1 Department of Photonics Engineering, Technical University of Denmark2 Structured Electromagnetic Materials, Department of Photonics Engineering, Technical University of Denmark3 Diode Lasers and LED Systems, Department of Photonics Engineering, Technical University of Denmark4 Experimental Surface and Nanomaterials Physics, Department of Physics, Technical University of Denmark5 Department of Micro- and Nanotechnology, Technical University of Denmark6 Silicon Microtechnology, Department of Micro- and Nanotechnology, Technical University of Denmark7 Linköping University8 Center for Nanostructured Graphene, Center, Technical University of Denmark
We demonstrate a light-extraction approach using a whispering gallery resonators array. The wavelength-scale resonant dielectric nanospheres support whispering gallery modes, which can be coupled with the confined waveguide modes inside the bulk material, thus dramatically improving light extraction. Broadband light-extraction enhancement across the entire visible spectral range is achieved by exciting three low-order and low-quality-factor resonances. As an example, the broadband extraction enhancement of about 50% is obtained for the emission of fluorescent SiC at all the tested angles. The experimental results are supported by numerical simulations. Our light-extraction strategy could enable the manufacturing of high-throughput, nondestructive, and affordable optical coating in a variety of optical devices.