Accuracy and beam pointing stability of surface mounted optical elements

Considerable efforts are presently being made in the fabrication of miniaturized optical devices. An automated assembly technique for small optical components based on standardized holders and on-line alignment of the optical elements has been developed. This optical surface mounted devices (O-SMD) technique consists of a flexible 2D arrangement of an universal tripod holder on a planar mounting plate. The compliant structure allows to align the optical elements during the mounting process in all 6 degrees of freedom and to attach them to the mounting plate in a one step procedure by laser point welding. The optical elements are interconnected by free-space propagation of the light. Flexibility, simple handling, high packaging density and low cost make this well established assembly technique suitable to both mass production and rapid prototyping of small optoelectronic devices. However, problems were encountered with the assembly of devices requiring very high angular beam precision adjustments. We report on a new improved version of the tripod holder which allows to considerably improve the beam pointing stability of the tripod holder. This allows to extend the field of applications of this technique to optical systems with more stringent angular specifications such as, e.g., spatial beam combiners and long distance free space optical transmission systems.