3-D opto-electronic system with laser inter-substrate communication, and fabrication method

Abstract

A 3-dimensional opto-electronic system employs an optical communications channel between spaced circuit substrates. The beam from an in-line laser on one substrate is deflected by a turning mirror that is monolithically integrated on the substrate along with the laser and its associated electronic circuitry, and directed to an optical detector on another substrate. The deflection is accomplished with a turning mirror that is specially fabricated with a focused ion beam (FIB) so that it focuses or collimates as well as deflects the laser beam onto the photodetector. The mirror is initially formed with a flat surface, and is thereafter processed with the FIB to produce focusing curvatures in both x and y directions. The mirror is preferably spaced away from the laser, and is illuminated over substantially the full laser height to maximize its focal length for a given reflected spot size. For a rectangular laser beam, the mirror curvature can be different along the mirror width than along its height to produce a smaller, more rounded spot. The mirror curvature is preferably established by raster scanning the mirror area in multiple series of FIB scans, with each series encompassing a different proportion of the mirror surface, and repeating each series a number of times that generally increases with its area. The area-dependent repetition pattern is preferably followed for two sets of scans, one with the scanning area's x dimension progressively reduced and the other with its y dimension progressively reduced.

Dependencies are inferred from the claim text.