High-density digital free-space photonic switches using micro-beam optical interconnections

We describe a compact free-space photonic-switching module that uses micro-beam optical interconnections based on stacked planar optics and exciton absorption reflection switch (EARS) arrays. The switching module has two-dimensional fiber array pigtails and a two-stage, 16-input, 16-output structure (four sets of 4/spl times/4 switches). The microbeam optical interconnections can provide a compact switching module (approximately 30/spl times/90/spl times/22 mm [60 cc]). A relay lens array inserted between stages eliminates beam spreading in the switch and decreases the coupling loss and crosstalk of interconnections. Two-stage switching at a data transmission rate of 4 Mbit/s is demonstrated.