Ambient Light Suppression - Agilent Technologies 83438A User Manual

Making Measurements

Ambient Light Suppression

Ambient Light Suppression

Ambient light can add significant errors to optical power measurements. This
is especially true when you are using or characterizing open beam devices.
The following example shows how the combination of the Agilent 83438A and
an Agilent 71450/1/2B optical spectrum analyzer can be used to eliminate this
error.
In order to perform this measurement, the Agilent 83438A's output is modu-
lated at 270 Hz. Because the optical spectrum analyzer has the ability to syn-
chronize its data acquisition with the modulated light, it can subtract out the
effects of ambient light. To learn more about using the optical spectrum ana-
lyzer's adc trigger feature, refer to Agilent Technologies Product Note
71452–4, "Pulsed or Time-Dependent Optical Spectra Measurements."
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