Interferometry: Polarization Stabilization to Maximize Contrast Ratio
The Keysight N7786A polarization synthesizer contains a high-speed Lithium-Niobate based polarization controller and a polarization analyzer plus a microcontroller based driving circuitry.
This unit can operate in various modes:
As Polarization Stabilizer it provides a stable output State of Polarization (SOP) even with fluctuations and drifts of the input SOP. The stabilized output signal is guided in a Standard Single-Mode Fiber (SMF). The output SOP can be defined in the following ways:
Set-and-forget: When the front button is pushed, the current SOP is stored and maintained, even if polarization changes occur on the instrument input.
Defined Stokes: The target output SOP can be defined by the user using the Stokes parameters
As Synchronous Scrambler the device switches the SOP of the output signal in a (pseudo) random way with a cycling speed of up to 100 KSOPs/s.
Switching of the SOP occurs within few microseconds. An electrical trigger input can be used to synchronize the scrambler with external events.
As SOP Switch the Keysight N7786A cycles through a sequence of SOPs with a speed of more than 40KHz, which corresponds to a cycle time of less than 25 microseconds. The sequence of SOPs can easily be defined by the user using Stokes coefficients.
Full coverage of the Poincaré Sphere is achieved within few ms.