In 100G optical modules, single-fiber modules save fiber resources through wavelength division multiplexing (WDM) technology, making them suitable for scenarios with limited fiber resources or long-distance transmission; dual-fiber modules have a simple structure and low cost, making them suitable for short-distance or high-reliability scenarios. The following is a detailed comparative analysis:

I. Physical Structure and Interface

Single-fiber Module: It has only one fiber optic interface and achieves bidirectional transmission through a single fiber. Its core lies in the use of wavelength division multiplexing (WDM) technology, which loads optical signals of different wavelengths (such as TX1330nm/RX1270nm) in the same fiber to achieve bidirectional data transmission at a rate of 100Gbps.

Dual-fiber Module: It has two independent fiber optic interfaces, one for transmitting and the other for receiving optical signals. One fiber is responsible for transmitting data, and the other for receiving data, eliminating the need for complex wavelength division multiplexing (WDM) technology.

II. Wavelength and Transmission Technology

Single-fiber Module: Uses two optical signals of different wavelengths for bidirectional transmission. For example, the wavelengths of a 100G single-fiber module may be 1271/1331nm, 1291/1311nm, 1304/1309nm, etc. This design allows the single-fiber module to transmit data in two directions simultaneously in the same optical fiber.

Two-fiber Module: These typically use optical signals of the same wavelength or different wavelengths but transmitted independently. In a two-fiber system, the wavelengths of the transmitted and received optical signals can be the same or different, but they are transmitted through two independent optical fibers, thus eliminating the need for complex wavelength division multiplexing (WDM) technology.

III. Transmission Distance and Application Scenarios

Single-fiber Module:

Advantages: Saves fiber optic resources, reducing fiber usage by 50%, making it particularly suitable for scenarios where fiber optic cabling is costly, such as metropolitan area networks and intercity data center interconnects (DCI). Simultaneously, single-fiber modules simplify cabling architecture, reduce cabling complexity, and improve operational efficiency.

Application Scenarios: 5G bearer networks, data center interconnection, high-definition video and security, etc. For example, in the backhaul link between the 5G core network and the base station, the 100G single-fiber module can meet the high-speed transmission requirements of massive user data, while also being suitable for scenarios where fiber optic resources on the base station side are limited.

Dual-fiber Module:

Advantages: Simple structure; the modules at both ends do not need to be paired; any two can be connected. Furthermore, dual-fiber modules are generally cheaper than single-fiber modules.

Application Scenarios: Short-distance data communication needs or situations requiring high reliability and simple maintenance, such as enterprise internal networks, campus networks, industrial control networks, etc.

IV. Cost and Compatibility

Single-fiber Module:

Cost: Initial costs are high due to the need for specialized BiDi transceivers and wavelength division multiplexing (WDM) technology. However, in the long term, the overall cost may decrease due to the reduction in the number of optical fibers.

Compatibility: Ensure the selected module is compatible with existing network equipment and fiber optic infrastructure. Some single-fiber modules may support common LC interfaces, allowing for easy network bandwidth upgrades without modifying existing fiber optic links.

Dual-fiber Module:

Cost: Initial costs are low because standard single-mode fiber and transceivers are used. However, in the long run, the overall cost may increase due to the need to lay two fibers.

Compatibility: The compatibility is relatively good because it uses standard fiber optic cables and transceivers.