Raman-free fibered photon-pair source

Abstract

Raman-scattering noise in silica has been the key obstacle toward the realisation of high quality fiber-based photon-pair sources. Here, we experimentally demonstrate how to get past this limitation by dispersion tailoring a xenon-filled hollow-core photonic crystal fiber. The source operates at room temperature, and is designed to generate Raman-free photon-pairs at useful wavelength ranges, with idler at the telecom, and signal at a visible range. We achieve a coincidence-to-accidentals ratio as high as 2740 combined with an ultra low heralded gH (0) = 0.002, indicating a very high signal to noise ratio and a negligible multi-photon emission probability. Moreover, by gas-pressure tuning, we demonstrate the control of photon frequencies over a range as large as 13 THz, covering S-C and L telecom band for the idler photon. This work demonstrates that hollow-core photonic crystal fiber is an excellent platform to design high quality photon-pair sources, and could play a driving role in the emerging quantum technology.Among the numerous platforms that have been tested in quantum information, χ (2) nonlinear media and, in particular, bulk crystals have been historically the workhorse for photon-pair generation due to the relative ease in terms of experimental setup, their cost and their availability 1 . Four-wave mixing mechanism in χ (3) media, and in particular waveguides and optical fibers have gained much attention in the recent years because of the new prospects they offer in terms of scalability and integrability. For instance, more than 550 silicon-based photonic components have been recently integrated on a single silicon chip, including 16 identical four-wave mixing photon-pair sources 2 . Alternatively, fiber-based photon-pair sources have many advantages; they are easily manufacturable, cost effective, robust, alignment-free and compatible with fiber optical network since the photon-pairs are directly emitted in the fundamental transverse guided mode of a fiber. Furthermore, and unlike silicon-based materials, optical fibers don't suffer from two-photon absorption or free carriers effect 3 , and a dispersion that can be readily engineered.Within the fiber-related endeavors, photon-pairs have been produced in many different architectures encompassing singlemode fiber 4, 5 , dispersion-shifted fiber 6-9 , birefringent single-mode fiber 10, 11 , micro/nano-fiber 12, 13 and photonic crystal fiber (PCF) [14][15][16][17][18][19][20] . However, the performances of these photon-pair sources are most often plagued by a concomitant nonlinear effect, Raman-scattering (RS). Indeed, in addition to the four-wave mixing process leading to photon-pair generation, an interaction between the pump and phonons in the medium results in the generation of scattered photons. Due to the amorphous nature of silica (i.e. the fiber core material), the Raman gain is broadband and continuous 21 , thus generating a large amount of scattered photons around the pump frequency. In fact, regardless of the photon-pair frequencies, some Rama...

Continuous-wave generation of photon pairs in silica nanofibers using single-longitudinal- and multilongitudinal-mode pumps

“…In the pulsed regime the clear quadratic evolution of counts and coincidence shows that we can consider we are in an almost Raman free FWM contribution similar to the one studied in [15]. By comparing coincidences rate (𝑅 ( = η " η # 𝜇 !…”

“…The second reason is the simultaneous presence of Spontaneous Raman Scattering, that generates a large quantity of noise photons that will mask the pairs. The broadband nature of the Raman emission spectra of silica, compared to crystalline materials such as Silicon [5,6,12], to liquids [13], or even to materials such as noble gases that do not present Raman transitions [14,15], will prevent any frequency filtering of these photons. This will be thus a major limitation of the use of silica fibers as sources of pairs of photons.…”

Angle-Resolved Hollow-Core Fiber-Based Curvature Sensing Approach

“…Among the application opportunities, which encompass, for example, the development of novel optical sources and atom optics experiments [8][9][10], the field of optical sensors acquires a prominent position within HCPCF technology due to the broad set of parameters that can be potentially monitored [11]. HCPCFs have been demonstrated, for example, to be a promising platform for probing concentrations of chemical species in gaseous and liquid samples [12][13][14][15][16][17][18].…”

An atomic Faraday beam splitter for light generated from pump degenerate four-wave mixing in a hollow-core photonic crystal fiber

“…When loaded with a highly resonant medium, such as an atomic gas, the HC-PCF system shows pronounced non-linear effects at low powers. Electromagnetically induced transparency [5], four-wave mixing [6], cross-phase modulation [7], photon memories [8] and singe-photon sources [9] have all been shown to be enhanced with an atomic gas loaded HC-PCF system.…”