Physical Review A

Filtering of two-photon quantum correlations by optical cavities: Cancellation of dispersive effects

G. S. Agarwal, Subhasish Dutta Gupta

Published May 1, 1994• 9 citations

Abstract

The spectral filtering of a field with strong quantum correlations is studied. The changes in the correlation characteristics of a field, produced by a down converter, passing through a strongly dispersive element like a Fabry-P\'erot cavity, are calculated. In the special case when the central frequency of the idler and signal photons coincides with the resonance frequency of the cavity, there is a cancellation of the dispersive effects of the cavity. Detailed numerical results for the two-photon joint counting rate are presented. The effects of the absorption in the medium on the two-photon correlations are also discussed.

DOI: 10.1103/physreva.49.3954

Related papers

An optical device for controlling dispersion in quantum communication

M. A. Sagioro, Sebastião Pádua

We theoretically demonstrate a new scheme for cancelling the dispersive effects in quantum communication with two entangled photons propagating in optical fibres. In the case of two entangled photons generated by spontaneous parametric down-conversion and propagating in two optical fibres, it is demonstrated that the dispersive effect in the biphoton wavepacket is cancelled by inserting only one Fabry–Perot cavity into one of the fibre's lines. No special dispersive material or interference of the transmitted photons in a beam splitter (or interferometer) is necessary. In the scheme, where one of the photons is reflected by the Fabry–Perot cavity before being transmitted by the fibre, a full dispersion cancellation is shown with no decrease in the number of photons at the optical fibres exit.

Journal of Physics B Atomic Molecular and Optical PhysicsNov 16, 20122 citations

Control of photon correlations in type II parametric down-conversion

Roger Andrews, Andrea T. Joseph, Edward R. Pike +1 more

In this paper we describe theoretically quantum control of temporal correlations of entangled photons produced by collinear type II spontaneous parametric down-conversion. We examine the effect of spectral phase modulation of the signal or idler photons arriving at a 50/50 beam splitter on the temporal shape of the entangled-photon wave packet . The coincidence count rate is calculated analytically for photon pairs in terms of the modulation depth applied to either the signal or idler beam with a spectral phase filter. It is found that the two-photon coincidence rate can be controlled by varying the modulation depth of the spectral filter.

arXiv:quant-ph/0509198Journal of Optics B Quantum and Semiclassical OpticsNov 4, 20055 citations

Quantum interference with femtosecond entangled two-photon fields

Jan Peřina, Alexander V. Sergienko, Bahaa E. A. Saleh +1 more

We investigate quantum interference effects of entangled two-photon states generated in a nonlinear crystal pumped by femtosecond pulses. Attention is devoted to the effects of the pump-pulse profile (pulse duration and chirp) as well as those originating in second-order dispersion, both in the nonlinear crystal and in the optical elements through which the down-converted photons propagate. The characteristics of the pump pulse, along with the dispersion, influence on the visibility and the symmetry of the coincidence-count interference pattern. Nonlocal dispersion cancellation occurs in some cases.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEJul 14, 19990 citations

Bragg grating based entangled biphoton dispersion management

Sahar Armaghani, Ali Rostami, Hamit Mirtagioğlu

Abstract In the realm of quantum information processing and precision measurements, a range of non-classical effects based on entangled photon pairs are employed. Non-local dispersion cancellation is one of these properties, in which the second photon (idler) can be manipulated to cancel the effects of dispersion on the first photon (signal). In the present study, a thorough investigation is conducted into non-local dispersion cancellation by using excitation modes within a Bragg grating slab waveguide. We present a complete theoretical analysis of non-local dispersion cancellation for frequency-limited entangled photon pairs. For the analysis of the effect of dispersion cancellation, we use a spontaneous parametric down-conversion (SPDC) photon pair source with frequency correlation and anti-correlation as the entangled source. To evaluate the dispersion cancellation effect for information processing applications, the second correlation function is used and calculated as a practical and tangible metric. Considering different cases for Bragg Grating waveguide the results on both photons are extracted and discussed. Moreover, we will show that the physical parameters of the waveguide that the second photon is propagated inside will be effective in minimizing the width of the temporal correlation function. Hence, this study underscores the feasibility of achieving non-local dispersion cancellation through strategic optimization of optical and geometric parameters in the Bragg Grating waveguide, with potential implications for quantum information processing and high-resolution sensing endeavors.

Physica ScriptaSep 19, 20235 citations

Quantum communication with spectrally correlated photons (Conference Presentation)

Piotr Leszek Kolenderski, Mikołaj Lasota, Karolina Sedziak +1 more

Single-photon sources are crucial components for the implementation of quantum communication protocols. However, photons emitted by some of the most popular types of realistic sources are spectrally broadband. Due to this drawback, the signal emitted from such sources is typically affected by the effect of temporal broadening during its propagation through telecommunication fibers which exhibit chromatic dispersion. Such problem can be observed e.g. when using sources based on the process of spontaneous parametric down-conversion (SPDC). In the case of long-distance quantum communication temporal broadening can significantly limit the efficiency of temporal filtering. It is a popular method, which is based on the reduction of the duration time of the detection window, used for decreasing the number of registered errors. In this work we analyzed the impact of the type of spectral correlation within a pair of photons produced by the SPDC source on the temporal width of those photons during their propagation in dispersive media. We found out that in some situations the width can be decreased by changing the typical negative spectral correlation into positive one or by reducing its strength. This idea can be used to increase the efficiency of the temporal filtering method. Therefore it can be applied in various implementations of quantum communication protocols. As an example of the application we subsequently analyzed the security of a quantum key distribution (QKD) scheme based on single photons. It was realized in the configuration with the source of photons located in the middle between the legitimate participants of a QKD protocol (called typically Alice and Bob). We demonstrated that when the information about the emission time of the photons produced by the SPDC source is not distributed to Alice and Bob, the maximal security distance can be considerably extended by using positively correlated photons, while in the opposite case strongly (no matter positively or negatively) correlated photons are optimal. We also found out that the results of our calculation may be very sensitive to the spectral widths of the photons produced by the SPDC source. In addition, we concluded that in realistic situation Alice and Bob would have to optimize their source over both the spectral widths of the generated photons and the type of spectral correlation in order to maximally extend the security distance. The results of our work are, in particular, important for the QKD systems utilizing commercial telecom fibers populated by strong classical signals. In those systems temporal filtering method can be used to reduce not only the dark counts registered by the detection system, but also the channel noise originating from the process of Raman scattering, which is the main factor limiting their performance.

Quantum Communications and Quantum ImagingSep 19, 20170 citations

Reducing detection noise of a photon pair in a dispersive medium by controlling its spectral entanglement (Conference Presentation)

Mikołaj Lasota, Karolina Sedziak, Piotr Leszek Kolenderski

Single-photon sources are crucial components for the implementation of quantum communication protocols. However, photons emitted by some of the most popular types of realistic sources are spectrally broadband. Due to this drawback, the signal emitted from such sources is typically affected by the effect of temporal broadening during its propagation through telecommunication fibers which exhibit chromatic dispersion. Such problem can be observed e.g. when using sources based on the process of spontaneous parametric down-conversion (SPDC). In the case of long-distance quantum communication temporal broadening can significantly limit the efficiency of temporal filtering. It is a popular method, which relies on the reduction of the duration time of the detection window, used for decreasing the number of registered errors. In this work we analyzed the impact of the type of spectral correlation within a pair of photons produced by the SPDC source on the temporal width of those photons during their propagation in dispersive media. We found out that in some situations this width can be decreased by changing the typical negative spectral correlation into positive one or by reducing its strength. This idea can be used to increase the efficiency of the temporal filtering method. Therefore, it can be applied in various implementations of quantum communication protocols. As an example of the application we subsequently analyzed the security of a quantum key distribution (QKD) scheme based on single photons. The investigation was performed for the configuration with the source of photons located in the middle between the legitimate participants of a QKD protocol (called typically Alice and Bob). We demonstrated that when the information about the emission time of the photons produced by the SPDC source is not distributed to Alice and Bob, the maximal security distance can be considerably extended by using positively correlated photons, while in the opposite case strongly (no matter positively or negatively) correlated photons are optimal. We also found out that the results of our calculation may be very sensitive to the spectral widths of the photons produced by the SPDC source. In addition, we concluded that in realistic situation Alice and Bob would have to optimize their source over both the spectral widths of the generated photons and the type of spectral correlation in order to maximally extend the security distance. The results of our work are, in particular, important for the QKD systems utilizing commercial telecom fibers populated by strong classical signals. In those systems temporal filtering method can be used to reduce not only the dark counts registered by the detection system, but also the channel noise originating from the process of Raman scattering, which is the main factor limiting their performance.

Jun 8, 20170 citations

Single-photon sources are crucial components for the implementation of quantum communication protocols. However, photons emitted by some of the most popular types of realistic sources are spectrally broadband. Due to this drawback, the signal emitted from such sources is typically affected by the effect of temporal broadening during its propagation through telecommunication fibers which exhibit chromatic dispersion. Such problem can be observed e.g. when using sources based on the process of spontaneous parametric down-conversion (SPDC). In the case of long-distance quantum communication temporal broadening can significantly limit the efficiency of temporal filtering. It is a popular method, which relies on the reduction of the duration time of the detection window, used for decreasing the number of registered errors. In this work we analyzed the impact of the type of spectral correlation within a pair of photons produced by the SPDC source on the temporal width of those photons during their propagation in dispersive media. We found out that in some situations this width can be decreased by changing the typical negative spectral correlation into positive one or by reducing its strength. This idea can be used to increase the efficiency of the temporal filtering method. Therefore, it can be applied in various implementations of quantum communication protocols. As an example of the application we subsequently analyzed the security of a quantum key distribution (QKD) scheme based on single photons. The investigation was performed for the configuration with the source of photons located in the middle between the legitimate participants of a QKD protocol (called typically Alice and Bob). We demonstrated that when the information about the emission time of the photons produced by the SPDC source is not distributed to Alice and Bob, the maximal security distance can be considerably extended by using positively correlated photons, while in the opposite case strongly (no matter positively or negatively) correlated photons are optimal. We also found out that the results of our calculation may be very sensitive to the spectral widths of the photons produced by the SPDC source. In addition, we concluded that in realistic situation Alice and Bob would have to optimize their source over both the spectral widths of the generated photons and the type of spectral correlation in order to maximally extend the security distance. The results of our work are, in particular, important for the QKD systems utilizing commercial telecom fibers populated by strong classical signals. In those systems temporal filtering method can be used to reduce not only the dark counts registered by the detection system, but also the channel noise originating from the process of Raman scattering, which is the main factor limiting their performance.