User`s guide

Specifications Definition of Terms
26 Agilent 81618A/9A and Agilent 81623B/4B/6B/8B Optical Heads, Fourth Edition
Power range
The power range is defined from the highest specified input power level to
the smallest input power level that causes a noticeable change of
displayed power level.
Conditions: wavelength, averaging time as specified.
Wavelength range
The range of wavelengths for which the power meter is calibrated.
Note: Selectable wavelength setting of the power meter for useful power
measurements (operating wavelength range).
Literature
[1]Fiber optic test and measurement, Hewlett Packard Professional
Books, edited by Prentice Hall, ISBN 0-13-534330-5
Relative uncertainty (spectral ripple) due to
interference
Uncertainty of power reading when using a coherent source, due to a
periodic change of the power meter's responsivity caused by optical
interference between reflective interfaces within the power meter's
optical assembly.
Conditions: constant wavelength, constant power level, angled connector
as specified, linewidth of source <100 MHz, temperature as specified.
Spectral ripple is measured by stepping the source wavelength over the
wavelength range specified.
NOTE