Agilent/Keysight 81634B,InGaAs Optical Head (Large Area)

The Keysight 81634B is an InGaAs optical power sensor head designed for precision measurements across the 800 nm to 1700 nm wavelength range. It integrates into Keysight 8163, 8164, and 8166 multichannel lightwave mainframes, delivering traceable measurement performance across single and multi-channel configurations. The thermally stabilized, hermetically sealed detector operates behind a glass window to isolate measurements from environmental factors including humidity, dust, and temperature variations.

Technical Specifications

• Wavelength Range: 800 nm to 1700 nm


• Power Measurement Range: +10 dBm to −110 dBm


• Accuracy at Reference Conditions (1260–1630 nm): ± 3%


• Total Uncertainty (1260–1630 nm): ± 5% ± 20 pW


• Low Power Uncertainty: ± 2.5%


• Polarization Uncertainty: < ± 0.005 dB


• Spectral Ripple Uncertainty: < ± 0.005 dB


• Power Linearity: 40 dB


• Noise Floor (1260–1630 nm): < 20 pW peak-to-peak


• Minimal Averaging Time: 100 µs


• Data Logging Capacity: 20,000 samples


• Operating Temperature: 0°C to +35°C


• Warm-up Time: 20 min


• Recalibration Interval: 2 years

Key Features

• Detector traceability to NIST and PTB standards


• Analog output for external integration


• Hardware trigger lines, filtering, and event trigger capability


• Hardware timer support for time-stamped logging


• Flexible connector interface: optimized for 2.5 mm ferrule; compatible with LC and MU 1.25 mm ferrule connectors via adapters; accepts both straight and angled-polish connector types


• Records minimum and maximum values over measurement intervals

Typical Applications

• Optical power monitoring in communication systems


• Stability analysis and trending measurements


• Spectral characterization with tunable laser synchronization


• Multi-channel power distribution assessment

Compatibility & Integration The 81634B fits all Keysight 8163, 8164, and 8166 mainframes. For LC or MU connectors, use adapters 81002LI or 81002MI respectively. Dimensions: 75 mm × 32 mm × 335 mm. Weight: 0.6 kg.