An optical transceiver module, often simply called an optical module, acts as a signal conversion interface in fiber optic networks. It transforms high volumes of electrical signals into optical signals for transmission over fiber cables, or reverses the process at the receiving. PON networks enable simultaneous access for multiple users over a single optical fiber, supporting point-to-multipoint (P2MP) transmission. Data transmission from the OLT to the ONU is defined as downstream, while transmission from the ONU to the OLT is upstream; full-duplex transmission is adopted. The optical module serves as a crucial component in optical fiber communication systems, operating at the physical layer, which is the lowest layer in the OSI model. They form the backbone of long-distance, high-capacity data transport in modern telecom networks.
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