What is the difference between a single-fiber optical module and a dual-fiber optical module?

So how do we differentiate?

1. Appearance and use: the single-fiber optical module has one optical fiber interface, which is connected to one optical fiber; the dual-fiber optical module has two optical fiber interfaces, which are connected to two optical fibers;

2. Conventional wavelength: the single-fiber module has two different wavelengths, and the dual-fiber module has only one wavelength;

The conventional wavelengths of single fiber mainly include the following:

Gigabit single fiber:

TX1310/RX1550nm;

TX1550/RX1310nm;

TX1490/RX1550nm;

TX1550/RX1490nm;

TX1310nm/Rx1490nm;

TX1490nm/Rx1310nm;

10 Gigabit single fiber:

TX1270nm/RX1330nm

TX1330nm/RX1270nm

TX1490nm/RX1550nm

TX1550nm/RX1490nm

Conventional wavelength of dual fiber: 850nm 1310nm 1550nm

3. Speed: Compared with dual-fiber optical modules, single-fiber optical modules have a wider range of applications in 100M, 100M and 10G speeds; but few in 40G and 100G high-speed transmission; but dual-fiber modules are It's a solution that everyone often chooses.