Abstract

Free-space optical switches are attractive candidates to replace conventional electrical switches in future supercomputers and telecommunication systems[1]. The switches have the potential to handle a large number of high speed signals without suffering from such problems as electromagnetic interference, signal delay, and clock skew. Liquid crystal light modulators which can control the polarization state of light are promising as the switching devices in such switches, because they make it easy to construct large arrays, and they are transparent to the lights being switched over a wide wavelength region. Several free-space multichannel optical switches based on these devices have been proposed for multistage optical switching networks [2],[3]. The optical switches are the one-way type in which optical signals enter one side of the switch body and are output from the other side. Input and output fiber arrays must, therefore, be situated on both sides of the switch. In applying such switches to intra-board chip-to-chip interconnects in a multiprocessor system, the input and output links of each processor have to be connected to the optical switch via input and output optical fibers, respectively [4]. This scheme causes wiring congestion and restricts the architecture of the system if the number of processors is increased.

© 1993 Optical Society of America