Coherent optical pulse sequencer for quantum applications

Abstract

The bandwidth and versatility of optical devices have revolutionized information technology systems and communication networks. Precise and arbitrary control of an optical field that preserves optical coherence is an important requisite for many proposed photonic technologies. For quantum information applications, a device that allows storage and on-demand retrieval of arbitrary quantum states of light would form an ideal quantum optical memory. Recently, significant progress has been made in implementing atomic quantum memories using electromagnetically induced transparency, photon echo spectroscopy, off-resonance Raman spectroscopy and other atom-light interaction processes. Single-photon and bright-optical-field storage with quantum states have both been successfully demonstrated. Here we present a coherent optical memory based on photon echoes induced through controlled reversible inhomogeneous broadening. Our scheme allows storage of multiple pulses of light within a chosen frequency bandwidth, and stored pulses can be recalled in arbitrary order with any chosen delay between each recalled pulse. Furthermore, pulses can be time-compressed, time-stretched or split into multiple smaller pulses and recalled in several pieces at chosen times. Although our experimental results are so far limited to classical light pulses, our technique should enable the construction of an optical random-access memory for time-bin quantum information, and have potential applications in quantum information processing.

Towards high-speed optical quantum memories

“…In the AFC protocol 4,22 , an artificially created AFC absorbs the incident signal, and the periodic structure of the absorption spectrum results in a subsequent re-phasing and re-emission of the stored signal. These protocols are resonant; off-resonant light storage has also been implemented by means of four-wave mixing 9 , stimulated Brillouin scattering 23 and through the gradient echo memory (GEM) protocol 24 . For all these protocols, typical storage times range from microseconds to milliseconds, achieved efficiencies from 1 to 15% (although two experiments have reported higher values for either storage time or efficiency 25,26 ) and reported bandwidths from a few kilohertz to several megahertz.…”

Photonic quantum memory in two-level ensembles based on modulating the refractive index in time: Equivalence to gradient echo memory

“…It might be interesting to consider counter-propagating signal and control fields in this context, for which no such cancelation would occur. This might result in a protocol similar to Raman-GEM [22].…”

Control of Photon Storage Time in Photon Echoes using a Deshelving Process

“…Since the first observation of coherent retrieval of a stored optical pulse in a Bose Einstein condensate using slow light (Liu et al, 2001), interest in quantum memories has increased in the last decade (Alexander et al, 2006;Afzelius et al, 2010;Chaneliere et al, 2005. Choi et al, 2008110 Ham, 1998;Ham 2009a;Ham, 2010a;Hedges et al, 2010;Hetet et al, 2008;Hosseini et al, 2009;Julsgaard et al, 2004;Kocharovskaya et al, 2001;Kraus et al, 2006;Liu et al, 2001;Moiseev & Kroll, 2001;Moiseev et al, 2003;Neumann et al, 2009;Nilsson & Kroll, 2005;Sangouard et al, 2007;Turukhin et al, 2002;Van der Wal, et al, 2003). Because temporal multimode storage capability is required for the quantum repeaters, a photon echo-type protocol has emerged as a best candidate.…”