An anastigmatic White cell for diode laser spectroscopy

We report on a multiple-path optical White cell which is fully corrected for astigmatism by adequate alignment of the three spherical cell mirrors. A simple model is derived which allows for a qualitative understanding of the total astigmatism. More quantitative results were obtained by ray tracing calculations. The results were experimentally verified with a 100 m White cell for diode laser gas analysis applications.