HP Agilent 70951B Optical Spectrum Analyzer OSA 600-1700nm DWDM Fiber Module

HP Agilent 70951B Optical Spectrum Analyzer OSA 600-1700nm DWDM Fiber Module: Wideband Spectral Analysis with Double-Pass Monochromator Precision

The HP Agilent 70951B Optical Spectrum Analyzer OSA 600-1700nm DWDM Fiber Module is a modular optical spectrum analyzer that delivers spectral measurements from 600 to 1700 nm with the sensitivity and dynamic range needed for DWDM system verification, laser characterization, and fiber-optic component testing. Built as a component of the 71451B Optical Spectrum Analyzer System and part of the HP 70000 Modular Measurement System, it targets telecom engineers, optical component manufacturers, and R&D labs that need repeatable, calibrated spectral data across the visible and telecom bands.

Key Features and Benefits of the HP Agilent 70951B Optical Spectrum Analyzer OSA 600-1700nm DWDM Fiber Module

• 600 to 1700 nm wavelength coverage — Single instrument spans visible, O-band, E-band, S-band, C-band, and L-band, eliminating the need for band-specific OSAs.
• Unique double-pass monochromator — Two passes through the grating deliver stray-light rejection and dynamic range that single-pass designs cannot match.
• Real-time sweep rates — Fast acquisition supports live tuning, alignment, and production test workflows without waiting between sweeps.
• -90 dBm sensitivity — Resolves low-level signals for ASE noise measurements, sidemode analysis, and weak-carrier characterization.
• 60 dB dynamic range — Cleanly separates strong signals from adjacent low-level features for accurate OSNR and sidemode suppression measurements.
• ±0.3 nm absolute wavelength accuracy — Reliable for ITU channel verification and laser source qualification.
• Excellent amplitude accuracy — Delivers trustworthy absolute power readings for gain, loss, and level measurements.
• Low polarization dependency — Reduces measurement uncertainty when working with polarized sources and polarization-sensitive components.
• Wavelength and amplitude calibration across full range — Calibrated over the entire 600–1700 nm span rather than at a handful of reference points.
• Modular MMS architecture — Integrates into the HP 70000-series mainframe alongside other modules to build custom optical/RF test benches.

Advanced Capabilities

The double-pass monochromator is the defining engineering choice in the 70951B. In a single-pass grating instrument, stray light and diffraction sidelobes limit how closely a low-level signal can be measured next to a strong carrier — a critical limitation when characterizing EDFA output, where a -20 dBm signal may sit only a fraction of a nanometer from a +10 dBm carrier. Routing the optical path through the grating twice suppresses that stray light dramatically, which is what enables the 60 dB dynamic range on real spectra rather than only on ideal test signals. For OSNR measurements on live DWDM channels, this distinction is the difference between a number you can defend and a number you have to caveat.

As a component of the 71451B system and the broader 70000 Modular Measurement System, the 70951B is designed to work as part of a larger test platform rather than as a standalone box. Combined with other 70000-series modules — RF spectrum analyzers, sources, and power meters — it becomes the optical front end of an integrated optical-RF test system that can characterize a full transmitter or receiver chain from a single rack. For labs already running 70000-series MMS infrastructure, the 70951B slots in directly rather than requiring migration to a new platform.

Calibration and Quality Assurance

Every HP Agilent 70951B is calibrated prior to shipping to OEM specifications. The order includes a Calibration Certificate, Calibration Label, and full Calibration Data. This means the instrument arrives traceable, audit-ready, and ready to use straight out of the box — no need to schedule a calibration cycle before putting it into service.

Specifications