We studied the impact of the thickness of GaN buffer layer on the properties of distributed Bragg reflector (DBR) grown by metalorganic chemical vapor deposition (MOCVD). The samples were characterized by using metall...We studied the impact of the thickness of GaN buffer layer on the properties of distributed Bragg reflector (DBR) grown by metalorganic chemical vapor deposition (MOCVD). The samples were characterized by using metallographic microscope, transmission electron microscope (TEM), atomic force microscopy (AFM), X-ray diffractometer (XRD) and spectrophotometer. The results show that the thickness of the GaN buffer layer can significantly affect the properties of the DBR structure and there is an optimal thickness of the GaN buffer layer. This work would be helpful for the growth of high quality DBR structures.展开更多
Light scattering by a two-dimensional photonic-crystal slab(PCS)can result in marked interference effects associated with Fano resonances.Such devices offer appealing alternatives to distributed Bragg reflectors and f...Light scattering by a two-dimensional photonic-crystal slab(PCS)can result in marked interference effects associated with Fano resonances.Such devices offer appealing alternatives to distributed Bragg reflectors and filters for various applications,such as optical wavelength and polarization filters,reflectors,semiconductor lasers,photodetectors,bio-sensors and non-linear optical components.Suspended PCS also have natural applications in the field of optomechanics,where the mechanical modes of a suspended slab interact via radiation pressure with the optical field of a high-finesse cavity.The reflectivity and transmission properties of a defect-free suspended PCS around normal incidence can be used to couple out-of-plane mechanical modes to an optical field by integrating it in a free-space cavity.Here we demonstrate the successful implementation of a PCS reflector on a high-tensile stress Si_(3)N_(4) nanomembrane.We illustrate the physical process underlying the high reflectivity by measuring the photonic-crystal band diagram.Moreover,we introduce a clear theoretical description of the membrane scattering properties in the presence of optical losses.By embedding the PCS inside a high-finesse cavity,we fully characterize its optical properties.The spectrally,angular-and polarization-resolved measurements demonstrate the wide tunability of the membrane’s reflectivity,from nearly 0 to 99.9470±0.0025%,and show that material absorption is not the main source of optical loss.Moreover,the cavity storage time demonstrated in this work exceeds the mechanical period of low-order mechanical drum modes.This so-called resolved-sideband condition is a prerequisite to achieve quantum control of the mechanical resonator with light.展开更多
基金supported by the National Hi-Tech Research and Development Program of China ("863" Project) (Grant No. 2006AA03Z409)
文摘We studied the impact of the thickness of GaN buffer layer on the properties of distributed Bragg reflector (DBR) grown by metalorganic chemical vapor deposition (MOCVD). The samples were characterized by using metallographic microscope, transmission electron microscope (TEM), atomic force microscopy (AFM), X-ray diffractometer (XRD) and spectrophotometer. The results show that the thickness of the GaN buffer layer can significantly affect the properties of the DBR structure and there is an optimal thickness of the GaN buffer layer. This work would be helpful for the growth of high quality DBR structures.
基金funded by the Agence Nationale de la Recherche programs‘ANR-2011-BS04-029 MiNOToRe’and‘ANR-14-CE26-0002 QuNaT’the Marie Curie Initial Training Network‘cQOM’+2 种基金the DIM nano-K Ile-de-France program‘NanoMecAtom’supported by the Marie Sklodowska-Curie Individual Fellowship programsupported by a fellowship'Research in Paris'from the city of Paris.
文摘Light scattering by a two-dimensional photonic-crystal slab(PCS)can result in marked interference effects associated with Fano resonances.Such devices offer appealing alternatives to distributed Bragg reflectors and filters for various applications,such as optical wavelength and polarization filters,reflectors,semiconductor lasers,photodetectors,bio-sensors and non-linear optical components.Suspended PCS also have natural applications in the field of optomechanics,where the mechanical modes of a suspended slab interact via radiation pressure with the optical field of a high-finesse cavity.The reflectivity and transmission properties of a defect-free suspended PCS around normal incidence can be used to couple out-of-plane mechanical modes to an optical field by integrating it in a free-space cavity.Here we demonstrate the successful implementation of a PCS reflector on a high-tensile stress Si_(3)N_(4) nanomembrane.We illustrate the physical process underlying the high reflectivity by measuring the photonic-crystal band diagram.Moreover,we introduce a clear theoretical description of the membrane scattering properties in the presence of optical losses.By embedding the PCS inside a high-finesse cavity,we fully characterize its optical properties.The spectrally,angular-and polarization-resolved measurements demonstrate the wide tunability of the membrane’s reflectivity,from nearly 0 to 99.9470±0.0025%,and show that material absorption is not the main source of optical loss.Moreover,the cavity storage time demonstrated in this work exceeds the mechanical period of low-order mechanical drum modes.This so-called resolved-sideband condition is a prerequisite to achieve quantum control of the mechanical resonator with light.
