Agilent/Keysight 81654A,Tunable Laser Source

The Agilent/Keysight 81654A is a dual-wavelength Fabry-Perot laser source module for optical communication system testing. Operating at 1310 nm and 1550 nm, it delivers 1 mW output power with ±0.03 dB stability over 24 hours. The module integrates into the Agilent Lightwave Solution platform and pairs with optical power meter modules for insertion loss, optical return loss, and polarization-dependent loss measurements on broadband components and fiber.

Technical Specifications

• Laser Type: Fabry-Perot


• Wavelengths: 1310 nm and 1550 nm


• Output Power: 1 mW (< 0 dB or < 1.8 mW)


• CW Power Stability: ±0.03 dB (24 hours)


• Output Attenuation: 0 dB to 6 dB in 0.1 dB increments


• Internal Digital Modulation: 270 Hz, 330 Hz, 1 kHz, 2 kHz, or 200 Hz to 10 kHz (user-selectable), 50% duty cycle


• Coherence Control: Internal linewidth broadening


• Beam Waist Diameter: 9 µm


• Numerical Aperture: 0


• Maximum Permissible CW Output Power: 15.6/10 mW


• Laser Classification: Class 1 (IEC 60825-1, 2001); complies with 21 CFR 1040.10 per Laser Notice No. 50

Key Features

• Insensitive to back reflections for stable measurements


• Short and long-term stabilization


• Adjustable output attenuation in 0.1 dB steps


• Front-panel laser enable with green LED indicator


• Built-in safety circuitry for fault detection


• Plug-in module format

Typical Applications

• Insertion loss measurements


• Optical return loss measurements


• Polarization-dependent loss (PDL) characterization


• Broadband optical component and fiber testing

Compatibility & Integration Operates within 8163B, 8164B, and 8166B mainframes. Designed for paired operation with optical power meter modules within the Agilent Lightwave Solution platform.