A dielectric subwavelength diffraction grating structure is designed and fabricated in order to enhance fluorescence-based detection of biomolecules. Two separate phenomena, enhancement of the local energy densities of the excitation illumination and direction of the emitted signal toward the detector, are examined theoretically and experimentally. 530-fold enhancement of detected signal is achieved compared with the signal from flat surface. Also, changes in polarization and coherence properties of the fluorescent light are found to be remarkable.
© 2009 Optical Society of America
Original Manuscript: July 10, 2009
Revised Manuscript: September 9, 2009
Manuscript Accepted: September 15, 2009
Published: October 13, 2009
Vol. 4, Iss. 12 Virtual Journal for Biomedical Optics
Petri Karvinen, Tarmo Nuutinen, Jussi Rahomäki, Outi Hyvärinen, and Pasi Vahimaa, "Strong fluorescence-signal gain with single-excitation-enhancing and emission-directing nanostructured diffraction grating," Opt. Lett. 34, 3208-3210 (2009)