Comparison of spatial and planar lightwave switches: an overview

摘要

Planar and spatial lightwave (LW) switches (synonym: all-optical switches) are reviewed and compared with rgard to their (i) architectural principles (ii) possible implementations and (iii) performance. The first step towards spatial LW switches are spatial LW coupler which are aimed to utilize symmetries and circular geomeries covering several planar LW couplers. Then spatial LW switches, capable to generate simultaneously several rearrangeable nonblocking interconnections, are the next more involved step. The glaol are switch architectures with a low number of subsequent switching sections/stages. The spatial LW switches may be applied as (i) single compoents and (ii) switches within large 3-D LW circuits. For integrated switch architectures problems arise and the restriction of the number of layers causes additional difficulties.