This is my first 2009 article

Now I come here again.

From now on I want to share with you my research experiences and personal opinion on  time dependent quantum system, photonic/sonic crystals, and metamaterials.  I would also like to write some articles on science teaching stuff.

I come from Taiwan. Usually I speak chinese, and have no many oppernituties to practice my English, so I wish someone can help me to improve my English. Thanks !