Laser Principle and Its Implementation

Introduction

Laser, which stands for Light Amplification by Stimulated Emission of Radiation, is a technology that has been widely applied in various fields such as communication, medicine, and industry. The principle of laser is based on the process of photon emission, which is stimulated by radiation absorption. This article aims to discuss the principle of laser and its implementation.

The Principle of Laser

The principle of laser is built upon two principles of quantum mechanics, which are the emission and absorption of photons. According to quantum mechanics, when an atom is excited by radiation, it can jump from a lower energy state to a higher energy state, which is called an excited state. This excited state is not stable, and the atom will return to its original ground state by emitting photons.When radiation interacts with an atom in a higher energy state, it can stimulate the atom to release its energy in the form of photons. This process is called stimulated emission. The photons that are emitted here have the same frequency, direction, and phase as the original radiation.The process of laser operation requires an active medium, which contains atoms or molecules that can be excited by external energy sources. When a sufficient amount of energy is supplied to the active medium, the atoms in the ground state will be excited to the excited state. These excited atoms will then release their energy in the form of photons through stimulated emission, which induces other atoms to emit more photons. This process causes the photons within the cavity of the laser cavity to become more and more concentrated, eventually forming a highly collimated, coherent, and monochromatic beam of light.

Implementation of Laser

The implementation of laser involves various components that work together to generate the highly concentrated beam of light. These components include the active medium, the optical resonator, and the pumping source.The active medium is a material that contains atoms or molecules which can be excited to produce stimulated emission. The choice of active medium depends on the desired wavelength of the laser beam and the application in which it will be used. Common active media include gas molecules (such as carbon dioxide), semiconductor crystals (such as gallium arsenide), and solid-state materials (such as ruby).The optical resonator is a cavity that can trap light within it, which allows stimulated emission to occur multiple times. The resonator is made up of two mirrors, one mirror is highly reflective, and the other is partially reflective. When photons are emitted by stimulated emission, they bounce back and forth between the mirrors, and each time they pass through the active medium, additional photons are produced. This process leads to the buildup of photons within the resonator, which eventually form the highly concentrated beam of light.The pumping source provides the external energy needed to excite the active medium. The pumping source can take various forms, such as electrical discharge, optical pumping, or chemical reactions. The choice of the pumping source depends on the type of active medium being used.In conclusion, laser technology is built upon the principles of quantum mechanics, which involves the emission and absorption of photons. The implementation of laser involves various components working together to generate the highly concentrated beam of light. The use of laser technology has revolutionized various fields and has provided numerous benefits to society.