Agilent/Keysight 81495A – Optical Head

The Keysight 81495A Optical Head is a Reference Receiver Module delivering optical-to-electrical conversion for advanced optical transceiver testing. Operating across 750 nm to 1650 nm, it supports data rates from 622 Mb/s to 12.5 Gb/s with 9.3 GHz O/E bandwidth, enabling precise eye diagram analysis and compliance validation for IEEE 802.3ae and 10G Fibre Channel standards. The module integrates an optical average power meter for direct signal verification, eliminating setup uncertainty and ensuring measurement confidence across multi-mode fiber links.

Technical Specifications

• Wavelength Range: 750 nm to 1650 nm


• Data Rate Capability: 622 Mb/s to 12.5 Gb/s


• O/E Bandwidth: 9.3 GHz


• Fiber Type: Standard multi-mode 62.5 µm/125 µm


• Maximum Safe Input Power: 2 mW


• Maximum Linear Input Power: −3 dBm


• Analog Output Voltage: 0 to 0.4 V (0 V at no input; 0.4 V at ~1 mW input)


• Dark-Input Electrical Offset: Typically ±50 mV; remotely adjustable via SCPI


• O/E Conversion Ratio: Wavelength-dependent; queryable for 850 nm, 1310 nm, and 1550 nm


• Optical Input Connector: Straight contact type (angled connectors introduce ≥7 dB loss)

Key Features

• Integrated optical average power meter for fast signal verification


• Clean eye diagrams across full wavelength range


• SCPI remote control for conversion ratio queries and offset calibration


• Optimized for transceiver loopback testing per IEEE 802.3ae-LR, -ER, and 10 GFC


• Extended standard compliance support (802.3ae-LR, -LRM, -ER, -SR) with N4917A Optical Receiver Stress Test solution

Typical Applications

• Optical transceiver stress eye testing and characterization


• O/E conversion in scientific optical measurement setups


• Compliance validation for multi-gigabit optical standards


• Average optical power monitoring and diagnostics

Compatibility & Integration Designed for the Keysight LMS 816xB platform. Provides RF output and analog data output (voltage proportional to optical signal strength). Supports full SCPI command interface for remote operation and measurement automation.