Development of small port-count ROADM using MEMS type 2x2 OSWs and VOAs

We developed a low cost small port-count ROADM(Reconfigurable Optical Add-Drop Multiplexer) using simple MEMS (Micro Electro-Mechanical System) type 2times2 OSWs (Optical Switches) and VOAs (variable optical attenuators). The ROADM module consisting of components all developed in-house performed fast and reliable add/drop function with channel equalisation. The output power flatness was controlled to less than 0.5 dB over four CWDM channels

I. Introduction

As information traffic and complexity of optical networks are increased, it is desired for the network nodes to have agility, such as adaptive optical wavelength switching and channel equalisation. ROADM[1] is one of the important components in the transparent optical networks. Large port-count MEMS switches have been developed to serve the needs for the ultimate DWDM all-optical networks. However, the sophistication in the fabrication and control, and the incurring cost are at a level which is too high for small to medium scale optical networks. In a local or metro area network that handles only small number of wavelengths, discrete 2×2 MEMS OSWs and VOAs can be robust and low-cost budding blocks for the ROADM nodes. It is the motivation of our research to meet the demand for the small channel-count ROADM with simple sub-components.