For those interested in accessing a free PDF download of "Optical Communication Systems" by John Gowar, there are several options available:
That weekend Mira wrote an email instead of a rant. She mapped out her experiments, annotated the parts list, and attached carefully crafted figures showing how she had adapted Gowar’s formulas to a low-cost rig. She proposed a departmental initiative: lend affordable lab kits and maintain a legal library copy for students who couldn’t buy expensive books. The reply was slow but not hostile. They agreed to investigate creating a course pack, and the bookstore offered a discounted bundle if the department could guarantee enough buyers.
: Developed specifically in the context of optoelectronic components like III-V semiconductors. System Design Considerations