This course covers the basics of optical communications. The first half of the course is spent describing optical devices including the LED, laser, optical fiber, PIN photodiode, APD detectors, optical amplifiers, modulators, etc. Characteristics of devices and their effect on the overall system are discussed. The second half of the course is devoted to system design and analysis. The emphasis is on modulation/demodulation and channel control methods, defining performance measures, and describing network architectures. Common applications of optical communications are then discussed. This course is intended to complement training in communications and in optics.