In modern information networks, optical fiber communication occupies a dominant position. With the wider coverage of the network and the continuous increase of communication capacity, the improvement of communication links is also an inevitable development. Optical modules realize optoelectronic signals in optical communication networks. It is one of the main components of optical fiber communication.
However, we usually talk about optical modules, so what are the main parameters of optical modules? Let's find out together next!
After years of development of optical modules, their packaging methods have also undergone great changes. SFP, GBIC, XFP, Xenpak, X2, 1X9, SFF, 200/3000pin, XPAK, QAFP28, etc. are all optical module packaging types.
Low speed, 100M, 1000M, 2.5G, 4.25G, 4.9G, 6G, 8G, 10G, 40G, 100G, 200G and even 400G are the transmission rates of optical modules.
The unit of the central wavelength of an optical module is nanometers (nm). There are currently three main types:
1. 850nm (MM, multimode fiber module, low cost but short transmission distance, generally only 500m can be transmitted).
2. 1310nm (SM, single-mode fiber module, large loss but small dispersion during transmission, generally used for transmission within 40km).
3. 1550nm (SM, single-mode fiber module, small loss but large dispersion during transmission, generally used for long-distance transmission of more than 40km, and the farthest can be directly transmitted 120km without relay).
The transmission distance of an optical module refers to the distance that the optical signal can be directly transmitted without further amplification, in units of kilometers (also called kilometers, km). Optical modules generally have the following specifications: multi-mode 550m, single-mode 20km, 40km, 60km, 80km, 100km and 120km etc.
1. Loss and dispersion of optical modules
The two mainly affect the transmission distance of the optical module. In general, the 1310nm optical module calculates the link loss at 0.35dBm/km, and the 1550nm optical module calculates the link loss at 0.20dBm/km. The calculation of the dispersion value is very complicated and generally only used for refer to.
2. Laser types of optical modules
At present, the most commonly used lasers are FP and DFB. The semiconductor materials and resonator structures of the two are different. DFB lasers are expensive and are mostly used in optical modules with transmission distances greater than 40km. FP lasers are cheap and generally used for optical modules with a transmission distance of less than 40km.
1. Optical fiber interface of optical module
SFP optical modules are usually LC interfaces, and there are also single-fiber SCs on the market; GBIC optical modules (1×9) are conventionally SC interfaces, and other interfaces include FC and ST.
2. The service life of the optical module
International unified standard, 7×24 hours of uninterrupted work for 50,000 hours (equivalent to 5 years).