Optical Communication and Silicon Photonics

Optical Communication is a communication method that uses light waves as the transmission medium. Current applications achieve high-speed data transfer through the process of “Electrical-to-Optical” (E/O) and “Optical-to-Electrical” (O/E) conversion.

Why is Optical Communication Necessary?

Compared to traditional copper wire transmission, optical communication offers the following advantages:

  • High Speed and Large Bandwidth: Capable of carrying the massive data volumes generated by AI computing.
  • Low Power Consumption and Low Latency: Reduces heat generation and power loss during transmission.
  • Long Transmission Distance: Signal attenuation is significantly lower than that of electrical cables.
  • High Security: Optical signals are more resistant to interference.

Silicon Photonics is an advanced chip manufacturing technology used to implement optical communication transmission architectures.

Why is Silicon Photonics the Trend in Optical Communication?

Silicon photonics addresses the bottlenecks faced by traditional optical communication in the AI era:

  • Extreme Miniaturization: While traditional optical modules are bulky, silicon photonics integrates multiple optical functions into a single, tiny chip.
  • Significant Power Reduction: Electrical transmission consumes high power and generates heat. Silicon photonics uses photons for transmission, reducing power consumption per bit to only 1/10 to 1/20 of that of electronic circuits.
  • Breaking Transmission Bottlenecks: As AI computing demands surge, copper wiring can no longer handle high-speed transmissions above 800G. Silicon photonics is the key technology for achieving 1.6T and even higher bandwidths.

Signal Modulation and RF Testing

Optical signal modulation involves converting ultra-high-frequency electrical signals into light waves. High-frequency electrical signals, such as 112 Gbps PAM4, correspond to a frequency of approximately 28 GHz, while 224 Gbps PAM4 corresponds to approximately 56 GHz. Consequently, RF testing cables and peripheral equipment must meet increasingly higher frequency requirements, making stability a critical factor.