34 Keysight 81618A/9A and Keysight 81620B/3B/4B/6B/8B Optical Heads User’s Guide3 SpecificationsConditions: constant wavelength, constant power level, angled connectoras specified, linewidth of source <100 MHz, temperature as specified.Return lossThe ratio of the incident power to the reflected power expressed in dB.Symbol: RL.Conditions: the return loss excludes any reflections from the fiber end usedas radiation source.Spectral width of optical sourceFull width at half maximum. The 3 dB width of the optical spectrum,expressed in nm. Symbol: FWHM.Total uncertaintyThe uncertainty for a specified set of operating conditions, including noiseand drift.Conditions: power level, beam diameter or fiber type, numerical aperture,wavelength, spectral width, ambient temperature, re-calibration period asspecified. Noise and drift observed over a specified observation time, witha temperature change of not more than ±ΔT.Uncertainty at reference conditionsThe uncertainty for the specified set of reference conditions, including alluncertainties in the calibration chain from the national laboratory to thetest meter.Wavelength rangeThe range of wavelengths for which the power meter is calibrated.Note: Selectable wavelength setting of the power meter for useful powermeasurements (operating wavelength range).Literature[1]Fiber optic test and measurement, Hewlett Packard Professional Books,edited by Prentice Hall, ISBN 0-13-534330-5RL 10 P inP back-------------- log=
