Optical interferometry-based array of seafloor environmental sensors using a transoceanic submarine cable.

Optical fiber-based sensing technology can drastically improve Earth observations by enabling the use of existing submarine communication cables as seafloor sensors. Previous interferometric and polarization-based techniques demonstrated environmental sensing over cable lengths up to 10,500 kilometers. However, measurements were limited to the integrated changes over the entire length of the cable.

Optical polarization-based seismic and water wave sensing on transoceanic cables.

Seafloor geophysical instrumentation is challenging to deploy and maintain but critical for studying submarine earthquakes and Earth's interior. Emerging fiber-optic sensing technologies that can leverage submarine telecommunication cables present an opportunity to fill the data gap. We successfully sensed seismic and water waves over a 10,000-kilometer-long submarine cable connecting Los Angeles, California, and Valparaiso, Chile, by monitoring the polarization of regular optical telecommunication channels.

Interplay between Raman and polarization effects in next-generation passive optical networks.

In this paper, we study in details some Raman-induced impairments that arise in Next-Generation Passive Optical Networks (NG-PON2) in a full coexistence scenario between GPON and TWDM-PON. The main new contribution of this paper is to take into account the polarization launches of the different signals at the transmitter, in order to find the best polarization arrangement. We found that launching the TWDM-PON wavelengths on alternately orthogonal polarization minimizes the Raman depletion effect on GPON over all possible PMD values, thus resulting in the optimal polarization launching condition, while any other polarization launch has a higher out of service probability for realistic PMD values.