Reception (Rx): After transmitting through the optical fiber, the optical signal reaches the receiving interface. A photodetector diode converts the light signal back into an electrical signal. In the era of 5G, AI, and high-speed data centers, optical modules serve as the core bridge for converting electrical signals to optical signals (and vice versa), enabling fast, reliable data transmission across networks. Optical modules typically have an electrical interface on the side that connects to the inside of the system and an optical interface on the side that connects to the outside. The Transmitter Optical Sub Assembly (TOSA) is responsible for the emission of light. We'll cover everything from physical form factors to spectral characteristics, modulation formats.