Fiber Optic Tutorials

This is continuation from the previous tutorial - Microscopes   1. INTRODUCTION During the initial stages of an optical design, many optical engineers take advantage of existing configurations that exhibit useful properties. This tutorial is a compilation of reflective and catadioptric objective designs that should help inform the reader of available choices and provide reasonable starting solutions. This tutorial also includes a cursory introduction to some of the more important topics in system analysis, such as angular and linear blur size, image irradiance, scaling, and stray light control.     2. GLASS VARIETIES Glasses used in the designs are represented in...

This is a continuation from the last tutorial- Electro-Optic Modulators.   1. INTRODUCTION Liquid crystals possess physical properties that are intermediate between conventional fluids and solids. They are fluidlike, yet the arrangement of molecules within them exhibits structural order. Three types of liquid crystals have been studied extensively: (1) thermotropic, (2) lyotropic, and (3) polymeric. Among these three, the thermotropic liquid crystals have been studied extensively and their applications have reached mature stage. The potential applications are in areas such as flat panel displays, light switches, temperature sensors, etc. Lyotropic liquid crystals are receiving increasing scientific and technological attention because...

This is a continuation from the previous tutorial - Metal-coated fibers.   1. OVERVIEW Elliptical Core Optical Fiber Most polarization-maintaining \(\textbf{(PM)}\) fibers work on the basic principle of creating two decoupled paths by introducing anisotropic stress generated by the different thermal expansions of the glass materials across the optical core region. In comparison, the elliptical core single-mode fiber employs the distinct property of geometry or form birefringence, rather than stress, to achieve its polarizationpreserving characteristics. By separating the propagation constants of the two fundamental modes, the elliptical core fiber is able to reduce intermodal coupling. As a result, the polarization is...

This is a continuation from the previous tutorial - Timing synchronization in coherent optical transmission systems.     1. INTRODUCTION Carrier recovery is another important building block for modern coherent optical communication systems. Since both amplitude and phase of an optical carrier are used for carrying the data, phase and frequency synchronization between the signal source and the local oscillator (LO) is required in order to correctly demodulate a coherently modulated optical signal. Early coherent optical communication experiments (1980s to early 1990s) employed optical phase-locked loops (PLLs) for phase synchronization; however, this type of optical method was too complex for practical implementation....

This is a continuation from the previous tutorial - Optical beams and resonators: an introduction   1. PARAXIAL OPTICAL RAYS AND RAY MATRICES Ray matrices or "ABCD matrices" are widely used to describe the propagation of geometrical optical rays through paraxial optical elements, such as lenses, curved mirrors, and "ducts." These ray matrices also turn out to be very useful for describing a large number of other optical beam and resonator problems, including even problems that involve the diffractive nature of light. Therefore, we begin the discussion of optical beams and resonators with a detailed review of paraxial ray theory and...