Role of All-Optical Switches in Quantum Networking

In this Blog Post, Rohit Kunjappa, Head of Commercial Business Unit at HUBER+SUHNER Polatis, explains the role of and need for all-optical switching in the emerging Quantum Networking space.

Quantum Computing
The quantum computing market is projected to be worth $65 Billion by 2030 (from $507 million in 2019 with 56% CAGR ). Quantum Computing solves problems that classical computers cannot due to computational challenges such as processing power and storage. Some problems that can potentially be addressed by quantum computing are:
  • Improving security by creating private keys for encryption for secure data transmission using QKD (Quantum Key Distribution)
  • Improving healthcare – in the design and analysis of molecules for drug development quantum computers can simulate the properties of the molecules that classical computers can not
  • Teleportation of information without physically transmitting the information from one location to another with a new quantum internet
  • Modelling and simulation of complex natural processes like weather and climate warming
  • Accelerating machine learning

Unlike classical computers, quantum computing uses quantum properties like superposition, entanglement, interference and uncertainty to achieve a deterministic outcome. Qubits are the basic unit of quantum information, carried or housed in a physical device like a chip or processor, and are the building blocks of quantum computing. You increase the computational potential by increasing the number of qubits that can be processed into controllable quantum states. It is difficult to add more qubits as they are very sensitive to environmental factors like noise, meaning they have very low fault tolerance. When you add qubits, it multiplies the noise.

Quantum computer growth
  • 2019 – Google - 53 qubits
  • 2020 – IBM – 65 qubits
  • 2021 (projected) – IBM – 127 qubits
  • 2022 (projected) – IBM – 433 qubits
  • 2023 (projected) – IBM – 1000 qubits
  • In 10 years (projected) – Google – 1M qubits

Quantum Networking is required to scale and commercialize Quantum Computing.

Quantum Networking
Until a quantum internet is built, one of the many ways to realize qubits for larger, stable systems and to transmit over longer distances (potentially using quantum multiplexing with quantum error correction) is to send photon based qubits over conventional DWDM communication networks to distribute entanglement and route quantum information to multiple nodes.

This comes with challenges:
  • With increase in distance travelled, the photon loss increases exponentially making it one of the biggest hindrances to quantum transmission
  • Entanglement degrades or is destroyed with phase decoherence making quantum communication challenging
  • When you move beyond point-to-point communication, distributed synchronization is also an issue

Traditional OEO (optical-electrical-optical) switches have a challenge preserving quantum coherence and optical amplifiers in addition to amplifying the signal also amplify noise, making them less than ideal for quantum transmission. There is a higher probability of going longer distances and preserving quantum coherence by using data-rate independent, protocol agnostic, all-optical switches that do not regenerate the signal the way OEO switches do.

Some of the leading quantum research groups worldwide are performing cutting edge quantum networking research using Polatis all-optical switches.

If you would like to know more about HUBER+SUHNER Polatis all-optical switches and how the technology would benefit your quantum networking application, you can contact us by email or phone:

Americas: +1 781 275 5080
EMEA/Rest of World: +44 (0)1223 424200