N778-C Polarization Test Products

Polarization Analyzers and Polarization Controllers

Overview

Test & measurement capabilities for analyzing polarization properties of optical signals and components are indispensable in today´s optical R&D labs and manufacturing floors. The Keysight N778xC polarization test products enable highspeed, high performance characterization and verification of optical components and sub-systems.

N7781C Polarization Analyzer

The Keysight N7781C is a compact high-speed polarization analyzer that provides comprehensive capabilities for analyzing polarization properties of optical signals. This includes representation of the state of polarization (SOP) on the Poincaré sphere (Stokes parameter). The on-board algorithms together with the on-board calibration data ensure highly accurate operation across a broad wavelength range.

Due to its real time measurement capability of 1 M samples/s, the instrument is well suited for analyzing disturbed and fluctuating signals as well as for control applications requiring real time feedback of polarization information, for example in digital control loops in automated manufacturing test systems.

The built-in user interface allows a comprehensive analysis of the obtained measurement data and replaces the Polarization Navigator software that was required with the N7781B, the predecessor of N7781C. Programming uses a new SCPI command set and the instrument is addressed as a VISA resource.

The instrument comes in a compact form factor of just one rack height unit, with LAN and USB interfaces.

Applications

Monitoring and measurement of:

• State of polarization (SOP)

• Stokes parameters

• Degree of polarization (DOP)

• High-speed analysis of SOP/DOP of recirculating signal

• Analysis of PM-fiber extinction ratio

• Performance analysis of polarization scramblers

• Intrusion detection

Key features

• High-speed operation up to 1 M samples/s

• Memory for up to 1 M samples

• Up to 250 kHz analog bandwidth

• Compact size, one rack height unit

• Robust, no moving optical parts

N7785C Synchronous Scrambler

The Keysight Technologies N7785C is a high-speed synchronous scrambler that can repeatably switch through a series of states of polarization (SOP) with both input and output triggering functions. This unit can operate in various modes: 

• As a synchronous scrambler, the device switches the SOP of the output signal in a random but repeatable pattern. Switching of the SOP occurs within a few microseconds. The SOP is stable for a predefined time until it again switches to a new SOP. An electrical trigger input can be used to synchronize the scrambler with external events.

• As an SOP switch, the N7785C allows switching the internal waveplates to user definable angles with very high speed and repeatability.

• As a traditional scrambler, the N7785C varies the output SOP smoothly in a random walk pattern.

• As a polarization stabilizer, the N7785C uses feedback via program commands to set and stabilize the SOP based on an external reference. 

Programming uses a new SCPI command set and the instrument is addressed as a VISA resource. The instrument comes in a compact form factor of just one rack height unit, with LAN and USB interfaces. The instrument does not contain any moving optical parts.