Agilent/Keysight 81680B,Tunable Laser Module

The Agilent/Keysight 81680B is a tunable laser module providing precise wavelength control and stable output power across the S- and C-bands for telecommunications and optical component characterization. The module delivers mode-hop-free tuning with dual optical outputs: one optimized for low source spontaneous emission (SSE ≥ 63 dB/nm) enabling accurate crosstalk measurements in DWDM systems, and a second with higher power and built-in attenuation for flexible level adjustment.

Technical Specifications

• Wavelength range: 1460 nm to 1640 nm (S- and C-band coverage)


• Wavelength resolution: 0.1 pm (12.5 MHz at 1550 nm)


• Absolute wavelength accuracy: ±0.01 nm


• Relative wavelength accuracy: ±2 to ±5 pm


• Wavelength repeatability: ±0.5 to ±1 pm


• Wavelength stability: ≤ ±1 pm/24 hours at constant temperature


• Tuning speed: 400 ms (1 nm step), 600 ms (10 nm step), 2.8 s (100 nm step)


• Linewidth: 100 kHz (coherence control off); >50 MHz (coherence control on, typical 1480–1580 nm)


• Output power: Peak ≥ 6 dBm typical; minimum −60 dBm (attenuation mode)


• Power stability: ±0.01 dB/hour, ±0.03 dB/24 hours


• Power repeatability: ±0.01 dB


• Power flatness vs. wavelength: ±0.1 to ±0.2 dB


• Side-mode suppression ratio: ≥ 40 dBc (1480–1580 nm)


• Source spontaneous emission (SSE): ≥ 63 dB/nm (1520–1570 nm)

Key Features

• Mode-hop-free tuning across full operational range


• Dual output ports with independent power control


• Ultra-low SSE output for precision crosstalk analysis


• Fine wavelength resolution supporting narrow-band measurements


• Integrated optical attenuator on high-power output

Modulation Capabilities

• TTL modulation input: 45% duty cycle, <300 ns fall time, 200 Hz to 1 MHz


• 5 Vp-p modulation input: <15% modulation depth, 5 kHz to 20 MHz

Typical Applications

• DWDM system characterization and validation


• Optical component and subsystem testing


• Crosstalk and signal integrity measurements


• Wavelength-dependent loss and gain analysis