Characterizing and tailoring the spectro-temporal mode of photon pairs generated in few-mode fiber

Liang Cui, Shengjie Zhu, Xiaoying Li

Published May 8, 2024• 0 citations

Abstract

We investigate the spectro-temporal mode property of the photon pairs generated via inter-spatial-mode spontaneous four-wave mixing in a few-mode fiber (FMF) that supports two linearly polarized spatial modes in the 1550 nm telecom band. The two pulsed pumps for the process are in distinct spatial modes, while the created signal and idler photon pairs are also occupying different spatial modes. By exploiting the unique inter-mode phase matching condition in the FMF, we can tailor the spectro-temporal mode structure of the photon pairs by changing the pulse duration (spectral bandwidth) of the two pumps. Especially, photon pairs with a nearly round-shaped factorable joint spectrum are experimentally realized. The techniques are valuable for generating and manipulating quantum states in FMFs and exploiting the spatial degree of freedom in quantum information processing.

DOI: 10.1364/opticaopen.25479328.v1

Related papers

Tailoring the spectro-temporal mode of photon pairs generated from interspatial-mode four-wave mixing

Shengjie Zhu, Liang Cui, Xiaoying Li

We investigate the spectro-temporal mode property of the photon pairs generated via interspatial-mode spontaneous four-wave mixing (FWM) in a few-mode fiber (FMF) that supports two linearly polarized spatial modes in the 1550 nm telecom band. The two pulsed pumps for the process are in distinct spatial modes, while the created signal and idler photon pairs are also occupying different spatial modes. By exploiting the unique inter-mode phase matching condition in the FMF, we can tailor the spectro-temporal mode structure of the photon pairs by changing the pulse duration (spectral bandwidth) of the two pumps. Especially, photon pairs with a nearly round-shaped factorable joint spectrum are experimentally realized. The techniques are valuable for generating and manipulating quantum states in multi-mode waveguides and exploiting the spatial degree of freedom in quantum information processing.

Optics LettersJun 3, 20248 citations

Spectrally indistinguishable intermodal-vectorial four-wave-mixing in birefringent few-mode fibers for spatial-polarization-frequency hybrid-entangled photon-pairs generation

Andrzej Gawlik, Marta Bernaś, Kinga Żołnacz +1 more

In this paper, we use a birefringent few-mode fiber to demonstrate an intermodal-vectorial four-wave mixing process that generates two pairs of spectrally overlapping signal-idler bands. Using phase-matching conditions, we show that the pairs of bands become spectrally indistinguishable when the group refractive indices of the signal and idler modes intersect at the pump wavelength. Our theoretical predictions are confirmed through experimental observations corroborated by numerical simulations. Furthermore, we introduce the two-photon state associated with the overlapping bands, which exhibits hybrid entanglement in spatial-polarization-frequency degrees of freedom. We explain that its degree of entanglement can be manipulated by tailoring the spectral position of the overlapping pairs of bands with respect to the Raman band and varying the excitation ratio of the pump modes. This study introduces a scheme for a fiber-based source of photon pairs with spatial-polarization-frequency entanglement.

arXiv:2412.09214Dec 12, 20241 citation

Generation of Telecom Band Photon Pairs with Factorable Spectrum by Using Few-Mode Fiber

Liang Cui, Jinjin Wang, Xiaodong Liu +1 more

We demonstrate that telecom band photon pairs with a factorable joint spectrum can be generated via inter-modal spontaneous four-wave mixing in a two-mode few-mode fiber supporting the LP01 and LP11 spatial modes.

Conference on Lasers and Electro-OpticsJan 1, 20200 citations

State engineering of photon pairs produced through dual-pump spontaneous four-wave mixing

Bin Fang, Offir Cohen, Jamy B. Moreno +1 more

We study theoretically the joint spectral properties of photon-pairs produced through spontaneous four-wave mixing (SFWM) with two spectrally distinct pump pulses in optical fibers. We show that, due to the group velocity difference between the pulses, the signature of the interaction can be significantly different from spontaneous parametric down-conversion or SFWM with a single pump pulse. Specifically, we study the case where temporal walk-off between the pumps enables a gradual turn-on and turn-off of the interaction. By utilizing this property, we develop a new approach towards tailoring the spectral correlations within the generated photon pairs, demonstrating the ability to produce factorable photon-pair states, and hence heralded single photons in a pure wave-packet. We show that the use of two pumps is advantageous over single-pump SFWM approaches towards this goal: the usage of the dual-pump configuration enables, in principle, the creation of completely factorable states without any spectral filtering, even in media for which single-pump SFWM tailoring techniques are unsatisfactory, such as standard polarization-maintaining fiber.

Optics ExpressJan 28, 201388 citations

Generation of polarization-entangled photon pairs in higher-order spatial mode using a mode-maintaining few-mode fiber

Sheng-Jie Zhu, Liang Cui, Xiao-Ying Li

Abstract The spatial degree of freedom has enabled a wide range of applications in quantum information processing (QIP), such as increasing the capacity of quantum channels and realizing novel QIP protocols. In such applications, generating and manipulating quantum states in different spatial modes is one of the primary tasks. In this paper, by utilizing a telecom-band panda-type mode-maintaining few-mode fiber (MM-FMF) with a Sagnac loop configuration, we generate polarization-entangled photon pairs in higher-order spatial modes, namely the LP 11 modes, via intermodal spontaneous four-wave mixing process. The polarization- and spatial-mode-maintaining capabilities of the MM-FMF, combined with the automatic phase-stabilization of the Sagnac loop, provide a robust architecture for entanglement generation. We verify the polarization entanglement by two-photon interference measurements, yielding raw visibilities exceeding 76%. The visibilities are mainly limited by spontaneous Raman scattering noise, which could be reduced by cooling the fiber. The photon pairs directly emerging from MM-FMF are in a well-defined spatial mode, which greatly facilitates further manipulation and transmission of the entanglement. Our work demonstrates that the MM-FMF is a robust platform for developing devices and protocols exploiting the spatial degree of freedom in QIP applications.

Chinese Physics BMay 20, 20260 citations

Progress toward photon-pair efficiency optimization using four-wave mixing in few-mode fibers

Seyedehnajmeh Montazeri, Mina Esmaeelpour

Intermodal four-wave mixing (FWM) process in few-mode fibers (FMFs) could be utilized for entangled photon-pair generation. Previous studies mainly performed in single-mode fibers suffered from the significant Raman scattering background from the glass fiber. Therefore, the instantaneous Raman and FWM effects would compete; this could be avoided in FMFs if the modal dispersion is larger than the Raman gain spectra. Utilizing two pumps in different modes in FMFs will generate photon pairs in various modes. Here, we study the effect of pump spectral separation on the intermodal FWM power and bandwidth using a seeding technique. It is concluded that the further the pumps and intermodal FWM idler and signal are from each other spectrally, the smaller the photon efficiency and larger the bandwidth. Experimental results for two FMFs of different differential mode group delay values are presented.

Applied OpticsApr 7, 20251 citation