Generation of front-surface low-mass epoxy-composite mirrors by spin-casting

Spin-casting liquid mixtures followed by in situ polymerization offers an e legant and inexpensive method of generating front surface paraboloidal mirr ors of almost any focal length, aperture, and on- or off-axis character, re quiring no post polishing. Mirrors have been made from a variety of substra tes including epoxy-composite mixtures, with focal lengths ranging from 2 t o 80 m, and apertures from 5 to 76 cm. The goal of this project was to make spin-cast mirrors for use as reflectors, telescopes, and cat's-eye retrore flectors in open path Fourier transform infrared (OP/FT-IR) spectrometry. T hese mirrors were designed for portable outdoor use, and thus have been opt imized for maximum ruggedness and mechanical strength, and minimal mass, co efficient of thermal expansion, and cost. After spin-casting, the only prep aration prior to silvering is a thermal post-cure. Results are presented gi ving details of the materials, hardware, and procedures used to spin-cast p araboloidal mirrors. (C) 2001 Society of Photo-Optical Instrumentation Engi neers.