Emerging Physics

2

Lasers and Laser Applications

Chapter Outline

2.1 Introduction

2.2 Interaction of radiation with matter

2.3 Einstein's prediction

2.4 Metastable state

2.5 Laser pumping

2.6 Optical feedback

2.7 Characteristics of lasers

2.8 Types of lasers

2.9 Applications of lasers

2.1 INTRODUCTION

The word laser is an acronym for light amplification by stimulated emission of radiation. The basic principle of stimulated emission underlying the laser action was postulated in the year 1917 by Einstein. However, it took about 43 years thereafter for the construction of the first laser. On May 16, 1960, Theodore Maiman successfully operated the first ruby laser in the Hughes Research Laboratory, California, USA. At the time of its invention, laser was called ...