Experimental quantum state engineering with time-separated heraldings from a continuous-wave light source: A temporal-mode analysis
Kun Huang, Hanna Le Jeannic, Varun Boehm Verma, Matthew D. Shaw, Francesco Marsili, Sae Woo Nam, E Wu, Hao‐Sheng Zeng, Olivier Morin, Julien Laurat · Physical Review A · 2016
Conditional preparation is a well-established technique for quantum state engineering of light. A general trend is to increase the number of heralding detection events in such a realization to reach larger photon-number states or their arbitrary superpositions. In contrast to pulsed implementations, where detections only occur within the pulse window, for continuous-wave light the temporal separation of the conditioning detections is an additional degree of freedom and a critical parameter. Based on a theoretical study by Nielsen and M\o{}lmer [A. E. B. Nielsen and K. M\o{}lmer, Phys. Rev. A 75, 043801 (2007)] and on a continuous-wave two-mode squeezed vacuum from a nondegenerate optical parametric oscillator, we experimentally investigate the generation of two-photon state with tunable delay between the heralding events. The present work illustrates the temporal multimode features in play for conditional state generation based on continuous-wave light sources and quantifies the compromise between preparation rate and fidelity in this scenario.