The Keysight 81634A is a high-performance InGaAs optical power sensor module designed for use with the 8163A/B, 8164A/B, and 8166A/B optical mainframes. It features a large 5 mm detector diameter and offers exceptional power range, high linearity, and low noise, making it suitable for precise optical power measurements in both single-mode and multimode fiber applications.

Specifications

General

ParameterValue
InterfacesNone (uses mainframe interfaces: GPIB, LAN, USB)
DisplayNone (uses mainframe display)
Warm-up Time40 min
Recommended Calibration Interval2 years

Physical

ParameterValue
Power SupplyPowered by mainframe backplane slot
Operating Temperature0 °C to +40 °C
Dimensions (W×H×D)75 mm × 32 mm × 125 mm

Optical Characteristics

ParameterValue
Sensor ElementIndium Gallium Arsenide (InGaAs)
Detector Diameter5 mm
Wavelength Range800 nm to 1700 nm
Power Measurement Range-90 dBm to +10 dBm
Maximum Continuous Input Power+16 dBm (40 mW)
Fiber Type CompatibilitySingle-mode (9/125 µm) and Multimode (up to 100/140 µm, NA ≤ 0.3)
Optical Return Loss> 55 dB

Accuracy & Calibration

ParameterValue
Calibration Uncertainty at Reference Conditions±2.5% (at 1310 nm and 1550 nm, 23 °C ±5 °C)
Spectral Uncertainty (1000 nm to 1600 nm)±3.0%
Spectral Uncertainty (800 nm to 1700 nm)±5.0%
Power Linearity (+10 dBm to -70 dBm)±0.015 dB
Power Linearity (-70 dBm to -80 dBm)±0.030 dB
Noise Peak-to-Peak< 50 fW (1200 nm to 1600 nm, 1 s averaging time)
Zero Set±50 fW
Zero Drift±50 fW (over 1 hour at constant temperature)

Measurement & Acquisition

ParameterValue
Averaging Time Range100 µs to 10 s
Data Logging Memory Capacity20,000 points

Physical & Mechanical

ParameterValue
Optical Connector Adapter TypeKeysight 81000xI series (FC, SC, ST, LC, MU, bare fiber)
Module Slot WidthSingle-slot module

System Integration

ParameterValue
Compatible MainframesKeysight / Agilent 8163A/B, 8164A/B, 8166A/B

Environmental

ParameterValue
Storage Temperature Range-40 °C to +70 °C
Operating Humidity Range15% to 95% R.H. (non-condensing)

Optical Performance

ParameterValue
Polarization Dependence< ±0.01 dB (1250 nm to 1580 nm)

Performance

ParameterValue
Spectral Ripple due to Interference< ±0.005 dB (typically, 1460 nm to 1620 nm)

Compliance & Standards

ParameterValue
EMC ComplianceEN 61326-1
Safety ComplianceIEC 61010-1 / EN 61010-1

Technology

InGaAs Optical Power Sensor

Applications

Fiber Optic Power Measurement