In this half-day tutorial, we present the current state-of-the-art in optical networks. We begin by discussing the various optical devices used in optical networks. Then, we present wavelength-routed networks, which is currently the dominant architecture for optical networks. We discuss wavelength allocation policies, calculation of call blocking probabilities, and network optimization techniques. Subsequently, we focus on the various protocols that have been proposed for wavelength-routed networks. Specifically, we present a framework for IP over optical networks, MPLS, LDP, CR-LDP, and GMPLS. Next, we discuss optical packet switching and optical burst switching, two new emerging and highly promising technologies.