Optical crossconnects for high-capacity lightwave networks

Optical crossconnects are rapidly emerging as critical elements for provisioning and restoration in high-capacity wavelength-division-multiplexed optical networks. High port count appears to be emerging as particularly important in this core-network application, with 500-port optical crossconnects (OXCs) widely expected to be needed within about five years. This requirement severely strains current optical-switching technologies. The emergence of this new application is, however, beginning to stimulate new device technologies. One of these is the free-space micromachined optical switch (FS-MOS). This approach combines the advantages of free-space interconnection and monolithic integrated optics, thus offering the possibility of achieving high port-count in a small, low-cost system with excellent optical quality. In this paper, we review the fundamental principles, fabrication, and performance of the FS-MOS, and discuss both its port-count scalability and its ability to incorporate advanced optical-networking functionality within the switch fabric itself.

[1]  R.W. Tkach,et al.  High-density micromachined polygon optical crossconnects exploiting network connection-symmetry , 1998, IEEE Photonics Technology Letters.

[2]  Charles Clos,et al.  A study of non-blocking switching networks , 1953 .

[3]  Gaylord W. Richards,et al.  16/spl times/16 strictly nonblocking guided-wave optical switching system , 1996 .

[4]  M. Wu,et al.  Surface-micromachined free-space fiber optic switches with integrated microactuators for optical fiber communication systems , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).

[5]  Larry A. Coldren,et al.  Suppressed modal interference switches with integrated curved amplifiers for scaleable photonic crossconnects , 1998 .

[6]  R. W. Tkach,et al.  Fundamental limits of optical transparency , 1998 .

[7]  Masayuki Okuno,et al.  Low-Loss and High-Extinction-Ratio Silica-Based Strictly Nonblocking 16 · 16 Thermooptic Matrix Switch , 1999 .

[8]  H. Fujita,et al.  Electrostatic micro torsion mirrors for an optical switch matrix , 1996 .

[9]  H. Fujita,et al.  A quantitative analysis of Scratch Drive Actuator using buckling motion , 1995, Proceedings IEEE Micro Electro Mechanical Systems. 1995.

[10]  Akio Tajima,et al.  A 2.56 Tb/s throughput packet/cell-based optical switch-fabric demonstrator , 1998, 24th European Conference on Optical Communication. ECOC '98 (IEEE Cat. No.98TH8398).

[11]  R. W. Tkach,et al.  Free-space micromechanical optical crossconnect with bridging functionality for optical-layer restoration , 1998, 24th European Conference on Optical Communication. ECOC '98 (IEEE Cat. No.98TH8398).

[12]  R. Tkach,et al.  Free-space micromachined optical switches with submillisecond switching time for large-scale optical crossconnects , 1998, IEEE Photonics Technology Letters.