Introduction to Applied Optics for Engineers introduces the reader to applied optics and presents ideas on coherent optical data processing. Topics covered include applications and approximations for radiation fields; physical realizations of phase transformers, lenses, and systems; applications of optical filtering to data processing; and partial coherence. Several examples from bioengineering-related research are provided. This book is comprised of 10 chapters and begins with an introduction to the basic equations of physical optics that are derived using the wave treatment approach, resulting in the simpler geometrical (ray) optics approximation. The differential form of Maxwell's equations is considered, along with propagation in free space and Fermat's principle. The following chapters explore applications and approximations for radiation fields, with emphasis on Fraunhofer fields, circular and multiple apertures, and phase effects in apertures; physical realizations of phase transformers, lenses, and spherical and parabolic surfaces; and system transform concepts including Fourier transform representation of fields and calculation techniques for imaging through a lens. The remaining chapters focus on interface devices, interferometry, holography, and scattering. This monograph is intended for students and engineers with a traditional background in electromagnetic wave theory.