a waveguide for inputting light; and

a photonic crystal slab comprising: a two dimensional periodic lattice of holes, said two dimensional periodic lattice of holes comprising: a first nearest neighbor direction and a second nearest neighbor direction; a lattice constant; and a defect hole, said photonic crystal slab configured to couple said light from said waveguide along said second nearest neighbor direction and configured to confine said light in said defect hole at an operating wavelength, wherein a coupling efficiency of said light along said second nearest neighbor direction is greater than a coupling efficiency along said first nearest neighbor direction.