Aberration correction in an adaptive free-space optical interconnect with an error diffusion algorithm

Abstract

Aberration correction within a free-space optical interconnect based on a spatial light modulator for beam steering and holographic wavefront correction is presented. The wavefront sensing technique is based on an extension of a modal wavefront sensor described by Neil et al. [J. Opt. Soc. Am. A 17, 1098 (2000)], which uses a diffractive element. In this analysis such a wavefront sensor is adapted with an error diffusion algorithm that yields a low reconstruction error and fast reconfigurability. Improvement of the beam propagation quality (Strehl ratio) for different channels across the input plane is achieved. However, due to the space invariancy of the system, a trade-off among the beam propagation quality for channels is obtained. Experimental results are presented and discussed.

Use of wavefront encoding in optical interconnects and fiber switches for cross talk mitigation

“…(12). Thus, taking into account the relay system lenses, L 2 and L 3 , the demagnification of the original SLM kinoform pattern increases the defocus to f H2 0.444 m. This resulted in the replay plane for the 1 order being shifted toward L 4 by a distance, d1 90 mm.…”

“…In previous work, Neil et al [11] demonstrated how a binary diffractive element can be used to arbitrarily aberrate different diffraction orders. A similar approach was used by Gil Leyva et al [12] for aberration analysis and corrections in a free-space optical interconnect, a technique which was described as also having the potential for cross talk control. We show how cross talk can be reduced in a fiber switch or free-space reconfigurable interconnect based on one of the simplest aberrations, defocus.…”