High-resolution optical spectrum measurements using an interferometer

There is an increasing need to perform optical spectrum analysis with better wavelength resolution. These requirements come from the application of wavelength (light frequency) multiplexed communications and high-density optical disks. Two major optical spectrum analysis approaches are that of dispersion and that of interference. The interference approach that uses Michelson interferometer has the advantage of higher resolution and accuracy. A basic illustration of the analyzer is shown. The authors have achieved a resolution of O.Olnm in the 1550-nm band and 0.0001nm in the 500-nm band, using the Q8347 Optical Spectrum Analyzer which has an interferometer with a maximum optical path difference of+l65mm