This is the delicate part of the discussion. If you have searched for this keyword, you have likely encountered a mixed bag of results.
The last third of the book pulls everything together.
John Gowar’s Optical Communication Systems provides a foundational analysis of optical fibers, sources, and detectors, balancing theoretical communication principles with practical optoelectronics. The text covers essential system components—transmitters, channels, and receivers—while addressing key challenges like attenuation, dispersion, and, in the second edition, advancements in single-mode fibers and coherent detection. Detailed insights and previews of the text are available through Google Books and the Internet Archive. Optical communication systems : Gowar, John, 1945 optical communication system by john gowar pdf
Let’s examine the specific engineering value hidden within the typical chapters of Gowar’s text.
Gowar’s original edition (circa 1993) does not cover coherent optical transmission or the explosion of DWDM (Dense Wavelength Division Multiplexing). Use his foundation to understand modern texts. Once you understand Gowar’s explanation of a Fabry-Perot laser, moving to a DFB (Distributed Feedback) laser is easy. This is the delicate part of the discussion
Unlike modern texts that assume perfect electronics, Gowar dives deep into the transimpedance amplifier. He shows you, with algebra, how the feedback resistor dictates the noise penalty. For a student looking for the pdf, the receiver sensitivity calculations—involving Boltzman’s constant, temperature, and the photodiode responsivity—are pure gold.
The detection section covers:
Gowar presents the signal-to-noise ratio (SNR) derivation for optical receivers, considering thermal noise (Johnson noise), shot noise (quantum nature of light), and dark current. He emphasizes the concept of quantum limit and the transition from thermal-noise-limited to shot-noise-limited performance.