMA functionality

Abstract

With avionic platforms moving toward integrated optical networks, platforms are replacing electrical components with their optical counterparts. Replacing electronic components and copper wire with photonic chips and optical fibers provide large means of reducing the overall Size Weight and Power (SWaP), which is highly desirable for deployed avionic platforms [1–2]. In an optical LAN, optical fibers provide a conduit for high data rates with low loss and ultra low crosstalk between Wavelength Division Multiplexing (WDM) channels used by the connected modules. However, as a LAN expands and evolves with demands of new functionality, the number of modules increase and the problem of efficiently communicating between each element with a high degree of confidentiality becomes exponentially more difficult. To address the interconnect demand, an optical cross-connect with ultra small SWaP specifications capable of reconfiguring paths to selectively connect modules is necessary. However, in LAN communication between modules, the security level may not necessarily be the same, and the optical extinction ratio between unsecure channels may not be enough for practical deployment. For military and commercial applications, where security between data channels is critical, Optical Code Division Multiple Access (OCDMA) can be employed to achieve the appropriate security between channels in a network [3–5]. In this paper we present a WDM reconfigurable bi-directional optical cross-connect using chip-scale silicon photonics, with functionality of serving as an encoding source for OCDMA. The cross-connect utilizes slow-light photonic crystal waveguides as directional couplers to reduce the size and power requirements for reconfigurable operation, while similar photonic crystal elements can be used to impose an encoding technique on the propagating optical data signals. This proposed architecture allows for fast, efficient, low power, bi-directional routing for WDM or OCDMA optical networks.