Passive devices

Abstract

The chapter presents devices which ensure the following generic functionalities: (i) physically connecting devices, (ii) splitting and coupling of light, (iii) separating and redirecting light travelling into opposite directions (optical circulators), and (iv) isolating light travelling into one direction from light travelling into the reverse direction (optical isolators). The coverage includes theoretical aspects, standardisation issues, and typical characteristics of fibres and fibre-optic cables. The treatment of optical circulators and isolators includes their fundamental principles, polarisation-independent 3D (free space) implementations, and planar integrated waveguide-based solutions as well.