The local optical field of a semiconductor micrograting (GaAs, 10×10 μm) is recorded in the middle field region using an optical scanning probe in collection mode at a constant height. The recorded image shows the micrograting with high contrast and a displaced diffraction image. The finite penetration depth of the light leads to a reduced edge resolution in the direction of the illuminating beam while the edge contrast in the perpendicular direction remains high (∼100 nm). We use the discrete dipole model to calculate the local optical field to show how the displacement of the diffraction image increases with increasing distance from the surface.
© 2006 Optical Society of America
Optics at Surfaces
Original Manuscript: August 24, 2005
Manuscript Accepted: November 24, 2005
Wolfgang Bacsa, Benjamin Levine, Michel Caumont, and Benjamin Dwir, "Local optical field variation in the neighborhood of a semiconductor micrograting," J. Opt. Soc. Am. B 23, 893-896 (2006)