The Keysight 81656A is a 1550 nm Fabry-Perot laser source module engineered for optical component characterization within the 8164B lightwave measurement system. This single-wavelength source delivers stabilized output with exceptional insensitivity to back reflections, making it ideal for precision measurements of insertion loss, optical return loss, and PDL across broadband components and fiber-optic assemblies.
Technical Specifications
• Wavelength: 1550 nm ±15 nm
• Laser Type: Fabry-Perot Laser Diode
• Output Power: >+13 dBm (20 mW)
• Spectral Bandwidth: <7.5 nm
• Fiber Output: Standard Single-Mode 9/125 µm
• CW Power Stability (15 min): <±0.005 dB
• Back Reflection Sensitivity: Insensitive
• Output Attenuation Range: 0 dB to 6 dB in 0.1 dB steps
• Operating Temperature: 0°C to +45°C
• Humidity: Non-condensing
– Key Features
• Internal digital modulation modes selectable from 270 Hz, 330 Hz, 1 kHz, 2 kHz, or user-defined 200 Hz to 10 kHz
• All outputs pulse-shaped with 50% duty cycle
• Internal coherence control for linewidth broadening
• Short-term and long-term output stabilization
• Compact plug-in module format: 75 mm × 32 mm × 335 mm; 0.5 kg
– Typical Applications
• Insertion loss measurements of broadband optical components
• Optical return loss characterization
• Polarization-dependent loss (PDL) testing
• Single-mode fiber-optic system verification
– Compatibility & Integration
Designed as a plug-in module for the Keysight 8164B Lightwave Measurement System. Compatible with Keysight 8163A/B, 8164A/B, and 8166A/B mainframes. Laser safety classification: Class IIIb (USA, 21 CFR 1040.10) and Class 3A (International, IEC 60825-1).
