Free-space optical MEMS-based transparent switch matrices based on analog beam steering optics are the preferred choice for applications requiring matrices ...
Invited Paper
Modular MEMS Design and Fabrication for an 80 x 80 Transparent Optical Cross-Connect Switch Andres Fernandez, Bryan P. Staker, Windsor E. Owens, Lawrence P. Muraya, James P. Spallasa, William C. Banyai Glimmerglass, 26142 Eden Landing Rd, Hayward, CA 94545 ABSTRACT The ability to transparently switch optical signals from one fiber to another without conversion to the electrical domain is a basic functionality that has a wide range of applications within the fiber optic industry. The so-called 3D-MEMS architecture has emerged as the preferred approach for building transparent, scalable systems with port-counts ranging from 16x16 to 1024x1024. The primary components of the 3D-MEMS architecture are fiber array, lens array, and MEMS mirror array. While a central theme in the MEMS industry is integration, we adopted a strategy of modularization. The key MEMS components, which include mirror array, ceramic substrate, and high-voltage drivers, were manufactured separately and then combined to yield a working product. Central to our modular approach was critical design parameter tolerancing to ensure manufacturability. Results from a large sampling of MEMS components and MEMS assemblies are presented to highlight manufacturability and performance. Keywords: Microelectromechanical systems (MEMS), optical switching, optical cross-connect (OXC).
1. INTRODUCTION 1.1 Transparent Optical Switching In the most general terms, transparent optical switching refers to the operation of an optical system that interconnects pairs of optical fibers—typically single mode—by directly relaying light between input and output fiber faces. When there are N input and M output fibers, the optical system is deemed an NxM switch matrix. When any two connections within the switch matrix can be interchanged without interfering with other existing connections the switch matrix architecture is non-blocking. Non-blocking NxM switch matrices can be constructed with either guided wave or freespace optical switching devices, with each device type having unique features and benefits. All approaches have the principal benefit that their switching operation does not depend on the modulation properties of the light being switched; in other words, their operation is independent of or transparent to signal bit-rate and format. Transparent non-blocking NxM switch matrices based on bulk electro-mechanical free-space optical switching devices have tracked the development of fiber optics, finding application in switching various pieces of optical test equipment for optical component testing. The switches are slow (1s), bulky, expensive, and limited in size to 16x16 or more typically 2x48. Nevertheless, they display outstanding optical performance in terms of optical insertion loss (
