Measurement Uncertainty in Infrared Spectroscopy with Entangled Photon Pairs

Abstract

Spectroscopy with entanglement has shown great potential to break limitations of traditional spectroscopic measurements, yet the role of entanglement in spectroscopic multi-parameter joint measurement, particularly in the infrared optical range, remains elusive. Here, we find an uncertain relation that constrains the precision of infrared spectroscopic multi-parameter measurements using entangled photon pairs. Under such a relation, we demonstrate a trade-off between the measurement precisions of the refractive index and absorption coefficient of the medium in the infrared range, and also illustrate how to balance their respective estimation errors. Our work shall provide guidance towards the future experimental designs and applications in entanglement-assisted spectroscopy.