Agilent/Keysight 81533A – Optical Head

The Agilent/Keysight 81533A is an optical head interface module that connects compatible optical heads to mainframe units for optical power measurement systems. It functions as the interconnect bridge between 81500-series optical heads and mainframe controllers, enabling single-channel optical power characterization across the visible and near-infrared spectrum.

Technical Specifications

• Wavelength Range: 450 to 1020 nm


• Power Range: +10 to −100 dBm


• Display Resolution: 0.001 dBm or 0.1 pW


• Measurement Uncertainty: ±2.2% at reference conditions


• Linearity: +3 to −80 dBm


• Noise Floor: <50 pW


• Operating Temperature: 0° to +40°C


• Channels: 1


• Analog Output: BNC connector


• Dimensions: 12.4 in. (L) × 1.25 in. (W) × 2.7 in. (H)


• Weight: 1 lb

Key Features

• Single-channel optical power measurement interface


• Wide dynamic range from +10 to −100 dBm accommodates both high-power and ultra-low-power measurement scenarios


• Sub-picowatt noise performance enables detection of weak optical signals


• Fiber compatibility includes parallel beam configurations from 9/125 µm to 100/140 µm with numerical aperture <0.3


• Compact form factor integrates into benchtop and rack-mount test systems


• Analog signal output via BNC connector supports external data acquisition and instrumentation

Compatibility & Integration The 81533A interfaces with optical heads 81521B and 81524A, connecting to mainframe units in the 8153, 8163, and 8164 series. This modular architecture supports flexible optical test configurations for communication, photonic component characterization, and power monitoring applications. Proper mainframe and optical head selection ensures accurate measurements within specified uncertainty bounds.