The GN NETTEST FD440 is a field-portable chromatic dispersion transmitter designed for precise measurement of chromatic dispersion in optical fibers. This two-unit system characterizes dispersion behavior across C- and L-band wavelengths, enabling network operators to optimize data rates, increase channel capacity, and extend reach between optical amplifiers in high-speed DWDM systems. The instrument performs chromatic dispersion measurements, relative spectral attenuation analysis, and supports dispersion compensation management schemes essential for planning, building, and upgrading fiber optic networks where dispersion limits bandwidth or renders links unsuitable for high bit-rate transmission.
Technical Specifications
• Chromatic Dispersion Measurement Range: 32 dB (standard and FD425 HP LEDs); 40 dB (1550 XHP LED) or optional 40 dB configuration
• Operating Wavelengths: 1250–1350 nm and 1500–1600 nm for chromatic dispersion; 1200–1350 nm and 1450–1650 nm for spectral attenuation
• Preferred Windows: 1310 nm, 1550 nm, and 1625 nm
• Dispersion Accuracy: ±1.5% ±0.02 ps/nm
• Slope Accuracy: ±1.5%
• Wavelength Accuracy: ±0.5 nm
• Receiver Laser: Near-infrared, 1550 ±20 nm, maximum 700 µW CW peak power
• Measurement Method: Differential Phase Shift (Double Demodulation variant, U.S. Patent 4,750,833) for temperature immunity and speed
– Key Features
• Windows 98–based software with single-button operation and customizable test parameters
• IEEE 488 bus control interface (preset addresses: 0 for computer, 11 for FD440)
• FC/PC optical connectors
• Dual-unit configuration: Receiver (120 W max) and Transmitter (40 W max)
• AC mains powered, 90–260 V, 50/60 Hz; 2.0 A (T) fuse rating
– Typical Applications
• DWDM network commissioning and troubleshooting
• Fiber link characterization and dispersion mapping
• Dispersion compensation scheme validation
• High bit-rate transmission feasibility assessment
– Compatibility & Integration
• Requires Windows 98 laptop with 64 MB RAM, 4 GB HDD minimum
• IEEE interface card required for control
• Includes Perkin Elmer FD440 Software Version 3.3.5 with NI-DAQ, NI-GPIB, and NI-VXI support
