Photonic computing: an introduction

Photonic computing refers to the idea of using light to process information. The interest in photonic computing is motivated by the inherent advantages of light in terms of speed, bandwidth, and parallelism. Photonic computing has a long history. As early as the 1960s, researchers delved into the use of optical lenses to compute the Fourier transform—an inherently computationally intensive task even for cutting-edge digital computers. Remarkably, optical lenses achieved this feat with zero energy consumption and at the speed of light. Since then, photonic systems have been exploited for computing. Nevertheless, the pursuit of generalized digital optical computers in past decades encountered hurdles, primarily due to the need for more scalable and efficient optical transistors. In recent years, the computing landscape has undergone a transformative shift, with emerging paradigms such as neural networks and quantum computing demanding the parallel processing capabilities in which photonic technology excels. Furthermore, the advent of new materials and advanced fabrication techniques has vastly expanded the possibilities for designing and manufacturing photonic components and circuits. With these breakthroughs, photonic computing is gaining renewed attention.