L. Fan, M. C. Wu, H. C. tee, and P. Grodzinski, "Singie-chip photonic banyan network realized by arrays of beam-steering VCSELs and reflective Fresnel zone plates,"
in Conference on Lasers and Electro-Optics, J. Bowers, D. Miller, D. Scifres, and A. Weiner, eds.,
Vol. 9 of OSA Technical Digest
(Optical Society of America, 1996), paper CFH5.