We combine lossless, phase-only transformations with fully-transmitting linear-optical scatterers to define the principle of linear-optical phase amplification. This enables a physical phase shift ϕ to be nonlinearly mapped to a new space γ(ϕ) using linear optics, resulting in a completely general and enhanced phase shifter that can replace any standard one. A particular phase amplifier is experimentally realized, allowing the phase enhancement parameter dγ/dϕ to be continuously tuned. Placing this enhanced phase shifter in one arm of a Mach-Zehnder interferometer led to an intensity-phase slope more than twenty times steeper than what can be obtained with its unamplified counterpart.
@article{arxiv.2405.03868,
title = {Tunable linear-optical phase amplification},
author = {Christopher R. Schwarze and David S. Simon and Abdoulaye Ndao and Alexander V. Sergienko},
journal= {arXiv preprint arXiv:2405.03868},
year = {2024}
}