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

Company Founder's work at Cambridge University Published

in Applied Optics

On April 20 2012, the work carried out by the founder of Wuxi OptonTech Ltd, Dr Jinsong Liu, and other scientists at the University of Cambridge is published in Applied Optics.

By Brian Robertson, Zichen Zhang, Haining Yang, Maura M. Redmond, Neil Collings, Jinsong Liu, Ruisheng Lin, Anna M. Jeziorska-Chapman, John R. Moore, William A. Crossland, and D. P. Chu^,

Photonics and Sensors Group, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, CB3 0FA, Cambridge, UK

Abstract: 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 -40dB 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.