The HP/Agilent 81625B is a high-power InGaAs optical head for near-infrared power measurement across the 850 nm to 1650 nm spectrum. This detector module delivers dynamic range to +27 dBm, making it suited for characterizing optical components and systems with elevated signal levels. The 5 mm diameter InGaAs sensor provides low polarization-dependent loss, low spectral ripple, and high return loss performance. Operation requires integration with either the Agilent 81618A (single-channel) or 81619A (dual-channel) interface modules within Agilent 8163, 8164, or 8166 series multichannel mainframes. The detector operates from 0 °C to +35 °C at relative humidity less than 80%, with wavelength measurement uncertainty of ±5.0% across the 950 nm to 1630 nm range. No analog output is provided. Connector adapters are sold separately.
## Technical Specifications
• **Sensor Element:** InGaAs (Indium Gallium Arsenide)
• **Wavelength Range:** 850 nm to 1650 nm
• **Detector Diameter:** 5 mm
• **Power Range:** +27 dBm to −70 dBm (1250–1650 nm); +23 dBm to −70 dBm (850–1650 nm)
• **Dynamic Range:** Up to +27 dBm
• **Wavelength Accuracy:** ±5.0% (950 nm to 1630 nm)
• **Polarization Dependent Loss:** Low PDL design
• **Spectral Ripple:** Low
• **Return Loss:** High
• **Operating Temperature:** 0 °C to +35 °C
• **Operating Humidity:** <80% RH (10 °C to 35 °C)
• **Maximum Altitude:** 2000 m
• **Pollution Degree:** 2
• **Power Supply (Mainframe):** AC 100–240 V ±10%, 50/60 Hz
• **Power Consumption (Mainframe):** 280 VA maximum
## Key Features
• InGaAs semiconductor optimized for 900–1700 nm short-wave infrared detection
• Extended wavelength cutoff to 1.68 µm captures 1.3 µm and 1.55 µm fiber transmission windows
• 5 mm active aperture
• Magnetic D-shape adapter with safety stand included
• Wavelength measurement uncertainty ±5.0% over 950–1630 nm
## Typical Applications
• Telecommunications wavelength characterization (1310 nm, 1550 nm)
• Optical component power verification
• Fiber-optic system testing
• SWIR optical power analysis
## Compatibility & Integration
• Requires Agilent 81618A (single) or 81619A (dual) interface module
• Compatible with Agilent 8163A/B, 8164A/B, and 8166A/B mainframes
• Connector adapter sold separately
• Mainframe dimensions: 145 mm (H) × 426 mm (W) × 545 mm (L)
• Mainframe weight: 20 kg net
