User`s guide

Definition of Terms Specifications
Agilent 81618A/9A and Agilent 81623B/4B/6B/8B Optical Heads, Fourth Edition
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Averaging Time
Time defining the period during which the power meter takes readings for
averaging. At the end of the averaging time the average of the readings is
available (display- or memory-update). Symbol T
avg
.
Linewidth
FWHM spectral bandwidth. The 3 dB width of the optical spectrum,
expressed in Hertz. Symbol: ∆f.
Noise
The peak-to-peak change of displayed power level with zero input power
level (dark).
Conditions: Zero prior to measurement, averaging time and observation
time as specified, lowest power range selected and wavelength range as
specified.
Measurement: the measurement result is obtained by:
Noise = P
max
− P
min
expressed as peak-to-peak within
the given time span. Any offset is
automatically excluded this way.
Reference conditions
The specified conditions during the spectral responsivity calibration, or
conditions which are extrapolated from the conditions during calibration.
Conditions: power level, beam diameter or fiber type, numerical aperture,
wavelength, spectral width, ambient temperature as specified, at the day
of calibration. →Noise and drift observed over a specified observation
time, with a temperature change of not more than ±∆T.