CO2 Laser System for Re-flow of Toroidal Micro-cavities

Abstract

Toroid optical micro-cavities are emerging as the leading micro-cavity type for a variety of research areas and applications. The desirable properties of these cavities degrade with exposure to the atmosphere following the final step of production. A facility was designed and constructed allowing the final step in production of toroid micro-cavities, re-flow, to be performed locally, just prior to use. This facility consists of a high power CO2 laser for heating and re-flowing fused silica, a visible laser for targeting, a computer controlled multi-axis translation system for targeting, and a high resolution imaging system. The facility was tested successfully and several micro-cavities were completed. A model describing the re-flow process was developed and tested against observations. Having found discrepancies between the model and observations the model was revised, and successfully describes observations. Multiple procedures for the re-flow process were tested leading to finding the best practices and recommendations for future improvement and use.