Wavelength-division multiplexing free-space optical interconnect networks for massively parallel processing systems

Image fiber optic space-CDMA parallel transmission experiment using 8 x 8 VCSEL/PD arrays

We experimentally demonstrate space-code-division multiple access (space-CDMA) based twodimensional (2-D) parallel optical interconnections by using image fibers and 8 x 8 vertical-cavity surface-emitting laser (VCSEL)/photo diode (PD) arrays. Two spatially encoded four-bit (2 x 2) parallel optical signals were emitted fiom 2-D VCSEL arrays and transmitted through image fibers. The encoded signals were multiplexed by an image-fiber coupler and detected by a 2-D PD array on the receiver side. The receiver recovered the intended parallel signal by decoding the signal. The transmission speed was 64 Mbps/ch (total throughput: 512 Mbps). Bit-error-rate (BER) measurement with a laterally misaligned PD array showed the array had a misalignment tolerance of 25 microm for a BER performance of 10(-9).

Compact wavelength division multiplexers and demultiplexers

Compact devices for wavelength division multiplexing and demultiplexing, believed to be novel, are presented. These devices are based on planar optics configurations, comprising multiplexed diffractive optical elements. The principle, design, and recording of these planar devices are described, including the fact that the recording is done at a single wavelength in the green region. Experimental procedures and results for planar devices that can handle three wavelengths in the visible as well as in the near infrared are presented.