Passively athermalized broadband optical design using doublet combinations

In this paper we propose a method for broadband achromatic and passive athermal optical system design using a combination of three doublets. In the implementation of this method, the first-order color dispersion is corrected by distributing proper power to the elements inside the doublets; the thermal and secondary color dispersion are corrected by distributing proper power to the doublet group units. The theoretical deviation is given and we summarize the power distribution equations. A design of an example system using this method, which covers the 350-1200 nm wavelength band, is given and the image quality evaluation is presented. It is shown that the example system maintains high imaging qualities over the required wavelength and temperature range, which proves the effectiveness of the method.