1. Kauranen, M., & Zayats, A. V. (2012). Nonlinear plasmonics. Nature Photonics, 6(11), 737-748.
2. Nalwa, H.S. and Miyata, S., 1996. Nonlinear optics of organic molecules and polymers. CRC press.
3. Lenz, G., Zimmermann, J., Katsufuji, T., Lines, M. E., Hwang, H. Y., Spälter, S., ... & Aggarwal, I. (2000). Large Kerr effect in bulk Se-based chalcogenide glasses. Optics Letters, 25(4), 254-256.
4. Pelusi, M. D., Ta'eed, V. G., Fu, L., Mägi, E., Lamont, M. R., Madden, S., ... & Eggleton, B. J. (2008). Applications of highly-nonlinear chalcogenide glass devices tailored for high-speed all-optical signal processing. Selected Topics in Quantum Electronics, IEEE Journal of, 14(3), 529-539.
Which materials have highest electro-optic effect so that they are more sensitive to electric field. I am not worried about speed, even if response is slow that's fine
You can refer to this book http://www.springer.com/in/book/9783642026454. I would recommend Lithium Niobate but yes you can also refer to this paper http://scitation.aip.org/docserver/fulltext/aip/journal/apl/89/24/1.2402946.pdf?expires=1462425177&id=id&accname=2122919&checksum=BA49E77EBEC2A8083B68BEC50F2ECD34 for clear understanding.