HP / Agilent 81622B Ge Optical Head, 5mm Diameter

The HP/Agilent 81622B is a Germanium optical sensor head designed for precision optical power measurement across the infrared spectrum. This 5 mm diameter detector integrates with Agilent optical power meter systems via interface modules such as the 81618A or 81619A, delivering accurate readings from 850 nm to 1650 nm. The sensor achieves ±3.0% accuracy across 950 nm to 1630 nm and offers exceptional linearity of ±0.05 dB ±40 nW in the 950–1630 nm band. Built for demanding laboratory and industrial applications, the 81622B accepts standard single-mode and multi-mode fiber up to 100 µm core diameter (NA = 0.3) and delivers 0.001 dB power resolution with ±0.02 dB repeatability.

Technical Specifications

Sensor Element: Germanium (Ge)

Optical Diameter: 5 mm

Wavelength Range: 850 nm to 1650 nm

Power Measurement Range: +27 dBm to −55 dBm (1250–1650 nm); +23 dBm to −55 dBm (850–1650 nm)

Measurement Accuracy: ±3.0% (950–1630 nm)

Linearity (CW, 23°C ±5°C): ±0.05 dB ±40 nW (+27 dBm to −40 dBm, 950–1630 nm)

Power Resolution: 0.001 dB

Measurement Repeatability: ±0.02 dB

Noise (peak-to-peak): < 40 nW

Polarization Dependence: 45 dB

Maximum Input Power: 300 mW

Optical Damage Threshold: 500 mW/cm²

Analog Output: 0–2 V via BNC connector

Key Features

Germanium detector optimized for near-infrared and infrared wavelengths

Supports standard single-mode and multi-mode fiber (core up to 100 µm, NA = 0.3)

Real-time analog output for instantaneous signal monitoring

High return loss (> 45 dB) minimizes reflective artifacts

Compact 80 × 42 × 190 mm form factor; 0.4 kg

Typical Applications

Optical power measurement in fiber optic systems

Infrared detector calibration and validation

Laboratory characterization of broadband and narrowband sources

Industrial optical power monitoring

Compatibility & Integration The 81622B integrates with Agilent optical power meter platforms via the 81618A or 81619A interface modules. Optical input adapts to common fiber connectors (FC/PC, SC, ST) or bare fiber through available connector adapters. Threaded or D-type magnetic interface options are available depending on model variant.