Abstract-A broad-band ultrasonic sensor based on induced optical phase shifts in single-mode fibers is demonstrated over a frequency regime of 0550 MHz. In addition, a recently developed theory used to predict the magnitudes of acoustically induced strains in optical fibers is verified.

Coherent optical interconnects with up to 400-Gbps transmission rates and distances exceeding 80 km have been proposed to meet the increasing capacity demand of inter-datacenter communications. The interplay between the fiber Kerr effect and the receiver noise posses an upper-bound to the transmission distance. In this paper, we used numerical simulations to find the maximum achievable range of 400-Gbps unrepeated singlewavelength links with single and dual polarization. Simulations reveal that, for a forward error correction code limit of 10-3 , the maximum distance is 145 km for dual-polarization, which can be used as a benchmark to assess the transmitter/receiver-induced penalties.