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Biomedical subjects

Danaë Delbeke

Publications and source records attributed to Danaë Delbeke.

3 recordsLinked to original sources

Intracavity generation of radially polarized CO2 laser beams based on a simple binary dielectric diffraction grating.

We present experimental results on the intracavity generation of radially polarized light by incorporation of a polarization-selective mirror in a CO(2)-laser resonator. The selectivity is achieved with a simple binary dielectric diffraction grating etched in the backsurface of the mirror substrate. Very high polarization selectivity was achieved, and good agreement of simulation and experimental results is shown. The overall radial polarization purity of the generated laser beam was found to be higher than 90%.

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Polarization-selective beam splitter based on a highly efficient simple binary diffraction grating.

A polarization beam splitter (PBS) based on a giant-reflection to zero-order (GIRO) grating is presented. The GIRO grating is a simple binary diffraction grating with parameters chosen such that the excited optical modes in the grating interfere constructively and destructively at the respective interfaces. This interference results in high-zero-order reflection (>99%) with a high polarization-selective extinction ratio (+/-30 dB). The grating shows a low aspect ratio. The GIRO PBS is theoretically and experimentally shown to be an adequate PBS for use as an optical isolator in combination with a quarter-wave plate in a CO2-laser system.

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Rigorous electromagnetic analysis of dipole emission in periodically corrugated layers: the grating-assisted resonant-cavity light-emitting diode.

We study the grating-assisted light-emitting diode, an LED design for high brightness based on a resonant cavity containing one- or two-dimensionally periodically corrugated layers (grating). We give in detail a generally applicable electromagnetic analysis based on the rigorous coupled-wave theory to calculate the extraction efficiency of spontaneous emission in a periodically corrugated layer structure. This general model is then specified on the grating-assisted resonant-cavity LED, showing simulated efficiencies of more than 40%.

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