46 resultados para Reflective optics
Resumo:
Debates unfolding around the recent development of M Level programmes for teacher education are not unfamiliar to those being addressed in other professional disciplines such as business. A strong theme in our analysis is that reflective practitioners could be provided with a wider range of tools and methods to support them in their reflection. Considerable energies have been expended on e portfolios, but our experience of use of paper based reflective
sketchbooks suggests that they may have some distinct advantages over text-dominated electronic media. In fact such sketchbooks challenge typed text as the dominant route to learning and communication (Gilbert 1998), (New, 2005), (Hickman, 2007). Professionals in teacher education are currently exploring ways in which M level can be conceived in terms of professional learning. This is also important terrain in other professions. For example, best practice in business management involves constant innovation so that students do not experience a split between the research context of the business faculty and the experience of operating in the business situation. This is paralleled in education by the concern that trainees do not experience a split between the research or scholarly informed approach of university tutors, and the experience of practical teaching in school. Our research question is concerned with how a consciously developed reflective sketchbook method can generate levels of critical thought that are both postgraduate and professionally valued in the workplace. We are also interested in the contribution this form of enquiry at M Level can make in terms of life long learning.
Resumo:
Critical phenomena involve structural changes in the correlations of its constituents. Such changes can be reproduced and characterized in quantum simulators able to tackle medium-to-large-size systems. We demonstrate these concepts by engineering the ground state of a three-spin Ising ring by using a pair of entangled photons. The effect of a simulated magnetic field, leading to a critical modification of the correlations within the ring, is analysed by studying two- and three-spin entanglement. In particular, we connect the violation of a multipartite Bell inequality with the amount of tripartite entanglement in our ring.
Resumo:
We investigate the optomechanical properties of a periodic array of identical scatterers placed inside an optical cavity and extend our previous results. We show that operating at the points where the array is transmissive results in linear optomechanical coupling strengths between the cavity field and collective motional modes of the array that may be several orders of magnitude larger than is possible with an equivalent reflective ensemble. We describe and interpret these effects in detail and investigate the nature of the scaling laws of the coupling strengths for the different transmissive points in various regimes. © 2013 American Physical Society.
Resumo:
We present a scheme to strongly enhance the readout sensitivity of the squared displacement of a mobile scatterer placed in a Fabry-Pérot cavity. We investigate the largely unexplored regime of cavity electrodynamics in which a highly reflective element positioned between the end mirrors of a symmetric Fabry-Pérot resonator strongly modifies the cavity response function, such that two longitudinal modes with different spatial parity are brought close to frequency degeneracy and interfere in the cavity output field. In the case of a movable middle reflector we show that the interference in this generic "optical coalescence" phenomenon gives rise to an enhanced frequency shift of the peaks of the cavity transmission that can be exploited in optomechanics. © 2013 American Physical Society.
Resumo:
This paper offers a critical reflection upon the use of a grounded theory approach within a doctoral study. As well as providing an outline of grounded theory, it begins by noting the existence of some powerful critiques of a grounded theory approach, in particular around the key concepts of ‘theory’, ‘discovery’ and ‘ground’. It is argued that, in some cases, grounded theory struggles to counter these challenges, especially in its ‘purist’ forms. However, with reference to research carried out as part of a PhD study of sharing education in Northern Ireland which employed a grounded theory approach, a case is made for an open and critical grounded theory based upon three principles: pragmatism; research as practice; and reflexivity. It is concluded that a reasonable case can be made for grounded theory where: grounded theory researchers maintain a balance between belonging to and critique of the grounded theory community; where there is an emphasis upon theorizing rather than the discovery of theory; and where the strengths of grounded theory as 'practice' and 'craft' are maximised.