Gain-controlled semiconductor optical preamplifier for the 100 Gbit/s 40 km Ethernet receiver

Area of Science:

• Optical communications engineering
• Semiconductor device physics

Background:

• High-speed optical transmission systems require robust receivers.
• Semiconductor optical amplifiers (SOAs) are crucial components in optical receivers.
• Maintaining stable performance across varying input power levels is challenging.

Purpose of the Study:

• To numerically investigate the performance of an automatic gain-controlled SOA preamplified receiver.
• To evaluate its effectiveness in a 4x25 Gbits/s wavelength division multiplexing (WDM) system.
• To compare its performance against a fixed-gain receiver.

Main Methods:

• Numerical simulation of an optical receiver with automatic gain control on the SOA.
• Modeling of a 4x25 Gbits/s WDM transmission system with fiber lengths from 0-40 km.
• Analysis of receiver performance metrics, including error-free operation and dynamic range.

Main Results:

• The automatic gain control scheme significantly increases the input power dynamic range of the optical receiver.
• Error-free transmission is achieved regardless of fiber length with the gain-controlled receiver.
• Fixed-gain receivers exhibit poor performance due to SOA nonlinearity and photodiode overload.

Conclusions:

• Automatic gain control is essential for stable performance in SOA-based optical receivers.
• The developed receiver design is a practical alternative for next-generation high-speed Ethernet.
• Accurate simulation models are vital for understanding device limitations.