5,917 research outputs found
Kerr nonlinear switching in silicon fibre-based microcylindrical resonators
No full textWe investigate the Kerr nonlinearity in a a-Si:H microcylindrical resonator fabricated from the silicon fibre platform. The large resonant wavelength shift observed for pulsed excitation is used to demonstrate ultrafast all-optical switching
Semiconductor filled microstructured optical fibres with single mode guidance
No full textMicrostructured optical fibre (MOF) technology has generated new opportunities for the implementation of optical fibres with novel properties and functions [1]. It has been shown that silica MOFs make excellent 3D templates for semiconductor material deposition inside the capillary voids [2]. Recently a silicon MOF was designed and fabricated that had a high refractive index micron sized core, but yet only supported two guided modes [3]. This structure was realised via the complete filling of a hollow core photonic bandgap fibre (PBGF) with silicon so that the original air guiding PBGF was converted to a total internal reflection guiding fibre. Here, we extend the investigation by using a finite element method to model the optical properties of semiconductor filled MOFs of similar structures, with the aim to achieve broadband single mode guidance. Strategies to achieve single mode guidance both through the MOF template design and the selective filling of the voids of the original PBGF with semiconductor materials of different indices (silicon, silicon nitride, germanium) are proposed and investigated numerically. In particular, by selectively filling MOF templates with cladding rods that have a slightly raised index over that of the core, index guiding single mode operation can be observed in high index micron sized cores. Small index differences are achievable by controlling the nitrogen content in SiNx and an example of a single mode semiconductor MOF is shown in Figure 1, where the confinement loss of the fundamental mode is ~106 lower than the lowest order cladding mode
Healy, E N (Eric Norris), QX8299
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/391447Surname: HEALY. Given Name(s) or Initials: E N (ERIC NORRIS). Military Service Number or Last Known Location: QX8299. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 28069.207717
Item: [2016.0049.23740] "Healy, E N (Eric Norris), QX8299
Active semiconductor fibers and devices
No full textUnary and compound semiconductors have been deposited into microstructured optical fibers to make junction-based fiber devices, very high power infrared fibers, mid-infrared fiber lasers, and nonlinear hydrogenated amorphous silicon fibers
Low power resettable optical fuse based on the amorphous silicon ARROW fiber
No full textWe present a silicon antiresonance reflecting optical (ARROW) fiber that has power dependent transmission properties. When the throughput power exceeds a nominal value the transmission band structure closes and the fiber can no longer transmit light
Stillabothrium Healy et Reyda 2016, gen. n.
No full text<i>Stillabothrium</i> Healy et Reyda gen. n. <p>ZooBank number for genus:</p> <p>urn:lsid:zoobank.org:act: B2B660B1-E30D-4208-935E-F89C06A2D16D</p> <p> <b>Diagnosis</b>: Rhinebothriidea. Worms euapolytic, small. Scolex consisting of scolex proper and 4 bothridia; cephalic peduncle absent; short germinative zone present; apical organ absent. Bothridia stalked, consisting of anterior and posterior regions with distinctly different arrangement of loculi and septa; bothridial margins with thin rim. Anterior region with horizontally oriented loculi (i.e. loculi wider than long) with two (Figs. 2B, 4B) or more (Figs. 6B, 8B, 10B, 12B, 15) complete transverse septa, with (Figs. 2B, 4B) or without (Figs. 6B, 8B, 10B, 12B, 15) single partial medial longitudinal septum. Posterior region lacking medial longitudinal septum, divided into odd number of vertically oriented loculi (i.e. loculi longer than wide) by even number of nonmedial longitudinal septa; nonmedial longitudinal septa all incomplete (Figs. 6B, 8B, 10B, 12B, 15) or a combination of incomplete and complete (Figs. 2B, 4B); incomplete nonmedial longitudinal septa either abut posteriormost transverse septum of anterior region of bothridia (Figs. 2B, 4B, 10B,), or overlap one or more posteriormost transverse septa (Figs. 6B, 8B, 12B, 15). Lateral margins of posterior region of bothridium divided into additional loculi by marginally (Figs. 2B, 4B) or diagonally (Figs. 6B, 15) oriented septa in some species.</p> <p>Longitudinal septa of posterior region appear as ridges in section (Fig. 13) with proximal and distal portions different; proximal portion of septa formed by underlying bothridial wall, consisting of radial muscles oriented with proximal ends of fibres adjacent to each other; distal portion of septa formed by separate muscle bundle; proximal and distal portions of septa separated by triangular gap.</p> <p>Testes numerous, arranged in two columns, one layer deep in cross section, restricted to pre-poral region of proglottid. Cirrus sac extending medially to or past midline of proglottid. Cirrus spinitriches present. Vas deferens extending posteriorly to ovarian isthmus, entering cirrus sac at anterior margin. Vagina opening anterior to cirrus sac; vaginal sphincter absent. Ovary H-shaped in dorsoventral view, tetralobed in cross section. Vitellarium follicular; follicles in 2 lateral bands; bands interrupted by terminal genitalia and usually also by ovary. Uterus saccate, medial, extending from posterior margin of proglottid or ovarian isthmus, anteriorly to near anterior margin of proglottid. Parasites of batoid elasmobranchs (Rhinobatidae, Zanobatidae and Dasyatidae); Indo-Pacific and coastal Afro-tropics.</p> <p>I n f o r m a l s y n o n y m s: Rhinebothriinae New genus 3 Healy et al. (2009), Caira et al. (2014), Ruhnke et al. (2015), and Marques and Caira (2016).</p> <p> T y p e s p e c i e s: <i>Stillabothrium ashleyae</i> sp. n.</p> <p> A d d i t i o n a l s p e c i e s: <i>Stillabothrium amuletum</i> (Butler, 1987) comb. n.; <i>Stillabothrium cadenati</i> (Euzet, 1954) comb. n.; <i>Stillabothrium campbelli</i> sp. n.; <i>Stillabothrium davidcynthiaorum</i> sp. n.; <i>Stillabothrium hyphantoseptum</i> sp. n.; <i>Stillabothrium jeanfortiae</i> sp. n.</p> <p>E t y m o l o g y: From the Latin ‘stilla’, meaning drop, for the teardrop shape of the bothridia of species the genus.</p> <p> <b>Remarks.</b> <i>Stillabothrium</i> gen. n. is generally consistent with the diagnosis of the order Rhinebothriidea as given by Healy et al. (2009): Species of <i>Stillabothrium</i> possess facially loculated bothridia borne on stalks and possess a vas deferens that enters the cirrus sac at the anterior, rather than the medial, margin. <i>Stillabothrium</i> can be distinguished from all rhinebothriidean genera except <i>Escherbothrium</i> Berman and Brooks, 1994, <i>Phormobothrium</i> Alexander, 1963 and <i>Tritaphros</i> Lönnberg, 1889 in its possession of bothridia that are fully facially loculate, with posterior loculi that are longer than wide. <i>Stillabothrium</i> differs from <i>Phormobothrium</i> and <i>Tritaphros</i> in lacking an apical organ on the scolex. <i>Stillabothrium</i> is most similar to <i>Escherbothrium</i>, but <i>Stillabothrium</i> can be distinguished from the latter genus in lacking a medial longitudinal septum in the posterior region of the bothridium, thereby possessing an odd number of loculi. In <i>Escherbothrium</i>, the posterior region of the bothridium includes a short medial longitudinal septum (see fig. 6 in Berman and Brooks 1994) and an even number of loculi. In addition, <i>Escherbothrium</i> was described as possessing an apical sucker and rounded protrusions on its distal bothridial surfaces (see both in fig. 8 in Berman and Brooks 1994). Conversely, in <i>Stillabothrium</i> the feature on the anteriormost portion of the bothridium is considered to be a loculus, rather than a sucker, and no rounded protrusions were observed on the scolex of any surfaces of any of the six species of <i>Stillabothrium</i> examined with SEM in this study. Based on the recent designation of families within Rhinebothriidea by Ruhnke et al. (2015), <i>Stillabothrium</i> belongs to family Escherbothriidae Ruhnke, Caira et Cox, 2015.</p> <p> Species of <i>Stillabothrium</i> have appeared in previous works under different temporary names. The genus was first recognised by Healy (2006) in her dissertation, under a preliminary name which, as recommended by Article 8 of the ICZN (1999), she disclaimed. In addition to providing preliminary morphological characterisation of species, Healy (2006) included partial 28S rDNA sequence data for eight species of <i>Stillabothrium</i>. Subsequently, four molecular phylogenetic studies (Healy et al. 2009, Caira et al. 2014, Ruhnke et al. 2015, Marques and Caira 2016) have included the sequence data originally generated by Healy (2006). Each study, which refers to <i>Stillabothrium</i> as ‘Rhinebothriinae New genus 3’, supported recognition of those eight species as an independent, novel, genus.</p>Published as part of <i>Reyda, Florian B., Healy, Claire J., Haslach, Andrew R., Ruhnke, Timothy R., Aprill, Tara L., Bergman, Michael P., Daigler, Andrew L., Dedrick, Elsie A., Delgado, Illari, Forti, Kathryn S., Herzog, Kaylee S., Russell, Rebecca S. & Willsey, Danielle D., 2016, A new genus of rhinebothriidean cestodes from batoid elasmobranchs, with the description of five new species and two new combinations, pp. 1-28 in Folia Parasitologica (038) (038) 63 (38)</i> on pages 4-6, DOI: 10.14411/fp.2016.038, <a href="http://zenodo.org/record/8143428">http://zenodo.org/record/8143428</a>
Characterization of thermal induced nonlinear effects in silicon microcylindrical resonators
No full textWe explore the thermal nonlinearity in hydrogenated amorphous silicon microcylindrical resonators that are fabricated from the silicon optical fiber platform. In particular, we use a pump/probe technique to experimentally determine the thermal response time from which we can infer the material absorption coefficient
Whispering gallery modes in semiconductor optical fibres and optical bottle microresonators
No full textWe explore the optical properties of whispering gallery modes (WGMs) in silicon optical fibres and optical bottle microresonators. In particular, a pump-probe technique is used to experimentally demonstrate thermally induced all-optical modulation. High quality (Q) factors and small mode volumes are utilized to demonstrate ultrafast Kerr effect based modulation and switching. Q factors exceeding ~107 are demonstrated for novel microbottle resonators (MBRs), fabricated from standard telecommunications fibres
Interview with Dr David Healy, 13 February 2013
No full textDr David Healy is an internationally renowned and respected psychiatrist, psychopharmacologist, scientist and author. A professor of Psychiatry at Bangor University in Wales, he studied medicine in Dublin and at Cambridge University. He is a former Secretary of the British Association for Psychopharmacology and has authored more than 150 peer-reviewed articles, 200 other pieces and 20 books. Dr Healy�s main areas of research are clinical trials in psychopharmacology, the history of psychopharmacology, and the impact of both trials and psychotropic drugs on our culture. He has been involved as an expert witness in homicide and suicide trials involving psychotropic drugs, and in bringing problems with these drugs to the attention of American and British regulators, as well raising awareness of how pharmaceutical companies sell drugs by marketing diseases and co-opting academic opinion-leaders, ghost-writing their articles. Dr Healy is also a founder and Chief Executive Officer of Data Based Medicine Limited, which operates through its popular global website www.RxISK.org, dedicated to making medicines safer through online direct patient reporting of drug effec
Silicon fiber devices for nonlinear applications
No full textWe review our progress in the development of nonlinear devices from the silicon optical fibre platform. The nonlinear performance will be benchmarked through demonstrations of high speed all-optical wavelength conversion, modulation, and continuum generation
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