ANGULAR DISPERSION IN SPONTANEOUS PARAMETRIC DOWN CONVERSION: A TOOL TO GENERATE NARROW TEMPORAL BIPHOTONS AND PURE HERALDED SINGLE PHOTONS

2009 ◽  
Vol 07 (supp01) ◽  
pp. 9-15
Author(s):  
ALEJANDRA VALENCIA ◽  
MARTIN HENDRYCH ◽  
XIAOJUAN SHI ◽  
JUAN P. TORRES
Keyword(s):  
Fourier Transform ◽  
Pump Beam ◽  
Single Photons ◽  
Angular Dispersion ◽  
Joint Spectrum ◽  
Full Control ◽  
Parametric Down Conversion ◽  
Down Conversion

In this paper, we describe how introducing angular dispersion into the pump beam and the downconverted photons in spontaneous parametric downconversion allows us to manipulate the joint spectrum of the paired photons. In particular, when collinear geometries are used, we demonstrate an increase of the photons' bandwidth and discuss the implications of this method for the generation of narrow temporal Fourier transform limited biphotons. Additionally, we describe the situation in which angular dispersion is combined with noncollinear geometries. In this case, a full control of the joint spectrum is achieved and heralded pure single photons with controllable bandwidth can be obtained.

Joint spectrum mapping of polarization entanglement in parametric down-conversion

2007 ◽  
Author(s):  
Hou Shun Poh ◽  
Chune Yang Lum ◽  
Ivan Marcikic ◽  
Antia Lamas-Linares ◽  
Christian Kurtsiefer
Keyword(s):  
Joint Spectrum ◽  
Parametric Down Conversion ◽  
Down Conversion

scholarly journals Single-Pixel Imaging with Heralded Single Photons

2021 ◽  
Author(s):  
Steven D Johnson ◽  
Alex McMillan ◽  
Cyril Torre ◽  
Stefan Frick ◽  
John Rarity ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Single Photons ◽  
Probe Light ◽  
Temporal Reference ◽  
Laser Illumination ◽  
Sensing Applications ◽  
Parametric Down Conversion ◽  
Remote Sensing Applications ◽  
Down Conversion ◽  
Single Pixel

Abstract Traditional remote sensing applications are often based on pulsed laser illumination with a narrow linewidth and characteristic repetition rate, which are not conducive to covert operation. Whatever methods are employed for covert sensing, a key requirement is for the probe light to be indistinguishable from background illumination. We present a method to perform single-pixel imaging that suppresses the effect of background light and hence improves the signal-to-noise ratio by using correlated photon-pairs produced via spontaneous parametric down conversion. One of the photons in the pair is used to illuminate the object whilst the other acts as a temporal reference, allowing the signal photons to be distinguished from background noise. This heralding method shows how the noise regime is key to producing higher contrast images.

GENERATING AND DISTRIBUTING TWO-PHOTON ENTANGLED SPATIAL QUDITS

2007 ◽  
Vol 05 (01n02) ◽  
pp. 69-81 ◽  
Author(s):  
G. LIMA ◽  
LEONARDO NEVES ◽  
IVAN F. SANTOS ◽  
C. H. MONKEN ◽  
J. G. AGUIRRE GÓMEZ ◽  
...  
Keyword(s):  
Free Space ◽  
Pump Beam ◽  
Quantum Systems ◽  
Space Distribution ◽  
Entangled States ◽  
Original Form ◽  
High Fidelity ◽  
Two Photon ◽  
Parametric Down Conversion ◽  
Down Conversion

We report an experiment to generate and propagate two entangled spatial qudits, [Formula: see text]-dimensional quantum systems, using spontaneous parametric down-conversion. The manipulation, via pump beam, of the transverse spatial correlation between the photon pairs is explored. Inserting apertures with [Formula: see text]-slits in the arms of the down-converted photons, we associate the qudit space with the [Formula: see text] possible paths followed by each photon. Experimental results for qudits with [Formula: see text] and 8 are shown. We demonstrate that the generated states cannot be classically correlated. We also show the propagation of entangled states of spatial qudits. Their free-space distribution is performed at the laboratory scale and the propagated states maintain a high fidelity with their original form.

scholarly journals Experimental scattershot boson sampling

2015 ◽  
Vol 1 (3) ◽  
pp. e1400255 ◽  
Author(s):  
Marco Bentivegna ◽  
Nicolò Spagnolo ◽  
Chiara Vitelli ◽  
Fulvio Flamini ◽  
Niko Viggianiello ◽  
...  
Keyword(s):  
Quantum Computer ◽  
Single Photons ◽  
Experimental Demonstration ◽  
Random Input ◽  
Exponential Increase ◽  
Quantum Device ◽  
Parametric Down Conversion ◽  
Quantum Simulator ◽  
Down Conversion ◽  
Boson Sampling

Boson sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialized quantum computer. Current experimental schemes, however, are still insufficient for a convincing demonstration of the advantage of quantum over classical computation. A new variation of this task, scattershot boson sampling, leads to an exponential increase in speed of the quantum device, using a larger number of photon sources based on parametric down-conversion. This is achieved by having multiple heralded single photons being sent, shot by shot, into different random input ports of the interferometer. We report the first scattershot boson sampling experiments, where six different photon-pair sources are coupled to integrated photonic circuits. We use recently proposed statistical tools to analyze our experimental data, providing strong evidence that our photonic quantum simulator works as expected. This approach represents an important leap toward a convincing experimental demonstration of the quantum computational supremacy.

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