Photonics is the multidisciplinary branch of science and technology centered on the generation, detection, and manipulation of light particles, or photons. 

Unlike traditional electronics, which relies on the movement of electrons through a medium like copper, photonics utilizes the speed and unique properties of light to transmit and process information. 

Because photons lack mass and electric charge, they do not suffer from the same heat generation or electromagnetic interference that plagues electronic circuits, allowing for significantly higher data density and faster processing speeds. 

• This makes photonics the fundamental driver behind high-speed fiber-optic communication—crucial for the Digital India initiative—where light pulses travel through cables via Total Internal Reflection.
• In the strategic and industrial sectors, photonics is essential for the development of semiconductors through high-precision photolithography and for advanced defense technologies like LIDAR and Directed Energy Weapons. 
• It also plays a pivotal role in the National Quantum Mission, where individual photons are used for secure Quantum Key Distribution (QKD) to create unhackable communication networks. 
• Beyond data, the field encompasses Biophotonics, which revolutionizes healthcare through non-invasive surgeries and diagnostic imaging, and Photovoltaics, which is central to India’s renewable energy goals. 

As global computing reaches the physical limits of silicon-based electronics, the shift toward Silicon Photonics—integrating light-based functions onto traditional chips—is becoming a critical frontier for maintaining the growth of Artificial Intelligence and supercomputing.