Control Of Resolution And Noise - Agilent Technologies 86038B User Manual

Figure 15 Selecting Wavelength Step and Modulation Frequency for GD
Ripple

Control of resolution and noise

When measuring low-dispersion, narrowband devices at high
resolution, we face the noise limit implied by Equation 5.
Figure 16 provides an intuitive guide to the management of this
noise. The brick walls represent limits. The left-right axis of the
figure represents the trace noise of the group delay
measurement. The upper half of the figure shows the
modulation frequency. We reduce into achieve better resolution
(movement to the right in the figure), but eventually the trace
becomes noisier.
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Agilent 86038B Photonic Dispersion and Loss Analyzer, Second Edition