Analysis and design tool for optical multipass systems modeled with parametric surfaces

Abstract

A novel software tool has been developed to improve and optimize the design of optical multipass cells in long-path absorption spectroscopy. One of the main application fields of these cells is the monitoring of hazardous gases, where they become the transducers of a global fiber optic sensor. New techniques, based on solids modeling, have been applied for the description of the mirrors that constitute the multipass cell. These mirrors have been represented in terms of parametric surfaces known as NURBS (Non-Uniform Rational B-Spline). Under this approach, the design can reach a high degree of flexibility and versatility. The behavior of the multipass cell has been evaluated by means of different specific ray-tracing techniques that have been implemented taking into account the parametric nature of NURBS surfaces.