Mode Transforming Properties of Tapered Single-Mode Fiber Microlenses

The Gaussian approximation that is typically used to estimate single-mode fiber microlens performance is investigated. It is applied to hemispheric lenses on two types of tapered single-mode fiber. Theoretical and experimental results are compared. The first type of taper, which is fabricated by pulling a fiber while it is melted, has a tapered core and a tapered cladding. The second type of taper, which is fabricated by etching the cladding, has a tapered cladding only. For a tapered-core fiber, coupling to the cladding-guided modes and the finite radius of curvature of the wave front before the lens must be considered to predict the lens spot size accurately, whereas the spot size of a tapered-cladding lens can be predicted from the lens diameter alone. Thus the spot size of a lens on a tapered-cladding fiber is easier to predict and control than that of a lens on a tapered-core fiber. It is also shown that the usual theory used to predict the spot size gives accepted values for tapered-cladding lenses but not for tapered-core lenses

Single-Mode Fiber Microlens with Controllable Spot Size

A novel method for fabricating microlenses on tapered single-mode fibers is shown to be able to control the lens spot size. The fiber cladding is first symmetrically tapered by etching it with an evaporating ammonium bifluoride solution. A hemispheric lens is then melted on the taper tip with a CO2 laser. The lens can reduce the fiber mode radius to 40% of its original value. A theoretical calculation of the focused spot size agrees well with experimental results

Best practices for economic development organizations

In the past few years there has been a resurgence and emphasis on ‘Best Practices’ in commerce. The business section in any bookstore is loaded with volumes extolling us to seek even higher levels of sophistication and excellence in our business functions. As economic developers, we are challenged to respond to the demands of socioeconomic shifts driven by technology, globalization and governance. This paper is, in part, an account of how one economic development organization, the Leduc/Nisku Economic Development Authority (EDA), responded to these shifts and how ‘Best Practices’ were employed to accomplish the results targeted.  In the process it will describe how a paradigm shift took place, as ‘Best Practices’ became the actual program rather than the means of enhancing existing programs.  The examples will show the process, what can be achieved and the importance of working with the will and spirit of a community. Keywords: best practice, corporate culture, Leduc/Nisku Economic Development Authority (EDA)

From Simulation to Implementation: Two CAT Case Studies

Measurement specialists strive to shorten assessment time without compromising precision of scores. Computerized Adaptive Testing (CAT) has rapidly gained ground over the past decades to fulfill this goal. However, parameters for implementation of CATs need to be explored in simulations before implementation so that it can be determined whether expectations can be met. CATs can become costly if trial-and-error strategies are followed and especially if constraints are included in the algorithms, simulations can save time and money. In this study it was found that for both a multiple-choice question test and a rating scale questionnaire, simulations not only predicted outcomes for CATs very well, but also illustrated the efficiency of CATs when compared to fixed length tests. Accessed 910 times on https://pareonline.net from October 06, 2018 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Computer Centre Technical Report 34

PDF file, 12 pages, contains tables and graphs (colour).Weather records at Geneva, New York for the years 1893-2009 were examined for the presence of trends in air temperature. Records include daily maximum and minimum temperatures, and for each year in the series, mean, mean maximum, and mean minimum air temperatures were compiled. In addition, subsets of each year were examined to determine patterns of winter and summer temperatures. The figures suggest a cyclical pattern of temperature over the 117 years. Starting with lower temperatures at the beginning of the series (1893), there was an increase to the 1930s, a decline to about 1980, and a rise thereafter

The sounds of displacement : a portfolio of binaural compositions

The portfolio presented comprises of five binaural acousmatic works composed primarily for headphone reproduction but also for multi-channel loudspeaker concert diffusion. The commentary traverses the programmatic and aesthetic considerations involved in the construction of the portfolio and the influence of the in-ear binaural method of recording and reproduction thereof. The spectral watermark (the effect of the recordist on the resulting recording), negative space (the space left by the recordist, subsequently occupied by the listener), spatial strategy and the contextually rich results of the method are discussed, along with their creative applications within the portfolio

Muster and pay roll for John G. Barnard\u27s Company of Infantry

Muster and pay roll for John G. Barnard\u27s Company of Infantry for service during the Aroostook Warhttps://digitalmaine.com/aroostook_war_musterrolls/1083/thumbnail.jp

Escape FDI and the dynamics of a cumulative process of institutional misalignment and contestation: stress, strain and failure

We argue that escape foreign direct investment (FDI) happens when unknown future “rules of the game” cause concern about the continued productive capacity of the economy. Adapting the stress-strain-fail model of materials failure, we argue that escape FDI is a process with three cumulative phases. Conditions for escape FDI (stress) are created by institutional deterioration and contained contestation. Limited escape FDI (strain) results from periods of societal instability and/or inadequate institutional reforms. Extensive escape FDI (failure) results from pervasive societal instability and/or fundamental changes in institutions. Using a historical approach, we develop these propositions for South Africa, 1956 to 2012