The Bridge between Optical and Microwave Communication
- [Cambridge University, the United Kingdom]
- Overview
The "bridge" between optical and microwave communication refers to transducers and metasurfaces designed to convert signals between the two electromagnetic domains. This technology is essential for applications such as integrating complementary communication systems and networking quantum computers.
1. Key Technologies:
- Transducers: In quantum computing, low-noise microwave-to-optical transducers are critical for linking remote superconducting quantum processors through optical fibers. These devices convert microwave photons to optical photons and vice versa, preserving fragile quantum states. Researchers at institutions like Caltech have developed highly efficient, low-noise silicon electro-optomechanical resonators for this purpose.
- Metasurfaces: In classical wireless communication, hybrid time-varying metasurfaces act as direct signal converters, eliminating the need for complex intermediate relay systems. These integrated platforms can convert modulated light signals to microwave signals (and potentially the reverse) in free space, enabling seamless hybrid wireless communication links across different media like air and water.
- Optical Frequency Combs: These devices act as a "frequency gearbox" to link optical frequencies (hundreds of terahertz) to radio frequencies (hundreds of megahertz), bridging a vast frequency gap of up to six orders of magnitude with high precision.
2. Applications:
This bridging technology is used in several areas:
- Hybrid Wireless Networks: Enabling seamless integration of visible light communication (VLC) links into existing RF wireless infrastructures, which is important for environments where one type of communication performs better than the other (e.g., optical in water, microwave in air).
- Quantum Networking: Interconnecting remote superconducting quantum processors for quantum computation and communication.
- Precise Timing and Synchronization: The "Balanced Optical Microwave Phase Detector" (BOMPD) is a key component in large accelerator facilities worldwide, locking optical systems like lasers to electrical devices with femtosecond timing accuracy.
- 6G Technology: Microwave photonics is being investigated as an effective solution for integrating radar, wireless communications, and spectrum sensing for future 6G networks.
[More to come ...]
