1,720,960 research outputs found
Dual-process Bragg Grating Inscription in Bulk Fused Silica through Combination of IR Femtosecond and Continuous Wave UV Laser Direct Writing
No full textWe demonstrate femtosecond laser induced photosensitivity allowing to perform direct UV laser writing in pure fused silica, offering new 3D design freedoms. </p
Taking large optical quantum states out of the lab: engaging pupils and the public on quantum photonics sciences
No full textNovel research-inspired outreach activities allow scientists and members of the public to engage in a conversation, increasing the public's understanding and interest in scientific research. This paper reviews outreach and public engagement initiatives undertaken by researchers from the University of Southampton's Optical Engineering and Quantum Photonics Group during a 5-year research program grant entitled Building Large Optical Quantum States. The activities have been supported by a UK Engineering and Physical Sciences Research Council program grant and institutional, national and international professional organizations. The paper discusses activities and hand-outs that have been developed to increase the visibility and public understanding of integrated-photonics fabrication and testing facilities, including a cleanroom-based process for the design and fabrication of quantum outreach chips. More than 1,000 of these chips have been distributed to children, parents and government officials in public events and the activities have contributed towards the authors' research group receiving the 2017 South East England Physics Network Highly Commended Award for Best Research Group. This paper also discusses the impact of these activities and lessons learned.</p
Thermal approach to classifying sequentially written fiber Bragg gratings
No full textWe demonstrate thermal classification of sequentially written fiber Bragg gratings. This Letter presents a process to determine the type of fiber Bragg grating written in SMF28 and GF4A by introducing the gratings to thermal treatment. This technique can be applied to several approaches based on sequential writing, including the small spot direct ultraviolet writing technique. Four different types of gratings have been identified, which are dependent on the fiber type and fluence used during the writing process.</p
Insertion loss characterisation for UV written Bragg gratings in fiber and planar waveguides
No full textIntegrated optical systems offer high component density in a compact, stable and robust platform. However, there are many situations in which it is useful to transition from an integrated waveguide to an optical fiber, such as long distance transmission. The loss associated with coupling between the two platforms can be critical in applications such as quantum information processing (QIP)
Fabrication of more than 40 Superimposed and Superstructured Fiber Bragg Gratings
No full textWe demonstrated two different methods for fabricating a record number of over 40 co-located fiber Bragg gratings: consecutively written superimposed and digitally synthesized superstructure gratings fabricated through small spot direct UV writing. The development of 'AC' refractive index for superimposed gratings has been analyzed
Manipulation of Molecular Vibrations on Condensing Er3+ State Densities for 1.5 μm Application
No full textVibrational modes of chemical bonds in organic erbium (Er3+) materials play an important role in determining the efficiency of the 1.5 μm Er3+ emission. This work studies the energy coupling of the Er3+ intra-4f transitions and vibrational modes. The results demonstrate that the coupling introduces enormous nonradiative internal relaxation, which condenses the excited erbium population on to the 4I13/2 state. This suggests that vibrational modes can be advantageous for optimizing the branching ratio for the 1.5 μm transition in organic erbium materials. Through control of the quenching effect on to the 4I13/2 state and a reliable determination of intrinsic radiative rates, it is found that the pump power for population inversion can be reduced by an order of magnitude at high erbium concentrations compared to conventional inorganic erbium materials
Developing zinc-indiffused periodically poled lithium niobate ridge waveguides for quantum applications at visible wavelengths
No full textTailored laser sources at visible range wavelengths are in ever increasing demand as technologies for quantum computing, sensing, and remote imaging continue to evolve. As these technologies start to move out of the labora-tory and into the field, the requirement for compact, efficient, rugged laser sources makes wavelength conversion of established laser systems and diodes an obvious choice
Photosensitivity response of pulsed 213nm light in planar Bragg grating writing
No full textWe investigate the dynamics of pulsed 213 nm planar Bragg grating writing for a range of powers and fluences. We report the regime for achieving high index contrast, and where damage is likely to occur
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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