Free space communications, also known as optical communications, is a technology that uses light to transmit data through the air, instead of traditional methods like radio waves or cables. This type of communication is typically used for long-range communication between satellites, spacecraft, and ground stations in space missions, as well as for high-speed communication on Earth between buildings or across long distances. Free space communications offer several advantages, including higher data transfer rates, lower latency, and greater security compared to traditional communication methods. However, challenges such as atmospheric interference, limited line-of-sight communication, and the need for precise alignment between transmitters and receivers can also be obstacles to overcome. Research in free space communications focuses on developing advanced optical communication systems, improving signal processing techniques, optimizing network architectures, and exploring new technologies to enhance the performance and reliability of free space communication systems. This field is crucial for enabling efficient and reliable communication in space missions, satellite networks, and other applications where traditional communication methods are not feasible.