Affiliation:
1. Photonic Sciences Lab. Physical Research Laboratory Ahmedabad Gujarat 380009 India
2. Indian Institute of Technology‐Gandhinagar Ahmedabad Gujarat 382424 India
3. School of Physics and Astronomy University of Glasgow Glasgow G12 8QQ UK
Abstract
AbstractHong–Ou–Mandel (HOM) interference, bunching of two indistinguishable photons on a balanced beam‐splitter, has emerged as a promising tool for quantum sensing. There is a need for wide spectral‐bandwidth photon pairs (for high‐resolution sensing) with high brightness (for fast sensing). Here, the generation of photon‐pairs with flexible spectral‐bandwidth even using single‐frequency, continuous‐wave diode laser enabling high‐precision, real‐time sensing is showed. Using 1‐mm‐long periodically‐poled KTP crystal, degenerate, photon‐pairs with spectral‐bandwidth of 163.42±1.68 nm are produced resulting in a HOM‐dip width of 4.01±0.04 m to measure a displacement of 60 nm, and sufficiently high brightness to enable the measurement of vibrations with amplitude of 205 ± 0.75 nm and frequency of 8 Hz. Fisher‐information (FI) and maximum likelihood estimation enables optical delay measurements as small as 4.97 nm with precision (Cramér–Rao bound) and accuracy of 0.89 and 0.54 nm, respectively, therefore showing HOM sensing capability for real‐time, precision‐augmented, in‐field quantum sensing applications.
Subject
Electrical and Electronic Engineering,Computational Theory and Mathematics,Condensed Matter Physics,Mathematical Physics,Nuclear and High Energy Physics,Electronic, Optical and Magnetic Materials,Statistical and Nonlinear Physics