title: Gaussian beams from variable groove depth grating couplers in planar waveguides.
abstract: Analysis, fabrication, and characterization of variable groove depth planar waveguide grating couplers are presented. A formula is derived to describe the grating groove depth variation necessary to produce an outcoupled beam of arbitrary profile. A variable depth grating for producing a Gaussian beam profile is fabricated on a waveguide by ion-beam etching through a scanning slit apparatus. A photoresist grating placed on the waveguide provides a mask to define the grating etched onto the waveguide. The near-field irradiance of the outcoupled beam is measured and shown to approach a Gaussian profile.
authors.forename: K A
authors.initials: KA
authors.lastname: Bates
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: R L
authors.initials: RL
authors.lastname: Roncone
authors.forename: J J
authors.initials: JJ
authors.lastname: Burke