Conventional surface plasmons (SPs) or Bloch surface waves (BSWs) have a wave vector exceeding that of light in vacuum, and, therefore, the surface plasmon-coupled emission (SPCE) or Bloch surface wave-coupled emission (BSWCE) cannot escape from the corresponding structures. With the aid of a high-refractive-index prism or an oil-immersion objective, the SPCE or BSWCE can be coupled into free space. But the large volumes of the prism and objective are certainly unfavorable for miniaturization of the optical systems or inconvenient for applications such as the optical displays. Here we experimentally demonstrate a new method to extract the SPCE or BSWCE with a subsurface dielectric grating. The experimental results verify that the chip-like substrate with two decorated sides can bring out the directional fluorescence emission in free space. The emitting direction and emitting patterns can be tuned by the period size and dimensionality of the gratings. Our work provides a new strategy to realize free-space directional fluorescence emission at a very low cost and compact configuration, which has potential applications in fluorescence-based sensing, imaging, light-emitting diodes, optical displays, and other near-field optical devices.
© 2014 Optical Society of America
Optics at Surfaces
Original Manuscript: May 20, 2014
Revised Manuscript: June 16, 2014
Manuscript Accepted: June 17, 2014
Published: July 18, 2014
Dong Qiu, Douguo Zhang, Yikai Chen, Liangfu Zhu, Lu Han, Pei Wang, Hai Ming, Ramachandram Badugu, and Joseph R. Lakowicz, "Extracting surface wave-coupled emission with subsurface dielectric gratings," Opt. Lett. 39, 4341-4344 (2014)