Patent ID: 6885783

Claim:
A device for detecting polarization mode dispersion (PMD) in an optoelectronic transmission link comprising: a narrow-band tunable laser for providing a local optical signal that is sequentially adjusted to at least four different polarizations and tuned in wavelength within a range of wavelengths; means for superimposing the local optical signal on a digital optical signal from the optoelectronic transmission link to produce a superimposed optical signal; and an optoelectronic heterodyne receiver for receiving the superimposed optical signal and producing a measure of the PMD in the optoelectronic transmission link based on the polarizations and wavelengths of the local optical signal; wherein the optoelectronic heterodyne receiver further comprises a control and evaluation unit for calculating the measure of PMD from an electronic signal derived from the superimposed optical signal as a function of detected intensity of missed products for the various polarizations of the superimposed optical signal with respect to each other depending upon the wavelength of the narrow-band tunable laser.