EXFO IQS-5250B High-Resolution Optical Spectrum Analyzer, 950–1650 nm

EXFO IQS-5250B High-Resolution Optical Spectrum Analyzer

The EXFO IQS-5250B is a high-resolution optical spectrum analyzer designed for demanding optical component characterization, DWDM system testing, laser analysis, amplifier evaluation, production alignment, and photonics research. It operates across wavelengths from 950 nm to 1650 nm, covering important optical regions around 980 nm, 1310 nm, and the 1550 nm C+L band.

The IQS-5250B uses a double-pass monochromator design to provide sharp optical rejection and accurate spectral measurements for both continuous-wave and modulated signals. Its 33 pm resolution bandwidth in the C+L band supports analysis of closely spaced optical peaks, including 50 GHz ITU-grid WDM channels, high-speed modulated sources, and dense wavelength-selective components.

Designed as a three-slot module for the EXFO IQS-500 Intelligent Test System, the analyzer combines optical measurement hardware with automated software analysis, trace storage, comparison tools, internal wavelength referencing, and remote-control capabilities. It is suitable for research and development, optical component manufacturing, qualification laboratories, automated test stations, and production environments.

Features and Benefits of the EXFO IQS-5250B

• Broad wavelength coverage: Measures optical spectra from 950 nm to 1650 nm.
• High C+L-band resolution: Provides 33 pm FWHM resolution bandwidth from 1520 nm to 1610 nm.
• Fine data-point spacing: Samples spectral data with 2.5 pm resolution.
• High optical rejection: Provides up to 55 dBc rejection at 0.8 nm from a strong signal at 1550 nm.
• Wide optical power range: Supports measurements from +15 dBm to -75 dBm, with a typical upper range of +18 dBm.
• Fast spectral acquisition: Measures 4001 points over a 10 nm span and 40 dB range in less than 0.85 seconds.
• Internal wavelength reference: Supports automatic C+L-band wavelength referencing using a built-in reference source.
• User wavelength calibration: Accepts peak or absorption-line calibration for enhanced wavelength accuracy.
• Automated optical analysis: Supports DFB, Fabry-Perot, LED, ASE, spectral transmittance, and drift-analysis applications.
• Trace comparison: Displays and compares as many as four traces within the analysis software.
• Production automation: Supports SCPI commands, LabVIEW drivers, COM objects, GPIB, RS-232, and Ethernet control.
• Modular system integration: Installs in a compatible EXFO IQS-500 Intelligent Test System.

950 nm to 1650 nm Spectral Measurements

The IQS-5250B covers wavelengths from 950 nm to 1650 nm. This broad operating range allows the analyzer to support optical pump characterization near 980 nm, device evaluation around 1310 nm, and DWDM testing across the C+L band.

The measurement span can be adjusted from the complete wavelength range down to a 1 nm span. Users can choose a narrow span for detailed analysis of a specific signal or a wider span for evaluating multiple channels, broadband sources, filters, and amplifier spectra.

The analyzer supports between 401 and 40,001 data points per sweep. This flexibility allows acquisition settings to be balanced according to the required spectral detail, measurement speed, and file size.

33 pm C+L-Band Resolution Bandwidth

The EXFO IQS-5250B provides a 33 pm FWHM resolution bandwidth from 1520 nm to 1610 nm. This corresponds to approximately 4.5 GHz near 1550 nm and supports analysis of densely spaced optical signals.

The high-resolution response is suitable for characterizing 50 GHz ITU-grid WDM signals, DFB and DBR lasers, modulated transmitters, optical filters, Bragg gratings, and passive DWDM components.

Resolution bandwidth is 50 pm from 1280 nm to 1330 nm and 50 pm from 960 nm to 990 nm. The optimized response around 980 nm supports optical pump sources, wavelength stabilizers, pump combiners, and related components.

Optical Rejection and Closely Spaced Signal Analysis

The double-pass monochromator provides sharp optical rejection around strong signals. At 1550 nm, optical rejection is specified at 35 dBc at 0.1 nm from the signal peak, 45 dBc at 0.2 nm, 50 dBc at 0.4 nm, and 55 dBc at 0.8 nm.

This rejection performance helps the analyzer distinguish low-level spectral content near a strong optical carrier. It supports accurate measurement of optical signal-to-noise ratio, side-mode depth, crosstalk, channel isolation, and modulated signal profiles.

Optical rejection is also specified at 35 dBc at a 0.2 nm offset near 1310 nm and 40 dBc at a 0.4 nm offset near 980 nm.

Optical Power Measurements

The IQS-5250B provides a specified optical power range from +15 dBm to -75 dBm, with a typical upper measurement capability of +18 dBm for a single narrow spectral peak. The maximum safe input power is typically +25 dBm for up to 15 minutes of continuous applied optical power.

Absolute power uncertainty is specified at ±0.4 dB at 1550 nm, ±0.45 dB at 1310 nm, and ±0.8 dB at 980 nm under the documented conditions. Measurement linearity is ±0.1 dB from +5 dBm to -50 dBm.

The analyzer provides spectral uniformity of ±0.13 dB from 1520 nm to 1610 nm. Power repeatability is ±0.03 dB over the same wavelength region and ±0.05 dB across the complete 950 nm to 1650 nm range.

Internal Wavelength Referencing

The IQS-5250B includes an internal wavelength reference source for automatic calibration within the C+L band. The referencing procedure helps maintain long-term wavelength accuracy without requiring an external source for routine calibration.

Internal referencing provides wavelength uncertainty of ±30 pm from 1500 nm to 1610 nm under the documented conditions. Wavelength uncertainty is ±40 pm at 1310 nm and ±70 pm from 965 nm to 990 nm.

The standard internal reference is especially useful in production environments where repeatable measurements and reduced setup time are important.

User Wavelength Calibration

The analyzer supports user calibration using optical peaks or absorption lines. A tunable laser, DFB source, or broadband source with a traceable gas-cell reference can be used to improve wavelength accuracy within a working session.

With user calibration, wavelength uncertainty can be reduced to ±15 pm in the C+L band. Within 1500 nm to 1610 nm, this value applies with one calibration point during the same work session. Outside that range, the specification applies within ±10 nm of the calibration point.

Multiple user-calibration points can further improve performance when suitable traceable wavelength references are available. The instrument also allows users to return to the factory calibration.

High-Speed Production Measurements

The IQS-5250B is designed to deliver high-resolution and high-sensitivity measurements without unnecessarily slowing production. It can measure and analyze 4001 points over a 10 nm span and 40 dB range in less than 0.85 seconds.

Six detection ranges allow users to balance acquisition speed and sensitivity according to the expected optical power. Higher-sensitivity ranges support low-level alignment and feedback applications, while the largest measurement range captures signals across the analyzer’s full dynamic power span.

Fast acquisition and automated analysis help reduce test time when multiple devices, channels, temperatures, current levels, or production samples must be characterized.

DFB and DBR Laser Analysis

The IQS-5250B software includes automated analysis for distributed-feedback and distributed-Bragg-reflector laser sources. It calculates important spectral parameters and allows users to define the depth at which signal bandwidth is measured.

As many as four traces from the same laser can be displayed under different current, temperature, or operating conditions. This supports comparative analysis during source development, qualification, burn-in, and environmental testing.

Measurement results can be saved in ASCII format or retrieved through GPIB and compatible automation commands.

Fabry-Perot, LED, and Broadband Source Analysis

The analyzer supports generic spectral analysis of modulated lasers, LEDs, Fabry-Perot lasers, VCSELs, and other sources with broad or multimode spectral distributions.

Available calculations include central wavelength, RMS width, FWHM, and other fundamental spectral characteristics. Fabry-Perot analysis evaluates the multiple mode intensities within the measured distribution.

These capabilities support source development, incoming inspection, production testing, environmental evaluation, and comparison of optical emitters.

Spectral Transmittance Testing

The spectral transmittance application characterizes the wavelength-dependent insertion loss of passive optical devices. The user first acquires a reference trace, typically from a broadband source, and then measures the signal transmitted through the device under test.

The software can automatically calculate central wavelength, ripple, bandwidth, insertion loss, and other passband characteristics. Analysis settings can be changed without acquiring a new trace, allowing different bandwidth levels, thresholds, and passband definitions to be evaluated from the stored data.

This function supports optical filters, thin-film devices, gratings, gain-flattening filters, multiplexers, demultiplexers, couplers, and other wavelength-selective components.

Trace Comparison and Marker Functions

The IQS-5250B can acquire, display, and analyze up to four traces. The comparison function allows traces from filters, gratings, DFB lasers, Fabry-Perot sources, LEDs, or ASE profiles to be displayed simultaneously.

Markers can be used to compare power levels, integrated power, wavelength differences, bandwidth, and other characteristics between measured curves. Automatic peak and dip searches help locate relevant spectral features.

Auto-zoom functions can position the display around the nearest peak and arrange markers for faster analysis. Stored traces can be reanalyzed using different thresholds, noise bandwidths, or channel-width settings.

Multiwavelength Drift Analysis

The drift-analysis application measures changes in wavelength, optical power, and optical signal-to-noise ratio over time. It can monitor as many as 200 optical channels simultaneously.

This function supports source-stability testing, WDM system monitoring, environmental characterization, burn-in analysis, and evaluation of lasers under changing current or temperature conditions.

Results can be displayed and reported for long-term trend analysis and comparison against configured alarm or performance limits.

Typical Applications

• DWDM channel and component characterization
• 50 GHz-spaced optical system testing
• DFB and DBR laser analysis
• Fabry-Perot laser and VCSEL characterization
• 980 nm optical pump measurements
• 1310 nm transmitter and component testing
• Optical amplifier and ASE measurements
• Optical signal-to-noise ratio analysis
• Filter and Bragg grating characterization
• Spectral transmittance measurements
• Multiwavelength drift analysis
• Production, qualification, and automated optical testing

Product Overview

Brand	EXFO
Model	IQS-5250B
Product Category	High-Resolution Optical Spectrum Analyzer Module
Wavelength Range	950 nm to 1650 nm
C+L-Band Resolution Bandwidth	33 pm FWHM
Power Range	+15 dBm to -75 dBm
Module Format	Three-slot IQS module
Compatible Platform	EXFO IQS-500 Intelligent Test System
Primary Application	Optical source, DWDM component, amplifier, filter, and system spectral analysis

 

Wavelength Specifications

Specification	Details
Wavelength Range	950 nm to 1650 nm
Adjustable Span	Full range to 1 nm
Data-Point Resolution	2.5 pm
Resolution Bandwidth, 1520–1610 nm	33 pm FWHM
Resolution Bandwidth, 1280–1330 nm	50 pm FWHM
Resolution Bandwidth, 960–990 nm	50 pm FWHM
Wavelength Uncertainty, 1500–1610 nm	±30 pm after the documented referencing procedure
Wavelength Uncertainty at 1310 nm	±40 pm
Wavelength Uncertainty, 965–990 nm	±70 pm
Uncertainty with User Calibration	±15 pm under the documented conditions
Linearity, 1520–1610 nm	Less than ±15 pm
Typical Linearity, 965–990 nm	±20 pm

 

Optical Power Specifications

Specification	Details
Power Range	+15 dBm to -75 dBm
Typical Power Range	+18 dBm to -75 dBm
Typical Maximum Safe Power	+25 dBm for up to 15 minutes of continuous input
Absolute Uncertainty at 1550 nm	±0.4 dB
Absolute Uncertainty at 1310 nm	±0.45 dB
Absolute Uncertainty at 980 nm	±0.8 dB
Linearity	±0.1 dB from +5 dBm to -50 dBm
Spectral Uniformity, 1520–1610 nm	±0.13 dB
Power Repeatability, 1520–1610 nm	±0.03 dB
Power Repeatability, 950–1650 nm	±0.05 dB
Typical Polarization-Dependent Loss	±0.07 dB
Maximum Polarization-Dependent Loss	±0.15 dB
Optical Return Loss	Greater than 35 dB

 

Optical Rejection Specifications

Test Wavelength	Offset from Peak	Optical Rejection
1550 nm	0.1 nm	35 dBc
1550 nm	0.2 nm	45 dBc
1550 nm	0.4 nm	50 dBc
1550 nm	0.8 nm	55 dBc
1310 nm	0.2 nm	35 dBc
980 nm	0.4 nm	40 dBc

 

Sweep and Data Specifications

Specification	Details
Number of Data Points	401 to 40,001
Representative Sweep Time	Less than 0.85 seconds for a 10 nm span, 4001 points, and 40 dB range
Trace Capacity	Up to four displayed and analyzed traces
Drift Analysis	Up to 200 optical channels
Trace and Result Formats	ASCII and EXFO OSA format

 

Remote Control and Automation

Function	Details
Communication Interfaces	GPIB, RS-232, and Ethernet through a compatible platform
Programming Commands	SCPI
Instrument Drivers	LabVIEW
Software Automation	COM objects
Supported Analysis	DFB, Fabry-Perot, LED, ASE, spectral transmittance, trace comparison, and drift analysis

 

Physical and Environmental Specifications

Specification	Details
Module Height	12.5 cm
Module Width	11.2 cm
Module Depth	28.2 cm
Module Weight	3.1 kg or 6.8 lb
Required IQS Slots	Three
Operating Temperature	10 °C to 40 °C
Storage Temperature	-20 °C to 50 °C
Standard Warm-Up Period	One hour unless otherwise specified

 

Connector Configurations

Configuration	Connector Interface
IQS-5250B-EI-EUI-89	FC/UPC narrow-key connector
IQS-5250B-EA-EUI-89	FC/APC narrow-key connector

 

Platform and Compatibility Considerations

The IQS-5250B is a three-slot optical spectrum analyzer module and requires a compatible EXFO IQS-500 Intelligent Test System for operation. The host platform provides power, control, display, processing, file storage, and remote communication.

The complete product number should be reviewed to determine whether the optical input uses an FC/UPC or FC/APC interface. The installed connector must match the polish and mechanical keying of the attached fiber.

The IQS-5250B module should not be considered a standalone optical spectrum analyzer. A compatible controller or mainframe, system software, optical patch cord, and connector interface are required for measurements.

Connection and Measurement Considerations

All optical connectors should be inspected and cleaned before connection. Contamination can increase insertion loss, reduce return loss, create spectral artifacts, and damage the analyzer or mating connector.

The optical input should remain within the specified operating range. The typical +25 dBm safe-input value applies only under the documented time limitation and should not be treated as the normal measurement level.

Precision measurements should be performed after the recommended one-hour warm-up. The analyzer should also complete the appropriate internal or user wavelength-referencing procedure before wavelength-critical testing.

Measurement span, resolution, data-point count, detection range, averaging, and analysis settings should be selected according to the source type, channel spacing, optical power, expected noise, and required test speed.

Calibration Before Shipment

When technically applicable and selected, the EXFO IQS-5250B can be calibrated before shipment. Calibration may include wavelength accuracy, resolution bandwidth, power accuracy, linearity, spectral uniformity, repeatability, optical rejection, polarization-dependent response, and internal wavelength referencing.

Calibration can be performed at representative wavelengths near 980 nm, 1310 nm, and 1550 nm using suitable traceable laser sources, wavelength references, calibrated optical power standards, attenuators, and spectral measurement equipment.

Buyers requiring formal calibration should confirm the requested wavelength points, optical power levels, connector configuration, certificate type, recorded results, and measurement uncertainty before purchase.

Buyer Considerations

Buyers should confirm the complete IQS-5250B model designation and installed optical connector. The EI-EUI-89 configuration uses an FC/UPC narrow-key interface, while the EA-EUI-89 configuration uses an FC/APC narrow-key interface.

The product listing should identify whether the sale includes only the OSA module or a complete IQS system. The IQS controller, optical patch cords, communication interfaces, software, manuals, calibration records, keyboard, mouse, display, and other accessories may be required separately.

The condition of the optical input, module connectors, retaining hardware, enclosure, labels, and host-platform interface should be reviewed before purchase.

Only the optical spectrum analyzer module, IQS controller or mainframe, connector interface, patch cords, software, communication hardware, documentation, calibration records, and accessories specifically identified in the product listing should be considered included.

Why Buy from AssetRelay?

AssetRelay supplies professional equipment and product solutions for fiber optic, telecom, laboratory, production, optical test, inspection, cleaning, electronic test, RF/microwave, and photonics applications. The EXFO IQS-5250B supports engineers, optical component manufacturers, DWDM laboratories, qualification facilities, production teams, system integrators, and research organizations requiring high-resolution spectral measurements.

Buyers should review the product photographs, physical condition, complete model designation, optical connector, wavelength and power performance, mainframe compatibility, calibration status, included accessories, and available testing information before purchase.