I will discuss the optical properties and possible applications of graphene in photonics and plasmonics. I will review the basics of the single particle and collective excitations of graphene, discuss the mechanisms of photocurrent generation in graphene and the design and characteristics of graphene-based photodetectors. I will show that the coupling of light to localized graphene plasmons provides an excellent way of enhancing the strength of graphene-light interaction. Plasmon excitations in graphene micro- and nano-structures and their use in graphene devices in the infrared and terahertz ranges of the EM spectrum will be discussed. The interactions of graphene plasmons with intrinsic graphene and substrate phonons and their implications will also be analyzed.