HBM Genesis GEN5i User Manual page 565

I2679-4.0 en
L
−
optical
This formula also applies to singlemode systems
If for example two couplers are used in cable, c = 2, maximum length would be
L = 1 km
optical
The second limiting factor for cable length is fiber cable bandwidth.
Bandwidth limit is caused by light pulse dispersion in the optical fiber; this only
affects multimode fiber systems.
This limit is the product of GHS system maximum signaling speed and fiber
cable defined bandwidth.
GHS signaling speed over optical fiber
OM class defined bandwidth
Maximum fiber cable length
If for example OM2 type cable is used maximum length would be L
0,5 km
Maximum optical fiber length that can be used in a setup is the shortest
outcome of L or L
optical
If the two examples above are observed the optical fiber length must be limited
to L = 0,5 km
BW
dB + (c * 0.75 dB
−
3 5 . dB
−
BW
L
BW =
1000 MHz
BW
GEN5i
+ ( dB
−
km
(
: 1000 MHz
: BW
: L (km)
BW
(km)
BW
)
=
565