A CASCADABLE POLARIZATION-BASED 1-TO-9 MULTIMODE OPTICAL-FIBER SWITCHUSING A PMMA FIBER ARRAY HOLDER

We have constructed an optical fiber switch, which allows to route an information carrying laser beam to nine multimode optical fibers. The fibers are accurately positioned in a polymethylmethacrylate (PMMA) fi ber array holder, fabricated with deep proton lithography. To switch l ight from one fiber to another, we use active control of the polarizat ion of light by means of nematic liquid crystal retarders or ferroelec tric polarization rotators. The system shone insertion losses as low a s 3 dB and crosstalk ratios below -30 dB, These figures are still susc eptible to considerable improvements. The switching speed is on the or der of 10 Hz using nematic liquid crystals and was extended to 10 kHz with ferroelectric liquid crystals. Potential applications of the fibe r switch are discussed. As an illustration we have demonstrated the mu ltiplexing of optical fiber proximity sensors. We also describe scale reduction and cascadability issues.