Optics in Physics Optical Properties Categories Fiber Optics

Optics is a well-known branch of physics that determines the behavior and properties of light and vision. It also takes into account interactions with matter and ways of detecting it. Thus, optics describes the behaviors of visible light, infrared light, and ultraviolet light. Imaging is possible with the help of an image-forming optical system.

Optics studies how light interacts with matter and the tools used to detect it. The word “optics” is derived from an ancient Greek word “optike”, meaning “see, form” and “see, or about sight.”. Although the definition of optics is related to the science of vision, optics generally encompasses a wide variety of topics related to light and other areas of the electromagnetic spectrum.

optics

Physics needs optics to understand how humans see the world. Studying the behavior of light has allowed humans to build and use optical instruments such as telescopes, microscopes, and cameras. These devices open up more opportunities to learn about other fields of study.

Optics paved the way for producing groundbreaking inventions (e.g., lasers and holography), some of which are used in visual communication and medical techniques. The invention of fiber optics also played a vital role in the speedy communication and transmission of information. It made on-demand video and broadcast television and high-speed data available to everyone.

Optics in Physics

Light and Its optical Concepts:

Some fundamental terms related to optics are as follows:

Reflection:

Reflection is one of the main properties of light. This process is nothing but seeing images in mirrors. Reflection is called the change in the direction of light at the interface between two different media, and then the wave-front returns to the same medium from which it originated. For example, light reflection involves sound waves and water waves.

Speed ​​of light:

It is the speed at which light travels in free space. It differs from other types of media. It differs from one medium to another. Light travels 30% slower in water than in a vacuum.

Refraction:

The bending of light as it passes from one medium to another is called refraction. This refractive property applies to devices like microscopes, magnifying, and corrective lenses. According to this property, the polarization of electrons occurs with light transmission through the medium. Furthermore, it slows down the speed of light, thereby changing the direction of light.

Total internal reflection:

When a light beam hits the water, the light is partly reflected, and another part of the light is refracted. This whole phenomenon is called internal reflection. Due to this effect, we can see many things daily.

Scattering:

Scattering is a characteristic of light, where white light is divided into seven colors. This phenomenon can be observed in the form of a prism.

Categorization of the Optics

1. Geometric optics:

Geometric optics is a widely used concept in optics where geometric rays describe the propagation of light. An equivalent term is ray optics.

The following assumptions are made on light rays:

• They have no transverse extension, i.e., zero thickness.
• They are straight lines of inhomogeneous optical materials (e.g., optical glasses or air).
• At smooth optical interfaces, they may be reflected or refracted (refracted), with specific laws determining the directions of outgoing rays.
• They can be stopped, e.g., by Pressing some optical aperture.
• Light rays pass through each other without being affected.

Geometric rays are only an abstract representation of actual light rays. Geometric ray behavior can be obtained from wave optics in the limiting case of vanishing optical wavelength.

1. Physical Optics:

Physical optics, also known as wave optics, treats light as a wave. Light behaves as waves when interacting with objects close to its wavelength or smaller. It describes various optical phenomena such as interference, diffraction and polarization of light. 

• Interference is the superposition of two waves, forming a wave that is either smaller or larger than the original wave. Constructive interference occurs when two light waves in phase combine to form a wave with increased amplitude. 
• Destructive interference occurs when two out-of-phase waves superpose and produce a wave with reduced amplitude. The iridescent colors in the wings of moths and butterflies reflect light interference. Security features in banknotes, credit cards and licenses also use mild interference to discourage forgery.
• Diffraction refers to bending light as it passes through an opening or obstruction. The smaller the opening, the more deflection is produced. Rainbow patterns formed on a CD or DVD surface are a product of diffraction.

What is Fiber optics?

Fiber optics is a technique used to transmit the information as pulses of light over long distances through fiber strands made of glass or plastic.

Optical fibers have the diameter of a strand of human hair. When attached to a fiber-optic cable, it can transmit more data over greater distances and faster than any other medium. It is a technology that provides homes and businesses with fiber-optic Internet, phone and TV services.

What are examples of optics?

(1) Design of optical instruments like telescopes, cameras and microscopes

(2) Non-invasive laser surgery and optical diagnostic techniques using fiber optics

(3) High-speed Internet access through cable television, telephone lines, and optic fiber

(4) Some of the everyday life examples of Optics:

• Remote Controls & TVs. 
• Cameras.
• Optical fibers
• Barcode scanners.
• Traffic signals.
• Surveillance cameras.
• LED light bulbs.
• Surgical machines. 

Conclusion:

Optics and light serve various uses in our daily lives, but these are not always obvious. Learn about the bending of light and its uses in telescopes and mirrors, and explore other real-world applications such as lasers and fiber optics.