Demonstration of Multi-Casting in a 1×9 LCOS Wavelength Selective Switch

Company Founder's work at Cambridge University Published

in IEEE Lightwave Technology, Journal of

On December 5 2013, 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 IEEE Lightwave Technology, Journal of.

By Brian Robertson, Haining Yang, Maura M. Redmond, Neil Collings, John R. Moore, Jinsong Liu, Anna M. Jeziorska-Chapman, Mike Pivnenko, Sharon Lee, Adrian Wonfor, Ian H. White, 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: A multi-functional 1×9 wavelength selective switch based on liquid crystal on silicon (LCOS) spatial light modulator technology and anamorphic optics was tested at a channel spacing of 100 GHz and 200 GHz, including dynamic data measurements on both single beam deflection and multi-casting to two ports. The multi-casting holograms were optimized using a modified Gerchberg-Saxton routine to design the core hologram, followed by a simulated annealing routine to reduce crosstalk at non-switched ports. The effect of clamping the magnitude of phase changes between neighboring pixels during optimization was investigated, with experimental results for multi-casting to two ports resulting in a signal insertion loss of -7.6 dB normalized to single port deflection, a uniformity of ±0.6 %, and a worst case crosstalk of -19.4 dB, which can all be improved further by using a better anti-reflection coating on the LCOS SLM coverplate and other measures.