This paper designs an optical system and some lenses for the BD OPU, including collimator lens, beam shaping lens for laser beam shaping, and cylinder lens for signal detecting.

The planoconcave cylinder lens and prism properties of angular magnification in light scanning are analysed in the paper.

As the pump light incident port of the heating cylinder is provided with the convex lens to increase the light intensity of pump light, the performance of the cavity-cell system is guaranteed.