A simplified schematic of our stacked switch architecture is shown in Figure 1.
The top view shows the operation of each individual switch. On the left of the system is a two-dimensional array of optical fibres, containing both the input and output fibres. This is matched to two lenslet arrays, LS and LA. LS has one lenslet per fibre, and LA has one lenslet per group of nine fibres, where each group of fibres corresponds to an individual switch. The lenslet arrays work together to collimate the highly-divergent beams emitted by the optical fibres. Lenses L1 and L2 then relay the collimated beams onto the SLM, via the demultiplexing element at plane Pg.
The side view demonstrates how the individual switches share the optical components in the relay system. L1, L2, the demultiplexing element and the SLM are shared between all three switches. The fibre arrays and corresponding lenslets for each switch are stacked along the y-axis. In this example, one input fibre and eight output fibres are arranged in a square-packed structure. The wavelength channels for each switch are dispersed along the x-axis of the SLM, and the strips for each of the switches are stacked along the y-axis, having been mirrored by the relay system.
Figure 1 – Stacked WSS module schematic.