The Agilent 11980A is a Mach-Zehnder interferometer of fixed delay. Used with an Agilent 71400-series lightwave signal analyzer, it allows ,you to measure chirp and frequency modulation (FM) on DFB lasers. Traditional measurements of laser Iinewidth on single-line lasers can also be made. Together, the interferometer, lightwave signal analyzer, and a gateable RF source permit the display of a true power spectrum of single-frequency lasers. This includes the display of intensity modulation linellidth and componenrs of chirp caused by the intensity modulation. Specifications. Optical Insertion Loss, 1300 nm/1550 nm: < dB. Wavelength Range: 1250 to 1600nm. Delay Time: 3.5 us, 25 usec with Option 005. Option 005 replaces the standard 0.76 km of delay with 5.2 km, to measure laser linewidth down to 30 kHz. Connector Interface Options. Option 011: Diamond HMS,lQ Connector. Option 012: FC/PC Connector. Option 013: DIN 47256 Connector. Option 014: ST Connector. Option 015: Biconic Connector.