The Agilent/Keysight 81625A is a high-power optical sensor head designed for precision optical power measurements across extended spectral ranges. Built around an InGaAs detector element with a 5 mm aperture, it delivers accurate measurements from -80 dBm to +20 dBm across the 850 nm to 1650 nm band. The unit integrates with Agilent/Keysight lightwave multimeter mainframes through dedicated interface modules, enabling high-power laser and amplifier characterization in demanding measurement environments.
Technical Specifications
• Sensor Type: InGaAs
• Detector Diameter: 5 mm
• Aperture Diameter: 5 mm
• Wavelength Range: 850 nm to 1650 nm
• Optical Power Input Range: -80 dBm to +20 dBm
• Wavelength Accuracy: ±4.0% (950 nm to 1630 nm); ±2.5%
• Analog Output: Not available
• Physical Dimensions: 55 mm × 80 mm × 250 mm
• Weight: 0.9 kg (without heat sink)
– Key Features
• InGaAs sensor element optimized for near-infrared measurements
• Wide dynamic range spanning -80 dBm to +20 dBm
• Broad wavelength coverage from 850 nm to 1650 nm
• Compact 5 mm detector geometry
• Direct integration with Keysight lightwave multimeter ecosystems
– Typical Applications
• High-power laser characterization and monitoring
• Optical amplifier output measurement
• Spectral power analysis in telecommunications and fiber-optic systems
• Precision optical power validation across extended wavelength bands
– Compatibility & Integration
The 81625A requires either the 81618A single optical head interface module or 81619A dual optical head interface module for connection to Agilent/Keysight lightwave multimeter mainframes. This modular architecture enables flexible multi-channel measurement configurations within existing test systems.
Product Status: Manufacturer obsolete. Self-support resources available via Keysight website. Repair and calibration services may be available through Keysight Service Centers or authorized third-party providers.
