Design of an Alignment Tolerant Miniature Optical Subassembly Module

A miniature optical subassembly module incorporating a pair of collimating and focusing lenses was proposed and designed to provide affordable alignment tolerance in terms of optical coupling efficiency. The light source was specifically modeled taking advantage of multiple point sources placed on the emitting aperture. This scheme was practically verified to be superior to the conventional scheme involving a single point source by estimating the focal length and spot size of a focused beam. The performance of the proposed source modeling was scrutinized with respect to the number of point sources. The optical coupling of the subassembly to a fiber was investigated theoretically and experimentally in light of the characteristics of the displacement of the focused beam relative to the lateral displacement of the light source. Finally, a tradeoff between the positional 3-dB tolerance of the light source and the maximum available coupling efficiency was established with certitude.