Agilent Technologies 86038A User Manual page 105

Setup Menu
Laser Setup
Agilent 86038A Optical Dispersion Analyzer, Third Edition
pect to trade-off measurement speed.
• 201 samples per point is a good compromise of polarization scan coverage, col-
lecting enough data to average out noise, and keeping the measurement time
short enough to avoid drift effects. In many applications, 401 samples may not
improve the measurement accuracy due to drift effects.
Dynamic Drift Reduction
For stepped mode measurements only
This system function reduces measurement error contributed by gradual,
continuous temperature changes in the test path or the measurement
system itself. It is appropriate for use when the temperature of the room is
gradually rising or falling, or when the test device gradually transitions
from one temperature to another. This function is not suited to rapid or
stepped temperature changes. The movement of air over the test path can
generate rapid, small group delay changes. Reduce this type of error by
covering the test path to block air currents.
TLS Power
This control sets the TLS output power. The default value of –5 dBm is
available from the 81600B TLS over the full wavelength range. For the
81600B-160 TLS a power level of +5 dBm is available from 1520 nm to
1610 nm. For other tunable laser sources please refer to the individual TLS
specification. At higher TLS power levels, Amplitude Dynamic Range and
Group Delay Noise is improved, but phase dynamic accuracy (PDA) effects
are more pronounced. After changing the TLS power, normalization
(without PDA) is required.
The TLS power level can be lowered to eliminate artifacts of Gain Stage
Switching (possibly 200 fs, typically 50 fs, discontinuities in group delay).
These may occur when the power level at the receiver is comparable to a
0 dB insertion loss DUT with about –9 dBm TLS power, and again at a
power level 9 dB higher. Gain Stage switching only occurs at these two
power levels. Port 1 and Port 2 may switch at slightly different levels.
Alternatively, the TLS power can be increased to move the artifacts away
from the region of interest.
measurements but no error is visible in Gain/Loss" on page 268
example.
Refer to "If you see errors in Group Delay
Function Reference
for an
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