Required minimum feature spacing for commercial viability of raised surface micromachined optical systems

This paper derives a value for the required minimum feature spacing necessary for surface micromachined optical systems to achieve commercial viability. The poor performance of current surface micromachined optical systems, in large part, stems from the relatively large misalignment of their optical components. This paper aims to provide a closed-form solution expressing the insertion loss due to optical misalignment as a function of the minimum feature spacing. Assuming that the highest insertion loss acceptable in a commercial optical switch is 1 dB, the closed-form solution implies that the minimum feature spacing must be less then 0.37 μm for commercial viability.