Fiber Optic Tutorials

This is a continuation from the previous tutorial - Generalized paraxial resonator theory   1. ELEMENTARY PROPERTIES Before developing a more detailed analysis of unstable resonator eigenmodes, as we will do in following sections, let us look in this section at some of the elementary practical aspects of unstable resonators, including practical coupling methods, and the general structure of the near-field and far-field beam patterns of unstable resonator lasers, using a purely geometric approach.  Figure 1.  illustrates the general characteristics of the simplest form of hard-edged, single-ended, positive-branch, standing-wave confocal unstable resonator. We have already pointed out that unstable resonators in general: ...

This is a continuation from the previous tutorial - Optical fibers for industrial laser application     1. INTRODUCTION Optical fibers have revolutionized medicine in many ways. They have advanced both diagnostics and treatments capabilities. Their major advantages lie in the fact that they are thin and flexible so they can be introduced into the body to remotely sense, image, and treat. This capability enabled the introduction of minimally invasive procedures, which became the preferred choice for surgery. Such procedures minimize the postoperative pain and discomfort, as well as shorten—and sometimes eliminate— hospitalization time, thus saving on costs and reducing the...

This is continuation from the previous tutorial - Holography and holographic instruments   1. INTRODUCTION Radiometry is the measurement of the energy content of electromagnetic radiation fields and the determination of how this energy is transferred from a source, through a medium, and to a detector. The results of a radiometric measurement are usually obtained in units of power, i. e., in watts. However, the result may also be expressed as photon flux (photons per second) or in units of energy (joules) or dose (photons). The measurement of the effect of the medium on the transfer of radiation, i. e.,...

This is a continuation from the previous tutorial - Sapphire optical fibers     1.  FIBER LASERS AND AMPLIFIERS: AN INTRODUCTION Both optical amplifiers and lasers are based on the process of stimulated emission; a concept first proposed by Albert Einstein in 1916 but not demonstrated until 1954 when Charles Townes used stimulated emission to produce microwave oscillation in the ‘‘maser’’ (microwave amplification by stimulation emission of radiation). It was another 6 years later before Theodore Maiman demonstrated the first laser (light amplification by stimulated emission of radiation). In these devices, an ‘‘optically active’’ species has one of its electrons ‘‘excited’’...

This is a continuation from the previous tutorial - Complex paraxial wave optics   we will use the generalized paraxial-wave concepts of the preceding tutorial to analyze the Hermite-gaussian modes of generalized paraxial optical resonators. The resulting analysis will show how all such resonators can be classified into four categories of resonators whose modes are either real or complex gaussian in character, and either stable or unstable in behavior. It will also show how complicated multielement paraxial resonators can be analyzed based on knowledge only of their round-trip \(\text{ABCD}\) matrices, whether real or complex. The results of this analysis will provide...