Effects of Raman scattering and attenuation in silica fiber-based parametric frequency conversion

Four-wave mixing in the form of Bragg scattering (BS) has been predicted to enable quantum noise less frequency conversion by analytic quantum approaches. Using a semi-classical description of quantum noise that accounts for loss and stimulated and spontaneous Raman scattering, which are not currently described in existing quantum approaches, we quantify the impacts of these effects on the conversion efficiency and on the quantum noise properties of BS in terms of an induced noise figure (NF). We give an approximate closed-form expression for the BS conversion efficiency that includes loss and stimulated Raman scattering, and we derive explicit expressions for the Raman-induced NF from the semi-classical approach used here.Comment: 14 single col pages, 11 figure

Photon-pair generation by non-instantaneous spontaneous four-wave mixing

We present a general model, based on a Hamiltonian approach, for the joint quantum state of photon pairs generated through pulsed spontaneous four-wave mixing, including nonlinear phase-modulation and a finite material response time. For the case of a silica fiber, it is found that the pair-production rate depends weakly on the waveguide temperature, due to higher-order Raman scattering events, and more strongly on pump-pair frequency detuning. From the analytical model, a numerical scheme is derived, based on the well-known split-step method. This scheme allows computation of joint states where nontrivial effects are included, such as group-velocity dispersion and Raman scattering. In this work, the numerical model is used to study the impact of the non-instantaneous response on the pre-filtering purity of heralded single photons. We find that for pump pulses shorter than 1 ps, a significant detuning-dependent change in quantum-mechanical purity may be observed in silica

LSS, a problem solving skill for graduates and SMEs: Case Study of investigation in a UK Business School curriculum

Purpose - This research aims to investigate the feasibility of a systematic Lean Six Sigma (LSS) education through the curriculum of business schools to respond to the existing gap between the graduate’s expectation of employability and skill requirements by the Small and Medium Sized Enterprises (SMEs). Design/approach/methodology - One UK business school has been used as a case study to conduct an extensive module and programme review followed by a semi-structured interview with the potentially suitable core and programme-specific module leaders and also the comparative Analysis between content of these modules and the existing LSS high-street training themes. Findings – The result revealed a high potential of the existing modules in the business schools equivalent to the private sector training providers to increase the level of LSS problem solving knowledge and skill for all graduates and improve their employability and productivity for the SMEs. Practical implications/limitations – This research has been carried out in a single UK–based Business School through a qualitative approach. A further in-depth analysis in a broader scale is required to investigate the practical implications in a better way. Originality/Value – The result of this study highlights the role of LSS to reduce the knowledge and skill gap between the business schools as the source of the explicit knowledge, graduates as the knowledge and skill bearer, and SMEs as the knowledge and skill users