Reconfigurable optical power splitter/combiner based on Opto-VLSI processing

Abstract

A novel 1×4 reconfigurable optical splitter/combiner structure based on Opto-VLSI processor and 4-f imaging system with high resolution is proposed and experimentally demonstrated. By uploading optimized multicasting phase holograms onto the software-driven Opto-VLSI processor, an input optical signal is dynamically split into different output fiber ports with user-defined splitting ratios. Also, multiple input optical signals are dynamically combined with arbitrary user-defined weights. ©2011 Optical Society of America

A $1 \times N$ Lossless Adaptive Optical Power Splitter Employing an Opto-VLSI Processor

“…Illustrated in Fig. 1, an Opto-VLSI processor incorporates an array of liquid crystal (LC) cells addressed by a Very-LargeScale-Integrated (VLSI) circuit [23], [24] that generates phase holograms capable of arbitrary steering and/or multicasting input laser beams. By depositing a quarter-wave-plate (QWP) layer between the LC layer and the aluminum mirror, polarization-insensitive operation can be accomplished [25].…”

“…Several adaptive OPS technologies have been reported based on tuned fiber Bragg gratings (FBGs) [14], optical polarization splitters [15], semiconductor optical amplifiers [16], [17], waveguide couplers and planar lightwave circuits (PLCs) [18]- [20], MEMS [21], and Opto-VLSI [22]- [24]. However, these techniques have limited tolerance to environmental perturbations, high polarization dependence, and limited numbers of output ports.…”

“…The number of output ports for this structure was limited to two ports because the spacing of the fiber collimator array was large (3 mm), thus requiring a large beam steering angle which increases the insertion loss. To eliminate the need for large steering angles, the authors replaced the fiber collimator array with a fiber array with 250 m fiber-to-fiber spacing [24]. This approach doubled the output port count; however, with the use of a single-lens 4-f imaging system, further increase in the output port count was impractical, due to the high insertion loss experienced by the split optical beams routed to the outer fiber ports, which require large beam steering angles for optimum beam coupling.…”