Agilent/Keysight 81522A – Optical Head

The Agilent/Keysight 81522A is an optical head accessory for the 8152A series optical power meter, designed to measure optical power across infrared wavelengths. It integrates a cooled InGaAs PIN diode sensor with 500 µm diameter for high-accuracy absolute and relative power measurements in fiber optic systems. The head connects to compatible Agilent and HP mainframes via two optical inputs and derives operational power from the connected 8152A mainframe.

Technical Specifications

• Wavelength Range: 1000 nm to 1650 nm


• Measurement Range: −3 dBm to −100 dBm


• Resolution: 0.01 dB, 0.1 pW


• Sensor Element: Cooled InGaAs PIN diode


• Sensor Diameter: 500 µm


• Typical Bandwidth: 700 Hz


• Linearity: 1% typical


• Dimensions: 37.7 mm diameter × 140 mm length


• Weight: 0.45 kg

Key Features

• Dual optical inputs for flexible measurement configurations


• Factory-calibrated sensor ensures precise measurement results


• Compact form factor (1.5" × 5.5") for bench-top and system integration


• Fine resolution at 0.01 dB for detailed power trending


• Stable 700 Hz bandwidth minimizes noise floor in dynamic measurements

Typical Applications

• Optical power monitoring in long-haul and metro fiber networks


• Transmitter and receiver characterization at 1300 nm and 1550 nm bands


• Component insertion loss and gain measurements


• System power budgeting and commissioning

Compatibility & Integration The 81522A operates exclusively with the Agilent/Keysight 8152A Optical Average Power Meter mainframe, which supplies operational power at 100/120/220/240 Vrms, ±5%/−10%, 48–400 Hz. It is also compatible with legacy HP 8152A, HP 81521B, and HP 81520A meter platforms. The mainframe supports manual front panel control and GPIB remote programming. A 15-minute warm-up interval is recommended for the mainframe prior to measurement. Operation requires connector adapters and optical lenses matched to the measurement interface.