We experimentally demonstrate for the first time that a radially polarized field can be focused to a spot size significantly smaller [0.16(1)lambda(2)] than for linear polarization (0.26lambda(2)). The effect of the vector properties of light is shown by a comparison of the focal intensity distribution for radially and azimuthally polarized input fields. For strong focusing, a radially polarized field leads to a longitudinal electric field component at the focus which is sharp and centered at the optical axis. The relative contribution of this component is enhanced by using an annular aperture.
The focus of light-linear polarization breaks the rotational symmetry of the focal spot
Ralf Dorn,
Susanne Quabis,
Gerd Leuchs
JOURNAL OF MODERN OPTICS
50
(12)
1917-1926
(2003)
| Journal
We experimentally demonstrate for the first time that a linearly polarized beam is focused to an asymmetric spot when using a high-numerical aperture focusing system. This asymmetry was predicted by Richards and Wolf in 1959 and can only be measured when a polarization-insensitive sensor is placed in the focal region. We used a specially modified photodiode in a knife-edge-type set-up to obtain highly resolved images of the total electric energy density distribution at the focus. The results are in good agreement with the predictions of a vectorial focusing theory.
A pulsed source of continuous variable polarization entanglement
O Glockl,
J Heersink,
N Korolkova,
Gerd Leuchs,
S Lorenz
JOURNAL OF OPTICS B-QUANTUM AND SEMICLASSICAL OPTICS
5
(4)
PII S1464-4266(03)59741-5
S492-S496
(2003)
We have experimentally demonstrated polarization entanglement using<br> continuous variables in an ultra-short pulsed laser system at the<br> telecommunications wavelength of 1.5 mum. Exploiting the Kerr<br> non-linearity of a glass fibre we generated polarization squeezed pulses<br> with (S) over cap (2) as the only non-zero Stokes parameter, thus (S)<br> over cap (1) and (S) over cap (3) being the conjugate pair. Polarization<br> entanglement was generated by interference of the polarization squeezed<br> field with a vacuum on a 50:50 beamsplitter. The two resultant beams<br> exhibit strong quantum noise correlations in (S) over cap (1) and (S)<br> over cap (3). The sum noise signal of (S) over cap (3) was at the<br> respective shot noise level and the difference noise signal of (S) over<br> cap (1) fell -2.9 dB below this value.
Experiment towards continuous-variable entanglement swapping: Highly correlated four-partite quantum state
O Glockl,
S Lorenz,
Christoph Marquardt,
J Heersink,
M Brownnutt,
Christine Silberhorn,
Q Pan,
P van Loock,
N Korolkova, et al.
We present a protocol for performing entanglement swapping with intense<br> pulsed beams. In a first step, the generation of amplitude correlations<br> between two systems that have never interacted directly is demonstrated.<br> This is verified in direct detection with electronic modulation of the<br> detected photocurrents. The measured correlations are better than<br> expected from a classical reconstruction scheme. In an entanglement<br> swapping process, a four-partite entangled state is generated. We prove<br> experimentally that the amplitudes of the four optical modes are quantum<br> correlated 3 dB below shot noise, which is consistent with the presence<br> of genuine four-party entanglement.
Polarization squeezing of intense pulses with a fiber-optic Sagnac interferometer
J Heersink,
T Gaber,
S Lorenz,
O Glockl,
N Korolkova,
Gerd Leuchs
We report on the generation of polarization squeezing of intense, short<br> light pulses using an asymmetric fiber-optic Sagnac interferometer. The<br> Kerr nonlinearity of the fiber is exploited to produce independent<br> amplitude squeezed pulses. The polarization squeezing properties of<br> spatially overlapped amplitude squeezed and coherent states are<br> discussed. The experimental results for a single-amplitude squeezed beam<br> are compared to the case of two phase-matched, spatially overlapped<br> amplitude squeezed pulses. For the latter, noise variances of -3.4 dB<br> below shot noise in the S-0 and the S-1 and of -2.8 dB in the S-2 Stokes<br> parameters were observed, which is comparable to the input squeezing<br> magnitude. Polarization squeezing, that is, squeezing relative to a<br> corresponding polarization minimum uncertainty state, was generated in<br> S-1.
Quantum interferometry with intense optical pulses
Gerd Leuchs,
Christine Silberhorn,
O Glockl,
Christoph Marquardt,
N Korolkova
FORTSCHRITTE DER PHYSIK-PROGRESS OF PHYSICS
51
(4-5)
409-413
(2003)
| Journal
For intense optical pulses the optical Kerr interaction in matter such<br> as an optical fiber is large enough to generate quantum states of light<br> with significant non-classical properties. On this basis pairs of<br> entangled light pulses have been generated. This entanglement can be<br> used for novel schemes in high precision interferometry and for quantum<br> communication protocols such as quantum dense coding.
MPL Research Centers and Schools
Data Collection
This website uses cookies to ensure you get the best experience on our website.
