Automated Two-Axes Optical Fiber Alignment Using Grayscale Technology

In this paper, we report a new method for actuating an optical fiber in two axes. This device enables in package active alignment of an optical fiber towards reducing the time and cost of optoelectronic packaging by eliminating the need for expensive and slow macroalignment machines. Opposing comb-drive actuators with integrated three-dimensional (3-D) wedges (fabricated using grayscale technology) create a dynamic v-groove to alter the horizontal and vertical alignment of an optical fiber cantilever. All structural components are fabricated in silicon using a single lithography and dry-etching step, making the system conducive to batch fabrication, an essential element to minimize the cost of including in-package alignment capabilities. Actuation of a cleaved fiber tip greater than 30 mum in each direction is demonstrated, with automated fiber alignment times on the order of 10s, comparable to those achieved using macroalignment systems. Alignment tolerances are held below 1.25 mum over a 20-by-20-mum actuation area for the first time. The influences of alignment target location, actuation parameters, and alignment algorithm on total alignment time are also presented