Agilent / Keysight 86121A WDM system test

The Agilent/Keysight 86121A WDM Channel Analyzer is a Michelson interferometer-based instrument for wavelength division multiplexing system and component characterization. It delivers precise wavelength and optical power measurements for individual laser lines within WDM signals, operating across the 1270 to 1650 nm window. The unit combines laboratory accuracy with field portability, supporting both normal and fast update modes to balance measurement speed against resolution requirements.

Technical Specifications

• Range: 1270 to 1650 nm


• Absolute accuracy (Normal Mode): ±2 ppm (±0.003 nm at 1550 nm and 1310 nm) for lines ≥15 GHz separated


• Absolute accuracy (Fast Mode): ±3 ppm (±0.005 nm at 1550 nm, ±0.004 nm at 1310 nm) for lines ≥35 GHz separated


• Differential accuracy (Normal Mode): ±1 ppm


• Differential accuracy (Fast Mode): ±2 ppm


• Minimum resolvable separation (Normal Mode): 10 GHz characteristic


• Minimum resolvable separation (Fast Mode): 20 GHz characteristic


• Display resolution: 0.001 nm


• NIST-traceable accuracy Optical Power Measurement


• Calibration accuracy (±30 nm from 1310 and 1550 nm): ±0.5 dB


• Flatness (1250–1600 nm): ±0.2 dB characteristic


• Flatness (1250–1650 nm): ±0.5 dB characteristic


• Linearity (1270–1600 nm, lines >−30 dBm): ±0.3 dB


• Polarization dependence (1270–1600 nm): ±0.5 dB


• Polarization dependence (1600–1650 nm): ±1.0 dB characteristic


• Display resolution: 0.01 dB


• Sensitivity (single line, 1270–1600 nm): −40 dBm


• Sensitivity (single line, 1600–1650 nm): −30 dBm


• Sensitivity (multiple lines): 30 dB below total input power


• Maximum input level: +10 dBm displayed, +18 dBm safe


• Maximum laser lines: 200 Power Requirements


• 115 VAC: 110 VA / 60 W / 1.1 A maximum


• 230 VAC: 150 VA / 70 W / 0.6 A maximum

Key Features

• Dual operating modes (normal and fast) for application-specific trade-offs


• Channel separation down to 10 GHz in normal mode for closely-spaced wavelengths


• Support for up to 200 simultaneous laser lines


• High selectivity for crowded WDM bands

Typical Applications

• Dense wavelength division multiplexing (DWDM) system validation


• Optical component wavelength and power characterization


• Field and laboratory WDM signal analysis

Compatibility & Integration Standard AC mains connection (115 or 230 VAC) with low power consumption suitable for portable deployment.