Hewlett-Packard Company

Agilent Technologies, Inc.

Dennis Derickson

Roger Lee Jungerman

James R Stimple

Eugene Rudkevich

A polarization scrambling device randomly varies the polarization states of multiple applied optical signals. The scrambling device includes a polarization scrambler coupled to a wavelength-dependent polarization randomizer having cascaded birefringent elements in which the axes of polarization of the cascaded elements are rotationally offset. The scrambling device causes random variations in the relative and the absolute polarization states of the applied optical signals. The birefringence, lengths, and number of cascaded birefringent elements are chosen to assure that the polarization states of optical signals at the different wavelengths are sufficiently randomized, even when the applied optical signals are closely spaced in frequency.

Multi-wavelength polarization scrambling device

A detector array spectrometer simultaneously monitors wavelength, power, and signal-to-noise ratio of wavelength division multiplexed (WDM) channels in telecommunication networks. A spectrometer spatially separates signals from the WDM channels according to the channels' wavelengths. The separated signals are incident on an array of split-detectors that conforms to the spatial separation of the signals provided by the spectrometer. While the split-detectors are positioned to receive a signal from each WDM channel, a noise detector is positioned between adjacent split-detectors to measure noise. A common mode output from two halves of each split-detector indicates the power in a WDM channel, while a differential output from the halves indicates wavelength deviations in the WDM channels. The ratio of the common mode signal to the noise detector signal is used to monitor the signal-to-noise ratio of the WDM channel. An angled diffraction grating in the spectrometer achieves compact size and high measurement resolution for the detector array spectrometer.

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Windsor, CA, United States of America

Dennis Derickson