The concept of quantum temporal imaging is proposed to manipulate the temporal correlation of entangled photons. In particular, we show that time correlation and anticorrelation can be converted to each other using quantum temporal imaging.
The equations that govern the temporal evolution of two photons in the Schr\"odinger picture are derived, taking into account the effects of loss, group-velocity dispersion, temporal phase modulation, linear coupling among different optical modes, and four-wave mixing. Inspired by the formalism, we propose the concept of quantum temporal imaging, which uses dispersive elements and temporal phase modulators to manipulate the temporal correlation of two entangled photons. We also present the exact solution of a two-photon vector soliton, in order to demonstrate the ease of use and intuitiveness of the proposed formulation.
Temporal imaging is a technique that enables manipulation of temporal optical signals in a manner similar to manipulation of optical images in spatial domain. The main building block of temporal imaging, the time lens, is based on nonlinear optical processes such as the sum- frequency generation or the four-wave mixing. While classical temporal imaging is nowadays a well-established domain, its quantum counterpart is still in its nascent period. In this talk we shall give and overview of the quantum temporal imaging and its application for manipulation of non-classical states of the light.
Measurements of photon temporal correlations have been the mainstay of experiments in quantum optics. Over the past several decades, advancements in detector technologies have supported further extending photon correlation techniques to give rise to novel spectroscopy and imaging methods. This Perspective reviews the evolution of these techniques from temporal autocorrelations through multidimensional photon correlations to photon correlation imaging. State-of-the-art single-photon detector technologies are discussed, highlighting the main challenges and the unique current perspective of photon correlations to usher in a new generation of spectroscopy and imaging modalities.
Temporal ghost imaging is based on the temporal correlations of two optical beams and aims at forming a temporal image of a temporal object with a resolution, fundamentally limited by the photodetector resolution time and reaching 55 ps in a recent experiment. For further improvement of the temporal resolution, it is suggested to form a spatial ghost image of a temporal object relying on strong temporal-spatial correlations of two optical beams. Such correlations are known to exist between two entangled beams generated in type-I parametric downconversion. It is shown that a sub-picosecond-scale temporal resolution is accessible with a realistic source of entangled photons.