The book "Wavelength Filters in Fibre Optics" offers a comprehensive analysis of the role of wavelength filters in fiber optic communication. In recent decades, information and communication technology has rapidly evolved, with fiber optic communication systems playing a central role in transmitting information over medium and long distances. The ability to transmit different wavelength channels simultaneously over a single optical fiber is crucial for harnessing the enormous information potential. This specialized book addresses the necessity and functionality of wavelength filters, which are responsible for selecting, separating, and combining wavelengths. It explains how these filters can eliminate unwanted noise and compensate for the effects of wavelength dispersion. The content is relevant for both professionals and students in the field of optical communication.