Method for first-order design of a transfer optics system to throughput match a Fourier transform spectrometer to a sample cell without use of a field lens at the cell input

The realization that the usual optical geometry of an absorption cell is the frustrum of a cone and that a requirement can be put on any transfer optics system that eliminates the need for a field lens at the cell input leads to a powerful method of first-order optical system design through (1) determination of a required ray transfer matrix, unique except for sign, which requires a single concave spherical mirror (or lens) to implement and (2) getting additional degrees of freedom to make the system more practical at the expense of additional spherical mirrors (or lenses). Two successful applications of the method are described.