|Second Harmonic Generation in GaN-based photonic crystals for single molecule investigations |
Auteur(s): Coquillat D., Torres Jeremie, D'yerville Marine le vassor, Cassagne D., Teppe F., Diakonova N., Knap W., De la rue Richard, Bouchoule Sophie, Margeat Emmanuel, Royer Catherine
Conference: Conference on Gallium Nitride Materials and Devices VII (San Francisco (CA), US, 2012-01-23)
Actes de conférence: GALLIUM NITRIDE MATERIALS AND DEVICES VII, vol. 8262 p.82621R (2012)
Ref HAL: hal-00704334_v1
Résumé: III-Nitride semiconductors are promising nonlinear materials for optical wavelength conversion. However second harmonic generation in bulk GaN is weak because GaN is strongly dispersive. We show that appropriate photonic crystal patterning in GaN helps to overcome dispersion and provides quasi-phase matching conditions, resulting in substantially increased conversion efficiency obtained in a flexible manner. Enhancement factors of more than five orders of magnitude can be achieved. Use of photonic crystals makes it possible to reduce the effective observation volume, thereby opening new opportunities such as the study of single-molecule dynamics, even in high concentration solutions. We have demonstrated sharp enhancement of the fluorescence of single molecules immobilized on the surface of a GaN photonic crysta,l when the molecules are excited via the resonant second harmonic generation process.