# Classical light vs. nonclassical light: Characterizations and interesting applications

## TL;DR

This paper reviews the distinctions between classical and nonclassical light, emphasizing their modern applications such as quantum communication, spectroscopy, and astrophysics, with a focus on states like squeezed, antibunched, and entangled photons.

## Contribution

It provides a comprehensive overview of classical and nonclassical light applications, highlighting recent developments in quantum states like Fock states for communication.

## Key findings

- Nonclassical light states enable advanced quantum communication.
- Applications of squeezed and entangled states are expanding in modern optics.
- Classical light continues to be essential in traditional optical technologies.

## Abstract

We briefly review the ideas that have shaped modern optics and have led to various applications of light ranging from spectroscopy to astrophysics, and street lights to quantum communication. The review is primarily focused on the modern applications of classical light and nonclassical light. Specific attention has been given to the applications of squeezed, antibunched, and entangled states of radiation field. Applications of Fock states (especially single photon states) in the field of quantum communication are also discussed.