1. Page 1FO-DIV/GLBASICS_FO_2C.PPT
Applications Continuity Check / Fiber ID
for short distances (up to 5 km) visible light source (670
nm)
for longer distances: 1 or 2 KHz signal used for fiber
identification
ONU
ONU
OLT 2
OLT 1
CO
> 2s
PERM
1 550 nm1310 nm
Wa nd el & Golt er mann
ON
OFF
AUTO
dBm
Watt
dB
REF
ON
OFF
HOLD/
CONT
ABS
REF λ
> 2s PERM
+13dBmmax.
REF
BAT
PERMnm
dBm
OPTICALPOWERMETER OLP-15
Wandel &Goltermann
nm
dB
3. Page 3FO-DIV/GLBASICS_FO_2C.PPT
Use General Purpose Optical Power Meter
(either Ge-, or InGaAs-photodiodes)
Select the appropriate wavelength !
(recalls appropriate convertion factor out of
EPROM)
Measure the average system power level
Power Measurements Standard System
OLP-15B, -16B
850, 1310 or 1550 nm
4. Page 4FO-DIV/GLBASICS_FO_2C.PPT
Use Optical Power Meter for high power levels only !
(others may be destroyed !)
Highly recommended: InGaAs-Photodiodes
due to its better performance in the 3 rd optical
window !
Select the appropriate wavelength !
(recalls appropriate convertion factor out of EPROM)
Measure the average system power level
Power Measurements System with EDFA
OLP-18B
1550 nm
TX R
X
EDFA 1 EDFA 2
5. Page 5FO-DIV/GLBASICS_FO_2C.PPT
Power Measurements DWDM - System/1
You can´ t use general purpose optical power meters ! they
are broadband detectors and measure "all the light"
that hits the semiconductor (the aggregate power).
It is not able to perform "wavelength-selective" measurements !
1520...1580 nm
with 4, 8 or 16 carrier
6. Page 5FO-DIV/GLBASICS_FO_2C.PPT
Power Measurements DWDM - System/1
You can´ t use general purpose optical power meters ! they
are broadband detectors and measure "all the light"
that hits the semiconductor (the aggregate power).
It is not able to perform "wavelength-selective" measurements !
1520...1580 nm
with 4, 8 or 16 carrier
Editor's Notes
Wide-Band WDM didn't succeed in the long distance transmission for the following reason : Costs for electronics double for double capacity. Costs for electronic multiplexing equipment roughly grow with the square root of the bitrate => So for the same money you can get the fourfold capacity by selecting a higher multiplex rate. This relationship doesn't hold any more if - The bitrates hit technological barriers (today ~ 10Gbps) - The signals are of totally different formats for example analog CATV and digital data
Wide-Band WDM didn't succeed in the long distance transmission for the following reason : Costs for electronics double for double capacity. Costs for electronic multiplexing equipment roughly grow with the square root of the bitrate => So for the same money you can get the fourfold capacity by selecting a higher multiplex rate. This relationship doesn't hold any more if - The bitrates hit technological barriers (today ~ 10Gbps) - The signals are of totally different formats for example analog CATV and digital data
