Fiber Optic Tutorials

This is a continuation from the previous tutorial - analytical modeling of the impact of fiber non-linear propagation on coherent systems and networks.   1.  Principles of Operation The optical fiber falls into a subset (albeit the most commercially significant subset) of structures known as dielectric optical waveguides. The optical fiber works on principles similar to other waveguides, with the important inclusion of a cylindrical axis of symmetry. For some specific applications, the fiber may deviate slightly from this symmetry; it is nevertheless fundamental to fiber design and fabrication.   Figure 1. (a) Generic optical fiber design, (b) path of a...

This is a continuation from the previous tutorial - laser mirrors and regenerative feedback.   1. Why Are Analytical Models Important? Analytical models of the impact of non-linear effects on system and network performance are important for several reasons: in the context of point-to-point (PTP) systems, they allow to explore design strategies efficiently, without resorting to lengthy computer simulations; in the context of networks, they can help in the optimization of the network architecture and layout, and can provide physical layer awareness for real-time control-plane tasks such as channel routing. In all contexts, they can be used for research purposes,...

This is a continuation from the previous tutorial - chiral fibers   1. Laser Mirrors and Beam Splitters Laser mirrors and beam splitters have certain fundamental properties that are important to understand. Before discussing the use of mirrors in laser cavities, let us therefore review the more important of these properties.   Single Dielectric Interface   Figure 11.1. Reflection and transmission of optical waves at a dielectric interface.   The simplest example of a partial mirror or beam splitter is the interface between two dielectric media, as shown in Figure 11.1. Suppose we write the normalized fields for the incident and...

This is a continuation from the previous tutorial - introduction to gradient index optics.   1. Introduction Specialized fibers are increasingly being used to manipulate light and to couple light of different wavelengths into and out of fibers in telecommunications and sensing applications. The development of new communication modalities, such as cellular, satellite, and cable communications, has only spurred the growth of optical fiber networks. Wavelength selectivity is achieved by imposing a periodic modulation of the refractive index along the fiber. This is accomplished most often by exposing photosensitive fiber to modulated ultraviolet (UV) light. In gratings with periods greatly...

This is a continuation from the previous tutorial - polarization and nonlinear impairments in fiber communication systems.   1. Introduction   Figure 1. Light from point A emits or reflects in all directions. Light propagating several meters above the heated road travels in a straight line. Light passing through the lower index of refraction region near the road undergoes a bending. This light appears to have come from below the road.   Gradient index (GRIN) optics refers to the field of optics in which light propagates along a curved path. This contrasts with normal homogeneous materials in which light propagates in...