Polarization in photonic‐integrated circuits (PICs) is governed by transverse electric (TE) and magnetic (TM) polarizations due to the planar structure of the chips. Therefore, all states of polarization (SOPs) other than TE and TM, in particular circular polarization, cannot be routed without modification across the chips. Herein, the realization of rib‐channel chirowaveguides supporting elliptically polarized guided modes by combining linear and circular birefringences as predicted by the coupled mode approach is shown. The sol–gel process and the imprint technique to make channel chirowaveguides with different sizes and consequently modulate ellipticity of the eigenmodes from linear to quasicircular are used. Circularly polarized light propagates therefore with a low polarization beating and in particular without handedness inversion. These results open the field of application of PICs to all domains where circularly polarized light is relevant.
Rare earth emitters are promising in integrated optics but require complex integration on silicon. In this work, we have fabricated an Y2O3:Eu3+ micro-emitter on SiO2 on Si substrate without etching. Since pulsed laser deposition produces a high quality layer at room temperature, material can be locally deposited on top of substrates by lift-off processing. After annealing, microstructures exhibit good crystallographic quality with controlled dimensions for light confinement and narrow emission. This works allows envisioning rare-earth doped micro-photonic structures directly integrated on silicon without etching, which opens the way to integration of new functional materials on silicon platform.
A novel experimental method for power efficiency loss is presented in this paper. It is used to quantitatively determine the impact of dust deposition on the PV power generation panel. To determine the selection range of unknown parameters in the experiment process, a photovoltaic panel with five collected dust samples (Toner (C), Soil, Cement (CaO, SiO4), Gypsum (Ca2SO4.2H2O), and Sand (AL2O3, SiO4)) is designed. According to experimental results, the extinction coefficient for the five pollutants are recorded. Eventually, the impact of dusts on the results is proved by repeating in two continuous days of same conditions. The results show that the proposed process has a high effect on the reduction of output power (62% to 96%), decrease of irradiance (34% to 93%) and increase of output power due to increase of tilt angle as a doubling of power except toner. The experimental and calculated results are in agreement. The results show that non-uniform distribution of dust deposit pollutants on the photovoltaic panel significantly reduces the power output.
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