1,728,506 research outputs found
HORAK, Julius Lindley Inventory of documents
No full textCOVERAGE 1972, 1 File; 2,50 Metres.Private papers of J.L. Horak, United Party MP for Sunnyside [1958-1961
Cavities with Non-Spherical Mirrors for Enhanced Quantum Emitter-Cavity Photon Interaction
No full textThis dataset contains the results of numerical simulations supporting the corresponding article in Physical Review A "Cavities with Non-Spherical Mirrors for Enhanced Quantum Emitter-Cavity Photon Interaction" by D.V. Karpov and P. Horak.
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Horak and Vanhooren - "Somebody to Lean On" - supplementary materials
No full textAppendices for "Somebody to Lean On: Community Ties, Social Exchange, and Practical Help During the COVID-19 Pandemic" - published in City & Communit
Dataset for "Efficiency and intensity noise of an all-fiber optical parametric oscillator"
No full textDataset for article "Efficiency and intensity noise of an all-fiber optical parametric oscillator" by I. Begleris and P. Horak, accepted for publication in Journal of the Optical Society of America B (2019)
The set contains all the raw data generated by computer simulations that are analysed and plotted in the paper.</span
Dataset for Frequency-banded nonlinear Schrödinger equation with inclusion of Raman nonlinearity
No full textThis repository holds the data published in the paper:
Begleris, I., & Horak, P. (2018). Frequency-banded nonlinear Schrödinger equation with inclusion of Raman nonlinearity. Optics Express, 26(14).
The data is proof of the argument of the viability and efficiency of the Banded nonlinear Schrödinger equation against the Generalised nonlinear Schrödinger equation.</span
Multimode nonlinear fibre optics: theory and applications
Full text linkOptical fibres have been developed as an ideal medium for the delivery of optical pulses ever since their inception (Kao & Hockham, 1966). Much of that development has been focused on the transmission of low-energy pulses for communication purposes and thus fibres have been optimised for singlemode guidance with minimum propagation losses only limited by the intrinsic material absorption of silica glass of about 0.2dB/km in the near infrared part of the spectrum (Miya et al., 1979). The corresponding increase in accessible transmission length simultaneously started the interest in nonlinear fibre optics, for example with early work on the stimulated Raman effect (Stolen et al., 1972) and on optical solitons (Hasegawa & Tappert, 1973). Since the advent of fibre amplifiers (Mears et al., 1987), available fibre-coupled laser powers have been increasing dramatically and, in particular, fibre lasers now exceed kW levels in continuous wave (cw) operation (Jeong et al., 2004) and MW peak powers for pulses (Galvanauskas et al., 2007) in all-fibre systems. These developments are pushing the limits of current fibre technology, demanding fibres with larger mode areas and higher damage threshold. However, it is increasingly difficult to meet these requirements with fibres supporting one single optical mode and therefore often multiple modes are guided. Non-fibre-based laser systems are capable of delivering even larger peak powers, for example commercial Ti:sapphire fs lasers now reach the GW regime. Such extreme powers cannot be transmitted in conventional glass fibres at all without destroying them (Gaeta, 2000), but there is a range of applications for such pulses coupled into hollow-core capillaries, such as pulse compression (Sartania et al., 1997) and high-harmonic generation (Rundquist et al., 1998). For typical experimental parameters, these capillaries act as optical waveguides for a large number of spatial modes and modal interactions contribute significantly to the system dynamics.In order to design ever more efficient fibre lasers, to optimise pulse delivery and to control nonlinear applications in the high power regime, a thorough understanding of pulse propagation and nonlinear interactions in multimode fibres and waveguides is required. The conventional tools for modelling and investigating such systems are based on beam propagation methods (Okamoto, 2006). However, these are numerically expensive and provide little insight into the dependence of fundamental nonlinear processes on specific fibre properties, e.g., on transverse mode functions, dispersion and nonlinear mode coupling. For such an interpretation a multimode equivalent of the nonlinear Schrodinger equation, the standard and highly accurate method for describing singlemode nonlinear pulse propagation (Agrawal, 2001; Blow & Wood, 1989), is desirable. In this chapter, we discuss the basics of such a multimode generalised nonlinear Schrodinger equation (Poletti & Horak, 2008), its simplification to experimentally relevant situations and a few select applications. We start by introducing and discussing the theoretical framework for fibres with χ(3) nonlinearity in Sec. 2. The following sections are devoted to multimode nonlinear applications, presented in the order of increasing laser peak powers. A sample application in the multi-kW regime is supercontinuum generation, discussed in Sec. 3. Here we demonstrate how fibre mode symmetries and launching conditions affect intermodal power transfer and spectral broadening. For peak powers in the MW regime, self-focusing effects become significant and lead to strong mode coupling. The spatio-temporal evolution of pulses in this limit is the topic of Sec. 4. Finally, at GW peak power levels, optical pulses can only be delivered by propagation in gases. Still, intensities become so high that nonlinear effects related to ionisation must be taken into account. An extension of the multimode theory to include these extreme high power effects is presented in Sec. 5 and the significance of mode interaction is demonstrated by numerical examples pertaining to a recent experiment. Finally, we end this chapter with conclusions in Sec. 6
Dataset for: Designing silicon-core fiber tapers for efficient supercontinuum generation in the greenhouse has absorption region
No full textDataset supports: Campling, J, Horak, P. & Peacock, A.C. (2020).Designing silicon-core fiber tapers for efficient supercontinuum generation in the greenhouse gas absorption region. Journal of the Optical Society of America B</span
Feasibility study of SOA-based noise suppression for spectral amplitude coded OCDMA
Full text linkWe investigate the benefits of employing a saturated SOA to reduce optical noise in an incoherent light OCDMA system. In the context of spectrum-slicing, SOA-based noise suppression has shown significant potential for enhancing the signal quality of noisy light. In this paper, we evaluate the viability of the technique for spectral amplitude coded OCDMA, and show that the benefits of SOA-based noise suppression do not extend readily to this application, due to post-SOA optical filtering effects at the receiver. However, appreciable performance improvements can in principle be realized through optimized system and decoder design
Aspects of Inner-Korean relations examined from a German viewpoint
Full text linkThis paper series takes a look at several aspects of inner-Korean relations, primarily in the area of international relations and economic cooperation, from a German viewpoint. In fact, the complexity of the respective subjects touched in this frame would require a deeper and more comprehensive analysis than developed here. The underlying idea is to stimulate further thought in several areas of pre- and post unification aspects by deriving inspiration from Germany's historical experience. The pre-unification phase and, specifically, the post-unification experience in Germany are of value to both Koreas. Further joint research is recommended on historical and contemporary aspects of German reunification that is relevant and suitable to Korea. --international relations,policy,economic development,Korea,Germany
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