HP 11890A 3 port directional coupler
The Agilent 11890A is a 3 port directional coupler with a nominal coupling of 3 dB and 34 dB nominal directivity. Used with an Agilent 71400 series or Agilent 83810B Lightwave signal analyzer, it allows the measurement of chirp and frequency modulation on DFB Lasers. Traditional measurements of laser linewidth on single-line lasers cans also be made.
The 11890A splits the optical energy into two paths, delaying one path with respect to the other, and recombines them in a second optical coupler. A polarization adjustment helps align the optical fields for maximum interference.
Together the interferometer, lightwave signal analyser and a gateable RF Source permit the display of a true power spectrum of single frequency lasers. This includes the display of intensity modulation linewidth and components of chirp caused by the intensity modulation.
Option 012: FC/PC Adapter