Fiber Optic Tutorials

This is a continuation from the previous tutorial - Physical properties of gaussian beams   1. GRATING DIFFRACTION AND SCATTERING EFFECTS Optical elements in real life are often of good but not perfect quality. Optical beams may then be perturbed by various kinds of weak amplitude or phase perturbations, such as scratches, dust particles or blemishes on lenses or mirror surfaces, or bubbles and defects inside optical components. Optical imperfections of this kind may be modeled in many situations either as a collection of point scatterers, or as weak and more or less random amplitude or phase-perturbing screens or gratings. We will...

This is a continuation from the previous tutorial - Photonic integrations     1. INTRODUCTION Fiber-optic communication has seen tremendous growth over the last decade fueled mainly by the incessant and relentless demand for high capacity. This insatiable demand is spurred by the Internet traffic growth both in terms of number of users and the bandwidth consumed by each user. This trend of multifold increase in data traffic every year is expected to continue in the foreseeable future. In order to comply with the enormous bandwidth requirements posed by the growth in data traffic, fiber-optic communication networks have evolved drastically. For example,...

This is continuation from the previous tutorial - Scanners   1. INTRODUCTION This article outlines the physical basis of optical measurements in the wavelength/frequency and time domains. From the multiplicity of different apparatus, only simple examples are given of spectrometers designed for optical absorption, photoluminescence, and radiative decay measurements. Rather more detailed expositions are given of modern developments in laser spectrometers especially where high resolution is possible in both frequency and time domains. Included are specific developments for linewidth measurements down to tens of kilohertz using saturated absorption techniques as well as temporal decay characteristics in the sub-picosecond domain. A description...

This is a continuation from the previous tutorial - Wave optics and gaussian beams     1. GAUSSIAN BEAM PROPAGATION We first look in this section at what the analytic expressions for a lowest-order gaussian beam imply physically in terms of aperture transmission, collimated beam distances, far-field angular beam spread, and other practical aspects of gaussian beam propagation.   Analytical Expressions  Let us assume a lowest-order gaussian beam characterized by a spot size Wo and a planar wavefront \(R_0=\infty\) in the transverse dimension, at a reference plane which for simplicity we take to be \(z=0\). This plane will henceforth be known...

This is a continuation from the previous tutorial - Multimode, large-core, and plastic clad fibers     1. INTRODUCTION In applications that utilize specialty optical fibers, very often there are requirements placed on the optical fiber design that are not conducive to the launch or delivery requirements placed on the proximal and distal ends of the fiber. For example, in high-power medical applications, such as laser angioplasty or laser lithotripsy, a small-fiber diameter may be required so the fiber probe assembly will be able to bend easily inside the small blood vessels of the body. However, this may cause difficulty on...