Aspheres from Moulded Optics are available in 4 to 80 mm sizes
A line of precision-molded aspheric condenser lenses with or without outer flange, or with edge diameter, are made from Schott B270 Superwite Crown (nd = 1.5230), Duran borosilicate (nd = 1.4800), and F2 high-refraction index (nd = 1.62004) or equivalent glass materials. They come in more than 24 diameter sizes from 4 to 80 mm.
Moulded Optics
Hesse, Germany