Rudnicki, LukaszSánchez Soto, Luis LorenzoLeuchs, GerdBoyd, R. W.2023-06-162023-06-162020-08-150146-959210.1364/OL.392955https://hdl.handle.net/20.500.14352/6604© 2020 Optical Society of America. Funding: Foundation for Polish Science (ICTQT 2018/MAB/5); Ministry of Education and Science of the Russian Federation (14.W03.31.0032); Canada Excellence Research Chairs (501100002781). Ministerio de Ciencia e Innovación (PGC2018-099183-B-I00).We establish the ultimate limits that quantum theory imposes on the accuracy attainable in optical ellipsometry. We show that the standard quantum limit, as usually reached when the incident light is in a coherent state, can be surpassed with the use of appropriate squeezed states and, for tailored beams, even pushed to the ultimate Heisenberg limit.engjournal articlehttp://dx.doi.org/10.1364/OL.392955https://www.osapublishing.orgopen access535Phase-DifferenceNoiseÓptica (Física)2209.19 Óptica Física