Jds Uniphase Corporation

Viavi Solutions Inc.

Acterna LLC

Georg Rudolph

Eberhard Löcklin

Jörg Stooss

Eberhard Lothar Loecklin

An apparatus for mitigating polarization dependent loss (PDL) in an optical signal-to-noise ratio (OSNR) of a modulated optical signal is disclosed. The apparatus may comprise a spectrum analyzer to measure an optical power spectrum of a modulated optical signal. The apparatus may also comprise a measuring unit to select a first portion of the modulated optical signal and a second portion of the modulated optical signal, where each of the first and second portions of the modulated optical signals may include an independent noise distribution indicative of PDL, and measure a time-varying parameter of the first and second portions. The apparatus may also include a signal processor to PDL in an OSNR by transforming any elliptical polarization associated with the independent noise distribution into a ball polarization, determining a correlation between time-varying parameters of the first and second portions, and calculating a PDL mitigated OSNR.

Mitigating polarization dependent loss (PDL) by transforming frequency components to a ball

A lasing wavelength of a laser diode is determined by applying a forward current to the p-n junction of the laser diode and measuring a voltage across the p-n junction. The lasing wavelength can be determined by performing a simple wavelength calibration of the laser diode. This allows one to stabilize the lasing wavelength, and also to use the laser diode as a reference wavelength source.

Wavelength referencing by monitoring a voltage across a laser diode

A method and apparatus is disclosed for measurement and monitoring of in-band optical signal to noise ratio (OSNR). A two channel optical spectrum analyzer (OSA) is advantageously applied in acquiring wavelength division multiplex (WDM) signal data after it has been split according to polarization, then deriving the in-band OSNR from acquired data due to its narrow bandwidth, selective spectral shape, and capability to analyze two components of a polarized signal simultaneously. The in-band OSNR can be measured without interrupting optical transmission traffic in the network.

Growing community of inventors

Tübingen, Germany

Georg Rudolph