Near field optical apparatus

Abstract

A near field optical apparatus comprising a conductive sheet or plane having an aperture therein with the conductive plane including at least one protrusion which extends into the aperture. The location, structure and configuration of the protrusion or protrusions can be controlled to provide desired near field localization of optical power output associated with the aperture. Preferably, the location, structure and configuration of the protrusion are tailored to maximize near field localization at generally the center of the aperture. The aperture preferably has a perimeter dimension which is substantially resonant with the output wavelength of the light source, or is otherwise able to support a standing wave of significant amplitude. The apparatus may be embodied in a vertical cavity surface emitting layer or VCSEL having enhanced nearfield brightness by providing a conductive layer on the laser emission facet, with, a protrusion of the conductive layer extending into an aperture in the emission facet. The aperture in the emission facet preferably has dimensions smaller than the guide mode of the laser, and the aperture preferably defines different regions of reflectivity under the emission facet. The depth of the aperture can be etched to provide a particular target loss, and results in higher optical power extraction from the emission facet.