The HP/Agilent 81521B is a germanium optical head sensor for precision optical power measurement in fiber optic systems. Built around a 5 mm diameter Ge detector element, this optical head delivers accurate measurements across the 900 nm to 1700 nm wavelength band, making it suitable for telecommunications and research testing. It interfaces with HP and Agilent mainframe units and optical power meters to provide reliable, traceable power measurements in single-mode and multimode fiber installations.
Technical Specifications
• Detector Element: Germanium (Ge), 5 mm diameter
• Wavelength Range: 900 nm to 1700 nm
• Power Measurement Range: +3 dBm to −80 dBm (−64 dBm for OPT 001 variant)
• Wavelength Accuracy: ±2.2% (100 nm to 1650 nm / 1000 nm to 1650 nm)
• Linearity: ±0.04 dB from −60 dBm to 0 dBm
• Noise Performance: <600 pW peak-to-peak (1200–1600 nm, 1 s averaging); <50 pW (1200–1600 nm)
• Maximum Power Density: 10 mW/mm²
• Fiber Pigtail Repeatability: <0.02 dB (with 81000BA/CA bare-fiber adapter)
– Key Features
• Supports single-mode and multimode fibers up to 100 µm core diameter (NA <0.3)
• Compatible with parallel beam, 9/125 µm, and 100/140 µm fiber geometries
• Low-noise detector performance across the extended infrared band
• Compact 5 mm aperture for precise, localized measurements
– Typical Applications
• Fiber optic power measurement in telecommunications systems
• Research and development testing in wavelengths from 900 nm to 1700 nm
• Optical loss and component characterization
– Compatibility & Integration
The 81521B integrates with HP 8152A Optical Average Power Meter, HP 8153A Lightwave Multimeter (with 81533A/B interface module), and Agilent 8163/8166 series mainframes. Connector interfaces via 81000FA, 81000SA, and 81000VA adapters. The OPT 001 configuration is optimized for the Agilent E5574A Optical Loss Analyzer and 8169A Polarization Controller.
