Which diode is most commonly used in optical receivers because it is inexpensive and can be operated from a standard power supply?

The Positive-intrinsic-negative (PIN) diode is the most commonly used type of diode in optical receivers due to its practicality, cost-effectiveness, and ease of operation. The PIN diode is designed to be sensitive to light, allowing it to convert optical signals into electrical signals efficiently. Its structure includes a thick intrinsic semiconductor layer sandwiched between p-type and n-type materials, which facilitates effective photon absorption and subsequent charge carrier generation.

A major advantage of the PIN diode is its compatibility with standard power supplies. This means that it can be integrated into various systems without requiring specialized or expensive power management solutions. Additionally, the simplicity in design and availability contribute to its lower cost, making it ideal for a wide range of applications in optical communications.

In contrast, other types of diodes like Indium Gallium Arsenide (InGaAs) diodes are often used in higher-performance applications, but they tend to be more expensive and may require specific operating conditions or temperature management. Avalanche Photodiodes (APDs) provide greater sensitivity and gain but are also more complex and costly. Laser diodes are primarily used as light sources rather than receivers. Therefore, the affordability and straightforwardness of the PIN diode make it a popular choice in optical receiving applications