Since the release of the previous edition of this proven best-seller, Fiber Optic Communication Systems [FOCS] have revolutionized the telecommunications industry, and due to the advantages they have over electrical transmission, they have largely replaced copper communication wires. Now, the fourth edition continues the tradition of this reliable source that provides the most comprehensive coverage of FOCS by incorporating recent advancements in the field, emphasizing both physical understanding and technical issues.

There are two new chapters: one focuses on advanced modulation formats (such as DPSK, QPSK, and QAM) that are increasingly used to improve the spectral performance of WDM optical systems. The other focuses on new techniques such as fully optical regeneration, which is under development and may be used in future communication systems. All other chapters have been updated, and the material has been restructured to better suit a two-semester course on optical communications.

Students and researchers will benefit from extensive pedagogical enhancements, including:
- Extensive reference lists for each chapter
- A survey of recent research material for each topic
- Relevant end-of-chapter practical problems for instructors and students
- A solutions manual available to instructors upon request
- One of the best currently available software on the accompanying CD, which students can use to design point-to-point optical links, among other things, as well as additional problems for each chapter.

Used worldwide as a textbook in many universities, Fiber Optic Communication Systems are primarily intended for graduate students in the field of optical communications. It is also a valuable resource for undergraduate courses at an advanced level, as well as an essential professional reference source for engineers and technicians in the telecommunications industry and scientists working in the fields of optical fibers and optical communications.