Fast wavelength switching lasers using two-section slotted Fabry-Pérot structures

Fast wavelength switching of a two-section slotted Fabry–PÉrot laser structure is presented. The slot design enables operation at five discrete wavelength channels spaced by 10 nm by tuning one section of the device. These wavelengths operate with sidemode suppression ratio in excess of 35 dB, and switching times between these channels of approximately 1 ns are demonstrated

Closing the science-practice gap: Introduction to the special issue on psychological interventions for comorbid addictions and mental health problems

Guest editorial: Introduction to the special issue on psychological interventions for dual diagnosis

Soil pH governs production rate of calcium carbonate secreted by the earthworm Lumbricus terrestris

Lumbricus terrestris earthworms exposed to 11 soils of contrasting properties produced, on average, 0.8 ± 0.1 mgCaCO3 earthworm−1 day−1 in the form of granules up to 2 mm in diameter. Production rate increased with soil pH (r2 = 0.68, p < 0.01). Earthworms could be a significant source of calcite in soils

Fast switching tunable laser sources for wavelength division multiplexing in passive optical access networks

Tunable laser structures with nanosecond switching time between wavelength channels and low-power injection locking are demonstrated on a low-cost platform. These lasers are suitable as source or slave lasers in WDM passive optical access networks

A novel two-section tunable discrete mode Fabry-PÉrot laser exhibiting nanosecond wavelength switching

A novel widely tunable laser diode is proposed and demonstrated. Mode selection occurs by etching perturbing slots into the laser ridge. A two-section device is realized with different slot patterns in each section allowing Vernier tuning. The laser operates at 1.3 mum and achieves a maximum output power of 10 mW. A discontinuous tuning range of 30 nm was achieved with a side mode suppression greater than 30 dB. Wavelength switching times of approximately 1.5 ns between a number of wavelength channels separated by 7 nm have been demonstrated

Lasing from semiconductor microring on the end of an optical fiber

Isolated InGaAsP microrings with an outer diameter of 5.8 mum, a width of 1 mum, and a thickness of 0.41 mum were fabricated by epitaxial separation. Individual devices were bonded to multimode optical fiber using Van der Waals forces and optically pumped through the fiber. Lasing around 1505 nm was measured under pulsed and cw pumping at room temperature. The threshold pump power for pulsed operation was estimated to be 38 and 80 muW for cw operation. Multiple radial and azimuthal modes were present due to strong, three-dimensional confinement. Under strong pulsed pumping thermal effects caused the emission wavelength to chirp. (C) 2002 American Institute of Physics. (DOI: 10.1063/1.1496496

Il tema del “doppio” nel romanzo di A. Skaldin Stranstvia i priključenija Nikodima Staršego

L’«inspiegabile divisione» (неизъяснимое разделение) psicofisica della personalità sperimentata dal giovane barin Nikodim Michajlovič Ipat’ev, protagonista del romanzo filosofico di Aleksej Skaldin Stranstvija i priključenija Nikodima Staršego [Peregrinazioni e avventure di Nikodim il Vecchio]4, va certamente letta come un tributo dell’ultimo (in ordine cronologico) dei simbolisti russi ad un tema di antica memoria, caro alla mitologia e alla classicità – quello del “doppio” –, che, a partire da Pogorel’skij, passando per Puškin, Odoevskij, Gogol’ e Dostoevskij, aveva imperversato nell’Ottocento russo e, prima ancora, nell’ambiente letterario europeo barocco e romantico, confermandosi nel Novecento, secolo del relativismo e della crisi dell’io, come il tratto distintivo della modernità. Eppure lo sdoppiamento, a detta di Pasolini «la più grande delle invenzioni letterarie», se ricollega Skaldin alla grande tradizione culturale otto-novecentesca, è un Leitmotiv che l’autore desume non da fonti esterne ma dall’intimo della propria esperienza personale. La mia analisi della scissione identitaria del Nikodim skaldiniano si basa appunto sull’ipotesi di una totale o parziale identificazione dello scrittore con il suo personaggio, nella convinzione che solo un accurato esame del substratum autobiografico dell’opera ci possa restituire il significato e la funzione che in essa riveste il topos della destrutturazione e moltiplicazione dell’io

A brief cognitive behavioural intervention for regular amphetamine users. A treatment guide.

A brief intervention using motivational and cognitive behavioural approaches to help change drug use. Also offer alternative brief interventions for clients not suited to the current approach. This manual is divided into five sections: Section 1. Context • Key points from the National Drug Strategy Monograph No 51. Models of Intervention and Care for Psychostimulant Users are included to present the evidence supporting this type of intervention for regular amphetamine users. • A flow-chart to place the intervention in a treatment context. Section 2. Brief background to the study and summary of results of evaluation • A brief description of how the study was developed, undertaken and evaluated. • A brief description of the evaluation outcome data (detailed results will be published separately). Section 3. The intervention • The CBT intervention is presented in a clear and easy to use format for practitioners. Section 4. Suggested alternative brief interventions for those not suitable for the current intervention • This section provides an overview of recommendations for alternative interventions for psychostimulant users who are unsuitable for the CBT intervention (e.g. those who are not considering change, experimental users etc). Section 5. Other available resources • This section lists a range of other resources that are currently available for practitioners working with psychostimulant users. This treatment guide has not been designed to stand alone. Rather, practitioners are encouraged to: 1. Acquaint themselves with the current research and clinical literature. The recently completed monograph Models of Intervention and Care for Psychostimulant Users is an excellent resource for current evidence supporting practice in this area. 2. Undertake training in CBT and motivational enhancement techniques if unfamiliar with these approaches. 3. Obtain ongoing clinical supervision