H. L. Liew and V. Van, “Exact realization of optical transfer functions with symmetric transmission zeros using the double-microring ladder architecture”, IEEE/OSA Journal of Lightwave Technology., vol. 26, no. 14, pp. 2323 – 2331, 2008 (web)

A.M. Prabhu, H.-L. Liew and V. Van, “Elliptic optical filters with all-positive couplings based on the double-microring ladder architecture”, Conference on Lasers and Electrooptics (CLEO), San Jose, May 2008 (web)

A.M. Prabhu and V. Van, “General two-dimensional coupled-cavity microring filter architectures”, Conference on Lasers and Electro-optics, Baltimore, May 2007 (web)