36 research outputs found
Non-reciprocal phase shift induced by an effective magnetic flux for light
Photons are neutral particles that do not interact directly with a magnetic field. However, recent theoretical work has shown that an effective magnetic field for photons can exist if the phase of light changes with its direction of propagation. This direction-dependent phase indicates the presence of an effective magnetic field, as shown experimentally for electrons in the Aharonov–Bohm experiment. Here, we replicate this experiment using photons. To create this effective magnetic field we construct an on-chip silicon-based Ramsey-type interferometer. This interferometer has been traditionally used to probe the phase of atomic states and here we apply it to probe the phase of photonic states. We experimentally observe an effective magnetic flux between 0 and 2π corresponding to a non-reciprocal 2π phase shift with an interferometer length of 8.35 mm and an interference-fringe extinction ratio of 2.4 dB. This non-reciprocal phase is comparable to those of common monolithically integrated magneto-optical materials
Observation of an Effective Magnetic field for Light
Photons are neutral particles that do not interact directly with a magnetic
field. However, recent theoretical work has shown that an effective magnetic
field for photons can exist if the phase of light would change with its
propagating direction. This direction-dependent phase indicates the presence of
an effective magnetic field as shown for electrons experimentally in the
Aharonov-Bohm experiment. Here we replicate this experiment using photons. In
order to create this effective magnetic field, we construct an on-chip
silicon-based Ramsey-type interferometer. This interferometer has been
traditionally used to probe the phase of atomic states, and here we apply it to
probe the phase of photonic states. We experimentally observe a phase change,
i.e. an effective magnetic field flux from 0 to 2pi. In an Aharonov-Bohm
configuration for electrons, considering the device geometry, this flux
corresponds to an effective magnetic field of 0.2 Gauss.Comment: 15 pages and 4 figure
On-Chip Optical Squeezing
We present the first demonstration of all-optical squeezing in an on-chip
monolithically integrated CMOS-compatible platform. Our device consists of a
low loss silicon nitride microring optical parametric oscillator (OPO) with a
gigahertz cavity linewidth. We measure 1.7 dB (5 dB corrected for losses) of
sub-shot noise quantum correlations between bright twin beams generated in the
microring four-wave-mixing OPO pumped above threshold. This experiment
demonstrates a compact, robust, and scalable platform for quantum optics and
quantum information experiments on-chip.Comment: 7 pages, 5 figure
Experimental observation of three-color optical quantum correlations
Quantum correlations between bright pump, signal, and idler beams produced by
an optical parametric oscillator, all with different frequencies, are
experimentally demonstrated. We show that the degree of entanglement between
signal and idler fields is improved by using information of pump fluctuations.
This is the first observation of three-color optical quantum correlations.Comment: 3 pages, 3 figure
Casimir interaction between plane and spherical metallic surfaces
We give an exact series expansion of the Casimir force between plane and
spherical metallic surfaces in the non trivial situation where the sphere
radius , the plane-sphere distance and the plasma wavelength
have arbitrary relative values. We then present numerical
evaluation of this expansion for not too small values of . For metallic
nanospheres where and have comparable values, we interpret
our results in terms of a correlation between the effects of geometry beyond
the proximity force approximation (PFA) and of finite reflectivity due to
material properties. We also discuss the interest of our results for the
current Casimir experiments performed with spheres of large radius .Comment: 4 pages, new presentation (highlighting the novelty of the results)
and added references. To appear in Physical Review Letter
Quantum interference between transverse spatial waveguide modes
Integrated quantum optics has the potential to markedly reduce the footprint and resource requirements of quantum information processing systems, but its practical implementation demands broader utilization of the available degrees of freedom within the optical field. To date, integrated photonic quantum systems have primarily relied on path encoding. However, in the classical regime, the transverse spatial modes of a multi-mode waveguide have been easily manipulated using the waveguide geometry to densely encode information. Here, we demonstrate quantum interference between the transverse spatial modes within a single multi-mode waveguide using quantum circuit-building blocks. This work shows that spatial modes can be controlled to an unprecedented level and have the potential to enable practical and robust quantum information processing