An optical module (also called optical transceiver) is a core hardware device in fiber-optic communication. It converts electrical signals from network devices (such as switches, servers, routers) into optical signals for transmission over optical fiber, and converts received optical signals back into electrical signals. It acts as a "translator" between electricity and light.

1. Common Package Types:

SFP, SFP+

QSFP28, QSFP-DD

OSFP

CFP

2. Internal Structure:

TOSA (Transmitter Optical Subassembly): emits light

ROSA (Receiver Optical Subassembly): receives light

PCB & Driver Chips: control and amplify signals

Shell & Connector: protection and interface

3. How It Works:

Electric → Light: Electrical signals drive the laser to generate optical signals.

Transmit: Optical signals travel long distances through fiber cables.

Light → Electric: The photodetector converts light back to stable electrical signals.