EXFO PM-1600 High-Speed Power Meter - Manual (Page 72)

Performing Typical Tests with Your PM-1600
62 PM-1600
Characterizing an Optical Switch
6. Change the switch position from one channel to the other. For each
channel, take note of the relative power measurement when the
channel is active.
7. For each channel, the total switch deviation will be the highest positive
deviation minus the highest negative deviation relative to the original
reference (taken at step 4). The repeatability of the switch insertion
loss may be expressed as ± (total deviation in dB)/2.
Testing the Settling Time
The triggering and fast stabilization of the PM-1600 can be used to capture
fast power transitions. A good example of this is the optical switch settling
time measurement. When an electrical control signal for the switch is
available, a settling time including the electronics response time can be
measured. This is done by controlling the PM-1600 remotely to easily
retrieve the acquisition data (see Controlling the PM-1600 Automatically or
Remotely on page 67).
To measure the settling time,
1. Connect the instruments as shown below.
2. Set the power meter channel to the same wavelength as the source.
HIGH-SPEED POWER METER PM-1600
dB W/W
ENTER
dBm/W Ref
Null
Chan
Range λ Avg Shift
Store
Recall
Program
Setup
Analog Out C1 C2 Ext. Trig Display
PM-1600
OPTICAL LIGHT SOURCE FLS-2100
On/Off
ENTER
CW Up
λ Modulation Down
Store
Setup
FLS-2100
Attenuation
ACTIVE
DUT
(optical switch)
Control signals
Performing Typical Tests with Your PM-1600
62 PM-1600
Characterizing an Optical Switch
6. Change the switch position from one channel to the other. For each
channel, take note of the relative power measurement when the
channel is active.
7. For each channel, the total switch deviation will be the highest positive
deviation minus the highest negative deviation relative to the original
reference (taken at step 4). The repeatability of the switch insertion
loss may be expressed as ± (total deviation in dB)/2.
Testing the Settling Time
The triggering and fast stabilization of the PM-1600 can be used to capture
fast power transitions. A good example of this is the optical switch settling
time measurement. When an electrical control signal for the switch is
available, a settling time including the electronics response time can be
measured. This is done by controlling the PM-1600 remotely to easily
retrieve the acquisition data (see Controlling the PM-1600 Automatically or
Remotely on page 67).
To measure the settling time,
1. Connect the instruments as shown below.
2. Set the power meter channel to the same wavelength as the source.
HIGH-SPEED POWER METER PM-1600
dB W/W
ENTER
dBm/W Ref
Null
Chan
Range λ Avg Shift
Store
Recall
Program
Setup
Analog Out C1 C2 Ext. Trig Display
PM-1600
OPTICAL LIGHT SOURCE FLS-2100
On/Off
ENTER
CW Up
λ Modulation Down
Store
Setup
FLS-2100
Attenuation
ACTIVE
DUT
(optical switch)
Control signals