Here's the page we think you wanted. See search results instead:

Highlights

Compact tool for complex modulated optical signals
 
The Keysight N4391B Optical Modulation Analyzer enables development of the coherent technologies required to achieve the next level of performance in modern communication systems such as between, and in, datacenters. It consists of a UXR real-time oscilloscope and a calibrated coherent optical receiver. The N4391B builds on the UXR oscilloscope series’ industry-leading noise performance and Keysight’s reliable and flexible vector signal analysis (VSA) software.
 
The most compact OMA solution of its class, the N4391B not only solves your coherent measurement problems but also makes your test equipment decision easier and protects your investment: it provides two paths of upgradability that can be accomplished in minutes through the installation of licenses.
 
While complex modulated signals are commonly used in long-distance transmission across DWDM links, newly proposed technologies for intra-datacenter interconnect use the coherent approach in the O-band, addressing the higher data rate need with improved power efficiency. Keysight now provides OMA coherent receivers for the O-band in addition to the current coherent receivers that work in the C-band and L-band.
 
Applications
 
The ever-growing demand for higher transmission capability drives symbol rates on an ever-increasing trajectory. Yesterday’s systems at 64 GBaud are yielding to newly proposed ones at 124 GBaud and beyond to 200 GBaud. The Keysight N4391B helps you keep pace with this evolution that demands test equipment that can handle the symbol rate classes of transceivers for 800 Gb/s, 1.2 Tb/s to 1.6 Tb/s, from the first day in advanced research through the development phase.
Not only symbol rates are challenging, but also modulation formats are getting more demanding due to the higher-order quadrature amplitude modulation which requires a step up in noise performance. The N4391B meets this challenge with the UXR’s Effective Number of Bits performance having an industry leading ENOB of 5.4.
 
The Keysight N4391B provides an operating bandwidth up to 110 GHz and a myriad of options for selecting modulation formats. Even user-defined modulation formats are supported through an additional option, and all at an outstanding high ENOB at highest bandwidths.
 
Bandwidth upgradability
 
The N4391B is offered in two versions of optical coherent receivers: one is calibrated to 70 GHz operation and equipped with 1.85 mm connectors. It is available in C-band and O-band variants. A second one is factory calibrated to 110 GHz and equipped with 1.0 mm connectors. The bandwidth of operation is dependent on the oscilloscope bandwidth and the coherent receiver bandwidth chosen.
 
Each of the N4391B's configurations are upgradable to higher bandwidths: configurations based on the 1.85 mm connector can be upgraded from 40 GHz to 50 GHz, or 59 GHz, up to 70 GHz, while configurations based on the 1.0 mm connector can be upgraded from 40 GHz to 59 GHz, 70 GHz, 80 GHz, 100 GHz, up to 110 GHz. There are even configurations possible that feature different bandwidths for electrical and optical measurements.

Key Specifications

Download Data Sheet
ADC Resolution
10 bits
Frequency Range
DC to 110 GHz
DC to 70 GHz
Max Sample Rate
256 GSa/s
Maximum Record Length
2 GSa max
200 MSa standard
ADC Resolution
Frequency Range
Max Sample Rate
Maximum Record Length
10 bits
DC to 110 GHz
DC to 70 GHz
256 GSa/s
2 GSa max
200 MSa standard
View More
ADC Resolution:
10 bits
Analog Bandwidth:
70 GHz
110 GHz
Error Vector Magnitude Noise Floor:
< 1.6 % at 2.5 GHz frequency offset
< 2.9 % at 10 GHz frequency offset
Frequency Range:
DC to 110 GHz
DC to 70 GHz
Max Sample Rate:
256 GSa/s
Maximum Detectable Symbol Rate:
140 Gbaud
220 Gbaud
Maximum Frequency:
110 GHz
Maximum Record Length:
2 GSa max
200 MSa standard
Wavelength Range:
1527.60 nm to 1630 nm (Option 007)
1527.60 nm to 1620 nm (Option 011)
1270 nm to 1340 nm (Option E02)

See the coherent optical modulation analyzer in action

Watch this demo showcasing the Optical Modulation Analyzer (OMA) system, which includes a UXR-Series oscilloscope and coherent optical receiver, as well as an M8194B Arbitrary Waveform Generator, to achieve coherent optical testing speeds exceeding 100 gigabaud.

Learn how to calibrate the OMA and the optical waveforms to perform transmitter and receiver tests on a coherent optical device. 

Keysight N4391B (Agilent) Optical Modulation Analyzer

Interested in a N4391B?

Extend the capabilities for your Optical Modulation Analyzer

Software
See Related Software
Accessories
See Related Accessories
Services
See All Services
Support
See All Support

Featured Optical Modulation Resources

Data Sheets 2023.04.30

N4391B Optical Modulation Analyzer

N4391B Optical Modulation Analyzer

The N4391B is the next generation Optical Modulation Analyzer based on the UXR Oscilloscope series with two bandwidth options, one ranging from 40 GHz to 70 GHz and a second one ranging from 80 GHz to 110 GHz.

2023.04.30

Application Notes 2024.01.25

Coherent Optical Communications Test Challenges

Coherent Optical Communications Test Challenges

This application note describes the troubleshooting needs of coherent optical communication and how to use Keysight products to improve coherent optical system testing.

2024.01.25

Application Notes 2019.03.25

Everything You Need to Know About Coherent Optical Modulation

Everything You Need to Know About Coherent Optical Modulation

This is an introduction to the fundamentals of coherent optical modulation techniques.

2019.03.25

Technical Overviews 2020.09.03

Basic Vector Signal Analysis and Hardware Connectivity 89600 VSA Software Option 200

Basic Vector Signal Analysis and Hardware Connectivity 89600 VSA Software Option 200

Basic vector signal analysis is the foundation of the tools and user interface that make up the 89600 VSA software. Hardware connectivity allows the 89600 VSA software to link to over 40 instruments.

2020.09.03

White Papers 2014.07.30

Metrology of Optical Modulation Formats

Metrology of Optical Modulation Formats

Explore the metrology of optical modulation formats and discover the strengths and limits of the most frequently used methods in RF and wireless communication.

2014.07.30

Quick Start Guides 2021.12.31

N4391B Optical Modulation Analyzer Getting Started Guide

N4391B Optical Modulation Analyzer Getting Started Guide

Getting Started Guide

2021.12.31

Application Notes 2014.07.30

Digital Modulation in Communications Systems

Digital Modulation in Communications Systems

Understand concepts of digital modulation and learn new digital modulation techniques in communication systems to make informed decisions to optimize your systems.

2014.07.30

Posters 2019.10.17

Go to Market with 400G

Go to Market with 400G

Download the latest poster and go to market with 400G. Explore electrical detection, direct detection and coherent optical standards and related solutions.

2019.10.17

View All Resources

View All Resources

Frequently Asked Questions - Optical modulation

Optical modulation is the method of encoding data into optical carrier waves through variations in amplitude, phase, or frequency of the wave.

The different types of optical modulation are amplitude modulation, phase modulation, frequency modulation, quadrature amplitude modulation (QAM), differential phase shift keying (DPSK), and quadrature-phase shift keying (QPSK). QAM and QPSK can be used to encode multiple bits per symbol.

Optical fiber can transmit data faster over optical fiber compared to electrical cables, and optical modulation improves spectral efficiency by encoding multiple bits per symbol. QAM signals use amplitude and phase modulation to encode multiple bits of information into one symbol.

High-speed communications use a variety of modulation schemes to increase the data rate while keeping low signal degradation and high noise immunity, which is especially effective over long ranges compared to electrical cables. Coherent optical communications often use QAM, which allows for high-speed transmission between servers in a data center or between data centers.

The most common impairments in optical communications are chromatic dispersion, polarization mode dispersion, nonlinear effects, attenuation, and signal-to-noise ratio degradation.

Testing coherent optical communication systems and transceivers can involve many instruments depending on the testing. Calibrating test signals requires arbitrary waveform generators (AWG) and high-bandwidth real-time oscilloscopes running vector signal analysis software (VSA). For transceiver testing, optical modulation analyzers (OMA), optical power meters, tunable laser sources, and bit error rate testers (BERT) may be used depending on the test cases or issues being analyzed. The AWG, OMA, and BERT all need to support the data rates and modulation levels of the transceiver under test.

Want help or have questions?

Contact Us