Journal of the European Optical Society: Rapid Publications 

About: Journal of the European Optical Society: Rapid Publications is an academic journal published by Springer Nature. The journal publishes majorly in the area(s): Laser & Photonic crystal. It has an ISSN identifier of 1990-2573. It is also open access. Over the lifetime, 747 publications have been published receiving 8892 citations. The journal is also known as: Journal of the European Optical Society. Rapid publications & J Eur Opt Soc Rapid Publ.

Refractive index determination of SiO2 layer in the UV/Vis/NIR range: spectrophotometric reverse engineering on single and bi-layer designs

Abstract: In this paper we use spectrophotometric measurements and a Clustering Global Optimization procedure to determine the complex refractive index of SiO2 layer from 250 nm to 1250 nm. A special commercial optical module allows the reflection and transmission measurements to be made under exactly the same illumination and measurement conditions. We compare the index determination results obtained from two different single layer SiO2 samples, with high and low index glass substrates, respectively. We then determine the refractive index of SiO2 for a bi-layer design in which the first deposited layer is Ta2O5. The corresponding solutions are discussed and we show that the real part of the complex refractive index obtained for a bi-layer is slightly different to that found for a single layer investigation. When SiO2 is included inside a thin film stack, we propose the use of an index determination method in which a bi-layer is used for the real part of the complex refractive index, and single layer determination is used for the imaginary part of the refractive index in the UV range.

Terahertz imaging: a new non-destructive technique for the quality control of plastic weld joints

Abstract: We present the first investigation of plastic weld joints using terahertz waves. Terahertz time-domain spectroscopy clearly reveals contaminations like metal or sand within the weld joint of two high-density polyethylene sheets. Furthermore, areas can be identified where the welding process has failed and the parts to be joined are separated by a small air gap. We show that a three layer structure of polyethylene-air-polyethylene has a characteristic, frequency-dependent transmission behaviour. This allows for a distinction between welded and non-welded material as well as for the calculation of the air layer thickness from the relative transmission spectrum. Consequently, terahertz time-domain spectroscopy provides a promising new non-destructive and even contactless technique, which is desired by the plastics industry for detecting a variety of deviations from the ideal welding process.

Numerical analysis of a slit-groove diffraction problem

Abstract: We present a comparison among several fully-vectorial methods applied to a basic scattering problem governed by the physics of the electromagnetic interaction between subwavelength apertures in a metal film. The modelled structure represents a slit-groove scattering problem in a silver film deposited on a glass substrate. The benchmarked methods, all of which use in-house developed software, include a broad range of fully-vectorial approaches from finite-element methods, volume-integral methods, and finite-difference time domain methods, to various types of modal methods based on different expansion techniques.

Recent advances in miniaturized optical gyroscopes

Abstract: Low-cost chip-scale optoelectronic gyroscopes having a resolution ≤ 10 °/h and a good reliability also in harsh environments could have a strong impact on the medium/high performance gyro market, which is currently dominated by well-established bulk optical angular velocity sensors. The R&D activity aiming at the demonstration of those miniaturized sensors is crucial for aerospace/defense industry, and thus it is attracting an increasing research effort and notably funds. In this paper the recent technological advances on the compact optoelectronic gyroscopes with low weight and high energy saving are reviewed. Attention is paid to both the so-called gyroscope-on-a-chip, which is a novel sensor, at the infantile stage, whose optical components are monolithically integrated on a single indium phosphide chip, and to a new ultra-high Q ring resonator for gyro applications with a configuration including a 1D photonic crystal in the resonant path. The emerging field of the gyros based on passive ring cavities, which have already shown performance comparable with that of optical fiber gyros, is also discussed.

Independent trapping, manipulation and characterization by an all-optical biophotonics workstation

Abstract: Optical trapping has enabled a multitude of applications focusing, in particular, on non-invasive studies of cellular material. The full potential of optical trapping has, however, not yet been exploited due to restricted access to the trapped samples, caused by high numerical aperture objectives needed to focus the trapping laser beams. Here, we use our recently developed biophotonics workstation to overcome this limitation by introducing probing and spectroscopic characterization of optically trapped particles in a side-view geometry perpendicular to the trapping beams rather than in the traditional top-view geometry parallel to the trapping beams. Our method is illustrated by CARS and fluorescence spectroscopy of trapped polystyrene beads. The side-view geometry opens intriguing possibilities for accessing trapped particles with optical as well as other types of probe methods independent from the trapping process.