Engineering the spectrum of photons for quantum metrology applications
Valencia, A.; Torres, J.P.
ICFO-Institut de Ciencies Fotoniques

Quantum metrology: the use of Quantum Mechanics to provide enhancement on the accuracy of measurements, might be applied to positioning and timing procedures [1]. Quantum-enhanced positioning and clock synchronization schemes have been considered theoretically [2], as well as experimentally [3]. Importantly, the usefulness of these quantum strategies demands the ability to implement sources of quantum light with specific frequency properties; namely, an appropriate waveform, frequency bandwidth and type of frequency correlations between the photons. Here we report recent experiments where we demonstrate new techniques to generate quantum light with the sought-after photonic properties. Interestingly, the reported methods can be applied in any frequency band of interest [4]. We will discuss how these new sources of quantum light open the possibility to implement certain protocols for quantum-enhanced timing and positioning measurements, which potentially could offer higher accuracy that currently used methods. The techniques that we will discuss here also offer the possibility of generating light with ultrahigh bandwidth [5]. We will consider the possibility of using such sources for imaging atmospheric properties with unprecedented resolution. References 1. V. Giovannetti, S. Lloyd, and L. Macconne, Nature 412, 417 (2001). 2. V. Giovannetti, S. Lloyd, and L. Macconne, Phys. Rev. A 65, 022309 (2002). 3. A. Valencia, G. Scarcelli, and Y.Shih, Appl. Phys. Letters 85, 2655 (2004). 4. M. Hendrych, M. Micuda, and J. P. Torres, accepted for publication in Opt. Lett. (2007). 5. S. Carrasco, M. B. Nasr, A.V. Sergienko, B.E.A. Saleh, M.C. Teich, J.P. Torres, and L. Torner, Opt. Lett. 15, 253 (2006).