PROTOCOL: A mixed methods systematic review on the effects of arts interventions for at‐risk and offending children and young people on behavioural, psychosocial, cognitive and offending outcomes

This is the protocol for a Campbell systematic review. The proposed systematic review question is: What is the effectiveness of arts interventions for at‐risk and offending children and young people (8‐25 years)? There are three objectives: (1) To evaluate evidence on the effectiveness and impact of arts interventions on keeping children safe from involvement in violence and crime; (2) To synthesise evidence on factors impacting the implementation of arts interventions, and barriers and facilitators to participation and achievement of intended outcomes; (3) To develop a theory‐of‐change approach to ensure the development of an evidence‐led framework of the processes by which arts interventions might work in preventing offending behaviours

A mixed methods systematic review on the effects of arts interventions for children and young people at‐risk of offending, or who have offended on behavioural, psychosocial, cognitive and offending outcomes: A systematic review

Background: Young people who enter the justice system experience complex health and social needs, and offending behaviour is increasingly recognised as a public health problem. Arts interventions can be used with the aim of preventing or reducing offending or reoffending. Objectives: 1. To evaluate evidence on the effectiveness and impact of arts interventions on keeping children and young people safe from involvement in violence and crime. 2. To explore factors impacting the implementation of arts interventions, and barriers and facilitators to participation and achievement of intended outcomes. 3. To develop a logic model of the processes by which arts interventions might work in preventing offending behaviours. Search Methods: We searched AMED, Academic Search Complete; APA PsycInfo; CINAHL Plus; ERIC; SocIndex; SportDiscus, Medline, CENTRAL, Web of Science, Scopus, PTSDPubs and Performing Arts Periodicals Database, Sage, the US National Criminal Justice Reference Service, the Global Policing and British Library EThOS databases, and the National Police Library from inception to January 2023 without language restrictions. Selection Criteria: We included randomised and non‐randomised controlled trials and quasi‐experimental study designs. We included qualitative studies conducted alongside intervention trials investigating experiences and perceptions of participants, and offering insight into the barriers and facilitators to delivering and receiving arts interventions. We included qualitative and mixed methods studies focused on delivery of arts interventions. We included studies from any global setting. We included studies with CYP (8–25 years) who were identified as at‐risk of offending behaviour (secondary populations) or already in the criminal justice system (tertiary populations). We included studies of interventions involving arts participation as an intervention on its own or alongside other interventions. Primary outcomes were: (i) offending behaviour and (ii) anti‐pro‐social behaviours. Secondary outcomes were: participation/attendance at arts interventions, educational attainment, school attendance and engagement and exclusions, workplace engagement, wellbeing, costs and associated economic outcomes and adverse events. Data Collection and Analysis: We included 43 studies (3 quantitative, 38 qualitative and 2 mixed methods). We used standard methodological procedures expected by The Campbell Collaboration. We used GRADE and GRADE CERQual to assess the certainty of and confidence in the evidence for quantitative and qualitative data respectively. Main Results: We found insufficient evidence from quantitative studies to support or refute the effectiveness of arts interventions for CYP at‐risk of or who have offended for any outcome. Qualitative evidence suggested that arts interventions may lead to positive emotions, the development of a sense of self, successful engagement in creative practices, and development of positive personal relationships. Arts interventions may need accessible and flexible delivery and are likely to be engaging if they have support from staff, family and community members, are delivered by professional artists, involve culturally relevant activity, a youth focus, regularity and a sustainable strategy. We found limited evidence that a lack of advocacy, low funding, insufficient wider support from key personnel in adjacent services could act as barriers to success. Methodological limitations resulted in a judgement of very low confidence in these findings. Authors' Conclusions: We found insufficient evidence from quantitative studies to support or refute the effectiveness of arts interventions for CYP at‐risk of offending or who have offended for any outcome. We report very low confidence about the evidence for understanding the processes influencing the successful design and delivery of arts interventions in this population of CYP and their impact on behavioural, psychosocial, cognitive and offending outcomes

Supercontinuum and frequency comb generation in tantalum pentoxide waveguides

In this thesis, the design, simulation, fabrication, and characterisation of tantalum pentoxide (Ta2O5) waveguides and micro-resonators on silicon substrates is presented as a potential technology for the generation of supercontinuum and Kerr frequency combs. Vertical external-cavity surface-emitting lasers and membrane external-cavity surface emitting lasers that operate on two frequencies simultaneously are shown for the purposes of either acting as pump sources for the waveguide systems or as sources for generating THz radiation through the beat between the two frequencies. The fabrication process of the Ta2O5 waveguides is discussed in detail, including the relevant fabrication parameters. The Ta2O5 layer is deposited using radio-frequency (RF) sputtering onto a 4 ” diameter silicon wafer, with a 5 µm thick layer of thermal silica on the top surface, using a Ta2O5 powder target. The waveguide and micro-ring structures are realised using photolithography and ion beam milling, and the samples are cladded with a layer of silica using either RF sputtering or plasma-enhanced chemical vapour deposition with a liquid precursor. Linear waveguides in Ta2O5 are presented for the purpose of generating supercontinuum; Experimental outputs from linear Ta2O5 waveguides for a range of pump wavelengths from 900 to 1500 nm are reported with hundreds of nm of spectral broadening being seen for each pump wavelength. The expected spectral broadening emission of the waveguides is shown, which is calculated using a generalised nonlinear Schrodinger equation (GNSLE) solver that is capable of solving for multiple modes. The GNLSE solver is used to estimate which mode is propagating through the waveguide. The propagation losses of linear waveguides, including an investigation into the impact of waveguide width and cladding deposition technique, are presented, with the lowest propagation loss reported to be on the order of 2.5 dB/cm. The dispersion engineering for new Ta2O5 linear waveguide samples is shown with a focus on the waveguide geometry, leading to the finalisation of a waveguide design that corresponds to the optimised dispersion relation for nonlinear broadening. Micro-ring and racetrack resonators are presented for the purpose of generating Kerr frequency combs. The dispersion relations for micro-resonators are calculated and compared to that of linear waveguides, this followed by an investigation into the critical coupling lengths of micro-ring resonators. Racetrack resonator systems are presented as a suitable alternative to micro-ring resonators due to the fact that the critical coupling lengths are larger than the micro-ring geometries. A Lugiato-Lefever equation solver, based on the GNSLE solver, is described and confirmed against the literature, and is used to simulate the expected frequency comb emission from the Ta2O5 micro-resonators. A brief investigation into the effect of propagation loss on the comb generation is presented using the LLE solver. Experimental Q-factor measurements are presented for Ta2O5 micro-ring and racetrack resonators with the highest Q-factor being 1.91×10^5. Frequency comb generation was not observed, this is expected to be due to the propagation losses being too high. Finally, vertical external-cavity surface-emitting lasers and membrane external-cavity surface-emitting lasers operating simultaneously on two distinct spatial modes, and therefore two distinct frequencies, are reported. The laser systems are forced to operate on two modes simultaneously through the inclusion of laser ablated masks on an intracavity high reflectivity mirror that introduces spatially dependent losses on the cavity modes in order to suppress the lasing threshold of the fundamental Hermite Gaussian, HG00, mode and allow the higher order, HG11, mode to operate. Simulated mode losses are calculated, and the lasers are characterised for a range of spatially dependent loss values and pump powers. The spectral emissions of the lasers are shown, with wavelength separations on the order of 5 nm, which corresponds to a beat frequency of 1.41 THz. These laser technologies also represent an exciting potential pump laser system for the micro-resonators with the aim of generating a Kerr frequency comb

Dataset supporting the University of Southampton Doctoral Thesis "Supercontinuum and frequency comb generation in tantalum pentoxide waveguides"

Dataset supporting the University of Southampton Doctoral Thesis &quot;Supercontinuum and frequency comb generation in tantalum pentoxide waveguides&quot; by Jake Daykin. Dataset includes data and scripts required for reproducing the majority of figures present in the thesis. The dataset does not include versions of simulation code such as the GNLSE or LLE models.</span

High power 739 nm VECSELs for future Yb⁺ ion cooling

We present an operational characterization of a vertical-external-cavity surface-emitting laser emitting around 739 nm with over 150 mW in a single fundamental spatial mode. Results show that the laser is capable of oscillating on a single cavity axial mode at 740 nm for up to 22 mW. Tuning of the optical emission is shown to reach 737.3 nm. Furthermore, at best performance, the laser exhibits a slope efficiency of 8.3% and a threshold power of 1.27 W for an output coupler reflectivity of 98%.</p

Dataset for &quot;High power 739 nm VECSELs for future Yb+ ion cooling&quot;

This is the dataset for &quot;High power 739 nm VECSELs for future Yb+ ion cooling&quot;, authored by Jonathan Woods, Hermann Kahle, Alan Gray, Jake Daykin, Anne Tropper, Corin Gawith, Mircea Guina, and Vasilis Apostolopoulos in Applied Optics, DOI: 10.1364/AO.409970 Dataset contains raw data and instructions of recreating figures in the publication. The figures and process in required detail for recreation are described in the readme file. The figures are as follows: Fig. 2 Optical spectra Fig. 3 Efficiency curves Fig. 4 Spatial mode profile and fitting Fig. 5 RF spectra</span

Bi-frequency operation in a membrane external-cavity surface-emitting laser

We report on the achievement of continuous wave bi-frequency operation in a membrane external-cavity surface-emitting laser (MECSEL), which is optically pumped with up to 4 W of 808 nm pump light. The presence of spatially specific loss of the intra-cavity high reflectivity mirror allows loss to be controlled on certain transverse cavity modes. The regions of spatially specific loss are defined through the removal of Bragg layers from the surface of the cavity high reflectivity mirror in the form of crosshair patterns with undamaged central regions, which are created using a laser ablation system incorporating a digital micromirror device (DMD). By aligning the laser cavity mode with the geometric centre of the loss patterns, the laser simultaneously operated on two Hermite-Gaussian spatial modes: the fundamental HG00 and the higher order HG11 mode. We demonstrate bi-frequency operation over a range of pump powers and sizes of spatial loss features, with a wavelength separation of approximately 5 nm centred at 1005 nm

Towards dual frequency comb VECSELs with DMD laser-ablated spatial mode masks

Dual frequency comb generation is a field which has seen considerable interest in recent years, with notable implementations such as dual wavelength operation of a Mode-locked Integrated External-cavity Surface Emitting Laser (MIXSEL), CW pumping of orthogonal polarisation states in a microring resonator, and optical phase-locking of discrete frequency combs. Dual frequency operation of CW Vertical External Cavity Surface Emitting Lasers (VECSEL) has been demonstrated in a particularly well controlled way using sub-wavelength metallic masks fabricated onto the surface of the laser gain structure. We present a variation of this technique in which patterned loss masks are machined onto a VECSEL cavity mirror using a Digital Micromirror Device (DMD)-enabled femtosecond-laser ablation system, where the DMD is used as an intensity spatial light modulator. Interaction of the loss mask with the laser mode area results in the VECSEL oscillating preferentially on the spatial modes that observe the least loss within the aperture, and modulation of pump power enables control of the oscillating mode frequency separation. We describe the characteristics of the masks and the properties of the laser operation as progress towards eventual pulsed emission. Our technique has the advantages of discrete gain and Semiconductor Saturable Absorber Mirror (SESAM) structures, very fast fabrication times and the ability to fabricate multiple apertures on a single mirror

Dataset supporting the publication &quot;Bi-frequency operation in a membrane external-cavity surface-emitting laser&quot;

This dataset supporting the article &quot;Bi-frequency operation in a membrane external-cavity surface-emitting laser&quot;, by J Daykin, J Woods, R Bek, M Jetter, P Michler, B Mills, P Horak, J Wilkinson and V Apostolopoulos. PLOS One The dataset contains the raw data and MATLAB scripts required for recreating figures in the publication. The figures are as follows: Figures 3B - Simulated mode losses for a range of mask widths Figure 4 - MECSEL output power and spectrum while off-mask Figure 5 - Spectral emission from MECSEL while operating on each of the spatial loss masks and while on an unablated area. Requires the running of individual .m files from subfolders Figure 6 - Calculated etalon transmission plotted with spectral emission from MECSEL while centred on the 10&micro;m mask Figure 7C - Spectral profile from MECSEL while operating on the 50&micro;m mask at a pump power of 3.96W Figure 8 - RF spectral data for MECSEL operating on mask with detector both blocked and unblocked, as well as the residual of the two plots. </span