Application of the fractional Fourier transform to the design of LCOS based optical interconnects and fiber switches.

It is shown that reflective liquid crystal on silicon (LCOS) spatial light modulator (SLM) based interconnects or fiber switches that use defocus to reduce crosstalk can be evaluated and optimized using a fractional Fourier transform if certain optical symmetry conditions are met. Theoretically the maximum allowable linear hologram phase error compared to a Fourier switch is increased by a factor of six before the target crosstalk for telecom applications of -40 dB is exceeded. A Gerchberg-Saxton algorithm incorporating a fractional Fourier transform modified for use with a reflective LCOS SLM is used to optimize multi-casting holograms in a prototype telecom switch. Experiments are in close agreement to predicted performance.

[1]  Brian Robertson,et al.  Adaptive beam steering implemented in a ferroelectric liquid-crystal spatial-light-modulator free-space, fiber-optic switch. , 2002, Applied optics.

[2]  Brian Robertson,et al.  Cross-talk analysis in a telecentric adaptive free-space optical relay based on a spatial light modulator. , 2006, Applied optics.

[3]  Lin Xu,et al.  Influence of phase delay profile on diffraction efficiency of liquid crystal optical phased array , 2009 .

[4]  S. A. Collins.  Lens-System Diffraction Integral Written in Terms of Matrix Optics , 1970 .

[5]  Brian Robertson,et al.  Use of wavefront encoding in optical interconnects and fiber switches for cross talk mitigation. , 2012, Applied optics.

[6]  N Collings,et al.  High Quality Assembly of Phase-Only Liquid Crystal on Silicon (LCOS) Devices , 2011, Journal of Display Technology.

[7]  O. Soares,et al.  Fractional Fourier transforms and imaging , 1994 .

[8]  A. Lohmann.  Image rotation, Wigner rotation, and the fractional Fourier transform , 1993 .

[9]  T. Strasser,et al.  Wavelength-Selective Switches for ROADM Applications , 2010, IEEE Journal of Selected Topics in Quantum Electronics.

[10]  S. Frisken.  Advances in Liquid Crystal on Silicon Wavelength Selective Switching , 2007, OFC/NFOEC 2007 - 2007 Conference on Optical Fiber Communication and the National Fiber Optic Engineers Conference.

[11]  R. Gerchberg.  A practical algorithm for the determination of phase from image and diffraction plane pictures , 1972 .

[12]  Timothy D. Wilkinson,et al.  Hologram Optimisation Using Liquid Crystal Modelling , 2005 .

[13]  H. Ozaktas,et al.  Fractional Fourier optics , 1995 .

[14]  William A. Crossland,et al.  An algorithm for computing spot-generating holograms , 2008 .

[15]  D Mendlovic,et al.  Gerchberg-Saxton algorithm applied in the fractional Fourier or the Fresnel domain. , 1996, Optics letters.

[16]  Markus Testorf,et al.  Design of diffractive optical elements for the fractional Fourier transform domain: phase-space approach. , 2006, Applied optics.

[17]  Claudio Iemmi,et al.  Wavelength dependence of polarimetric and phase-shift characterization of a liquid crystal on silicon display , 2008 .

[18]  L. Bernardo.  ABCD MATRIX FORMALISM OF FRACTIONAL FOURIER OPTICS , 1996 .

[19]  Lars Sjöqvist,et al.  Intensity variations using a quantized spatial light modulator for nonmechanical beam steering , 2003 .

[20]  A H Greenaway,et al.  Simultaneous multiplane imaging with a distorted diffraction grating. , 1999, Applied optics.

[21]  Gozde Bozdagi Akar,et al.  Digital computation of the fractional Fourier transform , 1996, IEEE Trans. Signal Process..

[22]  W. Crossland,et al.  Holographic optical switching: the "ROSES" demonstrator , 2000, Journal of Lightwave Technology.

[23]  B Robertson,et al.  Dynamic holography for optical interconnections. II. Routing holograms with predictable location and intensity of each diffraction order. , 2001, Journal of the Optical Society of America. A, Optics, image science, and vision.

[24]  B. Dong,et al.  Beam shaping in the fractional Fourier transform domain , 1998 .