An analysis of SFP optical modules

Small Form-factor Pluggable, referred to as SFP, is a small hot-pluggable optical module, which can be simply understood as an upgraded version of GBIC. Its volume is half of that of GBIC module, and its function is basically the same as GBIC. The highest rate can reach 10G. Today, ETU-LINK will take you to understand the interface indicators and components of SFP optical modules.

1. Interface indicators of SFP optical modules

(1) Transmitting optical power refers to the output optical power of the light source at the transmitting end of the optical module.

(2) Receiving sensitivity, which refers to the minimum received optical power of the optical module at a certain rate and bit error rate. In general, the higher the rate, the worse the receiving sensitivity.

(3) Saturation optical power, also known as optical saturation, refers to the maximum input optical power when maintaining a certain bit error rate (10-10~10-12) at a certain rate. It should be noted here that for a long-distance optical module, since its average output optical power is generally greater than its saturated optical power, the main attention is paid to the length of the fiber used in use to ensure that the actual received optical power of the optical module is less than its optical saturation, so as to avoid cause damage to the optical module.

2. Components of SFP optical module

SFP optical modules are composed of optoelectronic devices, functional circuits and optical interfaces. Among them, the optoelectronic device includes a light-emitting component TOSA and a light-receiving component ROSA (BOSA light-emitting-receiving component). The functional circuit generally refers to the PCBA board, and the optical interface and other accessories are composed of the shell, the base, the pull ring, the buckle, the unlocking piece and the rubber plug.

For the convenience of identification, the color of the pull ring is generally used to identify the parameter wavelength of the fiber optic module. For example: the black pull ring is a multi-mode module with a wavelength of 850nm; the blue is a single-mode module with a wavelength of 1310nm; purple is a single-mode module with a wavelength of 1490nm; yellow is a single-mode module with a wavelength of 1550nm, etc.