Extinction Ratio - Cailabs Aroona Star Instruction Manual

B. Extinction ratio
A transceiver extinction ratio is the difference between
the laser source power coding "1" bits and the laser source
power coding "0" bits. The higher the extinction ratio the
• At 1 Gb/s, most transceivers around 1310 nm and around
1550 nm have a good extinction ratio (> 8 dB) (transceiver
type 1000BASE-LX or 1000BASE-EX)
• At 10 Gb/s, a transceiver around 1310 nm type
10GBASE-LR generally has an extinction ratio around
3.5 dB (marked "DML" on specifications for "Directly
Modulated Laser" or "DFB" for "Distrubuted FeedBack
Laser") while a transceiver around 1550 nm type
10GBASE-ER of good quality has a high extinction ratio
greater than 8 dB (marked "EML" on specifications for
"Externally Modulated Laser")
(*) Enf of link depending on the architecture of the link: existing multi-mode connector (link < 400 m), single mode connector (link
> 400 m and < 800 m) or AROONA-STAR additional unit (link > 800 m)
better the emitted signal quality – high extinction ratio can help
minimizing the impact of some fiber defects.
• The same applies to extinction ratios of transceivers
>10Gb/s type 40GBASE-LR4/-ER4 or 100GBASE-LR4/-
ER4/-CWDM4.
Notes: Each AROONA-STAR port can be used for either
sending or receiving. AROONA solutions are compatible
with bidirectional transceivers, allowing a simplex channel
to be created on a single fiber.
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