A model for the optical path difference introduced by a soap bubble in transmission is described. The model is then used with interferometric data to solve for the fringe order, and to define a procedure to extract the global film thickness in presence of turbulence flows occurring during the drainage process due to gravity. Experimental results on soap bubbles examined in single-pass phase-shift interferometry are presented.
The FLEX mission is defined to perform quantitative measurements of the solar induced vegetation fluorescence to monitor photosynthetic activity. The FLORIS payload is based on a spaceborne 3-channel grating spectrometer operating in the VNIR range.The retrieval of the faint fluorescence signal from the acquired vegetation spectra is particularly sensitive to straylight.As results, the straylight requirements on the FLORIS instrument are especially stringent.For FLORIS a two-step straylight reduction process has been put in place by the Leonardo-Thales Alenia Space team to achieve this requirement. Careful instrument design and manufacturing are followed by digital processing of the raw instrument data.In this paper we present the feasibility demonstration of the straylight digital correction process, based on simulation of the dedicated data processing and quantitative assessment of the residuals.
A detailed experimental investigation of the phonon-assisted emission in a high-quality c-plane GaN epilayer is presented up to 200 K. By performing photoluminescence and reflectivity measurements, we find important etaloning effects in the phonon-replica spectra, which have to be corrected before addressing the lineshape analysis. Direct experimental evidence for free exciton thermalization is found for the whole temperature range investigated. A close comparison with existing models for phonon replicas originating from a thermalized free exciton distribution shows that the simplified and commonly adopted description of the exciton-phonon interaction with a single excitonic band leads to a large discrepancy with experimental data. Only the consideration of the complex nature of the excitonic band in GaN, including A and B exciton contributions, allows accounting for the temperature dependence of the peak energy, intensity, and lineshape of the phonon replicas.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.