Agilent/Keysight N7785C Polarization Controller

The Keysight N7785C is a high-speed synchronous scrambler and polarization stabilizer designed for precise control and manipulation of the state of polarization (SOP) of optical signals. It offers comprehensive polarization control capabilities, making it suitable for applications such as loop-synchronous scrambling, transmission system testing, and component characterization.

### Technical Specifications

* **Functionality:** Synchronous scrambler and polarization stabilizer.
* **Wavelength Range:** 1240 nm to 1650 nm (N7785C-001 option) or 1480 nm to 1620 nm (N7785C-002 option).
* **Input Power Range:** Less than +20 dBm.
* **Insertion Loss:**
* Less than 4.5 dB at 1270 – 1375 nm.
* Less than 4.0 dB at 1375 – 1460 nm.
* Less than 4.0 dB at 1490 – 1620 nm.
* Typically 4.0 dB.
* **Polarization Dependent Loss (PDL):** Less than 0.18 dB typical at 1550 nm.
* **SOP Cycling Time:** Less than 10 µs.
* **State of Polarization (SOP) Uncertainty:** 1.5°.

### Operational Modes

The Keysight N7785C can operate in several modes:

* **Synchronous Scrambler:** Switches the SOP of the output signal in a pseudo-random but repeatable pattern. The SOP remains stable for a defined period before switching to a new state. This mode can be synchronized with external events via an electrical trigger input.
* **SOP Switch:** Allows for high-speed and repeatable switching of internal waveplates to user-defined angles.
* **Traditional Scrambler:** Varies the output SOP smoothly in a random walk pattern.
* **Polarization Stabilizer:** Utilizes feedback via program commands to set and stabilize the SOP based on an external reference.

### Interfaces and Control

* **Programming:** Uses a new SCPI command set and is addressed as a VISA resource.
* **Physical Interfaces:** LAN and USB interfaces are provided.
* **Triggering:** Features both input and output triggering functions for synchronization.

### Physical and Environmental Specifications

* **Form Factor:** Compact, one rack height unit.
* **Operating Temperature:** 5 °C to +40 °C.
* **Storage Temperature:** -40 °C to +70 °C.
* **Maximum Operating Humidity:** 85% RH, non-condensing.
* **Maximum Operating Altitude:** 2000 meters.
* **Cooling:** Internal cooling fan. Proper airflow is required, and the instrument should be mounted upright and horizontally.
* **Power Consumption:** 60 VA max (AC 100 to 240 V ± 10%, 50/60 Hz).
* **Warm-up Time:** 20 minutes.
* **Recommended Recalibration Period:** 2 years.
* **Dimensions:** 420 mm × 212 mm × 43 mm (excluding front and back rubber cushions and connectors).
* **Weight:** 4 kg (8 lb).

### Compatibility and Ordering

* **Related Products:** The N7785C is part of the Keysight N778-C Series, which includes other polarization instruments like the N7781C Polarization Analyzer, N7786C Polarization Synthesizer, and N7788C Optical Component Analyzer.
* **Connectors:** Options for angled contact connectors are available (e.g., N7785C-022). Angled contact connectors help control return loss by directing reflected light into the cladding.

### Safety and Compliance

* **Laser Safety:** All Light Emitting Diodes (LEDs) used are Class 1 LEDs per IEC 60825-1:2014. Laser radiation can cause eye damage; do not enable the laser without a fiber attached to the optical output.
* **Environmental:** Designed for use in a pollution degree 2 environment. Complies with WEEE Directive (2002/96/EC).
* **Power:** Must be connected to a protective earth ground. A mains switch should be provided if rack-mounted.

Why Choose Aumictech for Keysight N7785C?
At Aumictech, we specialize in supplying high-performance optical test and measurement equipment. Whether you need precise polarization control for advanced fiber optic testing, reliable component characterization, or robust solutions for transmission system analysis, our team ensures the Keysight N7785C delivers maximum performance for your application.