Agilent Technologies 86038B User Manual page 331

Gain (loss)
Gain is defined as the difference in the transmitted power,
expressed in dB, between the test device measurement, P , and
b
the normalization measurement, P , given a constant power of
a
the laser source, calculated as:
Gain[dB] = 10log (P /P ) = P [dBm]-P [dBm]
b a b a
Loss is calculated with the same formula as gain and
corresponds to negative values.
Note 1: The PDLA shows gain (rather than loss). That is, lossy
test devices are shown with negative values.
Note 2: Gain (loss) includes connector effects at normalization
and at test device measurement.
Note 3: In general, loss depends on wavelength and polarization
state.
Gain (loss) uncertainty
Specifies the maximum difference between measured and actual
"Gain (loss)" , expressed in dB.
Conditions: operation mode as specified. Loss range as
specified..
Group delay (GD)
The optical signal delay time caused by a device or fiber. The
signal delay time in the normalization measurement is defined
as zero.
Note: In general, group delay depends on wavelength and
polarization state. In some cases (for example to determine the
chromatic dispersion) only the variation of the group delay over
wavelength is of interest, not its absolute value. In these cases
the "Relative group delay (rGD)" can be used where an
arbitrary delay value is added to the group delay values,
typically to bring its minimum value to zero.
Intermediate frequency bandwidth (IFBW)
The setting for the bandwidth of the filter employed in the
network analyzer portion of the PDLA.
Note: the IFBW setting influences measurement noise and
measurement speed.
331
Agilent 86038B Photonic Dispersion and Loss Analyzer, Second Edition