Optical Switching

11Quantum Optical Switches

Surabhi Yadav and Aranya B. Bhattacherjee

Department of Physics, Birla Institute of Technology and Science‐Pilani, Hyderabad Campus, Telangana, India

11.1 Introduction

Enormous data transfer within optical fiber networks has created a global communication revolution that has impacted human life and modern economic activity. High bit rate optical connections have been extended to numerous other networks over the last few decades, from long‐distance transmission networks to short‐distance communications inside buildings [1]. A photonic switch with an ultrashort decay time is one of the main components in establishing a high‐speed optical signal processing device [2]. The high power requirement of photonic to electrical and electrical to photonic conversions inspired the concept of using photonic networks as a substitute for modern electronic switching. Terahertz switching speed is possible with an optical switch that controls light signals directly through another optical beam, with possible restoration times in the pico‐ or femtosecond range. The accessibility of such a system together with the use of low‐dissipation photonic waveguides and fibers could pave the way for a high bit rate, low‐cost optical network over short distances. For efficient all‐optical switching, optical non‐linearity with low power consumption (low photon number) is a necessary prerequisite. Optical non‐linearity at single photon level have been demonstrated in many studies ...