Article

Optimal coupling of entangled photons into single-mode optical fibers

ICL, Londinium, England, United Kingdom
Optics Express (Impact Factor: 3.49). 08/2004; 12(14):3264-9. DOI: 10.1364/OPEX.12.003264
Source: PubMed

ABSTRACT

We present a consistent multimode theory that describes the coupling of single photons generated by collinear Type-I parametric downconversion into single-mode optical fibers. We have calculated an analytic expression for the fiber diameter which maximizes the pair photon count rate. For a given focal length and wavelength, a lower limit of the fiber diameter for satisfactory coupling is obtained.

Full-text preview

Available from: arxiv.org
  • Source
    • "Hence, periodically poled fibres [14] and periodically poled waveguides of lithium niobate [15] have been shown to be bright pair photon sources. In poled fibres [16] the low non-linearity limits the brightness while in planar waveguides the non-circular mode limits the coupling efficiency into optical fibres [17]. It is well known that parametric gain can arise from the χ (3) non-linearity in optical fibres [18] [19] and phase matching can be achieved by using the modulation instability when pumping fibres in their anomalous dispersion regime. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We develop a theoretical analysis of four-wave mixing used to generate photon pairs useful for quantum information processing. The analysis applies to a single mode microstructured fibre pumped by an ultra-short coherent pulse in the normal dispersion region. Given the values of the optical propagation constant inside the fibre, we can estimate the created number of photon pairs per pulse, their central wavelength and their respective bandwidth. We use the experimental results from a picosecond source of correlated photon pairs using a micro-structured fibre to validate the model. The fibre is pumped in the normal dispersion regime at 708nm and phase matching is satisfied for widely spaced parametric wavelengths of 586nm and 894nm. We measure the number of photons per pulse using a loss-independent coincidence scheme and compare the results with the theoretical expectation. We show a good agreement between the theoretical expectations and the experimental results for various fibre lengths and pump powers. Comment: 23 pages, 9 figures
    Full-text · Article · Jan 2006 · New Journal of Physics
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We review on-going progress in the development of fiber-based telecom-band entanglement sources. Two different schemes (a Sagnac-loop scheme and a counter-propagating scheme) for generating polarization entanglement are reviewed and the pros and cons of each are summarized. A new scheme, called the double-loop scheme is proposed, which is theoretically shown to be capable of combining the benefits and avoiding the pitfalls of each previous scheme.
    Full-text · Article · Jan 2005 · Proceedings of SPIE - The International Society for Optical Engineering
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We demonstrate a picosecond source of correlated photon pairs using a micro-structured fibre with zero dispersion around 715 nm wavelength. The fibre is pumped in the normal dispersion regime at ~708 nm and phase matching is satisfied for widely spaced parametric wavelengths. Here we generate up to 10;7 photon pairs per second in the fibre at wavelengths of 587 nm and 897 nm, while on collecting this light in single-mode-fibre-coupled Silicon avalanche diode photon counting detectors, we detect ~3.2x10;5 coincidences per second at pump power 0.5 mW.
    Full-text · Article · Oct 2005 · Optics Express
Show more