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7-18
IM AQ1210-01EN
Explanation
Wavelength
The photodetector in the optical power measurement area has wavelength sensitivity characteristics.
The photodetector corrects the sensitivity according to the set wavelength and measures optical power
more accurately.
The wavelength setting range and setting step very depending on the wavelength mode set in the
detailed setup screen. Set the wavelength in the following range.
/SPM or /HPM Option
Wavelength Mode
Setting Range and Setting Step
Simple
Select from 850 nm, 1300 nm, 1310 nm, 1490 nm, 1550 nm, 1625 nm, 1650 nm.
Detail
Set the wavelength to a value from 800 nm to 1700 nm in 1 nm steps.
CWDM
Set the wavelength to a value from 1270 nm to 1610 nm in 20 nm steps.
Modulation Mode
You can select the modulation mode of the light to be measured from the following:
CW (continuous light), 270 Hz, 1 kHz, 2 kHz
Unit
Set the optical power display unit from the following.
dB (absolute value), dBm (absolute value), W (absolute value)
• Unit W is preceded by a prefix m (10
‒3
),
µ
(10
‒6
), n (10
‒9
), or p (10
‒12
).
• The following relation holds between the absolute display unit dBm and W.
P
dBm
= 10×log (P
w
×10
3
)
P
dBm
: optical power (unit dBm), P
w
: optical power (unit W)
Reference Value
You can set a reference value and display the relative measured values (the differences from the
reference value).
• When you tap the DREF button, the displayed measured value becomes the reference value. From
this point, relative values will be displayed. The unit changes to dB.
• When you tap the DREF button or set the unit to dB, the Reference box appears on the power
meter screen.
• You can set the reference value in the Reference box. The range is –80 dBm to 40 dBm.
• When you set the unit to dBm or W, the Reference box disappears, and the absolute measured
values will be displayed.
Wavelength Mode
You can select the wavelength mode of the light to be measured from the following:
Simple, Detail, CWDM
Like the “wavelength” item described earlier, the setting range and setting step vary depending on
the mode.
Average Times
The average value is displayed as the measured value. Select the average count from the following.
1, 10, 50, 100
7.3 Using the Optical Power Meter