Transversely excited atmospheric pressure CO2 and modulated continuous-wave laser marking of soda-lime borosilicate glasses has been investigated as a function fluence pulse duration. Marks are formed by combination surface crazing material removal, the latter occurring predominantly through particles that fractured from surface. Various possible fracture mechanisms analyzed residual stress following rapid heating is identified most likely cause microcracking. Scanning electron microscope...

Abstract Tin doped indium oxide (ITO) thin films provide excellent transparency and conductivity for electrodes in displays photovoltaic systems. Current advances producing printable ITO inks are reducing the volume of wasted during film patterning. However, their applicability to flexible electronics is hindered by need high temperature processing that results damage conventional polymer substrates. Here, we detail conditions under which laser heating can be used as a replacement oven...

Sapphire (Al2O3) and silica samples have been implanted with 400 keV europium ions at fluences between 5×1014 1×1016 cm−2. As-implanted, show luminescence 622 nm, although the intensity may be increased by furnace anneals up to 1000 °C, higher temperatures, 1200 result in less emission, as impurity form precipitate clusters. This problem can avoided use of pulsed laser which dissociate clusters quench atomically dispersed ions. The has factors 95 85 for sapphire silica, respectively,...

The COVID-19 pandemic posed significant challenges for practical teaching within the sciences. While many instructors adopted innovative alternatives to conventional practicals, relied on digital approaches that did not give students hands-on experience. In this study we evaluate use of 'at home' kits used in first year physics and biology at a UK university as an alternative laboratory classes. particular focus enforced independence over time, space help-seeking inherent at-home model...

Several applications of optical fibres for sensor and telecommunications require the polymer jacket to be stripped from fibre, e.g. inscription Bragg gratings. Here, we report an alternative approach chemical mechanical fibre stripping based on laser ablation. It is shown that excellent quality removal possible using ultraviolet excimer infra-red CO2laser, provided latter tuned a suitably strong absorption band in polymer. Characterization ablation properties acrylic material, are reported.

Abstract Binary transition metal fluorides are textbook examples combining complex electronic features with most fundamental molecular structures. High‐valent nickel among the strongest known fluorinating and oxidizing agents, but there is a lack of experimental structural spectroscopic investigations on NiF 3 or 4 . Apart from their demanding synthesis, also quantum‐chemical description difficult due to open shell nature low‐lying excited states. Distorted tetrahedral ( D 2d ) trigonal...

All the molecular molybdenum fluorides, MoF to 6 , have been identified in argon matrices with first characterisation of and 2 (bond angle ca. 133°), reassignment IR bands 3 identification a new band for 5 .

Laser processing of glass is significant commercial interest for microfabrication "lab-on-a-chip" microfluidic devices. High repetition rate pulsed lasers have been investigated and provide adequate speeds but suffer from the inherent risk laser-induced microcracking other collateral damage induced in glass. In this paper we present a comparative study between nanosecond deep UV (255nm) frequency doubled copper laser femtosecond Ti:Sapphire (800nm) regenerative amplifier machining...

Pulsed laser deposition (PLD) has been used to fabricate thin films (Fe, Fe/sub 0.9/Zr/sub 0.1/, TbFe/sub 2/, DyFe/sub 2/ and Tb/sub 0.3/Dy/sub 0.7/Fe/sub 1.95/) from a variety of magnetic materials that have potential for sensor microactuator applications. The magnetoelastic responses these studied assess the influence growth parameters such as incident fluence (Jcm/sup -2/) on behaviour. Magnetic characterisation magnetostriction measurements were made by VSM capacitance dilatometry...

Binary transition metal fluorides are textbook examples combining complex electronic features with most fundamental molecular structures. High-valent nickel among the strongest known fluorinating and oxidizing agents, but there is a lack of experimental structural spectroscopic investigations on NiF3 or NiF4. Apart from their demanding synthesis, also quantum-chemical description difficult due to open shell nature low-lying excited states. Distorted tetrahedral NiF4 (D2d) trigonal planar...

The high photon energy 157 nm F2 laser has potential applications as a source for modifying the refractive index of glasses telecommunication device fabrication, e.g. fibre Bragg gratings. At this wavelength even `pure' silica glass exhibits significant absorption and cladding on fibres may produce non-negligible beam attenuation. Here we report new results using grating in situ monitoring temperature rise produced by exposure. These results, coupled with thermal modelling, allow coefficient...

Abstract The laser irradiation of polyimide Kapton HN (PI), polyetheretherketone (PEEK), polyethyleneterephthalate (PET) and polypropylene (PP) by long pulse, radio frequency excited, CO 2 radiation has been studied. In the pulse duration range 47–757 µs minimum energy required to damage surface is found be independent exposure time. Hence, threshold fluence also duration; same effect achieved through application pulses at low irradiance as shorter ones higher irradiance. values these...

We describe the design and performance of a simple, fast-time-response (~2 ns) detector for 157 nm F2 laser based on Ni photoemissive cathode. The device is `solar blind' requires only modest bias voltage (<|90| V) vacuum (less than few mbar).

In this work, it is shown that controllable increases in chemical reactivity of borosilicate glass can be induced through spatially resolved femtosecond laser irradiation at fluence values significantly lower than the damage threshold. The hydrofluoric acid etch rate has been found to closely correlated reduction optical transmission 488 nm, which is, turn, governed by production boron–oxygen hole centers. combination below ablation threshold followed etching yield surfaces have a roughness...

Theoretical and experimental studies of the surface quality in 157 nm F<SUB>2</SUB> laser-ablated glasses are reported. Limitations set by statistical fluctuations multi- mode beam stationary non-uniformity explored together with materials issues such as laser-induced cracking. Experimental work on ablating polymethyl methacrylate, used a low threshold medium for recording VUV beam, soda lime glass described. Use is made probe deflection technique to determine ablation thresholds, variety...