Terahertz Communication
Terahertz (THz) frequencies—100 GHz to 10 THz—represent the next frontier in wireless communication. With bandwidths potentially exceeding 100 GHz per channel, THz could enable Tbps wireless links, but significant physics challenges remain.
The THz Gap
The electromagnetic spectrum between microwave (30 GHz) and infrared (10 THz) has been largely unexplored for communications. This "THz gap" exists because neither conventional microwave electronics nor optical photonics work well in this range. New materials and quantum cascade lasers are changing this.
Why THz Matters
Current 5G mmWave operates at 24-100 GHz, with channels up to 400 MHz wide. THz frequencies could support channels of 10+ GHz, enabling:
- Tbps wireless backhaul links replacing fiber
- Ultra-high-resolution radar and imaging
- Nanoscale communications for IoT
- High-speed device-to-device links
- Wireless乾涉 microscopy
Technical Challenges
THz faces severe propagation challenges:
- Path Loss: 10-100x higher than mmWave
- Absorption: Water vapor blocks many frequencies
- Penetration: Cannot pass through walls or foliage
- Transistors: Silicon doesn't work above 300 GHz; need InP, GaN, or graphene
Potential Applications
Despite challenges, THz has niche applications:
- Data center wireless links within racks
- Wireless取代 for HDMI/USB cables
- High-capacity wireless backhaul in urban areas
- Security screening and spectroscopy