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.
Comment: 12 pages, 7 figures