On the role of the local oscillator intensity in optical homodyne-like tomography

Abstract

In a recent research (S. Olivares, et al., New J. Phys. 21 (2019) 103045) we have demonstrated that a homodyne-like scheme, exploiting a "low-intensity" local oscillator, can be used to perform optical state tomography of both quantum and classical states of light. The reconstruction method directly uses the homodyne-like probability distribution retrieved from the detector. Here, we further investigate the role played by the local oscillator in this respect. In particular, we study to some extent how its intensity affects the quantum-state reconstruction procedure by focusing on the case of the Fock states |1 and |2 , whose homodyne-like probability distributions are sensibly affected by the actual value of the LO intensity. The analysis is performed on Monte Carlo simulated experiments taking also into account the quantum detection efficiency.

Exploiting the wide dynamic range of silicon photomultipliers for quantum optics applications

“…Thus, to successfully exploit SiPMs for applications, such as for the realization of a homodyne-like Figure 1 Main: Typical single-shot detector outputs of MPPC S13360-1350CS SiPMs. Inset: Zoom of the fast component of some of the waveforms detection scheme [9], it is important that the signal output is properly acquired and analyzed. All these observations led us to test different detection chains based on different devices and to compare their performance.…”

“…Through this analysis, we also study the limits imposed by nonlinearities and saturation effects of some parts of the acquisition chain, having in mind the exploitation of the high dynamic range of SiPMs to detect well-populated states of light. Indeed, reliably detecting the number of photons in every pulse of highly-populated states is the key resource to implement homodyne-like schemes with a mesoscopic local oscillator (up to 50 mean photon numbers), as required to achieve an optimal quantum state reconstruction [8,9]. Increasing the dynamic range is also required if the considered states of light are characterized by large fluctuations, such as in the case of superthermal states of light [10,11].…”

Exploiting the wide dynamic range of Silicon photomultipliers for Quantum Optics applications

“…On the contrary, no perfect proportionality between the total area and a portion of the area under the falling edge is expected. Thus, to successfully exploit SiPMs for applications, such as for the realization of a homodyne-like detection scheme [9], it is important that the signal output is properly acquired and analyzed. All these observations led us to test different detection chains based on different devices and to compare their performance.…”

“…Through this analysis, we also study the limits imposed by nonlinearities and saturation effects of some parts of the acquisition chain, having in mind the exploitation of the high dynamic range of SiPMs to detect well-populated states of light. Indeed, reliably detecting the number of photons in every pulse of highly-populated states is the key resource to implement homodyne-like schemes with a mesoscopic local oscillator (up to 50 mean photon numbers), as required to achieve an optimal quantum state reconstruction [8,9]. Increasing the dynamic range is also required if the considered states of light are characterized by large fluctuations, such as in the case of superthermal states of light [10,11].…”

Homodyne measurement with a Schrödinger cat state as a local oscillator

“…Related issues have been examined by Olivares et al in Refs. [18,19]. However in all these cases, the local oscillator here is always a coherent state which is generally considered to have classical properties.…”