Research in Quantum-Enhanced, Ultrafast Sensing and Imaging

University Of Rochester, Rochester NY

Investigators

Abstract

This document outlines a program of research to develop practical methods for ultrabroadband imaging with quantum enhancement of the detection sensitivity. In particular it presents several novel techniques for the characterization of ultrafast optical and X-ray waveforms, and then discusses ways to apply them to broadband dynamical imaging, including possibilities for going well beyond the shot-noise limit for phase and amplitude measurement accuracy. The program covers both development of appropriate dynamical image detection, protocols for image transmission, and the sources of particular quantum states needed for enhanced sensitivity. The program has four major experimental objectives. (I) The first goal consists of developing a novel method for measuring the conplete spatio-temporal properties of an ultrafast optical pulse. The basic idea involves extending interferometric methods of ultrafast pulse measurement into a new domain of accuracy and precision. In particular we shall develop an ultrafast multi-wavelength interferometry: for dynamical space-time imaging. (II) The second portion of our program entails the development of a novel method for obtaining attosecond temporal resolution for dynamical X ray imaging. The project will first study a recently demonstrated nonlinear optical mechanism for atomic ionization to implement an interferometric pulse measurement technique for completely characterizing the electric field of the attosecond pulse. This technique is based on the quantum interference on two pathways for ionizing an electron, which leads to an interference pattern in the electron energy spectrum. From this pattern the spectral phase of the ionizing attosecond pulse can be reconstructed using a simple, noniterative, algorithm. (III) Another project involves the use of entangled states of ultrashort photon wavepackets to implement time-resolved and quantum-enhanced sensitivity for near-field microscopy. This provides phase sensitivity in principle well beyond the shot noise limit, and will allow the development of ultrasensitive nanoscale measurement when combined with standard laboratory methods of near-field microscopy. A novel feature of the approach is that the nonclassical light does not need to enter the interferometer and probe the phase shifting object the quantum enhancement is achieved using local entanglement. (IV) The final effort will be to develop a means for the secure transmission of images encoded in ultrashort single photons: a type of ultrabroadband quantum teleportation. This work explores new avenues in quantum communications by exploring possibilities for multimode teleportation and builds upon recent work in the applications in quantum optics of high-quantum efficiency CCD array detectors. These provide a novel tool for both quantum state measurement, which itself has useful imaging applications, and for providing the broadband classical information needed for the teleportation protocol.