Publications by Year: 1998

D. M. Marom, N. Konforti, and D. Mendlovic, “All-optical stage of an Omega network,” Applied Optics, vol. 37, no. 29, pp. 6946-6950, 1998. Publisher's VersionAbstract

All-optical multistage interconnection networks are desirable for overcoming the limitations of optical signal regeneration in switching systems. We present a new implementation of the perfect-shuffle interconnection pattern that is coupled with an all-optical switching element, forming a complete stage of a multistage network. Switching is performed with birefringent calcite crystals and a ferroelectric liquid-crystal device, while interconnection is achieved with a space-semivariant imaging configuration. Cascading the layout allows this system to be used to construct an all-optical multistage interconnection network. An experimental demonstration of the stage is presented.

D. M. Marom, P. E. Shames, F. Xu, and Y. Fainman, “Folded free-space polarization-controlled multistage interconnection network,” Applied Optics, vol. 37, no. 29, pp. 6884-6891, 1998. Publisher's VersionAbstract

We present a folded free-space polarization-controlled optical multistage interconnection network (MIN) based on a dilated bypass–exchange switch (DBS) design that uses compact polarization-selective diffractive optical elements (PDOE’s). The folded MIN design has several advantages over that of the traditional transparent MIN, including compactness, spatial filtering of unwanted higher-order diffraction terms leading to an improved signal-to-noise ratio (SNR), and ease of alignment. We experimentally characterize a folded 2 × 2 switch, as well as a 4 × 4 and an 8 × 8 folded MIN that we have designed and fabricated. We fabricated an array of off-axis Fresnel lenslet PDOE’s with a 30:1 SNR and used it to construct a 2 × 2 DBS with a measured SNR of 60:1. Using this PDOE array in a 4 × 4 MIN resulted in an increased SNR of 120:1, highlighting the filtering effect of the folded design.

D. M. Marom, P. - C. Sun, and Y. Fainman, “Analysis of spatial–temporalconverters for all-optical communication links,” APPLIED OPTICS, vol. 37, no. 14, pp. 2858-2868, 1998. Publisher's VersionAbstract

We analyze parallel-to-serial transmitters and serial-to-parallel receivers that use ultrashort optical pulses to increase the bandwidth of a fiber-optic communication link. This method relies on real-time holographic material for conversion of information between spatial and temporal frequencies. The analysis reveals that the temporal output of the pulses will consist of chirped pulses, which has been verified experimentally. When the signal pulses are transmitted along with a reference pulse, the distortions of the received signal, caused by dispersion and other factors in the fiber, are canceled because of the phase-conjugation property of the receiver. This self-referencing scheme simplifies the receiver structure and ensures perfect timing for the serial-to-parallel conversion. © 1998 Optical Society of America