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, Volume: 10( 7) DOI: 10.37532/2320-6756.2022.10(7).284

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Optics, Photonics and Laser

*Correspondence:

Rosaline Miller
Managing Editor, Journal of Physics and Astronomy, UK
E-mail: physicsastronomyres@tradescience.org

Abstract

Introduction

Modern homes, factories, and research labs all use a variety of gadgets that are powered by photonics, the scientific study and use of light. Today, the discipline supports applications like fiber-optic transmission, data storage, flat-panel displays, and materials processing and is a billion dollar enterprise with a Nobel Prize-winning science.

Optical imaging and sensing

The technique known as optical imaging makes use of light to get imaging data for research purposes during medical procedures. Diffusive imaging systems and ballistic imaging systems are the two main categories of optical imaging. The principal examples include spectroscopy, optical coherence tomography, optical microscopy, and scanning laser ophthalmoscopy.

Physical and classical optics

Geometrical (or ray), optics and physical (or wave), optics are the two primary branches of classical optics. While light is thought to travel in straight lines in geometrical optics, it is thought to be an electromagnetic wave in physical optics. The study of physical optics focuses on the characteristics of light waves, which can be loosely divided into three categories: polarisation, diffraction, and interference. And Physical optics holds that light travels as a wave. This model makes predictions for phenomena like interference and diffraction that geometric optics cannot account for. In air, light waves travel at a speed of about 3.0108 m/s (or 299,792,458 m/s in vacuum).

Quantum and nano-optics

The study of optical techniques and phenomena on the manometer scale, which is close to or beyond the diffraction limit of light, is known as nano-optics. This rapidly developing area of research is driven by the need for appropriate tools and methods for creation, manipulation, and characterisation at this size in nanoscience and nanotechnology. The authors of Principles of Nano-Optics give a thorough overview of the theoretical and experimental ideas required to comprehend and work in nano-optics. They introduce and thoroughly describe all important techniques while covering optical phenomena pertinent to the nanoscale in a variety of fields, from quantum optics to biology.

Imaging and sensing through optics

The technique known as optical imaging makes use of light to get imaging data for research purposes during medical procedures. Diffusive imaging systems and ballistic imaging systems are the two main categories of optical imaging. The principal examples include spectroscopy, optical coherence tomography, optical microscopy, and scanning laser ophthalmoscopy.

The devices of photonics

Utilizing radiant energy, such as light, whose primary component is the photon, is the subject of the research field known as photonics. The photon is used in similar ways to how the electron is used in electronics in photonic applications. Over electrically powered devices, those that run on light have a variety of benefits. Photonics applications include Photonics has a huge range of applications.

Astrophysics and astronomy use optics

In order to obtain images of astronomical objects in space, these optics, which are a subset of optics and photonics, require light-controlling devices. The telescope would be the ideal illustration for this.

Geometrical optics

A model of optics known as geometrical optics, often known as ray optics, depicts how light travels along rays. In geometric optics, the ray is an abstraction that can be used to approximate the routes that light takes when certain conditions are met. Three fundamental laws: The transmission of the law of rectilinear propagation. The reflected ray stays inside the plane of incidence when a light ray is reflected at an interface separating two optical media, and the angle of reflection equals the angle of incidence.

Interferometer principle

Basic Interferometer Principle. The interferometer is a precise tool for visualising flows. The fundamental idea behind this system is the relationship between the refractive index of the flowing gas and density. The interference of light waves theory is employed.
Interferometer operation:

• A lens L1 collimates light rays coming from a source. In other words, as light rays leave lens L1, they form a parallel beam of light

• A beam splitter B1 then divides the collimated light rays

• The two beams cross each other at a straight angle.

Lasers for medical use

Laser surgery, photodynamic therapy, and other forms of laser medicine involve using lasers for medical diagnostics, procedures, or therapies. Although the history of lasers dates back to 1951, Goldman reports the first medical use in 1962. In 1963, McGuff performed the first experimental ablation of atherosclerotic plaques using a Ruby-Laser in cardiovascular surgery. Choy and Ginsburg carried out the first clinical applications of laser technology in 1983 after extensive research and significant advances in the field. Since then, numerous clinical trials have examined the effectiveness of laser angioplasty in treating coronary and peripheral vessels. The preliminary findings are positive, suggesting that laser therapy is about to find application in the management of cardiovascular disorders.

Different types of laser

There are four different types: semiconductor, gas, dye, and solid state. Each type's qualities will be discussed. A solid matrix of lasing material is used in solid state lasers. For instance, consider the Neodymium: YAG laser (Nd:YAG).

• Solid-state lasers: Solids are used as the laser medium in solid-state lasers. Glass or crystalline materials are employed in these lasers.

• A gas laser emits laser light by discharging an electric current through a gas contained within the laser medium. The laser medium in gas lasers is in a gaseous condition.

• A liquid laser is a laser that makes use of a liquid as its laser medium. Light provides energy to the laser medium in liquid lasers.

• Semiconductor lasers: Semiconductor lasers are crucial to daily life. These lasers are incredibly affordable, small, and power-efficient. Laser diodes are another name for semiconductor lasers.

Laser 3D triangulation

Trigonometric triangulation is a technique used by laser-based 3D scanners to precisely record a 3D geometry as millions of points. In order to capture an object's reflection, laser scanners project one or more laser lines onto the target surface. One or more sensors then pick up the reflection.

Different 3D scanning technologies and 3D scanners include:

• Low Cost 3D Scanners Typically, laser triangulation or structured light technology is used by short-range 3D scanners.

• 3D scanners that use lasers Trigonometric triangulation is a technique used by laser-based 3D scanners to precisely record a 3D geometry as millions of points. In order to capture an object's reflection, laser scanners project one or more laser lines onto the target surface. One or more sensors then pick up the reflection.

3D laser scanner advantages include:

• Capable of scanning challenging materials like bright or dark finishes

• Less responsive to ambient light and alterations in lighting conditions

• Frequently more mobile

• Easier to use and less expensive design

Applications for fiber lasers are expanded by new types and features

The industrial industry is currently seeing the highest demand for process automation due to the need to meet extremely high production standards and adapt to an increasingly intense competitive environment where time frequently plays a crucial role. The hunt for high-performance tools and technologies that can adjust to various needs is the most significant result of this. In the field of laser marking and its countless applications, fibre lasers unquestionably rank first in terms of efficiency and versatility. These are by far the most frequently used in businesses that employ this technology on the current market.

Fiber laser benefits include:

• No additional optical equipment

• Compactness

• Beam quality

• Speed

• Savings on energy

Space Photonics (SSSP)

The application of photonics in space poses particular environmental and functional difficulties. This conference will focus on current initiatives to create photonic systems and components that can meet rising needs for fast data transfer, precise timing, accurate navigation, and the collection of scientific data from Earth orbit to deep space.