A previously suggested birefringence-customized modular optical interconnect technique is extended for lens-free relay operation. Various lens-free relay imaging models are developed. We claim that the lens-free relay system is important in simplifying an optical interconnect system whenever the imaging conditions permit. To verify the validity of various proposed concepts, we experimentally implemented some 8 × 8 optical permutation modules. High-power efficiency and low channel cross talk were experimentally observed. In general, the larger the channel spacing, the less the cross talk. A quantitative cross-talk measurement of the lens-free relay system shows that, for a fixed channel width of 0.5 mm and channel spacings of 0.5, 1, and 2 mm, a less than −20-dB cross-talk performance can be guaranteed for lens-free relay distances of 40, 280, and 430 mm, respectively.
© 1998 Optical Society of America
(060.4250) Fiber optics and optical communications : Networks
(200.4650) Optics in computing : Optical interconnects
(260.1440) Physical optics : Birefringence
(260.5430) Physical optics : Polarization
Liren Liu, Ting Wang, and Yao Li, "Relay Lens-Free Birefringence-Customized Stackable Beam-Steering Modules for Optical Interconnects," Appl. Opt. 37, 2935-2943 (1998)