Agilent / Keysight 81940A 1520-1630nm Tunable Laser Source

The Keysight 81940A is a compact tunable laser source operating across 1520–1630 nm, delivering precise optical stimulus for component and system characterization. This module integrates a built-in wavemeter, coherence control, and SBS suppression to enable low-uncertainty measurements across the C and L bands with mode-hop-free tuning, high output power, and exceptional wavelength stability. Designed for modular integration with 8163A/B, 8164A/B, and 8166A/B mainframe systems, it excels in testing optical amplifiers, DWDM devices, and both active and passive optical components.

– Technical Specifications

• Wavelength Range: 1520 nm to 1630 nm (110 nm total tuning range)
• Wavelength Resolution: 1 pm; 125 MHz at 1550 nm
• Mode-Hop-Free Tuning: Full wavelength range
• Sweep Speed: 50 nm/s maximum
• Absolute Wavelength Accuracy: ±20 pm (typical ±5 pm)
• Relative Wavelength Accuracy: ±10 pm (typical ±5 pm)
• Wavelength Repeatability: ±2.5 pm (typical ±1 pm)
• Wavelength Stability (24 h): ±2.5 pm
• Linewidth: >50 MHz (1570–1620 nm, coherence control off); 100 kHz effective (coherence control on)
• Output Power: ≥+14.5 dBm peak (typical); ≥+13 dBm (1570–1620 nm); ≥+10 dBm (full range)
• Power Linearity: ±0.1 dB
• Power Stability: ±0.01 dB over 1 hour (typical); ±0.03 dB over 24 hours
• Power Flatness vs. Wavelength: ±0.2 dB (typical ±0.1 dB) across 1570–1620 nm; ±0.3 dB (typical ±0.15 dB) full range

– Key Features

• Built-in wavemeter for direct wavelength measurement and reduced calibration uncertainty
• Coherence control to suppress stimulated Brillouin scattering and cavity-induced interference
• Continuous sweep mode enabling repeatable, mode-hop-free operation across all bands
• High output power sufficient for direct amplifier stimulus without external boosters

– Typical Applications

Optical amplifier characterization, DWDM component testing, wavelength-dependent device response measurement, and multiband optical system validation.

– Compatibility & Integration

Pluggable module for Keysight 8163A/B, 8164A/B, and 8166A/B optical instrument mainframes.