Engineering topics

Wong, G K. L.

Publications and source records attributed to Wong, G K. L..

3 records

DOE OSTI2011

Optical Precursor of a Single Photon

We report the direct observation of optical precursors of heralded single photons with step- and square-modulated wave packets passing through cold atoms. Using electromagnetically induced transparency and the slow-light effect, we separate the single-photon precursor, which always travels at the speed of light in vacuum, from its delayed main wave packet. In the two-level superluminal medium, our result suggests that the causality holds for a single photon.

74 ATOMIC AND MOLECULAR PHYSICS↗

DOE OSTI2010

Stacked Optical Precursors from Amplitude and Phase Modulations

We report the generation of stacked optical precursors from a laser beam whose amplitude or phase is modulated by sequenced on-off step waveforms. Making use of the constructive interference between the precursors produced from different steps, as well as the main field, we generate optical transient pulses having peak powers of eight times the input power with electromagnetically induced transparency in laser-cooled atoms.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2010

Shaping Biphoton Temporal Waveforms with Modulated Classical Fields

We experimentally demonstrate a technique for shaping the temporal quantum waveform of narrow-band biphotons generated in a cold atomic ensemble via four-wave mixing by periodically modulating the two input classical lasers. We show that it is possible to generate nonclassical paired photons with a predesigned shape of the correlation function.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗