Range-scalable distributed acoustic sensing with EDFA repeaters demonstrated over 2227 km.

We demonstrate a new, to the best of our knowledge, range-scalable repeatered distributed acoustic sensing (DAS) solution sharing technology with existing long-haul subsea telecom networks capable of low noise and high spatial and temporal resolution. Single ended DAS interrogation through a 2227 km line comprising 39 repeatered fiber spans is demonstrated with a 10 m spatial resolution, a 1.78 kHz sampling rate, and a strain resolution of 35 pε/√Hz for the outermost span.

Continuous-wave broadly tunable high-power Cr:CdS laser.

We report spectroscopic characteristics and laser properties of the mid-infrared active laser medium Cr:CdS. Temperature-dependent absorption, luminescence and lifetime measurements of the E exited state allow determination of peak emission cross section value of 1.35 × 10 cm in -polarization at room temperature.