| Steady increase in the bandwidth of telecommunication and computer systems has prompted research in optical switching. This thesis presents a family of liquid crystal optical switches and networks based upon free space optics. I begin by reporting the design and experimental results of a polarization independent, broadcast capable 2 x 2 ferroelectric liquid crystal optical switch and show how it can be extended to form two novel rearrangeable networks: the cylindrical Spanke network and the combiner network. Next, I report the design and experimental results of a higher performance, more fault tolerant 1 x 4 ferroelectric liquid crystal optical switch. This optical switch can be used to build a crossbar network with double crosstalk rejection and path independent loss and crosstalk. The experimental results for such a 4 x 4 crossbar network are reported. To compare the three networks I introduce, I present an original analysis of crosstalk in space domain optical switching networks that predicts the bit error rate measured at the optical receivers connected to the networks as a function of the network size, crosstalk contributed by the individual optical switches in the networks, and thermal noise in the receivers for synchronous and asynchronous signals in the networks. Finally, I present the theory and experimental results of a nematic liquid crystal Fabry-Perot etalon. The device can be used in conjunction with, or in place of, the ferroelectric liquid crystal space domain optical networks. It can be used as a wavelength selective optical switch or an optical spectral filter. |
