The Agilent/Keysight 81633B is a Germanium optical power sensor head engineered for precision optical power measurements across the near-infrared spectrum. This 5 mm diameter detector module operates from 800 nm to 1700 nm and delivers absolute accuracy of ±0.15 dB with 0.001 dB resolution. The sensor accepts input power levels from -80 dBm to +10 dBm, with linearity of ±0.006 dB across the CW range (+10 dBm to -60 dBm). Rise and fall times measure less than 3.5 ns each, supporting fast transient measurements. Noise equivalent power reaches 10 pW/√Hz, enabling detection of weak optical signals. The module connects via FC/PC optical connector and outputs an analog signal (0-2V range) through a rear-panel BNC connector proportional to detected power. Responsivity is specified at 0.9 A/W. The sensor head measures 70 mm × 120 mm × 30 mm, weighs 0.2 kg, and operates from +15 V to +24 V at 3 W power consumption. A 20-minute warm-up period is required before measurement. The 81633B integrates with Agilent/Keysight mainframe instruments including the 8163A, 8163B, 8164A, 8164B, 8166A, 8166B, and 8153A, with interface modules 81618A or 81619A required for certain mainframe configurations. Operating temperature range is 0°C to 55°C; storage extends from -40°C to 70°C in non-condensing environments. Maximum input power is 100 mW. Calibration is valid within one year; an additional 0.3% uncertainty applies in the second year following calibration.
Technical Specifications
• Sensor element: Germanium (Ge), 5 mm diameter
• Wavelength range: 800 nm to 1700 nm
• Power range: -80 dBm to +10 dBm
• Absolute power accuracy: ±0.15 dB
• Power resolution: 0.001 dB
• Linearity (CW +10 dBm to -60 dBm): ±0.006 dB
• Noise equivalent power: 10 pW/√Hz
• Rise time: < 3.5 ns
• Fall time: < 3.5 ns
• Maximum input power: 100 mW
• Responsivity: 0.9 A/W
– Key Features
• FC/PC optical connector for industry-standard fiber coupling
• Analog voltage output (0-2V, BNC connector) for direct instrumentation integration
• Fast transient response enables sub-nanosecond timing measurements
• Operates across extended near-infrared wavelength band
• Low noise floor supports weak-signal detection applications
– Compatibility & Integration
The 81633B is designed for operation with Agilent/Keysight mainframe units: 8163A, 8163B, 8164A, 8164B, 8166A, 8166B, and 8153A. Interface modules 81618A or 81619A may be required depending on mainframe model.
