1.4 µm continuous-wave diamond Raman laser

The longest wavelength (~1.4 µm) emitted by a diamond Raman laser pumped by a semiconductor disk laser (SDL) is reported. The output power of the intracavity-pumped Raman laser reached a maximum of 2.3 W with an optical conversion efficiency of 3.4% with respect to the absorbed diode pump power. Narrow Stokes emission (FWHM 40 nm was achieved via rotation of an intracavity birefringent filter that tuned the SDL oscillation wavelength

InGaAs-QW VECSEL emitting >1300nm via intracavity Raman conversion

We report intracavity Raman conversion of a long-wavelength InGaAs-QW VECSEL to ~1320 nm, the longest wavelength yet achieved by a VECSEL-pumped Raman laser. The setup consisted of a VECSEL capable of emitting >17W at 1180nm and tunable from 1141-1203nm and a 30-mm-long KGd(WO4)2 (KGW) Raman crystal in a coupled-cavity Raman resonator. The Raman cavity was separated from the VECSEL resonator by a tilted dichroic mirror, which steers the Raman beam to an output coupler external to the VECSEL. The spectral emission of the VECSEL, and consequently of the Raman laser, was set by a 4-mm-thick quartz birefringent filter in the VECSEL cavity. The KGW Raman laser was capable of emitting 2.5W at 1315 nm, with M2~2.7 and >4% diode-to-Stokes conversion efficiency. The Raman laser emission was tunable from 1295-1340 nm, limited by the free spectral range of the birefringent filter. Spectral broadening of the fundamental emission was observed during Raman conversion. At the maximum Raman laser output power, the total linewidth of the VECSEL spectrum was ~0:7nm FWHM. As a consequence, the Raman laser emission was also relatively broad (~0.9nm FWHM). Narrow (<0.2nm FWHM) Raman emission was obtained by inserting an additional 100 µm etalon within the VECSEL cavity. With this configuration the fundamental intracavity power clamped at its value at the Raman threshold, suggesting an enhanced effective Raman gain, but the maximum output power of the Raman laser was 1.8 W

Cascaded crystalline Raman lasers for extended wavelength coverage : continuous-wave, third-Stokes operation

The development of high power laser sources with narrow emission, tunable within the water transmission window around 1.7 μm, is of interest for applications as diverse as medical imaging and atmospheric sensing. Where suitable laser gain media are not available, operation in this spectral region is often achieved via nonlinear frequency conversion, and optical parametric oscillators (OPOs) are a common solution. A practical alternative to OPOs, to avoid birefringent- or quasi-phase-matching requirements, is the use of stimulated Raman scattering within a suitable material to convert a pump source to longer wavelengths via one or more Stokes shifts; however, as this is a χ(3) nonlinear process, such frequency conversion is usually the preserve of high energy pulsed lasers. Semiconductor disk lasers (SDLs) on the other hand have very high finesse external resonators, suitable for efficient intracavity nonlinear conversion even in continuous-wave (CW) operation. Here we report the first continuous-wave third-Stokes crystalline Raman laser and the longest emission wavelength from an SDL-pumped Raman laser, achieving high power, CW output and broad wavelength tuning around 1.73 μm. The KGW Raman laser, which was intracavity-pumped by a 1.18 μm InGaAs-based SDL, demonstrated cascaded CW Stokes oscillation at 1.32, 1.50 μm, and 1.73 μm with Watt-level output achievable at each wavelength. The 1.73-μm Stokes emission was diffraction limited (M2 <1.01) and narrow linewidth (<46 pm FWHM; measurement limited). By rotation of a birefringent filter placed within the fundamental resonator, we attained three tuneable emission wavelength bands, one centred at each Stokes component, and achieved up to 65 nm tuning for the third-Stokes Raman laser from 1696 – 1761 nm. We have thus demonstrated a platform laser technology that takes well-developed InGaAs-based SDLs and provides spectral coverage and high performance in the near-infrared water transmission windows using commercially available components

Intra-Cavity Frequency-Doubled VECSEL System for Narrow Linewidth Rydberg EIT Spectroscopy

Vertical external-cavity surface-emitting lasers (VECSELs) augmented by intra-cavity nonlinear optical frequency conversion have emerged as an attractive light source of ultraviolet to visible light for demanding scientific applications, relative to other laser technologies. They offer high power, low phase noise, wide frequency tunability, and excellent beam quality in a simple and inexpensive system architecture. Here, we characterize the frequency stability of an intra-cavity frequency-doubled VECSEL with 690 mW of output power at 475 nm using the delayed self-heterodyne technique and direct comparison with a commercial external-cavity diode laser (ECDL). We measure the fundamental's Lorentzian linewidth to be $2\pi\times5.3(2)$ kHz, and the total linewidth to be $2\pi\times23(2)$ kHz. In addition, we perform Rydberg-state spectroscopy via electromagnetically induced transparency (EIT), observing narrow 3.5 MHz full-width half-maximum EIT. By doing so, we demonstrate that intra-cavity frequency-doubled VECSELs can perform precision spectroscopy at the MHz level, and are a promising tool for contemporary, and future, quantum technologies.Comment: 13 pages, 5 figure

A molecular-based identification resource for the arthropods of Finland

Publisher Copyright: © 2021 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd.To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the improvement in identification accuracy enabled by the current reference library, we ran 1000 Finnish insect and spider species through the Barcode of Life Data system (BOLD) identification engine. Of these, 91% were correctly assigned to a unique species when compared to the new reference library alone, 85% were correctly identified when compared to BOLD with the new material included, and 75% with the new material excluded. To capitalize on this resource, we used the new reference material to train a probabilistic taxonomic assignment tool, FinPROTAX, scoring high success. For the full-length barcode region, the accuracy of taxonomic assignments at the level of classes, orders, families, subfamilies, tribes, genera, and species reached 99.9%, 99.9%, 99.8%, 99.7%, 99.4%, 96.8%, and 88.5%, respectively. The FinBOL arthropod reference library and FinPROTAX are available through the Finnish Biodiversity Information Facility (www.laji.fi) at https://laji.fi/en/theme/protax. Overall, the FinBOL investment represents a massive capacity-transfer from the taxonomic community of Finland to all sectors of society.Peer reviewe

An Object-Oriented Modelling Framework for Probabilistic Risk and Performance Assessment of Complex Systems

This thesis introduces a modelling framework, which is developed for risk and performance assessment of large and complex systems with dynamic behaviours. The framework supports the most common reliability and operation modelling techniques, and permits their customisation. This ensures a high degree of freedom for the modeller to describe accurately the system without limitations imposed by an individual technique. The use of an object-oriented paradigm increases flexibility and decreases the semantics gap between the model and real world, which are issues with traditional techniques. The framework is named as Analysis of Things (AoT) to emphasise its universal nature and wide application possibilities. The AoT models are defined by using a Triplets data format, which is platform-independent and tabular. A single table declares the applied modelling techniques, creates the model structure, and assigns the parameter values. The format enables straightforward manual model edit while maintaining direct database compatibility. This thesis also documents a calculation engine, which has been developed for analysis of AoT models. The engine compiles dynamically the most efficient simulation algorithm for each modelling technique. A catalogue of built-in techniques is included in this thesis to demonstrate the application of the framework. The configuration of the simulation algorithm is presented for each technique. The AoT model creation is illustrated by using simple example models. Various techniques can be combined to build a comprehensive risk and performance model that systematically includes all essential details. The advanced features of the AoT framework have wide-ranging applications for analysis of reliability, availability, and operational performance of complex industrial products and processes

An Object-Oriented Modelling Framework for Probabilistic Risk and Performance Assessment of Complex Systems

This thesis introduces a modelling framework, which is developed for risk and performance assessment of large and complex systems with dynamic behaviours. The framework supports the most common reliability and operation modelling techniques, and permits their customisation. This ensures a high degree of freedom for the modeller to describe accurately the system without limitations imposed by an individual technique. The use of an object-oriented paradigm increases flexibility and decreases the semantics gap between the model and real world, which are issues with traditional techniques. The framework is named as Analysis of Things (AoT) to emphasise its universal nature and wide application possibilities. The AoT models are defined by using a Triplets data format, which is platform-independent and tabular. A single table declares the applied modelling techniques, creates the model structure, and assigns the parameter values. The format enables straightforward manual model edit while maintaining direct database compatibility. This thesis also documents a calculation engine, which has been developed for analysis of AoT models. The engine compiles dynamically the most efficient simulation algorithm for each modelling technique. A catalogue of built-in techniques is included in this thesis to demonstrate the application of the framework. The configuration of the simulation algorithm is presented for each technique. The AoT model creation is illustrated by using simple example models. Various techniques can be combined to build a comprehensive risk and performance model that systematically includes all essential details. The advanced features of the AoT framework have wide-ranging applications for analysis of reliability, availability, and operational performance of complex industrial products and processes

Youth barometer of Eastern Finland : View to the young peoples´s well-being in three regions of Eastern Finland 2010-2012

Itä-Suomen nuorisopuntari on Etelä-Savon, Pohjois-Savon ja Pohjois-Karjalan maakuntien nuorten hyvinvointia, arvoja ja asenteita selvittävä kysely. Itä-Suomen nuorisopuntari on toteutettu kaksi kertaa vuosina 2010 ja 2012 ja tässä julkaisussa on koottu yhteen näiden kyselyiden tulokset. Nuorisopuntaria koordinoi Mikkelin ammattikorkeakoulun nuorisoalan tutkimus- ja kehittämiskeskus Juvenia ja se toteutetaan yhteistyössä Itä-Suomen yliopiston, Humanistisen ammattikorkeakoulun ja Diakonia-ammattikorkeakoulun kanssa. Kyselyyn on vastannut vuosittain noin 2000 nuorta, jotka ovat iältään 15–25-vuotiaita. Vuosien 2010 ja 2012 kyselyissä selvitettiin nuorten alueelle kiinnittymistä, koulutukseen, työhön ja yrittäjyyteen suhtautumista, kansainvälisyyteen ja Venäjään liittyviä asenteita sekä nuorten yhteisöllisyyden ja osallisuuden kokemista.The Youth Barometer of Eastern Finland is a survey carried out among young people in the Eastern Finland. Eastern Finland consists of three regions, namely Southern Savonia, Northern Savonia and North Karelia. Survey studies the well-being of these young people and their values and attitudes. The Youth Barometer of Eastern Finland has been carried out twice in 2010 and 2012 and this publication collects the results of these surveys. The Youth Barometer of Eastern Finland is coordinated by the Juvenia research and development centre at the Mikkeli University of Applied Sciences in cooperation with the University of Eastern Finland, HUMAK University of Applied Sciences and Diaconia University of Applied Sciences. Around 2000 young people between the ages 15–25 have responded to the survey annually. The surveys of 2010 and 2012 examined young people’s attitudes towards regionality and regional attachment of the youth as well as their values and attitudes towards work, education and entrepreneurship. In addition, surveys studied young people’s attitudes towards international and multicultural issues, attitudes towards Russia and their views and experiences about communality and social participation

Advanced Fault Tree Analysis for Improved Quality and Risk Assessment

Traditional fault tree analysis (FTA) has formed a common language for the modelling and analysis of risks of complex systems. The approach can be used for a large variety of cases, and several tools exists for the method. Advanced FTA is needed to apply the FTA approach also for dynamic systems with time dependent activities. The traditional FTA is extended by including for example modelling and simulation of operation or phase changes of the systems, stochasticity and delays of relations, and maintenance actions for the components. The rules between the failures and other simulated properties are defined by including Java-based scripts to the model. This allows a great freedom to model any type of dynamic situations. A tool named ELMAS has been created to make the use of the advanced FTA approach as straightforward as possible. It allows to model the static and simple relations by using the traditional FTA method. Complex and dynamic relations are included by using modules that can be freely defined based on the needs of the case.acceptedVersionPeer reviewe