Abstract
Optical coherence tomography (OCT) systems have huge potential for applications beyond the traditional ophthalmology as a general-purpose medical instrument for optical biopsy. The widening of the range of applications is expected to significantly increase production volume and, consequently, puts pressure on unit cost. This trend calls for a flexible and miniaturized system fabricated in a batch process. In this paper, the different OCT configurations are compared for suitability in such an implementation. The required flexibility favors operation in the spectral domain, using a broadband light source in combination with a spectrometer, while the miniaturization and low unit-cost in batch fabrication can be achieved using silicon micro-system technologies. The feasibility of miniaturizing OCT components has already been demonstrated, amongst others a beam splitter using 45 degrees saw dicing of a glass substrate and appropriate thin-film coating the integration of the essential components into a single OCT microsystem remains a challenge. In this paper, the wafer-level fabrication of a Michelson interferometer for a miniaturized OCT system is presented, using an improved 45 degrees saw dicing process, which is suitable for wafer-level co-integration of also the other components of the OCT microsystem.

Abstract
Optical analog experiments have captured a lot of interest in recent years by offering a strategy to test theoretical models and concepts that would be otherwise untestable. The approach relies on the similarity between the mathematical model for light propagation in nonlinear optical media and the model to be mimicked. In particular, the analogy between light and a quantum fluid with superfluidlike properties has been studied extensively. Still, while most of these studies use thermo-optical media to perform these experiments, the possibility of using nematic liquid crystals to perform such optical analog experiments remains to be analyzed. This work explores how this medium can constitute an alternative to materials more commonly used in optical analogs, such as thermo-optical media, and how its tunable properties can be advantageous to explore and better control fluidlike properties of light. Moreover, we explore the analogy between the propagation of light and a quantum fluid, and propose a pump-probe experiment to measure the dispersion relation of the superfluid analog.

Abstract

Abstract
Experimental measurements of the extraction efficiency f of the photoelectrons emitted from a reflective CsI photocathode into Ar-CF4 and Xe-CF4 gaseous mixtures are presented, as a function of reduced electric field E/p in the range 0.1 to 3 V cm(-1) Torr(-1) and as a function of CF4 concentration. The experimental data is compared to Monte Carlo simulation results. The investigation confirms that backdiffusion of low-energy photoelectrons emitted from a photocathode into a gas medium depends strongly on the nature of the gas. The effect is especially significant in pure noble gases, but it can be considerably reduced by the admixture of certain molecular gases, like CF4.

Abstract
A remote sensor for radon continuous measurement using polymeric scintillation optical fibers was developed and evaluated. Successful preliminary results showed detection of natural occurring radon from a container with rocks rich in uranium oxides. © OSA 2018 © 2018 The Author(s)

Abstract
It is established that FTIR with chemometrics is a reliable technique to predict deterioration of meat from game species and from species grown in the wild such as, fallow deer and goat. Meat was minced and stored for periods of 12-432 h and examined for FTIR, pH, lipid oxidation, microbiological analysis, colour, and sensory analysis (SA). Spectral data was analysed with PCA and LDA. PLS-R was employed to establish relationships between spectral data and the microbiological counts. From PCA it was determined that wavenumber from 1656 to 1002 cm(-1) are linked to alterations during storage. LDA of spectral data was applied to sustain SA data. For fallow deer the room mean square error of prediction values for external samples were 0.75, 0.61, 0.81 and 0.73 log cfu g(-1), for TVC, psychrotrophs, LAB, and Enterobacteriaceae, respectively. For goat, the corresponding values were 0.74, 0.68, 0.78 and 0.79 log cfu g(-1). FTIR spectroscopy can be used as a reliable method for assessment of freshness of meat from fallow deer and goat during storage.