Discrete diffraction in waveguide arrays:: A quantitative analysis by tunneling optical microscopy

The authors report on a quantitative measurement of discrete diffraction in an array of tunneling-coupled optical waveguides using scanning tunneling optical microscopy performed with a cantilevered hollow pyramid tip. The impulse response of the array in terms of Bessel functions is reproduced with excellent accuracy, proving that photon transport in the array is fully analogous to the ballistic motion of electrons in a tight-binding lattice without disorder. (c) 2007 American Institute of Physics.