Browsing by Subject "Experimental investigations"

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Open Access
Asymmetric light propagation in chirped photonic crystal waveguides
(Optical Society of American (OSA), 2012) Kurt H.; Yilmaz, D.; Akosman, A.E.; Özbay, Ekmel
We report numerical and experimental investigations of asymmetric light propagation in a newly designed photonic structure that is formed by creating a chirped photonic crystal (PC) waveguide. The use of a non-symmetric distribution of unit cells of PC ensures the obtaining of asymmetric light propagation. Properly designing the spatial modulation of a PC waveguide inherently modifies the band structure. That in turn induces asymmetry for the light's followed path. The investigation of the transmission characteristics of this structure reveals optical diode like transmission behavior. The amount of power collected at the output of the waveguide centerline is different for the forward and backward propagation directions in the designed configuration. The advantageous properties of the proposed approach are the linear optic concept, compact configuration and compatibility with the integrated photonics. These features are expected to hold great potential for implementing practical optical rectifier-type devices. © 2012 Optical Society of America.
Open Access
Experimental investigation of critical Casimir forces in binary liquid mixtures by blinking optical tweezers
(OSA, 2017) Magazzu, Alessandro; Schmidt, F.; Callegari, Agnese; Gambassi, A.; Dietrich, S.; Volpe, Giovanni
We investigate, for the first time and by blinking optical tweezers, the effects of critical Casimir forces (CCFs) on the free dynamics of a pair of spherical colloidal particles, immersed in binary liquid mixtures upon approaching their critical points.
Open Access
Model based and experimental investigation of the heart rate response to inspiratory hold
(IEEE, 2007) Şengün, Esra; İder, Yusuf Ziya
The goal of this study is experimental and model based investigation of the respiratory effect on Heart Rate Variability (HRV). In this study, the ECG and respiration were recorded from 6 healthy volunteers who were told to hold their breath for 30 seconds. 5 recordings were taken from each volunteer and signal averaging was used. It was observed that HRV changes with oscillatory behavior at around 0.1 Hz and returns approximately to the value before the beginning of breath hold. Moreover, by using the characteristics of actual respiratory signals. the HRV predicted by the UrsinoMagosso model was calculated. The actual HRV and the model predicted HRV were compared in time domain, and were found to be in concordance in general.