"Optical amplifiers are essential in optical communication systems as they compensate loss induced by the transmission fiber ensuring signal integrity of the information being transmitted, as well as in other applications such as spectroscopy.This research proposal deals with phase-sensitive optical parametric amplifiers (PSA) that have unique and superior properties compared with all other optical amplifiers, most notably the potential of noiseless amplification, very broad optical bandwidth, and being an enabler of a range of ultrafast all-optical functionalities. In communication, there is an urgent need to develop new technologies that can break the ‘nonlinear Shannon capacity limit’, which is considered a serious barrier for continued capacity increase needed to meet the exponentially growing demand for bandwidth. The use of PSAs is expected to be an essential part of this development.The objective is to unleash the unexplored potential of PSAs by generating knowledge and implementing experimental demonstrations that go substantially beyond current state-of-the-art. This involves a mix of engineering and scientific challenges with telecom and non-telecom applications in mind. We will leverage advances in other areas e.g. low loss photonic crystal fibers and highly nonlinear materials to realize compact PSAs with unprecedented performance. Specifically, we will demonstrate:• Significant merits (reach, spectral efficiency, capacity) of PSAs in optical transmission systems• High coherence, low noise lasers by utilizing ultralow noise amplifier as gain element• Very broad gain bandwidth, low noise PSAs using specially tailored nonlinear gain medium• Compact (hybrid integration compatible) PSA using new nonlinear materials• Novel ultrafast all-optical operations/signal processing using PSAs• Capability of PSAs for detection of very weak optical signals for e.g. and quantum optics"