81199A Datasheet, PDF (12/17 Pages) Keysight Technologies – Wideband Waveform Center

12 | Keysight | 81195A Optical Modulation Generator Software - Data Sheet
Details
The SOP rate of change is defined by the pattern type (great circle, slicer, spinning coin),
the pattern length as well as the pattern play rate. Therefore, a broad range of SOP rates
can be achieved by different combinations of these parameters.
At the same time, the maximum SOP angular step between two pattern entries is
determined by the total pattern length. Large pattern lengths are used for small angular
steps. Once a suitable angular step size has been selected, the speed setting is used to
adjust the SOP rate of change and, at the same time, the pattern play time.
Example (great circle, 64 GSa/s):
Pattern length:
3600 steps
SOP angular step: 0.1°
SOP rate of change: 3.3 rad/s to 870 krad/s
While the great circle pattern gives a constant¹ SOP rate of change in a given plane in
stokes space, Spinning Coin mode allows for an almost constant SOP rate of change,
while providing good coverage of the Poincaré sphere. The Slicer mode, on the other
hand combines sphere coverage with varying rates of change.
In Dynamic mode (Pattern mode) and in Basic Static mode, polarization rotation is
defined by means of two subsequent stages of both a circular and a linear (H/V) retarder.
Each of the retarders covers a range of retardation of 360° at 0.25° step size.
An output trigger can be configured which sends a trigger signal at the start of the
rotation pattern. This can be used to start error counting in BERT or the DUT and identify
the exact SOP when bit errors or system outage occur.
Note: When using PMD emulation together with polarization rotation emulation, two
individual polarization control stages are available (one before and one after the PMD
emulation stage) with reduced pattern capabilities.
1.  The pattern will still advance in discrete steps, so the pattern parameters should be chosen for
sufficiently small SOP steps.