Abstract

The optical transpose interconnection system¹ (OTIS) is a simple means of providing a transpose interconnection using only a pair of lenslet arrays. This system has been shown useful for shuffle based multi-stage interconnection networks, mesh-of-trees matrix processors, and hypercube interconnections. The transpose interconnection is a one-to-one interconnection between L transmitters and L receivers, where L is the product of two integers, M and N. To implement the interconnection a $\sqrt{N}\times \sqrt{N}$ array of lenslets is placed in front of the input plane, and a $\sqrt{M}\times \sqrt{M}$ array of lenslets is located before the output plane. The M × N transpose is equivalent to a k-shuffle², where k equals N. For example, a 4096 channel (M = N = 64) interconnection can be implemented with two 8×8 lenslet arrays, Figure 1 shows the side view, and actual input and output for such a system. An interesting application occurs when $k=\sqrt{L}$; in this case only one stage of optics and two stages of optoelectronic switches are required for full routing between the input and output channels. If M = N, then both lenslet planes are identical; and with minor modifications, such as opaque areas on the lenses to prevent cross-talk, the system can be made bi-directional.

© 1995 Optical Society of America