Single-mode optical fiber - which type is best?


Following on from our earlier articles on Fiber Optics Technology (readnhere on Fiber Optics Theory) we now look closer at the single-mode fibernand explore the two most commonly used types – ITU-T G652D and G657A2.

Designsnof single-mode fiber have evolved over the decades and present daynoptions offer most often than not, the G652D fiber. This backwardsncompatible fiber has been used in networks for over 30 years and offersnrespectable attenuation (the amount of light lost between input andnoutput) and provides marginally lower loss transmission which is betternin facilitating long distance communication links (up to and greaternthan 100km). However, the biggest difference between G652D and G657A2ncan be found in their ability to bend.

Compared to G652D fibersnwhich have limited bend resistance, the G657A2 fiber offers an improvednbend radius and flexibility which may allow for better cable managementnand routing in congested areas and also allow for increased density innhigh-density patching fields. G657A2 fiber is becoming more popular fornuse in advanced access cable network installations, where bendnresistance is required for smaller cable and cords installation radii,nproviding for low-cost installation, miniaturisation and higher densitynconnectorization.

The below diagram clearly illustrates the difference in bending radii for G652 and G657 fibers