PURPOSE: To provide a summary of the methods used by clinical wavefront analyzers and their historical, current, and future applications. METHODS: Review of the literature and authors' experience with the various devices. RESULTS: A wide range of clinical wavefront aberrometers, which use different principles, are available to clinicians and researchers. CONCLUSIONS: Applications of wavefront analyzers in vision sciences range from assessment of refractive error, refractive surgery planning, evaluation of outcomes, optimization of contact lenses and IOL designs, evaluation of pathology relating to optical performance of the eye, and evaluation of accommodation alterations. [J Refract Surg. 2007;23:603-616.]

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.

We describe the modelling and fabrication of waveguide grating couplers with out-