Quantum tomography for time domain Balanced Homodyne Detection with high electronic noise
Martina Esposito, Daniele Fausti, Stefano Olivares, Fabio Benatti, Roberto Floreanini, Fabio Novelli, Federico Cilento, Francesco Randi, F. Parmigiani · arXiv (Cornell University) · 2013
Here we report on the design, construction and characterization of a time domain Balanced Homodyne Detection apparatus operating in the regime of high electronic noise. The experimental setup has been commissioned by studying coherent ultrashort ( ∼ 80 fs) light pulses using Pattern-function Quantum Tomography. Furthermore, we proved that the electronic noise can be treated as a detector inefficiency showing the effectiveness of this approach by measuring light coherent states with different energies. In Quantum Mechanics the measurement of the state of a physical system implies to estimate the expectation value of any observable of the system. For a generic operator the expectation value is obtained starting from the measurement of an ensemble of observables defined “quorum ” 1. In particular, for the electromagnetic field the quorum is a continuum set of the field quadra-tures2,3. Balanced Homodyne Detection (BHD) is an experimen-tal method for measuring a discrete set of the field