Multimode nanobeam cavities for nonlinear optics: high quality   resonances separated by an octave
  We demonstrate the design, fabrication and characterization of nanobeam cavities with multiple higher order modes. Designs with two high Q modes with frequency separations of an octave are introduced, and we fabricate such cavities exhibiting resonances with wavelength separations of up to 740 nm. 
Sonia Buckley, Marina Radulaski, Jingyuan Linda Zhang, Jan   Petykiewicz, Klaus Biermann, Jelena Vuckovic
physics.optics